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Canned Monkeys Don't Ship Well, the Remix Version

You thought you were rid of me. Sorry, Charlie's still on vacation for a few more days, so here's something that has nothing to do with current politics. Just to be annoying, I'm going to revisit that ever-giving fount of joy, slower than light (STL) interstellar travel. You may think that, because it's not physically impossible, that it's inevitable that humans will travel this way one day. Sadly, it looks like blasting your way between the stars the hard way requires magical technology too, just as FTL does.

We've talked about this before on the blog, but unfortunately, the really good conversation was about 800 comments in and about 8 (?) years ago, so you can't just google it. Here, I'm going to cover two points: why canned monkeys don't ship well, and what the precursors to STL would look like, so that we'll know if our society ever starts preparing itself to expand into space at less than the speed of light.

"Canned monkeys don't ship well" refers to the problem of keeping people alive in interplanetary or interstellar space (this for the two people who didn't know it already). There are a lot of problems, what with providing air, water, food, radiation protection, decent meteor defenses, a working clothes cleaner, producing food reliably, recycling trash, keeping people healthy and able to step onto a planet again, and last but not least, completing a human life cycle from conception through birth to maturity and senescence. Many of these are provided by Earth, and the rest require more space than anyone currently has on the International Space Station (ISS). That's why, for instance, they don't have a clothes washer on the ISS. They wear their clothes for a week or so depending on what it is, and throw them out. More insidious problems have to do with what the lack of gravity does to the health of humans, plants, and animals. Correct me if I'm wrong, but I don't think any plant or animal has successfully completed a life cycle (seed to seed or animal to animal) entirely in freefall. And, if you read Chris Hadfield's An Astronauts Guide to Life on Earth, he's quite candid about how extendedly unpleasant it was to reacclimatize to Earth after spending a year in space. It wasn't just reflexes--his feet couldn't tolerate the weight on them, he had rashes and all sorts of weird symptoms that took days to go away, and weakened bones that took at least a year to go away. It's uncomfortable to get into freefall, it's painful to get out of freefall after an extended time in it, it's not just humans that have problems, it seems to be most eukaryotes do, and we still need to figure out how to work around this. Magic, obviously. Just wave that wand, and the problems go away. But what exactly is the wand you're waving? CRISPR? Vibrating pants? Some wonderful pharmaceutical suitable for plants, humans, and fish (gravipramine?)?

Fine, you say, my interstellar ark will spin to make up for this problem. And the ship will be huge, so you can have not just your damned washing machine but vast pools of water as radiation shields (as in Anathem). This is great. Heck, we'll even assume that you have steering and propulsion systems that can handle pushing a great sloshing gyroscope in a precise direction for centuries. Yeah, that. It'll be fun to steer your spindizzy when there's a lot of weight moving around inside it. The wobbling thrust to compensate will be fun too, and keeping this coupled set of chaotic oscillators from going out of control will be easy, of course. All we need is a magic navigation system, magic because it doesn't just steer a wobbling gyroscope impeccably, it does it for centuries without error, and with rapid collision avoidance too. Isn't magitech wonderful?

This is where we get into the engineering challenges. I'm certain, for instance, that we can build computers that last 50 or 100 years. After all, the Voyager space probes are still kind of working, 40 years later. Actually, there's a fun little problem here: a few bespoke resilient computers for expensive space probes won't disrupt a consumer electronics market built on planned obsolescence, but what if you're building an effectively immortal (to a first approximation) system? Won't that decimate the local computer industry, when everybody wants a computer that they can pass on to their kids, rather than discarding, just so that a team of engineers can stay employed making replacements? After all, STL voyages last decades to centuries, and the electronics all have to work forever, with only onboard repairs. This is actually be one of the precursors to deep space colonization, that computers stop being made to fall apart, but instead are built simultaneously rugged, long-lived, and easy to repair. Or, of course, we could put an entire computer fabrication facility on every spaceship. I'm sure that won't take much weight. And swapping out the navigation system every few years should be really easy, too.

That's just one subsystem. If we're talking about a century or millennium long voyage (and note that these are optimistic given our current state of propulsive affairs), then to a first approximation, every bit of hardware either has to last the entire trip, or has to be totally repairable using the (recycled?) supplies brought along. Yes, yes, I know, 3-D printing. That will certainly be part of it, but don't you think that there's going to be critical infrastructure that just can't be reprinted ad nauseum, like critical structural elements and parts of the hull? You'll need really good (dare I say magical?) printing capabilities to reprint a big chunk of the ship from inside the ship. You'll also need a really efficient materials recycling facility to sort all the waste materials and efficiently remanufacture all the printer feedstocks. But heck, sorting stuff into pure materials streams and rebuilding it only takes lots of energy, time, know-how, and specialized technology, which is why we don't yet do this with municipal trash. Actually, trash management is another one of those little precursors: if idiot-proof urban recycling becomes a thing, we'll be one small step closer to space.

Then we've got the big noise, the interstellar medium and the fun of ramming into it at high speeds. Raising your kids in the middle of a firing range or next to the containment shell of a nuclear reactor is positively tame in comparison. Interplanetary and interstellar space are astonishingly good vacuums (better than we can readily make on Earth), but they're not empty. Worse, the stuff in space tends to move really, really fast, which means it has a lot of energy. Bullets travel at around 1 km/sec, but meteors travel at 10 km/sec and above, and an STL spaceship needs to get moving much faster than this to make decent time between the stars. Even the best steering system can't get a ship (especially a huge, spinning, sloshing ship) rapidly out of the way of some bit of interstellar debris. No, we need shields, and those shields need to be fixable or replaceable from inside the ship, because humans aren't going to survive very well either out in that shooting gallery. Yes, anti-micrometeorite armor (like Whipple shields) works on a different principle than terrestrial armor and wouldn't stop a bullet, but even it needs to be replaced, and a starship will occasionally run into bullet-sized space junk at ultraballistic speeds. So we need magical armor. And magical radiation shielding too, preferably in the shape of a mobile cowling, so that robots and humans can get outside and work on the starship hull, under cover, and not die rapidly. More magic! Or heck, I'd settle for a force field at this point.

And yes, there's a rocket firing for years to centuries to push the starship up to speed. How long do real world rockets fire for, again? The starship engine is another one of those magical technologies. While yes, ion engines have fired continuously for years (on the Dawn space probe, for example), their thrusts are tiny, equivalent to the weight of a piece or two of paper in your hand. Since space is effectively frictionless, those tiny thrusts add up, but only on relatively light-weight spacecraft, over interplanetary distances, and over a few years. We need extremely high thrust and for centuries, and it's not clear how to get this. The closest we might want to get is an Orion drive powered by hydrogen bombs, but then we've got to store those beasts indefinitely. And I'm sure everyone wants to grow up immediately adjacent to a nuclear test range, protected by some really, really good shielding that will have to be repaired in house, even though it's a wee bit radioactive.

Then, once we get to the new planet, we've got to land on it, repeatedly. So we need landers that can boost themselves back up to orbit, ideally in a single stage. That's easy, we're developing SSTO (single stage to orbit) technology now. Right? Well, the little interesting challenge is that your lander has to be full of fuel to take off again. Indeed, without magic fusion rockets or some such, almost all of the lander's weight when it lands has to be fuel. And it's going to be really hot on landing, as it decelerates from orbital speed (Mach 10+) down to zero. So you're flying the equivalent of an ostrich egg full of rocket fuel, and decelerating it from Mach 10 to zero, landing on a totally unimproved landing spot (so the lander either has to be able to hover or land in the water, take your pick), and then take off from that spot (or the water) again. And if you think the water launch of a supersonic plane is easy, you really should google "XF-2Y Sea Dart." Anyway, making conventional rocket landers more magitech to work. We could use Orion technology to land and take off, but then the lander is going to have to land, erm, quite a long distance from wherever the colony is. That's going to be a bit tedious, especially the part where they have to repair the road after every launch or landing.

Finally, we've got the problem of using the toilet. Yes, I know space toilets have come a long way. Here I'm talking about recycling nutrients, all 17 of them. People have tried living in closed ecosystems since the 1970s, and it's a chore. I saw a description of one DIY experiment that said that the man involved had to produce feces of the correct weight and composition every day, just to feed the recycling system that fed the plants that fed him. If you've got a small, closed ecosystem, shit can't just happen, it has to be excreted in precise amounts and on schedule. Earthly ecosystems are resilient to when poop happens because there are huge surpluses of some nutrients (like nitrogen in the air). This gives us a fair amount of slack in how nutrients get processed. Dead wood can lie around for centuries in the desert without causing all the plants around it to die from lack of carbon. Unfortunately, when you get into a smaller ecosystem, the surplus nutrient pools are smaller. So, if there's too much dead wood around (or unprocessed feces) you really could starve, and if you don't have enough oxygen for the microbes to break down the dead wood, you could suffocate as the microbes got to work recycling your waste. Biosphere 2 ran into problems associated with this. Ideally, you want the starship's biosphere to be as big as possible for stability. Simultaneously you need to minimize its weight and size to make it easier to send to another star system. Magic ecosystem handling? That's the easy solution. The hard solution is making sure that everyone on the ship is more capable of running an ecosystem than are almost all PhD ecologists currently working (that would include me, incidentally).

Speaking of which, the crew: all astronauts, the best of the best, right? Good breeding stock and all? And their grandkids are going to settle the new planet? Well, erm, yeah. There are problems here too. One is that humans don't breed true, so amazingly talented people tend to have less talented kids; it's called regression to the mean. In a multigenerational setting, you have to allow for incredibly talented initial crew getting old, becoming incompetent, and passing off their responsibilities to their less-talented offspring. That's tricky. You also have to allow for people being incapacitated, whether they are young, old, pregnant, sick, or drunk. Yes, drunk. One of my proposals for dealing with the shortcomings of a closed ecosystem was to designate 10% of the grain crop to making beer, so that people could get drunk occasionally. The point wasn't that alcoholism was good, it's that if your nutrient cycling is so tight that you can't afford the surplus crop needed for an occasional party, then you're absolutely incapable of dealing with problems that incapacitate part of the crew, let alone storing surplus food for when it's needed. Having a system that's resilient to people getting drunk occasionally is one way to make sure that your system can also deal with more serious problems. And, if there's a crop failure, the grain that would have gone to alcohol can be used for food.

I could go on, but there are three points that really need to be made instead. One is that STL can involve as much magic technology as FTL. It doesn't involve breaking Einstein, but Einstein's not the only scientific hurdle out there. All sorts of things are permitted by general relativity but physically or logistically impossible.

The second is that our species isn't ready for the stars. We're not magical enough. If we were getting close, the precursors for interstellar technology would already be around, changing our lives. For instance, if we could almost build a starship, it would be possible for an (evil) magnate to build a secret lair that was impenetrable to anything including a nuclear blast (starship shielding). His minions could take shelter in that lair, seal the entrances, and live in there under his dynasty for centuries, with no problem at all (closed ecosystem with indefinite recycling, plus social engineering). Climate change would be a non-issue for the super-rich, because their castles would be proof against anything the climate or outsiders could throw at them. And we'd have the equivalent of the GNP of Russia to literally throw away in making a starship that would send a few hundred people on a one way trip to a nearby star, since that's about the level of resources you'd need for a starship. So yeah, we're not there yet. This isn't to say that you can't write a story using STL, but it would be good if you spread the magic technology more widely than just in your ship. Why should people have starships in space, but only the Whole Earth Catalog planetside? Starship tech makes for great secret bases and mechanized armor, if nothing else. And every character won't be able to just fix a toilet, they'll have the whole system piped through their closet composting and growth chamber to feed them a treat a few weeks later. In an STL enabled world, proving you can take care of your own crap should be a rite of passage akin to getting a driver's license today.

The final point is one that I'm sure is well-known to SF cognoscenti: there's a reason so many SF writers have used FTL, gravity control, reactionless drives, and force fields. They make things easy. Instead of getting into the aeroponic weeds about how everybody must cycle their nutrients through the system for centuries, you just wave at least two of those magic wands and all of the difficult STL technical challenges go away. You can speed from star to star before your life support runs out, land on planets and take off as many times as you want, and interplanetary and interstellar meteors won't kill you, because you're not about to run into them at high speed without proper shielding. They're not stupid tropes, just overexposed because they're so gosh darned useful. I may be wrong, but I believe that the SF writers who originally proposed this tetrad knew enough about science and engineering to have a good idea of the problems they were avoiding by using them. Sadly, we've since discovered that the problems were even worse than they originally thought. Perhaps later generations of SF aficionados have forgotten and need to be reminded?

What did I miss? Heat, did you say? Power plants? Shipping corpsicles and thawing on arrival? Put 'em in the comments.

511 Comments

1:

You're giving short shrift to the economics:

And we'd have the equivalent of the GNP of Russia to literally throw away in making a starship that would send a few hundred people on a one way trip to a nearby star, since that's about the level of resources you'd need for a starship.

The GNP of Russia represents a staggering opportunity cost (what we would have to not produce to build a STL starship), and I suspect the cost would be much higher.

This is as big an issue as the technical problems of shipping canned monkeys. Any private enterprise who tried to allocate so many resources for zero benefit to the people who remain would go bankrupt, and any government who tried to do it would be voted out or otherwise deposed.

Sorry, I'm an economist, and one of the reasons I studied economics is that the economics in most SF jars my suspension of disbelief.

2:

Since you asked :-)

Yes, I agree about the problems of interstellar travel, which is one reason I did those causality calculations. While they are almost certainly all soluble, in theory at least, we are centuries away from solving them and might not be recognisably human by the time we have solved them (if we last that long, and do).

I would niggle about the behavioural aspect, because it is less about talents than about social behaviour. Anyway, such aspects of intelligence are largely epigenetic or even learnt, and there IS often quite a strong association between parents and children - we are a long way from knowing how to maintain high levels but, again, it's probably soluble - but probably not this century.

So let's assume wormholes, space warps, ultraspace or whatever. All completely beyond modern physics, but probably compatible with it. Don't hold your breath :-)

As far as cost goes, the other key requirement is an efficient way of escaping earth's gravity and utilising the asteroids and outer planets. Given that, it's affordable. Space elevators would work, but so would a suitable 'reactionless' drive. Fantasy? Not quite, because we have one today - when we are in a magnetic field. I don't consider a similar one that reacts against the structure of space (rather than the magnetic field) to be any more implausible than wormholes. Similar remarks apply.

The one where I actually disagree is the lander aspect. Surveying etc. can be done by drones and robots, even today, and they could all (or almost all) be one-way, which doesn't need much fuel. That's a proven technology. Yes, the canned monkeys would need to customise the probes, but that's soluble, given the previous assumptions. Colonisation? One-way again.

3:

Well, I gave short shrift to a lot of things, mostly because I checked the word count on that rather long essay and decided to end it.

Still, there's an important question about colonization. We have two colonization regimes that I know of. One is the colonial empires that gave rise to capitalism, where colonies were meant to do stuff for the metropole, either repay the investment in them or have some military benefit.

On the other side, we've got the rest of history, where in pure economic terms, colonization makes no sense. A good example are the Polynesians. Polynesia was a little unusual in that they have a birth-rank ordered society, so that the eldest child of the eldest child was the top, and the youngest child of the youngest child of the youngest child was on the bottom, and resources were divvied by rank. So far as we can tell, colonization of new islands happened when a junior chief, who managed a fairly crappy bit of land, had to make a choice. He could either accept his lot, rebel against his elders and try to get what they had (this is a very common trope in Polynesian history), or build a canoe and ship some of his people to a new island, where he could be the eldest chief.

If you parse Polynesian colonization in terms of modern economics, it makes no sense, but they did it anyway. Ditto with the Indians who colonized the new world and so forth. My question is how you square the reality of history (colonization) with the apparent paradox that it represents in pure economics?

I'll give you a hint of an answer: if you could bundle all the current political troublemakers in a generation ship and send them off to Trappist-1D (Alpha Centauri being too close, and not having a documented planet), would you do it?

4:

A couple of thoughts-

-You don't spin the whole spacecraft, just a cylinder (or better a pair of cylinders rotating in counter directions) inside of the ship.

-It's really not a stretch to imagine that a spacecraft meant to effectively establish a new human civilization in another solar system would be so huge that it would contain all kinds of fabrication and recycling plants. I'd honestly expect much of the ship to be replaced part-by-part over the years, something you'd have to do anyways with space colonies.

  • You wouldn't land its landers on an improvised landing spot. You'd send down robots and possibly an automated propellant manufacturing plant (something they've been discussing for Mars missions like Mars Direct) first, and then follow up with landings.

  • Stick a giant piece of ice on the front of the spacecraft. Ice is good for absorbing impacts and radiation.

  • I honestly don't know enough about closed-cycle ecological systems to saying anything about whether they'd work or not. Probably depends on how big your spacecraft ultimately is.

@Frank Landis I'll give you a hint of an answer: if you could bundle all the current political troublemakers in a generation ship and send them off to Trappist-1D (Alpha Centauri being too close, and not having a documented planet), would you do it?

Not if I thought they'd survive.

5:

Yeah FTL is a lot easier isn't it? Only ONE "impossible" Physics problem to solve.

6:

Lessee, yuo're skipping one possibility: mass-energy conversion, forget the 4% of fusion. Someone's post, a thread, from wikipedia: interstellar travel at 1G would take approximately 1 year + the distance in lightyears. Proxima Centauri (4.2 light years) for example would take 5.2 years.

So, now we can talk about sending something the size and cost of an aircraft carrier. And, of course, you'd drop your colonists to decel, while you swung around the first destination star, and either go to another, or go home.

And let's make it shaped like a rocket ship, why don't we - not for aerodynamics, but smaller cross section for intersteller debris, gas, and dust.

Computers that last decades? Um, er, ahh, just last year I surplused an SGI Altix 3000, a supercomputer, circa 2003. And then there's the regular servers that I finally got to surplus, I think it was last year, from '05. We've got machines running this minute from '09 and 10.

Did I mention that a few of these were in the steam explosion back in Feb?

But, hey, why not build a nice spherical one, and install the Orange Strumpet, and it'll echo nicely, so he'll only hear what he wants, and send him off to, say, Beta Centurii (I don't think there are planets there...), with his yes-people? (Sorry, no room for telephone sanitizers).

7:
Space elevators would work, but so would a suitable 'reactionless' drive. Fantasy? Not quite, because we have one today - when we are in a magnetic field. I don't consider a similar one that reacts against the structure of space (rather than the magnetic field) to be any more implausible than wormholes.

Alas, it is. You need the metric to not be Lorentz-invariant, or it will appear identical regardless of your velocity, which makes it hard to push on. This is quite unlikely.

But more importantly... reactionless drives mean a continuous and ongoing violation of momentum conservation. This is the same as violation of translation symmetry (i.e. you move somewhere else and the laws of physics change merely because you moved: physical law depends on your locatio), and while this symmetry is violated on the very largest scales (like the conservation of energy and its corresponding time-translation symmetry), good luck using this known violation to do something useful yourself, unless you find it useful to have a drive which you can just barely detect is violating conservation of momentum when you use it to take a billion years or so to travel to another galactic supercluster.

You could always build your own custom metric, I suppose. General relativity has whole families of solutions with useful properties here (that's where things like the Alcubierre warp drive come from, and you can possibly tweak that enough that conservation of momentum is violated locally, though I tried to get some idea whether that was possible and gave up when my head started hurting). Caveats of the Alcubierre drive in particular: massive practical problems. You need negative mass, though early designs that required amounts negative to the mass of the visible universe are now only negative a few hundred grams, if you have the ability to shape spacetime with enough precision to build your own pocket universe with a tunnel about 10^-20m across connecting you to the rest of spacetime; the walls of the pocket's leading edge may radiate at around 10^31K; entering or leaving the pocket exposes you to insanely massive tidal forces and oh yes that ludicrous temperature too; building the bubble in the first place may require even more insane tidal forces or simply be physically impossible so you can't just have it built aroud you; oh and stopping the bubble at the end of the trip may well, ah, one paper says "disrupt" the target environment. I think it's talking about the kind of disruption that turns stars into a scatter of superheated quark soup.

A good place to start when you're thinking of doing anything at all that involves playing with relativity, building your own custom spacetimes or anything like that is to assume that GR is a god's instruction manual. If you can throw galaxies around like confetti and spin up neutron stars on cue, GR is probably full of useful stuff for you technologically. Otherwise, well, we mostly use it to stop GR's barely-perceptible changes in time flow rate from messing up our clocks... And doing anything like building a reactionless drive is going to be solid relativity from beginning to end. It's much easier to just accept that physical law is what it is, and dump the momentum into something available in copious supply (like photons, or if you had a magic way of coupling to them, passing neutrinos: but if you can couple to neutrinos easily there are much more interesting things you can do with that, like really cheap transmutation).

8:

Oh, yes, I agree that it would involve some most interesting metrics, and possibly transformations as well :-)

But I disagree that it would necessarily violate translational invariance or even the conservation of momentum (which is a derived law, not a primary one, anyway). Remember that this is in the context of a LOCAL drive, out of earth's gravity and around the solar system - pushing against the structure caused by the local masses (in a very similar way to the way that magnetic drives work) isn't unreasonable - and there is no need for it to work except at low velocities (relative to light). No more than wormholes, anyway, speculations about which get published in all seriousness.

But, what the heck, I am merely supporting Frank Landis's point, except saying that I think that it could be done with only two technologies that are completely outside modern physics. And a few centuries of developing existing science ....

9:

I forgot to mention that I wholeheartedly agree with your last paragraph, except that I am extremely suspicious of whether GR is right when it approaches its various limits. All of the evidence we have for it being so is based on assuming GR - that's not good science - and I have NO time at all for the loons who extrapolate through singularities, with no definitive proof that they exist in the first place!

10:

I think you could solve a lot of these otherwise insurmountable problems by converting an asteroid into an interstellar ship. Having that enormous amount of matter to work with should give you enough space to develop the necessary resource banks, at the cost of introducing an impossible propulsion problem.

11:
One is the colonial empires that gave rise to capitalism, where colonies were meant to do stuff for the metropole [....] On the other side, we've got the rest of history, where in pure economic terms, colonization makes no sense.

I think this is a pretty narrow view, and seems really common online. Specifically, I'm looking at the idea that the point of colonization is short-term profit. I see people arguing that the point of colonizing other worlds is to seize gold and platinum from the natives and ship it back to the motherland. This obviously makes no sense with space, so it's a fundamentally ridiculous endeavor, QED.

Let's turn this around: imagine we colonize Mars (yes, I know the topic is interstellar travel). Will the Mars colony ship back Martian gold to enrich the Earth, and thus pay for itself? Obviously not. Even interplanetary travel is too expensive for that to make any sense. Recycling gold on Earth is always going to be cheaper.

But let's say millions of people already live mostly self-sufficiently on Mars. Can they participate in Earth's society and economy? Absolutely! There's trade (mostly information). There's cultural exchange. You can even outsource jobs to them (working remotely of course). People on Earth can work for Mars. Both societies can benefit from the others' existence. Looking at the project in hindsight hundreds of years later, it seems like a great idea to colonize Mars. After all, your mom works for MartianSoft in LA!

Now extend this to interstellar colonies: let's say five billion people lived around Tau Ceti. Sending anything physical is too expensive, so that's out. Talking, however, is cheap thanks to gravitational lensing -- with a 24 year delay. But was the colony project worthwhile, a thousand years later?

If you asked the people of Tau Ceti? The value of their home is obvious. They live there. If you went around asking them if the colony project was a good idea, they'd look at you like you were crazy. Duh. But does Earth benefit from the colony's existence?

Absolutely. There's a constant stream of knowledge beaming over those network links -- science, technology, art, trashy novels written in a hilarious caricature of Earth, and so on. Is it worth the investment of a couple years' worth of the US military? In hindsight, many centuries later, of course! A few more aircraft carriers is meaningless historically, compared to Tau Ceti.

So, to get back to science fiction here: the problem isn't that colonization is a bad idea. Colonies, in hindsight, are a pretty good idea if they work out. The problem is all about how you envision a society that sees creating them as a good idea. Maybe our society is fundamentally incapable of acting like that, so you need to imagine a society with different motivations, much longer term planning, and so on to get there.

12:

Different motivations, much longer term planning...

I seem to recall Charlie describing something like that. In “Neptune’s Brood”

13:

Not to mention solving these canned ape problems in the obvious way. :-)

14:

EDITED BY MOREDATOR

15:

Putting on my administrative hat: GWERN, YELLOW CARD. I edited out the most incendiary part of your comment, but drop it.

In fact, let's drop the whole genetics argument too, because it's been tested by accident.

There have been, worldwide, something like 500 astronauts and cosmonauts across all nations. Last time I'd checked, there were only one, maybe two, second generation cosmonauts, and no second generation astronauts. That's pretty good evidence that being an astronaut is less heritable than being US President (n=45, two being descendants of previous presidents and two being cousins). Based on this sample size, I'd suggest very strongly that a generation ship that needs a 100% astronaut crew at all times will fail if it relies on normal human breeding for replacement of crew members.

16:

This topic touches on one of my persistent peeves about current human spaceflight programs, such as they are.

Restricting the discussion to Mars and maybe the Jovian system rather than the stars, there is still no visible program to develop and demonstrate life support systems (ECLSS in the jargon) that would keep humans alive and reasonably healthy for the several years needed. Lots of individual .doc and .ppt on individual pieces, but no effort to put it all together and show that it works when messy meatbags are included.

What would be reassuring to see would be a demonstration habitat, maybe at EML-2, that autonomously supported four people for two years, after which they would come back to Earth in reasonably good shape. That might do for Mars, given current propulsion systems.

After that, ladder up to Jupiter, the Oort Cloud and the stars. Or invent a lot of magic technology.

17:

Frank Landis Erm err ... The Darwin family & their work? ( Across many disciplines ) I know, only one counterexample, does not a statistically- significant marker make, but, um .....

Yes, I know, this is very dangerous territory, because it can so easily be misused by people with very unpleasant motives.

18:

Or the Rothschilds? It's amazing how wealth and privilege are heritable, at least for some families, for a few generations.

The point here was specifically about astronauts. They're reportedly a closely knit community with spouses actively involved. For whatever reason (and for the record, I don't think it's just genetics) the children of astronauts almost never become astronauts. That's too bad, because the basic skill set of astronauts--being high-grade lifelong learners of complex skills, with excellent work ethics, who function well in emergencies--is exactly what you'd need to colonize a new planet.

19:

Some of these are obviously solvable: Use baffles so the water doesn't slosh. Land the propellant plant first, then land other stuff when that works.

Also, I think the attitude of using more (or more complex) technology to solve these problems may be the wrong approach. Instead of magitech, use steam tech. IOW, don't use more complex technology just because you can. One of the reasons the Voyager spacecraft computers still work after all these years is that they use fairly clunky electronics which are much less prone to radiation damage.

I was always amused on the Stargate SG-1 TV series that interstellar traveling aliens would leave instructions behind on stone tablets. OTOH, what would you leave them on that you KNOW will last literally thousands of years in adverse conditions?

20:

Regarding compute resources required, I think that’s a none issue. It’s hard to imagine the calculations described to be much of a load, you aren’t talking about automous driving or anything. Nothing much happening in the middle of interstellar space, it’s really orbital stuff that makes challenging. We’ve managed quite complicated orbital maneuvers with 1960’s technology, current computer tech is many orders of magnitude advanced from that

A lot of the forced obselence in c Mauler tech is more compute getting radically better and requirIng lower power then things actually wearing out. Even today with virtually no effort put in, you hear about thirty and forty year old hardware still working fine

Rather then trying to repair in flight you’d just invest a little bit to get a decent lifespan (say 100 years, that should not be hard) and then carry a lot of spares. Would not be much mass in the grand scheme of things

21:

I agree with your point that stuff needs to be sufficiently complex, but no more. The magitech is for when you have to do things like simultaneously maximizing and minimizing the size of the closed ecosystem to meet vital needs. That part doesn't scale with technology. A lightweight shield that can stop a nuclear blast or an engine that can move an arbitrarily large mass up to interstellar speeds are also beyond what we know how to do. I can go on, but it's not just about level of technology, it's that some of this stuff looks to be impossible at the moment.

22:

We're not going to attempt interstellar trips until we have the technology to effortlessly travel and live throughout the solar system. A generation ship is basically a space settlement, with better propulsion and recycling. So you can assume that most of your problems have been solved by those people, by the time anyone seriously wants to colonise other star systems. They are also the obvious population for the trip. (Independent space settlements who've had jack with this Earth-domination of the solar system.) They'll have solved most of the problems you describe. They'll know how lossy their recyc/ECLSS is. They have proven they can run the ship, possibly for the second or third generation; possibly the second or third generation of settlements built and populated by earlier settlements.

23:

Bury some bronze tablets. They can last a long time.

24:

Drop it means drop it.

25:

Once upon a time, 5,000 years ago, Vark the Strange commented that he imagined a day when giant boats made of metal would carry the whole tribe across the sea on marvellous adventures - and was promptly clouted for his stupid comments. Females refused to mate with Vark because he was so obnoxious, imagining that they could sew all the tribe's sails together to make one giant sail...

Do you want to colonize other stars? Keep our scientific and curious society alive for another 3000 years. See how easy that was?

26:

I agree with all points in the OP regrading magitech -- if you insist on sending live, organic fleshbeasts to another star, you will encounter all the problems listed. Those problems can all be neatly side-stepped, however, with only ONE piece of magitech: mind uploading. Wave that particular wand, and you can build a starship that is smaller than most manned aircraft, yet capable of carrying thousands (if not millions) of virtual colonists. This not only negates all the problems regarding recycling, life support, and the biosphere, it overcomes your concerns regarding competence of follow-on generations: there is no need for the originally-selected crew to ever die.

Further, problems of propulsion and navigation become exponentially less difficult as the mass of your starship decreases. (Although here, if anything, you're actually making it seem too easy -- even with a tiny starship, getting to your destination in less than a thousand years will STILL probably require an energy investment [say, in the form of beamed power for a laser sail] that might bankrupt a small country.)

Granted, if your digi-colonists want to build anything other than a Matrioshka brain when they get there (e.g., if they want to do something silly like grow crops and have flesh-and-blood children), you have to posit more magitech to grow bodies, etc., etc..

(And yeah, Charlie already beat me to it with Saturn's Children and Bit Rot -- although, I think you could go a fair bit smaller than the ship he envisioned in BR. Even trimmed-down robot bodies are too massive to ship between stars...)

Further granted: this particular bit of magitech (mind uploading) is a wee bit more difficult to attain than many of the others you list. This is why, to my mind, interstellar travel is a post-singularity technology. If you don't think we'll ever see a technological singularity (and that's a fair position to take!), then you probably have to conclude that we'll never leave this solar system.

27:

Charlie has minds in a box with a solar sail in their own singularity novel Accelerando.

Mind uploading gives you a completely different universe, though, so it's definitely cheating ;)

I don't think it follows that singularities necessarily have anything to do with leaving the system, though.

28:

There's two separate sets of problems here. 1) How to build a space habitat that can be fully and completely self sufficient in the long term. and 2) How to send such a habitat across interstellar space in a semi-reasonable time frame.

Right now, despite decades of optimistic dreaming, we still have only the barest foggiest notion of how many extremely diverse problems need to be solved before we can even begin to build a space habitat, let alone a long-term self-sufficient one. Hell, after sixty years of manned space flight, we still haven't even done any experiments with creating rotational gravity, let alone determining how much gravity is enough to preserve human health during trips to other planets.

If and when we manage to build a space habitat, we will be in a position to begin to determine just how difficult it will be to make such a habitat self-sufficient (and how large a population and biosphere it will have to have to achieve self sufficiency).

Then, and only then, it becomes possible to ask the question of how difficult it would be to move that habitat from here to Tau Ceti or wherever.

29:

Crap, I knew I was forgetting some bit of Strossian lit, but I overlooked the most famous of them all. My memory is shit. :/

Funny you should use the word "cheating" -- I almost used it, myself, but refrained because I was coming at it from the angle of, "What is most likely to work in our actual future?", rather than, "What is most compelling in a rigid SF framework?" Most non-singularity forms of interstellar travel just don't pass the smell test, for all the reasons spelled out in the OP.

In the interest of "not cheating", though (and I did leave myself an out, by using the weasel-word "probably" up above) ... I can think of one non-singularity approach to interstellar travel that doesn't make me immediately roll my eyes. Basically, start with Paul451's vision of a future solar system filled with multi-generation space habitats, then move towards something like the idea proposed by (I believe) Paul Glister at Centauri Dreams: learn to live on (or in) icy bodies in the Kuiper Belt and the Oort Cloud, and island-hop Polynesian-style all the way across to the next star. That is, (1) colonize one lump of ice; (2) grow the colony until it is not only self-sufficient, but capable of spawning daughter colonies; (3) colonize a new lump of ice, one to ten years of travel further into deep space; (4) repeat every one to three human generations, until you've crossed the invisible line that demarks the end of our Oort Cloud and the beginning of Alpha Centauri's. It would take tens, if not hundreds of generations and thousands of years, but it would get the job done -- and at no point do you have to travel more than a decade away from an established colony, which again side-steps many (but not all) of the problems from the OP.

30:

Not to mention the social issues involved. No matter how closely you screen your initial passengers/crew, I'd be very concerned about belief systems arising after a generation or two that were counter to the continued survival of the mission. Let me be clear that I'm not referring only to religion, but right now in the United States, there are outbreaks of diseases that were nearly extinct due to a subset of parents believing that the risk of autism is greater than the risk of measles. What happens when some charismatic third-generation colonist tells their peers that recycling their excrement is unhealthy, or that we can't trust the people from D-Ring, you know how those Navigators are...

31:

@ 23 Bronze Tablets ENCASED in Amber ... that really will last ....

32:

I think the necessary precursor discovery to any interstellar mission will be multi-generational research grants. The only really long range projects humans have undertaken have been religiously motivated: Pyramids, Cathedrals and so on. Maybe it will be so with interstellar expeditions; unless we're discovered by religious aliens who take exception to humanity introducing original sin to the universe and are looking for some compensation...

33:

"...And, of course, you'd drop your colonists to decel, while you swung around the first destination star, and either go to another, or go home. ..."

That makes a lot of economic sense for the civilisation dispatching the ship, but it's a bit stark for the first colonists dropped. They lose their home of generations, their industrial base and their chance of getting back on board if the colony doesn't work out.

34:

Spacemonkeys do have a whole lot of problems i agree.

Prearranged fuelplants and frozen embryos is the most plausible way to go if we want to leave the solar system. Robots to take care of the first generation.

Embryos can be packed very tightly together, and although sensitive to radiation I presume they can be put in a fairly small leadcontainer with a superconductor (if we got them at usable temperatures) to provide a mangnetic shield.

Micrometeorites might be a problem, but how common are they? Cant we just use statistics and build several ships based on how likely they are to fail?

The embryos are not conscious yet and if the bot are they can be backed up, so I cant see any big ethical problems with this approach.

Economics is a problem though, but once we colonized most of our own solar system I wouldnt think it impossible for UN, Nasa or some equivalent organisation to setup a mostly selfpropagating plant for this purpose.

The drive is a problem, but a lot less so if you dont have any non-frozen biological lifeforms onboard, since you could opt for a much slower speed.

Going intrastellar before that is unlikely imo, we simply need a whole lot more experience on how to set up planetary colonies. But if SpaceX's plan to colonize Mars doesnt fail completely we might be ready to start in a century or two.

35:

There's also one more option, one that produced the once planet's most productive society: How about if I want to get away?

Say, packing up all the politically problematic people is not an option, but leaving them behind is?

It is correct that the colony serving as an example here was founded for the purpose of feeding its riches back to the motherland but once it became independent, it started to drag colonists by sheer promise of opportunity.

As such, a space colony might not benefit earth (or a subsociety on earth) as a whole, at least not in economic terms, yet if enough humans see an opportunity in leaving earth behind, their benefit might be sufficient to make it happen.

36:

Drop it means drop it.

37:

Yes, but it's actually simpler than that. The lifetime of modern electronics is limited by diffusion, chemical decay and similar factors, all of which are made much worse by very small process and component sizes and high temperatures (which are needed for high clock rates). As with almost all engineering, a small increase in size can give a huge increase in robustness - and, in this case, a small reduction in clock rate can give a huge reduction in power demand. Because of that, there has been a LOT of work on error-correction, and there are known solutions to that, too. This is a soluble problem, at least for a timescale of centuries; millennia, I am not sure.

38:

I suspect that commentators here arguing about generation ships would enjoy "Aurora" by Kim Stanley Robinson. He assumes that most of the above problems would be solved, and instead gives his protagonists new and exciting problems(!) to deal with. He gets around many of the problems by assuming a very large ship, with multiple biomes and lots of biomass to act as buffers for short term resource problems.

39:

KSR also has humans beginning to shrink within 5 generations due to insular dwarfism. They also start to lose cognitive ability in that time.

If such things were to happen (possible, I suppose - I'm not a biologist), you'd think that it would happen over the scale of millennia, not 150+ years.

The story was enjoyable. Just not believable.

40:

That, or radical life extension.

Some of OP’s problems, particularly (but not only) sociological ones, go away if the original crew does not age. Or has age-related damage periodically repaired.

41:

It can happen in six generations, if the combination of the Mendelian genetic factors and the selective pressure is great enough; the calculations are simple enough, and it's been done deliberately in animals over similar numbers of generations. A more likely cause in that timescale would be poor nutrition, which is cumulative over that number of generations. But there is no way that a competently designed and managed mission would do either so, that could only be the result of social or biological engineering failure, not the cause of it.

42:

Now, that's REALLY well into fantasy! Sorry, but I will believe space warps, inertialess drives and impenetrable shields before I believe that.

43:

More fantastic than mind uploading?

44:

That is based on the premise that the current screening and selection process used for selecting astronauts / cosmonauts or mission specialists would select individuals with the appropriate characteristics and aptitude for operation of a generation ship. It very likely would not because the physical, social and mental demands and requirements would be different.

A generation ship must work with the resources at hand. That might mean a very different political, economic and social model for training, development and selection of occupation than exists for the current astronaut / mission specialist programs. The best and brightest children might be selected and schooled by / apprenticed to the current generation of ship operators / engineers rather than allowing they (and their parents) to make choices concerning education and training. A system like the Chinese imperial bureaucracy might be more sustainable.

On a related note, referencing back to your original post, I met Chris Hadfield shortly after his return from commanding the ISS. He had just finished a morning run with his wife but was lamenting the fact that he was going to miss an entire season of water-skiing because his bones had not recovered enough strength.

45:

That's a good question. About the same as non-destructive mind uploading, probably.

46:

Aurora...

Not my favorite KSR book, I think is the safe thing to say. It tripped over too many of the details to really enjoy it, or even do more than skim read after awhile.

47:

An etched nickel disk? Naked eye readable on the outer edge, getting smaller as you go in (fairly quickly, so that you need a 500x magnifier to read most of it). https://rosettaproject.org/

48:

I guess we are in disagreement then. I find repair at cellular level entirely plausible within several centuries, and far more plausible than non-destructive mind upload.

49:

Lessee, yuo're skipping one possibility: mass-energy conversion, forget the 4% of fusion

I'm pretty sure that any sufficiently easy mass/energy conversion mechanism is a Fermi paradox solution. Insofar as 1Kg of matter is roughly equivalent to 21 megatons if you convert it into hard radiation instantly.

Oh, and you know what else? It still doesn't get you a NAFAL (nearly as fast as light) drive. Tau of 0.5 c is, IIRC, about 80% of light-speed and requires energy equivalent to half the mass accelerated to that velocity; you need enough fuel to decelerate at the far end, so you still have an annoying mass ratio of 4:1 fuel/payload. And the waste heat problem is a stone pain in the ass (hint: when we're talking tens of megatons per kilogram, even 99.99% efficient conversion of mass into energy into momentum is going to leave you fielding kilotons per kilogram in waste heat). And the interstellar medium is equivalent to a hard radiation bath at that speed — stationary electrons hit like hard gamma radiation. At 80% of c each square metre of frontal area of a starship is sweeping up a column of near vacuum ~240 million metres deep every second: with, say, 100 free electrons per cubic metre, that's a background level of 240MBq, never mind the hard stuff (hydrogen and heavier nuclei).

No, really, high relativistic speeds are not user-friendly!

50:

and stopping the bubble at the end of the trip may well, ah, one paper says "disrupt" the target environment. I think it's talking about the kind of disruption that turns stars into a scatter of superheated quark soup.

Another Fermi-paradox solution: STL travel is borderline-achievable, but FTL via Alcubierre drive turns out to be relatively easy ... only the only way to decelerate is to aim for a star and disrupt it on impact.

Turns out you can track expansionist interstellar polities by the expanding wave-front of anomalous supernovae ...

51:

Mind you, Larry Niven nearly got there in the 1960s/early 1970s with his aphorism, "any reaction drive is a weapon of lethality directly proportional to its efficiency as a propulsion system".

52:

I agree that repair at a cellular level more likely to be feasible. But there is increasing evidence that (physical) aging is not simply a matter of cellular damage, but is intimately tied up with several systems that must not be compromised, including the immune system, damage repair system and ability to train.

The mental aspects are, if anything, worse. For example, there are very good reasons to believe that any system that must be able to adapt by changing itself (as the human brain does) is either going to have a limited lifetime or is going to get out of control.

53:

Great post!

Haven't read through the comments yet because kept getting ideas/comments as I read that I wanted to keep in mind and ask about. (Apologies if these ideas/questions were already mentioned by previous posters.)

‘… he had rashes and all sorts of weird symptoms that took days to go away, and weakened bones that took at least a year to go away.’ – what biochemistry/biochem reactions need to be guided by gravity? Hadfield and other astronauts had some major immune system issues. Much of the immune system is stored in the large bones as bone marrow stem cells – so what’s the interaction between bones (which need a lot of Ca, Mg, VitD, etc.) and the immune system? Surprised that hearing doesn’t show up as a major problem for former astronauts given the inner ear has made up of the smallest bones in the body in combination with widespread osteopenia.

Computer systems that can last for centuries – cloud computing/Internet? Two issues in space – independent/separate backup of copies, plus cleaning of excess multiple copies. (Need full-time data editor on board - probably best handled by an AI supervised by a few humans.)

'... keeping this coupled set of chaotic oscillators from going out of control will be easy ....' So, no military band practice (or military of any type) marching or playing of (and stomping to) Queen’s ‘We Will Rock You’ at mass assemblies? Has the ISS ever even tried to see what happens to the station if there's prolonged rhythmic pounding in one section? (Probably something that should first be modeled on a really good computer.)

'Won't that decimate the local computer industry, when everybody wants a computer that they can pass on to their kids, rather than discarding, just so that a team of engineers can stay employed making replacements?' – No, because the engineers will move on to other, new tech. Besides it’s not just the hardware that needs to be passed on but the data. However, there should probably be some museum or well-maintained cache of older tech just I case.

‘critical infrastructure that just can't be reprinted ad nauseum,’ … this is where new materials science becomes essential – because if you’re going to be reprocessing/recycling forever, you want the equipment made of materials that can be reprocessed. Not sure which current metals/materials would qualify. Also, a lego-based (small number of parts) that can be used in a myriad of designs/equipment would help keep inventory low. So, ‘design science’ also needed.

‘magical radiation shielding’ – spaceship hull design that deflects – although there might be an occasion where you want that space debris to hit you so that you can collect needed ores/minerals/ice. An armada of minion spaceships/drones/tractors to clear the way ahead and guard the sides and rear from threats. Assume that early detection would be a priority and as soon as threat is detected, put in Plans A, B, C, (depending on threat) into action ASAP.

‘ We need extremely high thrust and for centuries’ – are you sure? And, yes, you want to keep the nuke-powered thrusters/engines them so that you can eventually decelerate.

‘And it's going to be really hot on landing, as it decelerates from orbital speed (Mach 10+) down to zero.’ – Not sure fast re-entry is essential – maybe it’s only because it's 'always been done that way' because the first astronauts were running out of oxygen. Maybe we need to look at slow fuel-free re-entry (gliders) which means you reduce the amount of fuel you need.

Feces – any idea how our GI and other bacteria fare in space/freefall? Which (if any) are sensitive to changes in gravity? If you can keep these bacteria happy and on schedule, you can (probably) also keep the poop running on schedule. Also, to reduce food waste, I’m assuming that meals and snacks would probably be pre-prepared en masse and the weekly menus would be created to ensure optimal balanced nutrition. Ditto snacking and festive occasions . Yes, some individual variation, but on the whole diet and poop could be managed.

‘One is that humans don't breed true, so amazingly talented people tend to have less talented kids; it's called regression to the mean.’ – This is where gene editing, plus better and more personalized and thorough education, universal public health, sane socio-economic systems come in. (Your description sounds as though we’d send up/out the worst of our socio-economic mess into space, plus zero advances in mental and physical health: advanced tech but cave-man mentality.) As you said: ‘Why should people have starships in space, but only the Whole Earth Catalog planetside?’ Apply across all disciplines, please: humanity is more than being able to make a fire or hammer in a few nails. Lastly, this is probably the best argument for having larger rather than smaller numbers of people on a spaceship.

Feeding the spaceship – I’m assuming that one’s caloric requirements drop in space because less muscle/effort needed overall. Plus, most of the ‘work’’ in space will probably be done by machines: how many calories do you need to push a bunch of buttons? From the Netherlands post-WW2 study we know that the size of a child can be safely reduced via prenatal nutrition: good quality nutrition in first trimester absolutely necessary, second and third trimesters are more for overall skeletal/muscle size. One caveat: Biggest nutrition demands (per kilo) are pregnant women and growing children and should not be messed with. Prolonged breast feeding would probably work to ensure infant/child health. Biodegradable (bamboo based textiles?) poopy diaper processing also a must.

Sickness – unless some accident with plant/animal habitats, labs, etc. which allows bad bacteria, viruses, etc. to go rampant, good /nutrition and sanitation would limit sickness in space to organ malfunction, accident or aging. And for this, you’d need surgery, organ replacement (machine or tissue culture) and/or drugs. Broken limbs – unlikely in space unless some really bad accident.

54:

Wasn't it proprotional to its INefficiency?

55:

No, Charlie quoted Niven correctly

56:

I'll chime in on the economics of space travel. I'll also be restricting myself to the inner solar system for this discussion.

The biggest problem I have with economic arguments for space colonization is that most were made in the 60s and 70s. In other words, they were crafted when the economy was driven mostly by industrial work. While services dominated as a portion of GDP, they were dependent on the factories and couldn't really sustain the local economy to the extent they do now. This was proven by the problems de-industrialization caused in the 80s and 90s.

One of the reasons space tourism wasn't viewed as important back then is that it wasn't as important economically. It's not like today when tourism is hollowing out cities.

An early application of any FTL or fast STL would be to open the solar system to colonialization via tourism. I'm assuming the workload in a year drops s.t. month-long vacations become viable. If that happens, humans could end up colonizing whatever is within that travel time.

57:

"Disrupt" the local environment?

So, a perfectly good scientific reason to not go into FTL near (near being defined as, say, within the orbit of Neptune? - not sure how big "local" is) a star, or planet.

And we're back to a long trip to where you can leave, blip and a long trip to where you're headed.

58:

Re SG-1 - hey, you're dealing with servants and slaves who are very low-tech, late neolithic to early bronze age. You want to make sure the appropriate ones can read it. I mean, it's not like you want to give them higher tech, I mean, look where that leads, they start building weapons and shooting back at you!

Oh, crap, and my thoughts have just cycled back to politics - why the psychotic of the 1% don't like public education, they start thinking they can do something that's reserved for Real People....

59:

'Won't that decimate the local computer industry, when everybody wants a computer that they can pass on to their kids, rather than discarding, just so that a team of engineers can stay employed making replacements?' – No, because the engineers will move on to other, new tech. Besides it’s not just the hardware that needs to be passed on but the data. However, there should probably be some museum or well-maintained cache of older tech just I case.

I'm surprised that there isn't a TV Trope somewhere, an engineer is crying.

You'd spend decades and billions training a workforce to produce the most advanced computing equipment known to humanity, along with global supply chains and huge manufacturing infrastructure. Then, when the market was saturated with these devices, you'd let the entire thing go to waste, tell everybody that their computer engineering degrees are worthless and to go, I don't know, be biochemists, or greeters at Walmart.

Then, when the equipment you made this way starts falling apart three generations later, you'd ask someone else to do it all again before it was too late?

Yeah.

Mind you, the alternative can be just as brutal. Take a look at the NRA, the advertising and lobbying arm of the American gun industry (with some, ahem, investments from overseas). Their problem was that not very long ago, the US gun market was saturated with really well-made guns that could last generations. There wasn't a big war on, the CCCP had collapsed, and gun manufacturers were going out of business. What to do? Well, a bunch of things, like taking over a rather banal non-profit that sponsored gun safety courses and turning them into a fulminating right-wing political action group to scare everybody into buying more guns, work unstintingly to make controlling any sort of guns as difficult as possible, and foster international politics that favored mass gun purchases overseas, all the while making guns that were addictively fun to use on the firing range, customizable (to attract users into buying all sorts of after-market extras), and above all, not durable. It's worked, sort of: the remaining gun manufacturers seem to be doing okay, and they've got a whole industry of after-market manufacturers of everything from bump stocks and oversized magazines to pink Hello Kitty stocks and fittings for your wife's new assault rifle.

I won't draw the parallels between what the NRA does and what the computer industry does, because that might be controversial.

The point is that you've got two bad alternatives. One is to have a boom-bust tech cycle that costs huge amounts and ruins lives. The other is to have a Red Queen forced innovation race that keeps skilled people employed, at huge cost and ruining lives. Trying to get away from the huge cost and ruining lives part of these alternatives seems is one of the core sustainability challenges going forward, because it's not just guns and computers that face these problems.

60:

Thanks to both of you. It ain't what you don't know that causes the trouble; it's what you know for sure that ain't so.

61:

The challenge of space tourism is that space travel is on a scale with cave diving in terms of safety. Yes, in an emergency, you can get ten people out of a cave with a few days of training, but that was properly considered a heroic feat. Right now, tourists can go into space as live cargo with a large bank account, provided they pass a six month training course.

This plays into the general problem of generation ships, but basically, when you see proposals for space tourism or even settling other planets, substitute "cave diving" for "space travel," and see if it still makes sense.

62:

Re: 'One is to have a boom-bust tech cycle that costs huge amounts and ruins lives. The other is to have a Red Queen forced innovation race that keeps skilled people employed, at huge cost and ruining lives.'

Please clarify - I'm not sure whether you're fer or agin sending our most tech-advanced space-can filled with highly educated and motivated folk and insisting that they hold 'holy' some Victorian-era industrialist's version of economics, i.e., only stuff/activity that makes a profit for its owners matters.

More relevant is that if these space-faring tech folk are that bright, they will probably be overwhelmed with things to invent once they get out into space because reality tends to be stranger than whatever the quickie space survey showed if a survey was even conducted. Then you're faced with the problem that none of your techs want to waste their time servicing old tech.

63:

You'd spend decades and billions training a workforce to produce the most advanced computing equipment known to humanity, along with global supply chains and huge manufacturing infrastructure. Then, when the market was saturated with these devices, you'd let the entire thing go to waste,

We have a worked example of your scenario, on national scales at least, the nuclear power reactor construction industry. A country builds a lot of nuclear reactors in a short period (the US has a hundred or so reactors, France about 40) nearly all built over a period of 10 to 15 years. After they stop building reactors, having enough for their needs and having built the existing reactors to operate for over half a century at least they lose the recipe and the production lines for parts and the expertise to build more reactors at anything like the rate they did during the first construction boom. The Chinese are the current matter experts in this industry but they're not building a lot of reactors every year compared to their demand for electricity so it's unlikely they'll saturate their market and stop any time soon (they have vague plans for new reactor construction starts out to 2050, over 30 years from now). The other matter experts seem to be the South Koreans who can apparently construct reactors on time and on budget but we don't quite know if the paperwork is up to snuff in their case.

64:

Their problem was that not very long ago, the US gun market was saturated with really well-made guns that could last generations.

Not strictly true. While the firearm itself may last for fifty or a hundred years (I know some people who are members of the local historic firearms club), barrels wear out. How long that takes depends upon the ammunition, calibre, and required accuracy. Military rifles get rebarrelled after 10,000 rounds or so; that’s a maximum of a few years use for a soldier, even if only training. Granted, civilian enthusiasts who have to pay for their own ammunition will use less - from their perspective, barrel wear isn’t really an issue.

The moral of the story is that stuff wears out, faster than you might think.

65:

One is to have a boom-bust tech cycle that costs huge amounts and ruins lives. The other is to have a Red Queen forced innovation race that keeps skilled people employed, at huge cost and ruining lives.

One obvious solution is to figure out the natural attrition/wear-out rate of guns, computers, or whatever, scale the production down to just the replacement rate, and train just enough engineers to maintain this production rate.

I was going to say "and this is incompatible with basic premises of capitalism", but then realized that piano industry seems to be doing exactly that. How do they manage it?

66:

I could be wrong, but I think that, if you look around, you'll find there aren't as many piano manufacturers as there used to be.

More generally, having stable technology isn't hard. People have been doing variations of this since probably before we were fully human. What is hard is trying to deal with things like market saturation, where one solution is to limit the lifespan of your products and keep your work-force occupied in constant change (sometimes erroneously called innovation).

One problem I was pointing to is that, for a generation ship, you want constant tech. Ideally you want to have enough clever people that problems can be innovated around as they crop up, but that can't be guaranteed, both because you can't guarantee that you'll have the necessary supplies or infrastructure, or that you will have the brilliant young specialist when you need that person.

The bigger problem is that, when generation ship technology starts to become available (per Gibson) the street will find its own uses for these things, and that is as likely to disrupt industries. Do I want an affordable gun barrel that can fire a million rounds, or a computer that lasts 100 years? Absolutely. I'm not sure what that would do to Colt's or Apple's bottom line, though.

67:

I could be wrong, but I think that, if you look around, you'll find there aren't as many piano manufacturers as there used to be.

That's kind of the point of "scale the production down to just the replacement rate". My question is: How did they manage to do it, yet stay in business?

68:

Prearranged fuelplants and frozen embryos is the most plausible way to go if we want to leave the solar system. Robots to take care of the first generation.

This proposed method has been demolished endlessly over the years on this forum.

TLDR version: human beings don't mature from embryos to adulthood automatically, they require extensive socialization and training, which in turn requires adults: all an embryo gives you is a tabula rasa platform for Human Firmware 1.0 and derivatives. Any "robots" capable of acceptably socializing human neonates would be, in fact, human-equivalent general AIs — in which case, why send embryos when there's no human-compatible biosphere at the destination?

(Supporting evidence: you raise a baby in isolation from humans, using only robot proxies, and see how well it turns out. Don't be surprised when they prosecute you for child abuse ...)

69:

Say, packing up all the politically problematic people is not an option, but leaving them behind is?

Congratulations, you just derived the religious imperative for space colonization — only renamed "religion" as "politics" (for most of human history those have been the same thing).

70:

I'm going with aging being a bunch of superimposed problems, most of which are cumulative metabolic malfunctions emerging over a period of time >> average age to reproduction, so that they're not weeded out of our lineage by evolutionary selection. See, for example, CJD, which was thought to be a genetic/hereditable condition because it ran in families and victims typically died of it aged 40-60: children were infected in utero and had more kids before they succumbed. It's actually a prion disease ...

I'm not suggesting that "aging" is a bunch of prion diseases. But there may be multiple comorbidities that only cut in late in the game, some of which have really twisty hereditable mechanisms (e.g. epigenetic modulation of immune system traits) and some of which may have genetic origins.

So a general "cure" for senescence may well be a hard problem (for "hard" as in "non-destructive mind uploading" hard). But there may be a bunch of treatments that in combination stretch out life expectancy so that we can all expect to live to 120 and get in 100 years of productive work, with the upper limit on safe childbearing age raised to 60 or 70 — which would have really major sociological effects (not just the childbearing thing: the being productive into the second century thing is more than enough).

See, right now human societies run on a 40% employment rate, plus or minus. The other 60% isn't down to people being unemployed, it's down to people being infants, or students, or pensioners, or taking a few years out to have babies, and a chunk is also down to people who can't get jobs appropriate to their skills so they're marking time doing something else — the proverbial Arts graduate working Starbucks, for example.

If you keep the number of years during which people are dependents the same but double our productive lifespan (from ages 20-65 to ages 20-110, say) then you utterly change the size of the population you need to maintain a complex system. And you change family and social structures, too.

71:

You'd spend decades and billions training a workforce to produce the most advanced computing equipment known to humanity ... Then, when the market was saturated with these devices, you'd let the entire thing go to waste

Then, when the equipment you made this way starts falling apart three generations later, you'd ask someone else to do it all again before it was too late?

Yeah.

This is what actually happened to the US (and British) nuclear weapons infrastructure. (And I'd call it an unmitigated good if only all the other nuclear weapons powers would do the same.)

72:
See, for example, CJD, which was thought to be a genetic/hereditable condition because it ran in families and victims typically died of it aged 40-60: children were infected in utero and had more kids before they succumbed. It's actually a prion disease ...

Err, citation please? ;)

Sorry, I'm somewhat sceptical, bu AFAIR it's somewhat more complicated; please note for your scenario, you'd most likely have the phenomenon of only a maternal history of CJD in the family being determiningr risk for CJD in offspring, e.g. uniparental inheritance.

It's quite common with some mitochondrial diseases,

https://en.wikipedia.org/wiki/Mitochondrial_disease

so people should have realized.

CJD usually is sporadic, but there are some similar syndromes that are familial, e.g.

https://en.wikipedia.org/wiki/Gerstmann%E2%80%93Str%C3%A4ussler%E2%80%93Scheinker_syndrome

https://en.wikipedia.org/wiki/Fatal_insomnia

but according to wiki they show an autosomal dominant inheritance mode; there are mutations in the prion gene that might make the switch to the misfolded form much easier:

https://en.wikipedia.org/wiki/Prion#Structure

No idea if that was already mentioned, but there seems to be some difference in susceptability for other alleles,

https://www.ncbi.nlm.nih.gov/pubmed/18849290

with some indications for positive selection for kuru resistance in Europeans in the past; Feorag mentioned excarnation as a possible burial practice in one thread about human sacrifices, makes for interesting thoughts.

Whatever, funny thing about prions, there might be allosteric ligands slowing down misfolding or even dissolving protein aggregates due to misfolded proteins. Might be an interesting context, there are a bunch of genetic syndromes where it could help, e.g. Huntigton or the tauopathies.

As for why prions etc. have the potential for misfolding might have something to do with their funtion (similar to some oxidases creating free radicals), might be a spandrel, might be...

73:

Right. Yes, an average lifespan of 120 is the current best guess at a feasible limit, but I would guess a productive life of only 80 years (25 to 105, for the highly-skilled), but that's still 67%. It would certainly make major differences to our society, but nothing under several hundreds would help with the interstellar travel problem.

74:

double our productive lifespan (from ages 20-65 to ages 20-110, say)

Just from looking around right now, I see both ends creeping up. I.e., the lower end is headed to > 20, and I see a lot of 70-yo and some 80s still hanging in there and productive. Of course, some of this depends on what one means by "productive."

75:

Re: Aging in space (micro-gravity)

Can find only Russian articles on this topic:

https://www.ncbi.nlm.nih.gov/pubmed/10826054

'On the other hand, the spaceflight environment (microgravity) stimulates growth mechanisms. In our opinion, behind these gravitational effects are altered levels of energy spent by cells to overcome the force of gravity. Opposite trends were observed in experiments with cell cultures in vitro. During space microgravity, fibroblast cultures on the solid substrate decreased the growth rate, and inhibited cell division and migration within the substrate.'

Sounds like two opposite things being said: 'stimulates growth mechanisms' and then 'decreased growth rate and inhibited cell division etc.'. If both are true - depending on cell type - this could really screw up fetal development.

76:

Allen Thompson & Charlie SLIGHT problem here. I'm now 72, I have an engineering MSc which I have NEVER used for pay. DO I want to be employed again? [ Assuming I live to 125-130, which would be nice ) YES: Loadsamoney that I have never had NO: Because the fucking bastards in charge will simply screw me AGAIN

( Which is why "We can't get the trained staff" of course. Human Remains departments are total aresholes, but, they do recognise that employing older, experienced people is TROUBLE - because you can't cheat them, or not so easily as people under 25, at any rate. Um, err ....

77:

they do recognise that employing older, experienced people is TROUBLE - because you can't cheat them, or not so easily as people under 25, at any rate

Last year someone leaked a report prepared by a consultant for the principals' federation(1) (as background for their bargaining with the government about their working conditions). Apparently one of the "difficulties" that principals face is an experienced teaching staff, because they are more resistant to directives and less likely to comply with requests to volunteer(2) for extra duties.

Likewise conversations with friends in my former profession (engineering) leads me to believe that there is no 'engineering shortage', but rather a shortage of engineers willing to work for half the pay of the average cop. I suspect that one reason many engineers leave the profession is that they see there are no real career prospects if they stay in it — the rewards flow mainly to management.

Sounds like the situation in Britain is about the same. I wonder if other industrialized countries are the same?

(1) That would be headmasters in England, I believe.

(2) Already a loaded word among teachers my generation Ontario after the last Conservative government brought in "mandatory volunteering" as a solution to budget shortages in education.

78:

My wife was briefly upset when she saw the thread title.

She thought it had to do with actual canned monkey meat.

79:

Stone is less likely to get melted down and cast into something else.

80:

Re Pianos: The tightened strings (wires) on a piano exert many tons of force on the piano frame (the big metal bit shaped a little like a harp.) You can't build poor-quality pianos as they tend to implode, so pianos tend to be over-engineered.

81:

On the other hand, worked stone tends to be quite attractive to people who are building or repairing later stone structures and could do without having to work it themselves.

One way around this is to write on a ruddy great big stone, so that people leave it alone in favour of ones they can lift. Even better, you can hoist it up onto the top of a couple more great big stones, so that more determined people are faced with a bigger problem moving it and may also be put off by seeing the squashed remnants of people who tried it before and dropped it. But even then it still erodes off in a few thousand years and leaves no trace by the time someone guesses what you were trying to do.

82:

One way around this is to write on a ruddy great big stone

Australians may have beaten you to this idea, with their habit of writing on every bloody thing they can find then coming back 50,000 years later to see which bits lasted. Their idea of "on a big rock" includes things that bridge the gap between "geological feature" and "technically it's A rock".

https://www.ancient-origins.net/news-history-archaeology/new-research-may-establish-australian-rock-art-oldest-world-005406

Even the stuff so new that it can be carbon dated is old enough to give archeologists funny ideas...

https://www.theguardian.com/world/2012/jun/18/rock-australia-art

83:

"What is hard is trying to deal with things like market saturation"

Only if you are fool enough to allow the term to have a meaning in the first place. One advantage of the generation ship approach, if you can make it work at all, is that the extremely constrained closed environment makes the foolishness sharply and inescapably apparent, and the generation that eventually gets off at the other end is accordingly likely to have a powerful ingrained cultural bias towards not behaving in such a manner. The generation ship environment has to be favourable to the propagation of humans, which is not identical with an environment favourable to the propagation of existing cultural demons, and the differences should be sufficient to extinguish most of them.

84:

rather a shortage of engineers willing to work for half the pay of the average cop

This is increasingly a problem across a whole range of occupations, including police. More than a few problems can be traced to policies of encouraging early retirement in favour new recruits with minimum training. With police you see a spike in the killing rate, with military it's more symmetric. Either way is bad.

The solution is, as noted, economic and political. If you make "only duty is profit" a slander on the order of "works for the russians" (well, until recently that was a slur in the US) you might start to hear about solutions. But instead we're seeing a determined and successful effort to lift the Gini Coefficient despite the problems with that being common knowledge. If nothing else it proves that rich people aren't smarter than average, just richer.

https://theconversation.com/skill-vs-luck-who-really-deserves-the-rewards-from-success-99766 Conclusion: In simulations… the most skillful people were almost never the most successful. Instead, lucky individuals tended to be the most successful.

85:

There was a snippet in New Scientist this week about killing off senescent cells having interesting effects. Remarkably they only needed two chemicals to do it... in mice :)

My bet is that there will be a whole bunch of things like that, each of which does part of the job and each will have its own side effects. But it will still be an exponential filter - to get those 20 fit and active 150 year olds you will need a billion babies born 150 years ago. Which is better than 20x100 year olds needing a billion by an order of magnitude... but you still need the billion babies.

The really radical changes still seem to be lifestyle. A bricklayer is still screwed after 20-30 years and that hasn't changed in the last century. What's changed is fewer bricklayers, and we're also starting to see small movement in mechanisation. The core problem is that to be useful at what bricks do the actual brick has to be dense and heavy... you can't use ten 1-kilogram bricks instead of one 10-kilogram brick, it just doesn't work.

You can see much the same across a whole raft of fields. So barring "robots" (they're machines, at this stage making smart machines is magitech) doing all the heavy work or some wild fantasy-level rejuvenation magic making it possible to take a clapped-out peasant and repair them for less than the cost of a new peasant, all we can do is work on ways to reduce the need for peasants.

Sadly, we're currently just shuffling those jobs round - rather than farming we have them burning circuit boards and sorting medical waste to extract the recycleable bits. Yay, what a giant leap forward.

86:

The radiation problem could probably be solved by dropping by a handy comet and sticking a dirty great chunk of ice on the front of your ship before you start turning the juice on, as suggested by Arthur C Clarke. The obvious objection is the amount of mass involved. But this is not actually a problem, because if you haven't got a magic energy source already you don't need a comet on the front, and if you have got one all you need to do is wave your wand a bit harder.

It seems to me that STL space travel stories involve just as much magic as FTL ones do, even if it's just the hidden magic of not saying how big anything is and hoping people don't notice how big it would have to be. Perhaps the least magical / most workable expedient is the Bussard ramjet, but it still needs other magic to happen before it can function even if its functioning is entirely mundane. The apparently widespread notion that STL SF is inherently "harder" than FTL is an indication of the magic's effectiveness.

87:

That's always my assumption. Until you can reasonably make at least a colony out round Neptune or the Oort cloud the idea of making one out past there seems a bit optimistic. Given that technology there will be a period where they're not entirely self-replicating and the usual colony factors will push them to cast adrift. "if you won't make us an X we'll leave and found a planetary civilisation that will".

I tend more towards the idea that once you have these giant space ships that are more or less self-sufficient the real question is why they would ever decant onto a planet. There are even SF stories that deal with the question.

88:

You don't spin the whole spacecraft, just a cylinder (or better a pair of cylinders rotating in counter directions) inside of the ship.

Has anyone actually lived on a merry-go-round for any appreciable amount of time? Whenever I consider the notion of simulating gravity in space through centripetal acceleration, I start wondering about how big the cylinders would need to be to avoid water hammer effects when you suddenly turn around.

89:

KSR also has humans beginning to shrink within 5 generations due to insular dwarfism. They also start to lose cognitive ability in that time.

Huh... Brian Aldiss had that, too, in his novel "Non-Stop", although it was caused by a virus picked up on the colony planet. Is there a third example, so we can claim "Generation Ship Midgets" as a genre?

90:

Robt Prior @ 76 AIUI, this problem does not occur in Germany or the Netherlands ... and their industrial economies are doing very well - I wonder why that might be?

Troutwaxer @ 79 Oh dear, the big metal bit shaped a little like a harp. Yes well ... the Marx brothers enlarged on that didn't they?

91:

Hm, the grass is always greener on the other side[1], but going by some stories I heard from teachers, it's not that different here...

[1] But somewhat more expensive outside the Netherlands...

92:

Isn’t this just a variant of island dwarfism?

93:

Ah... never mind. I didn’t note the reference to insular dwarfism (different term, same basic effect).

94:

There was a snippet in New Scientist this week about killing off senescent cells having interesting effects. Remarkably they only needed two chemicals to do it... in mice :)

I have this itchy need to write a superhero story in which our protagonist acquires powers following an unfortunate accident in a CRISPR lab. The money shot from the medics who are diagnosing their condition: "turns out, your genome — in every cell in your body — has been entirely replaced with that of Mus musculus ... and it looks like the epigenetic mods are also murine!"

As we know, if humans had the mouse genome, by now we'd all be living to 400, immune to cancer, able to see in the dark, and bench press 500 kilograms/run a double marathon. Oh, and we'd have six different cures for AIDS.

Of course, the hack affected every cell in $PROTAG's body at present. Over time, cells will die and be replaced from their stock of now-murine stem cells. So they're going to devolve into a giant misshapen mouse over the next century or so. But in the meantime, they fight crime!

(I wish I had the guts to perpetrate this crime against genetics in fiction, for realz.)

95:

It certainly used to be VERY different, at least in the wider STEM arena.

Once survey I saw (about 30 years ago) was that 70% of German engineering companies had at least one qualified engineer on their board of directors. What was the figure for the UK? 2%. I could give other examples, but the glass ceiling for technical staff has been getting lower, and is now often (probably usually) well below decision-making level. Yes, I mean that the technical reports are presented to those to take a decision by a managerial intermediary, and the technical leaders told the decision without seeing (let alone contributing to) the discussion. And it often is invented out of thin air, and is infeasible: "That's the decision, it's your job to make it work."

The result is that the best UK students now avoid STEM subjects in favour of politics, management and law, now because of the poor pay, but because of the very low status, poor treatment and promotion prospects. In many (probably most) leading research laboratories in the UK, a minority of the staff and very small minority (10% or so) of the students are from the UK.

96:

The downside being that you can be tracked wherever you go by the trail of urine. A problem when the cat based super villain turns up.

97:

I like it! But after your break.

The obvious problem with preventing cells from becoming senescent is increasing divergence (including cancer), but my guess is that simply killing senescent cells would lead to tissues eventually fading away - unless replaced in the fashion you mention, which I thought was normal only for some tissues. What effects replacing ALL tissues (especially in the brain) from even the human's own stem cells would have, I can't guess. Maybe you can. But the mouse stem cell theme is funnier :-)

98:

Also: the fastest turnover tissues will tend towards murine morphology first.

Which includes the gonads. Specifically the testes.

Little-known fact: rodent balls are huge. If human male genitalia were proportionate in size to those of rats, our penises would be slightly smaller ... but we'd need a wheelbarrow to carry our balls around (they'd be the size of watermelons). (Yes, there's an explanation for this in terms of R/k reproductive strategies, but that's not the point.)

Mouse Man is immune to cancer and AIDS, can expect to live to 400, can bench-press 1000kg and run a double-marathon and a two-minute mile, but on the downside he drips urine constantly and needs kevlar-reinforced Y-fronts with shoulder straps to support his package (a noteworthy vulnerability in superhero/supervillain punch-ups).

He's also the ultimate manspreader. Awkward.

It might be better to make our murine mutant female — but she's going to want a radical bilateral orchidectomy or hysterectomy fast, lest she start going into heat every six weeks.

99:

Actually, not really. We HAVE to tackle this problem, because of the waste issue, as you know. But your premises are a bit off, and there are actually many more alternatives. What they all have in common is that they need a radical change to society.

Very, very few 'engineers' in IT companies are actually creating new products - far more are propping the infrastructure up or fighting the fires cases by the latest crapware. In many cases, the majority are not even doing anything approaching engineering. Producing computers that cost 3 times as much, appear 1/3 as often and last 3 times as long would be trivial (except for getting there from here!) The engineers would simply be spending more time on getting them right, both in terms of RAS and usability, and testing them. What it WOULD reduce is the number of salesdroids and marketing suits.

To move to ten or more times would be more radical, but could usefully be done by moving more engineers to developing genuine innovations, not simply marketing tweaks. And doing some proper ab initio design, development and production, to flush out the historical disasters that dominate modern computer systems.

Unfortunately, even the former needs a social revolution, and the latter is mere wishful thinking. But it's NOT because the alternatives don't exist.

100:

Little-known fact: rodent balls are huge. ... but we'd need a wheelbarrow

Buster Gonad... is real?

101:

"The challenge of space tourism is that space travel is on a scale with cave diving in terms of safety."

Where did you get this number? Is it by taking the number of deaths of the Shuttle + Soyuz over the number of flights? If so, then the safety rate is BS. It would be the same as calculating the failure rate of the modern Delta IV or Atlas V rocket based on the failure rate of the Delta I and Atlas I.

Here's how I would calculate it. First, remove the death rate of any rocket built before 1990. This is because rocket reliability improved massively with the Delta II (launched in 1989) and Atlas II designs. In other words, it is safe to ignore the deaths due to the Shuttle. Likewise, the Soyuz has flown since the 1960s, so early deaths I think skew the safety of the system as a whole.

What you should do is take the total failure rate of Delta II + Atlas II + Delta IV + Atlas V + Falcon 9 + Falcon Heavy + Ariane 4 + Ariane V + Minotaur I + Minotaur-C. From these rockets, partial failures can be ignored since people would have survived these. So that gives you 1 failure from Delta II and Falcon 9, 3 failures from Minotaur-C and Ariane 4, and 2 failures from Ariane V. The Delta III, Atlas III, Minotaurs IV and V would not have flown the minimum 7 flights needed to be certified so can be ignored. I'm not about to hunt the failure rates of rockets from Japan, India, China, and Russia right now.

To this, you can add the number of deaths on the Mir and ISS (0 deaths).

"Right now, tourists can go into space as live cargo with a large bank account, provided they pass a six month training course."

That was the policy for any tourist riding the Soyuz. However, Blue Origin so far requires only a weekend of training. SpaceX's policy is TBD at the moment, and I don't remember Virgin Galactic's training period.

103:

To this, you can add the number of deaths on the Mir and ISS (0 deaths).

Mir, however, came bloody close to a fatal accident on at least two occasions: when it caught fire and when Progress M-34 collided with it. And you can argue that the Salyut-1/Soyuz-11 fatal accident should be counted. (A design flaw in Soyuz that surfaced only after 10 crewed flights coincided with a dodgy firing sequence in the explosive bolts linking the OM to the CM after undocking resulted in depressurization of the CM and the crew asphyxiating. And there are still occasional issues with CM/OM separation, $BIGNUM flights later — e.g. Soyuz TMA-11's exciting and unpleasant (but non-fatal) return to earth.)

104:

"More generally, having stable technology isn't hard. People have been doing variations of this since probably before we were fully human."

Most of the time humans have only had "stable technology" because of ignorance of others' achievements and expediency - Find something that works, anything, and stick with it....Then it kills you because it's use became inappropriate, and it gets retroactively redefined as "laziness."

Having genuinely "stable technology" in just about any field is actually very hard. You need to eliminate the incentive to improve the product by every actual and even potential market participant. Effectively you are trying to overcome your own impulse to improve your market share at the expense of your competitors. (And you are hoping that they do the same.)

You would do this by having or requiring massive costs for market entry to deter prospective competitors, the product probably needs to be some sort of commodity product where the production processes are known, virtually identical for each competitor and, critically, the profit per unit is razor thin. The reason for that is that it's then very difficult to simply slowly build market share stealthily because there is so little incentive to look for each tiny piece of new business, which you are barely going to make any money upon if you do manage to find it.

Otherwise capitalism works precisely upon the notion that you are either building better products for people, you are selling more of a given product, or you are encouraging people to throw an example of the old product away and buy a new one, possibly by designing it so it has a limited life, and maybe even a consciously selected "death date," similar to the documented firing life of gun barrels that you mentioned.

ilya187 - "One obvious solution is to figure out the natural attrition/wear-out rate of guns, computers, or whatever, scale the production down to just the replacement rate, and train just enough engineers to maintain this production rate.

I was going to say "and this is incompatible with basic premises of capitalism", but then realized that piano industry seems to be doing exactly that. How do they manage it?"

Massive costs to entry, a commodity product (A tuned piano is just the same as any other.) and not a lot of profit per unit because of the level of effort in respect to expanding the market is great. Digital keyboards like Casio and Yamaha marketed disrupted the whole thing briefly but are still just an exercise in "massive costs to entry" as to compete with them now you need to be an electronics manufacturer.

105:

Insular dwarfism...

This is one of those mine fields, at least for attributing it in humans. I'm thinking of all the short women I know who were born on islands (predominantly the Philippines), all of whom have advanced degrees and are extremely intelligent. The point here is that it's really easy to slip into "short island people are stupid" if you're not careful.

Thing is, humans are morphologically plastic, and height and weight are in part due to what you eat as a child. This is the well-known effect of short people coming to America and their 20th century descendants becoming much larger. Obese even. This skews our idea of what "normal size" means in humans, and that in turn messes with the discussion of insular dwarfism. Were people in Napoleon's Paris pygmies? They weren't any taller than are phillipinos are now.

What goes on in islands in NON-HUMAN species is that vertebrates below the size of rabbits tend to get larger (insular gigantism), while species above the size of rabbits tend to get smaller. It can be relatively quick in fossil terms (this is a general problem in our perception of evolution--it can be rapid. What we consider human artificial selection has been matched by some cases of natural selection, so if humans can breed a toy dog in a few generations, so can an island, if it has just the right selective landscape). The problem on islands is that the resource base is limited by the size of the island. Animals that need less food to survive and reproduce are favored. Small animals (especially mammals) have high metabolic rates, and increasing in size can give them more more to store fat, making it harder for them to starve and allowing them to exploit a broader range of foods. Big animals that reach sexual maturity when smaller also have an advantage on islands--they need less food to survive and reproduce. This tends to favor them becoming smaller, insular dwarfs.

This is where the discussion gets a little squicky, because in humans, premature puberty (as in when the child is seven or eight) is considered a medical problem that stunts growth, not a trait to be selected for by evolution. However, there's some evidence that premature puberty is where human pygmy populations come from (IIRC there are eighty-odd pygmy groups around the world, and they aren't closely related to each other). Pygmies aren't midgets with defective growth hormone receptors. Instead, they reach puberty earlier, which stops their growth. Most human pygmy groups reportedly show up, not in areas with little food, but in areas with horrendous disease problems. If the average adult age of mortality is in the 20s or early 30s due to disease, one can see how women having children in their teens gets favored by that particular environment. Some of these pygmy populations are on islands, many are not. This probably isn't the only cause, but when some researchers tested various hypotheses for where pygmies came from, disease was the best correlate in their data set, and premature puberty halting growth was the functional cause for short stature.

Turning to hominid insular dwarfs, we've got to talk about hobbits (Homo florisiensis) and the island of Flores, where their remains were found. There are plenty of short people currently living on Flores, and determining that the few hobbit remains weren't islanders with microcephaly was a real issue. The hobbits are assumed to have been insular dwarf offshoots of Homo erectus or some similar species. Although there are only a few bones, IIRC they date from enough different times that they look like remains of an extinct human species, not isolated, pathological individuals.

As for the modern short Floresians, it's not at all clear to me whether they are short due to early puberty and disease or due to poor diet. If anyone was interested in figuring this out, some expensive blood work looking at genomes and blood chemistry would sort it out. However, doing such work without appearing to be a bigot or racist would be rather harder. I'm sure you'd want to spend the years explaining to Indonesia's labyrinthine bureaucracy that you're simply curious to see if their islanders are mutants or deficient, and not pursuing some political agenda in doing so...

I'd also note that I'm not touching the idea that Floresians are in any way mentally deficient, whatever their height. That's a whole other can of worms, and there's no evidence that known pygmy populations are mentally defective either.

106:

The bigger point is that astronauts on missions train for years before they go up, and even space tourists have to go through a six-month training course to go up. This has a big role in keeping mortality down. I suspect that if cave divers rehearsed particular dives in full-sized mockups with crews of trainers for months to years before they went in the water, fewer of them would die too.

Unfortunately, they don't, in large part because cave-divers don't have to spend $20,000 per kilogram getting themselves into the water. The converse is equally true: if space travel gets cheaper, training will go away, and mortality will almost certainly skyrocket as the population in orbit increases dramatically.

107:

My question about shipping humans far away for a long time is more cultural than technological. Let's assume that all the STL magic works and your generation ship arrives at its destination. You have a a ship crewed by people whose whole culture is based on working in a cramped environment where every decision is governed by a strict set of protocols and maintaining stability and safety is of paramount importance. How is this risk-averse society going to handle an alien environment where surprises are common and decisions need to be made that don't have clear outcomes? It might be so disorienting and uncomfortable that the settlers prefer to replicate what they're comfortable with (an enclosed habitat with little/no interaction with the outside) rather than expand beyond the original landing site.

108:

Mouse Man is immune to cancer and AIDS, can expect to live to 400, can bench-press 1000kg and run a double-marathon and a two-minute mile, but on the downside he drips urine constantly and needs kevlar-reinforced Y-fronts with shoulder straps to support his package (a noteworthy vulnerability in superhero/supervillain punch-ups). Nice idea, except he probably should also be mouse-sized, for the provisions of square-cube law and similar limitations.

As I mentioned in last post about that ensemble of problems, I've spend a lot of time brooding over implications of space travel. Even armed with achievements and ideas of Tsiolkovsky, I came to conclusion that, indeed, monkey meat does not ship well anywhere beyond the host planet. We may really modify humanity to cope with these factors extensively and be able to compensate for heightened risks of radiation, weightlessness, confined space, limited life support and other optional factors. But the thing is, it would not be our well-known monkey then. It will be something different, almost certainly we will have to trade off something else to create organism that can survive those factors. Those which we can not compensate in the space flight, not to say about interstellar space flight.

On the bright side, there's still hope for indefinite procreation. I mean, with a hint of technology that does not involve things that blatantly break our known laws of universe - artificial gravity, FTL, immortality and time paradoxes. Assume, we can create a machine that will be able to rebuild the humanity elsewhere, if something goes wrong. You will be able to take a template, a batch of information related to human behaviour, genetic code, physical development, socialization, education and so on. You create an environment, that can be able to produce a pretty average, intelligent, sociable, decently-mannered - person, family, or even the entire tribe. You do not need to actually put the living "meat" in hundred-years old freezer or ship it in enclosed life-supporting cage. You ship out a cold, somewhat super-intelligent (if only in design) assembly machine that can make a human being on a spot. Yes, this might seem to be slightly disturbing for the first time, but it certainly less disturbing than models of brain uploading and, uh, downloading. This, quite probably, will take considerably less time than figuring out brain uploading (without depolarization of neurons, no less), or maybe even genetically modifying people beyond recognition.

On the other hand, we must also be able to solve the problems of autonomy of our machines. These machines should be able to trespass interstellar spaces and find suitable environments. Say, if we can register a fairly earth-like body for every 100 to 150 light-years, we should be able to hop onto it, terraform it somewhat to our minimal requirements, and settle down. Our autonomous machines really need to participate only in transportation part, after which human intelligence will be able to take over again, if we are too worried about our plans for future.

Ok, having said that, in the next comment post, I'm going also explain how I imagined the concept of that over the years, and also add some other further speculations. I was rather inspired by "Deepness in the Sky" STL model by Vernor Vinge, with slow ships carrying living humans between stars, but decided to add a little twist later on.

109:

Nice idea, except he probably should also be mouse-sized

Go back and read the original comment, #94. Already addressed.

110:

Re: 'How is this risk-averse society going to handle an alien environment where surprises are common and decisions need to be made that don't have clear outcomes?'

Don't see this as a problem because space flight itself is likely to be risky with both known and unknown risks (i.e., unknowable outcomes). Planet-fall then will be just anther risk to be evaluated: variety of approaches modeled and continually re-evaluated as new data is gathered. Basically, as long as these folks are open to the idea that life is just learning one thing after another until they drop, they'll probably make it.

Even 'known risks' can catch experts unaware like a couple of neutron stars exploding: the probability of X events over Y years might be known but that's not the same thing as knowing this will happen at exactly Z date/hour. Minimizing surprises is key, therefore good scouting via drones followed by lots of lab work and enough time to really get to know the planet you'll be settling. (See McCaffrey's Pern series for what 'enough time' means wrt to checking out a planet/solar system).

Also, as mentioned by other posters above, even if the ship culture tends toward conflict- and risk-avoidance, these attributes can re-emerge out of dormancy given the right environment/stimulus.

111:

In Ontario police salaries have been trending upwards for the last couple of generations.

As of January 1, 2015, a Constable-in-Training at the Ontario Police College (OPC) earns $55,146/ annually. Upon graduation from OPC, members will become 4th Class Constables earning $64,336/ annually. As a 1st Class Constable, you can earn $91,909 to $100,183/ annually.

To enter the OPC you need a high school diploma. And the salary range doesn't include overtime and paid duty*.

For comparison, the average engineer in Canada makes in the mid-60s, with starting salaries (after a 4-year university degree during which they don't get paid) in the upper 40s.

Things may be different in Australia (I know they are in the US).

*Contractors doing road work must hire a police officer to direct traffic, at $70 per hour.

113:

First things first.

Space Engineer has come with a concept of "mothership" spacecraft with certain design features that we decided to be crucial for interstellar voyage. It can be viewed on the forum, along with pictures, gameplay ideas and discussion. http://forum.spaceengine.org/viewtopic.php?t=34

Yes, the ship is supposed to be FTL, but it has some features that allow it to travel at considerable STL speeds. So not to let you completely read the entire thread, I will try to summarize by describing major parts and specifications of it's design (or maybe how I imagine it):

Size: on 1+ kilometre side long, 100-200 meters in diameter. Mostly this volume is hollow, filled with , with major parts given wide berth.

Engines: thermonuclear-powered, with anti-matter infusion. To be easily controllable it has to have more baryon mass in exhaust, so pure photonic engine would be highly problematic with it's gamma-radiation. Engines are either two-directional or can be rotated, since we do not assume we need to rotate the entire ship for deceleration. Power plant is purely optional and only needed for providing power during passive flight (I'll talk about that later).

Fuel: Solid-compressed hydrogen and antimatter in magnetically stabilized environment, which constitute to most of the mass of the ship itself. If there's such thing as metallic fraction of hydrogen that can be preserved in near-zero conditions, we should be able to use it. Anyway, with this amount of antimatter and energy involved, it is probably not safe to fuel such thing within a million kilometre of populated areas.

External protection: consists of general anti-radiation shields all around the body and forward-looking shield of great thickness. Yes, interstellar medium can be pretty dangerous at speeds as high as a fraction of lightspeed, but we shouldn't also forget about other types of radiation, in fact, most energetic galactic particles would just go right through the thinner parts of the spaceships without causing cascade of secondary particles. Collision with even lightest mote of dust is, in fact, quite dangerous affair, so a system of avoidance is needed.

Last but most important: part is a repair system. Practically, it should be able to replace any part of the ship as good as new, should it degrade from radiation or constitutional damage over century-long flight. Shield will certainly need regular replacements, as well as internal parts that are damaged by high-energy radiation. Constantly. In fact, I've been thinking, it almost puts the ship into the category of living creature capable of self-healing. In the end of long flight, it might be made by 20, 40, 80% from materials that has been reprocessed from parts that need replacement (fuel not included).

Payload: As I said before, it there's probably only one thing that needs to be transported across such far distances with any purpose. The information and self-replication systems. They will require a very thick protection against the radiation, and quite possibly can survive for longer than the ship itself, should anything bad happen.

Flight parameters: For reasons mentioned by Charlie above, we may safely assume that reasonable speed for STL flight by known principles of physics is below 30%, maybe 20% of light speed. Which limits us to 500 years of flight for each 100 light years distance.

Early on, when I was contemplating Eclipse Phase rulebook, I created a little .xls file that can find a solution for linear transit flight, with acceleration, passive flight and deceleration in the end. You can only give it a distance in AU, an acceleration in "gee" and a coefficient which indicates, how long your ship is accelerating. With little input, it said that to fly to Barnard star at moderate 0.33 c with engine provided acceleration of 0,1 g - will take about 22 years. 40 years, if we reduce speed to 50 000 km/s. Pretty bearable.

Go back and read the original comment, #94. Already addressed. Excuse me if I wasn't too elaborate. But I can not imagine what the mouse stem cells will do if they find themselves in a body the size of human being (given the autoimmune reactions are suppressed enough to eat the body inside out outright). Not because it is impossible at all, but because it is too nasty to imagine. https://en.wikipedia.org/wiki/Morphogenesis#Cancer_morphogenesis

114:

Most of the time humans have only had "stable technology" because of ignorance of others' achievements and expediency - Find something that works, anything, and stick with it....Then it kills you because it's use became inappropriate, and it gets retroactively redefined as "laziness."

Um, no.

This is what powers the back to the land movement, the communists, and every other social critic, and the criticism has only grown sharper over time.

Our history as Homo sapiens sapiens is about 300,000 years long. We ignore all of that history (to a first approximation) because it left almost no evidence. The only reason we know we've been around for 300,000 years is a single, 300,000 year-old skull. Whatever our ancestors did, they did correctly, for they lasted 300,000 years.

Compare that with the last 200-odd years, where we've been increasingly concerned, and with good cause, about wiping ourselves out. Going back to Marx, people have noted that capitalist society strongly resembles either a financial bubble or a Ponzi scheme. Well-intentioned methods of trying to solve problems like global famine have instead massively increased populations and absolute numbers of people in poverty, and in the meantime we seem to be very good at weaponizing any new technology to make it as lethal as possible, always for the ostensible aim of deterrence.

On this basis alone, it is totally rational to assert that what people did for the 300,000 years of their history prior to the present was far more rational than what we're doing now, which is the exact opposite of what you claimed above.

One thing you need to become aware of is Boserup's Ratchet. This is Esther Boserup's proposed mechanism for getting around Malthus. What happens is that, when population grows to hit its limit to keeping everybody fed and happy, people start innovating with agricultural techniques and culture, to find ways around that limit. When they find a way around, everybody rapidly adopts the innovation so that it become standard, and the population then increases again, spurring innovation, which leads to more changes, more growth... This continues until new innovations fail to materialize or existing systems fail (as with irrigation systems failing due to salting and/or seismic activity, something that has happened for thousands of years), at which point Malthusian dynamics bite down, and the population falls to a point at which it can maintain itself with whatever system it can piece together with the pieces of what fell apart. This is a major cause for all those dead cities the world is dotted with.

Or you can work within a stable technology and keep your population around its limits. This works too.

So basically, you're only correct if you claim that effectively all of human history is wrong, and what we're doing right now is the only right way to live.

115:

suppressed enough to Correction: supposed enough to NOT. Anyway, morphogenesis is a pretty interesting thing. http://www.crg.eu/en/news/crg-researchers-confirm-mathematical-theory-first-proposed-alan-turing-1952-can-explain-formation-fingers

116:

Re: Mouse stem cells

This article (full Abstract below) seems relevant to your point.

https://www.ncbi.nlm.nih.gov/pubmed/21822871

Xeno-free culture of human pluripotent stem cells. (Bergström R1, Ström S, Holm F, Feki A, Hovatta O.)

'Abstract

Stem cell culture systems that rely on undefined animal-derived components introduce variability to the cultures and complicate their therapeutic use. The derivation of human embryonic stem cells and the development of methods to produce induced pluripotent stem cells combined with their potential to treat human diseases have accelerated the drive to develop xenogenic-free, chemically defined culture systems that support pluripotent self-renewal and directed differentiation. In this chapter, we describe four xeno-free culture systems that have been successful in supporting undifferentiated growth of hPSCs as well as methods for xeno-free subculture and cryopreservation of hPSCs. Each culture system consists of a xeno-free growth medium and xeno-free substratum: (1) TeSR2™ with human recombinant laminin (LN-511); (2) NutriStem™ with LN-511; (3) RegES™ with human foreskin fibroblasts (hFFs); (4) KO-SR Xeno-Free™/GF cocktail with CELLstart™ matrix.'

117:

But if you build a stable basis of production, where people who order planned obsolescence are taken out and summarily shot, why, than, the company CEOs, etc, can't get richer than they are, and may have their pay and bonuses cut to, oh, only 275% of the factory floor sweeper, and that would be dreadful, dreadful I tell you.

Fun note: around '95 or '96, Robert Reich, Clinton's first(?) Sec. of Labor, asked in an opinion piece on NPR (before they broke and sold their souls to the GOP), what is it that a CEO does that is worth 10 times what the company president does... because that's about the pay differential.

118:

I won't mention my age in a public forum, but it's up there. My father retired at full US social security a few years younger than I am now. Some people do find that what they do is worth doing, and keep on; the majority do it because they can't afford to live otherwise.

Detail note: I think it was in Studs Terkel's book from 78(?), Working, that he cited a study then that showed that 80% of working people weren't just unhappy with their job, but actively hated it... and that's when the US was almost 25% unionized, and had 40 hr weeks....

119:

There was an article a couple of years ago in Slate? The Atlantic? entitled "Your HR Department Hates You".

We used to have personnel depts, with folks who knew the company, and often specialized, and knew what they were hiring for. Now, HR knows NOTHING WHATSOFUCKINGEVER, doesn't know what they're hiring for, doesn't know the organization, and outsource every damn thing (so I don't understand why they have jobs).

Brother Guy used to teach about half the year around the US at various Catholic colleges, and one course he taught was "science for non-science majors". About a dozen years ago, on a list we're both on, he ran down the food chain of the majors that took that course. Next to the bottom were the business majors, who didn't get it, but didn't let that worry them. The bottom of the food chain, who didn't get it and didn't know that they didn't get it, were the communications majors... y'know, folks who go into HR, and pr, and journalism? Doesn't that explain a lot?

Anyway, they want certs and magic acronyms, so that can do a d/b search (yes, really), because they DON'T KNOW, AND AREN'T INTERESTED IN LEARNING>

Come the Revolution, we'll lead the HR depts into the parking lot, toss asphault on them, and PAVE THEM INTO THE ROADWAY, and then they'll have some social utility.

120:

There's another argument that I think supports your (Frank's) view. I think you'll like it, partly because it also has a close parallel in evolutionary biology.

A standard argument in growth economics is that the rate of innovation (new ideas, technological progress, etc.) is increasing in population size. The argument is simple. Once a good idea (innovation, new tech) comes up it spreads through the population. More people means good ideas come along more frequently. This argument has been used to look at economic growth over time scales of decades to 100,000s of years.

The evolutionary biology analogue is the relationship between population size and non-neutral mutations. Bigger population means more mutations in absolute terms, and when a good mutation comes along it spreads, hence a larger population can mean a faster rate of evolution. I'm sure you know this stuff better than I do.

(Of course there's more to explaining the rate of technological progress / evolution than just this.)

Anyway, you could argue from this that static technology in smallish communities engaged in STL travel is a reasonable assumption.

121:

You forgot being able to make younger people think that they don't have a life outside the company, and that working "whatever it takes", if that's 10, 12, 16 hr days, for months on end, means they're "valuable" people....

122:

Of course it's a bunch of things. Just like there's no one "cancer", or, for that matter, "cold virus".

And no one in this thread has mentioned tellomeres....

123:

Well, he would already have a name, a costume, and a theme song.... "Here he comes to save the day! You know that Mighty Mouse is on his way!"

Of course, there are the ones done in the nineties, I think, by Bakshi, and the, um, origin story is, uh, well... peculiar.

124:

But, I mean, how can you be in management, and not have your MBA, which proves you don't know shit from shinola, that you should internally break up the company so the divisions "compete" against each other, and there are no profit sinks (tha is, say, billing is a customer of IT....)?

No Modern Business Can Succeed* That Way!

  • Succeed, def: no foothold for unions, no limits to working days, and CEO profits, bunuses and stock options maximized.
125:

Does that mean that if I put on a superhero costume, and take a leak against a wall, Catwoman will come find me?

Here, kitty, kitty, lovely kitty....

126:

About Challengar and Columbia...

They got the Shuttle approved, partly by doing what LBJ did, except more so, so that the solid fuel boosters, were built in Utah, and shipped to the Cape, and then assembled. For that reason, they needed the giant O rings.

Raygun was going to give a speech, and they wanted a launch so he could refer to it in his speech, never mind if was too fucking cold, and out of spec for the O ring.

columbia... My late ex was an engineer at the Cape for 17 years, and worked on the Shuttles, and Station. Let's gloss over why she wasn't still there, but her analysis of why Columbia failed was not the tiles, they had them falling off all the time. She assigned blame to stress corrosion cracking of the hydraulic lines (we are on the Atlantic Ocean - those of you old enough here might remember what chrome bumbers on cars looked like after a couple years near the salt air. And she doubted they were doing the extensive examination of the state of the lines. To do so required a) someone who knew what they were looking at... and b) someone small enough to get into the wheel wells.

And she was both, being 5' on a good day, and 105lbs soaking wet, and a metallurgist. Not a lot of them there that met both criteria.

Max stress is reentry... and she thought the hydraulic lines had burst, at which point, as she put it, you have the aerodynamics of a Mach 25 flying set of keys.

Goddamn fucking politcs. NASA's budget during the height of the Space Race was $20B. Now, on a good year, it's $20B... except adjust that for inflation, so in '65 dollars, we're talking about $2B. But, I mean, where the ROI?

127:

FL @ 114 EXCEPT that, "now" ( In the past 10 years approx ) something new really has appeared - dropping birthrates as indiividual survival rates increase. "All" it needs is for this demographic change to encompass the whole human race & problem solved. ( First thing to do is hang all the priests )

whitroth @ 121 Yeah, that too ...... [ It's a subset of "not being cheated" actually ]

& 124 See my extremely nasty remarks about MBA's in previous threads?

@ 125 😻

128:

Massive costs for market entry... but then you can keep selling. Things wear out, albeit slowly, and accidents and negligence happen.

129:

Dwarfism... smart...

I can't remember if I've told this story here.... The morning that Randy Newman's album, with Short People, was released, Randy woke up in sheer terror. He quickly dialed the personal number of a close friend. As the phone was answered, he started babbling to the still-sleepy aswerer, "Don't kill me, Harlan, I didn't mean anything by it!!!!"

130:

@ 127 Bugger HUNDRED years, not "10" ( ! )

131:

Slightly less in Queensland but definitely comparable ($40k in police college, $58k plus 20% shift allowance at the most junior constable-on-the-beat pay grade). Not clear on equivalence between the middle level ranks. For comparison in the public service a team leader in a technical division (say, the person in charge of the firewall team) gets about the same as a senior sergeant and a manager (say, the person in charge of the larger network team) gets about the same as an inspector (assuming a large government department with its own IT). The public service grades generally pay about 90% the equivalent private sector jobs, but this is flattening. It used to be less pay but more benefits in public, but the trend is toward fewer benefits in public and less pay in private. Cops still get pretty good benefits, though. Not bothering to specific AU$ vs CA$, looks like they are roughly the same at the moment anyway.

132:

something new really has appeared - dropping birthrates as indiividual survival rates increase.

I don't think this is really a new thing. See Frank's discussion of the demographic transition above, but my view is that this is evidence to show that the dynamic to increase population is cultural and depends on economic circumstances, meaning that when these change the dynamic also changes. The premise of infinite demand is a cultural assumption, not something that is inevitable (that is, not part of the null hypothesis).

133:

Iain Aschendale @ 30:

"Not to mention the social issues involved. No matter how closely you screen your initial passengers/crew, I'd be very concerned about belief systems arising after a generation or two that were counter to the continued survival of the mission. Let me be clear that I'm not referring only to religion, but right now in the United States, there are outbreaks of diseases that were nearly extinct due to a subset of parents believing that the risk of autism is greater than the risk of measles. ..."

The real irony is that the risk from vaccination is so low as to be effectively zero. Especially when compared to the risks from the diseases being vaccinated against. The original link between vaccines and autism came from a PHONY, FRAUDULENT "study" published in The Lancet for the express purpose of furthering a lawsuit against the MMR vaccine manufacturers.

Further, it was later discovered that the "physician" who authored the study had a conflict of interest because he was partner in a company that was promoting a different vaccine that competed with the MMR. He ended up losing his license to practice medicine.

I've been thinking about how long a hypothetical Slower Than Light colony ship might take. For reasonably nearby stars it doesn't seem to take as long as you might think. It could probably be accomplished in a single generation.

Someone else is welcome to check my "math" (in fact, I insist on it), but I figure if you can accelerate at .25g for one year that puts you up at about .25C. A target star 10 light-years away would be a journey of about 42 years (allowing 1 year acceleration, coasting for 40 years [four years per light-year] & decelerating for 1 year).

It doesn't require that much magical thinking to envision an O'Neill cylinder capable of making the journey. Size it to handle a population of around 5,000 & seed it with a thousand initial colonists. Add in enough spin to create about 0.5g internally (have to figure in the .25g thrust and have a way to angle the "floors" so the resulting 0.5g spin "gravity"+ 0.25g thrust are normal).

I doubt I'll live to see even the first experiments, but it doesn't look like an impossibility to me. It's just engineering on a fairly extreme scale.

Seems to me the monkeys should be OK if they start out with a big enough can.

134:

The Polynesians were island-dwellers who searched for more islands. That's very different than leaving a continent in one huge jump across the ocean.

So if you want an analogy to Polynesia, then a better question to ask would be whether a human population of living largely in space might go inter-stellar.

A) Polynesian islands are small. They went through boom-bust population cycles. When it was bad, people starved. Pressure to move on to a new place was very high - and migration relieved population pressure.

B) They're canoe-building, navigating, fishing cultures. The core expertise to build, navigate, travel were there in the group already.

C) The group that went could largely build their own transport, and supply it themselves.

D) The group that went were a large enough proportion of an island's population that their leaving could create a lot of valuable land/fishing rights/etc behind to pay others to help them. Which is quite unlike 1,000 people in the USA paying another 2,000 people to help them build a spaceship to take them to the stars.

135:

A) Polynesian islands are small. They went through boom-bust population cycles. When it was bad, people starved. Pressure to move on to a new place was very high - and migration relieved population pressure.

That doesn't appear to be true. Most of the major colonization events (such as colonizing Hawai'i, New Zealand and Easter Island) happened well before peak population hit in central Polynesia. While exiling people to the ocean was a way of relieving population pressure on small islands like Anuta and Tikopia, in the most populous places (Hawai'i, Tonga, Fiji) warfare was the most common way of dealing with intolerable conditions, and typically the people from the drier parts of the islands (especially the Kona coast of Hawai'i) attacked people on the wetter, more fertile side.

B) They're canoe-building, navigating, fishing cultures. The core expertise to build, navigate, travel were there in the group already. C) The group that went could largely build their own transport, and supply it themselves.

As a subset of B, places like Hawai'i, New Zealand, and Easter Island stopped making huge voyaging canoes within two generations of settling. I can make two guesses as to why this happened, but it's one reason why I think extrasolar colonies would be extremely wise to focus early on making more interstellar capable ships, rather than assuming that population pressure will naturally lead to their creation. Evidence from Polynesia says that new settlements abandon their boats.

This is why you've got to read history (and here I recommend Pat Kirch's books). I thought what you did, but it turned out we were both absolutely wrong, and the real history is more interesting. And I'm not even getting into the fight over when population collapsed on Easter Island.

136:

And since Polynesia keeps coming up:

“Much human adaptation depends on the gradual accumulation of culturally transmitted knowledge and technology. Recent models of this process predict that large, well-connected populations will have more diverse and complex tool kits than small, isolated populations. ... Here, we show that in Oceania, around the time of early European contact, islands with small populations had less complicated marine foraging technology.”

“Population size predicts technological complexity in Oceania” Michelle A. Kline and Robert Boyd, Proceedings of the Royal Society B, 2010

137:

Size it to handle a population of around 5,000 & seed it with a thousand initial colonists.

I suggest you go and live in a semi-isolated town of even 10,000 people for a while. It's a good experiment that will show you a lot about what can and can't be done with 10,000 people. 1000 people is barely a hamlet - if the doctor is away, you don't have a doctor until they come back. In a spaceship that's going to be a bit of a problem.

I suggest the MVP for a generation ship is likely to be closer to a million than a thousand, and likely higher. You don't need a doctor, you need a medical school - someone has to become the next person who's good enough to teach the next wave of doctors. And by "doctor" I mean cardio-thoracic surgeon... and all the other really useful professions. Who makes sure you're not developing finely specialised gut bacteria as they co-evolve with your food plants? There's only so many tins of slightly fermenting tuna you can carry...

The 1632 series helps me think about what you'd actually want in a spaceship. That alt-history fantasy uses a few hundred people as a "spaceship" and drops them into a terraformed world with entirely compatible inhabitants, sure, but it's still based on the premise of a couple of hundred people trying to dig their way back to 1950's technology (making america great again?). The point that with only a few thousand people you either need magitech or miracles is, I think, entirely realistic. And that series gets round it by having a stunningly low death rate among an unbelievably lucky population. See above: it's not the brilliant that win, it's the very, very lucky. And a small colony ship is betting it all on that one in a billion chance with the alternatives all being "everybody dies".

138:

I remember that NPR took a rightward shift during first Reagan, than lurched harder right about the time of The Newt. In retrospect futile, the right has a large percentage of vengeance centric types.

139:

Thanks for the website. The one problem I have with it is that it regards partial failures as failures. I mean, the Atlas V only had 1 partial failure, which humans would have survived. That's the reason I excluded partial failures. Now that I think about it, I wonder how many of the actual total failures would be survivable by a human crew with a working ejection system for the capsule?

"Total launches 78 Successes 77 Partial failures 1 (401 – low orbit, customer declared success)"

https://en.wikipedia.org/wiki/Atlas_V

140:

So they're going to devolve into a giant misshapen mouse over the next century or so. But in the meantime, they fight crime!

I laughed. And I'd read it too, particularly if it was funny and being a superhero turned out to be a total shit-show! (Mind, I don't want to put you to work while you're on vacation, but if you write it I'll buy it!)

141:

If we are thinking about STL travel to other stars, what about really, really slow travel.

You start off building some O'Neill habitats in the inner solar system. First one is quite near Earth as we learn how to make them, and to keep them running. Then you build more further out, presumably at Lagrange points.

Once that is a mature technology, they start spreading outwards through the solar system, and more mobile orbits start getting used. You start getting habitats in big orbits that take them closer to different habitats at different points, allowing them to do slow but cheap (compared with flying a vessel directly between habitats) bulk trading between habitats.

Then after centuries of this, orbits start extending outwith the solar system. You still get habitats on trade routes between these outliers and those further in, so materials can slowly be passed outwards, and regular communications can easily be exchanged through a packet chain.

Then at some point some outliers start heading off towards another star forming a "string of beads" of circling habitats, each travelling a route which takes it within range of the ones on either side of it periodically then back towards the one on the other side.

Whether after the millennia it would take for the first ones to actually reach another star system the organic inhabitants would still be of the same species as those still in the home system is an entirely different question.

However an individual with sufficiently long lifespan (or a family over several generations) could then travel from one star to another by moving from one habitat to another, waiting the years until it gets into range to the next one along and transferring to that etc.

It would make an interesting scenario for a STL based SF novel at least.

142:

I can't find the article now, but I did read that since 2010 all population growth except Subsaharan Africa has been in 500 cities > 1 million.

Which is bringing up something else interesting. It seems that while "The average amount of meat consumed per person globally has nearly doubled in the past 50 years, from around 23kg in 1961 to 43kg in 2014"

in the UK, " The UK’s 2017 National Food Survey found consumption of raw beef, lamb and pork had fallen by 4.2% and that of meat products including sausages, bacon and poultry by nearly 7% since 2012."

Even in countries where it's not falling, it's shifting

http://www.wri.org/blog/2018/01/2018-will-see-high-meat-consumption-us-american-diet-shifting

A huge part of this is due to the fact that vegetarian and vegan food tastes much better than 10 years ago, never mind 20.

So it seems that a lot of vices have a U-shaped pattern. The same holds true for national parks. Beyond an inflection point, they increase as a percentage of the country as said country grows richer. They increase as the country gets wealthier, then decrease beyond an inflection point. I've heard anecdotally that people shop less for items than they did decades ago. Keeping up with the Jones no longer entails buying as much stuff as opposed to experience. Don't know if this is true?

143:

Ioan @ 142 My "meat" consumption is probably down by about 5% per year ... but I'm even more careful about what I eat than 50 years ago .... I wonder if people are eating smaller-quantites of better stuff? Though, given my "only home-grown veg" (excepting onions - for growing-space rasons ) I suspect I'm an outlier. Never mind "vegeteraian & vegan food" - what you appear to be saying is that quality-control is getting better?

144:

It doesn't require that much magical thinking to envision an O'Neill cylinder capable of making the journey.

Firstly: the classic O'Neill cylinder doesn't work — it uses mirrors and windows to focus sunlight on croplands in the interior and it turns out that thermal expansion/contraction makes it a non-starter. But okay, let's pretend we're talking about a spun habitat cylinder design rather than a classic O'Neill.

The numbers do not look good, in the absence of magic wand tech.

Let's be incredibly generous and assume we can cram a closed-cycle life support system and all the machinery we need for interstellar colonization into the same mass budget as a contemporary space capsule or airliner, i.e. about 1000kg/passenger. (A fully loaded 580 seat Airbus 380 weighs up to 520 tons at take-off; a 180 passenger Boeing 737-800 is about 90 tons with pax and fuel, and so on. This is the same order of magnitude, plus a little more baggage and stuff — air, for example — than a package holiday.) Note that at this point we're using magic wand tech already to keep our biosphere going, i.e. direct conversion of faeces, urine, and emitted gases into potable water, food, and air, at no significant weight penalty.)

Our 5000 ton starship peaks at 0.25c. Ignoring general relativity, it's kinetic energy is 0.5 * 5,000,000 * (75,000,000) ^2 = 1.40625e22 joules, which is equivalent to 3.3 million megatons. To put this in perspective, global energy consumption for human civilization in 2015 was 6.066e20 watts, so your starship is soaking up the equivalent of 25 years' worth of human energy production at current rates.

But that's not the punch line. The punch line is that this figure (which assumes a 100% efficient magic wand space drive, converting energy into momentum) is only for reaching peak velocity. To slow down again? We need, at a minimum, the same amount of energy all over again. And this doesn't take into account the energy budget for accelerating the mass of fuel up to 0.25c and back down again.

If you have an insanely efficient antimatter drive that can get you to 0.25c on a mass ratio of 1:1 (without cooking your canned apes), then you just doubled your starship's mass ... but if you want to decelerate at the other end afterwards, you then need to square it.

Final note: per my earlier prognostications, you just sent 5000 canned apes on a one-way trip to a place where there is no biosphere. Are 5000 canned apes enough to create a biosphere including a self-propagating human civilization capable of training the next generation, indefinitely? I think you're low-balling the numbers required by 3-5 orders of magnitude if you want a viable technological civilization, unless we invoke further magic wand technology like mind uploading or AI.

Now, if you run the numbers for a peak velocity of 0.025% of c they make a lot more sense, because of that pesky v2 term in the equation. But that's going to take a lot longer.

145:

You don't need a doctor, you need a medical school - someone has to become the next person who's good enough to teach the next wave of doctors.

Iceland has around 350,000 people and a health system that includes training around 5 doctors a year. This seems to be sustainable (going by OECD and WHO figures over the last several years).

And by "doctor" I mean cardio-thoracic surgeon... and all the other really useful professions.

That's where it gets a lot harder - as I understand it Icelandic surgeons and other specialists generally train overseas. Doesn't mean a different model for education may not work, one where to be productive requires a much higher level of multidisciplinary educational attainment than our society believes is normal.

146:

Approximately 48 per year, it seems

But yes, it's the specialists that are the issue, in this and other fields.

147:

Iceland has around 350,000 people and a health system that includes training around 5 doctors a year. This seems to be sustainable (going by OECD and WHO figures over the last several years).

I have some big doubts as to how closed this system of 5 docs training 5 docs really is.

148:

thermal expansion/contraction makes it a non-starter

Which means the already dubious energy budget needs to include a generous allowance for powering grow lamps, as per Silent Running.

149:

I came here to read this to educate myself of the precursors needed for STL and was somewhat disappointed to see only no-no's and "it needs magic, dummy" proposals. So.. here is my short list of feasible precursors we need for STL, in more or less organized random order.

A local star system space economy which is: - profitable - self sustainable - has many production facilities around the resources of this solar system - is creating an overload condition and it is looking for new resources, there has to be a business case for travel

In short: we need a mature space business, where human lives are already spent in space entirely, in good health etc.

This means that the human precursor is:

  • Humans or human-like beings which are / have genetic modifications for health and longevity, perhaps the ability to hibernate themselves for long periods of time

Before making any decisions to go anywhere the precursors are:

  • Space telescopes which can detect the best candidates for either way points or colonization targets
  • Interstellar probes, which have mapped the systems above - going in blind isn't a good investment

Using rail gun launches for getting the probes moving might accelerate the process. We do 60 000 G's right now with Blitzer and other rail gun projects. We can build electronics which survive that no problem, heat is the problem with longer rails. Sequential rail gun is possible, use the moon surface/near space or drill through the moon to build a big rail gun. "Send probes everywhere" might be cheap and fast!

After making a decision to travel somewhere:

  • VLF/other frequency transmitter equipped ship, which creates a huge bubble around itself for radiation protection (google "submarine vlf bubble earth")
  • Radars for detecting space debris
  • MW/GW size lasers to either evaporate or deflect them, nuclear missiles to deflect bigger objects
  • Ship forward facing radiation shield is better to be far away from the monkey cage, giving the ship Eiffel tower look
  • Industrial electronics/automation/computation already exists, which is hardened against wear and radiation and can be maintained for hundreds or thousands of years with minimal amount of spares. I don't see a problem there. Consumer electronics market is not disturbed, because you can't play the latest games with them.

All these proposals are feasible, but I share your pessimism Mr. Stross. It feels like we are the Romans wondering how stupid the Heron's steam ball is. It seems that interstellar STL travel has to be a business before anyone attempts it, with or without monkeys. Just like we are pondering the stupidity and short-sightedness of the Romans in the past the future generations will entertain themselves by reading these comments.

"See, he was right, but instead they decided to fuck like rabbits and have religious wars! Hahah they deserved to die!"

150:

One thing you need to become aware of is Boserup's Ratchet....What happens is that, when population grows to hit its limit to keeping everybody fed and happy, people start innovating with agricultural techniques and culture, to find ways around that limit.

It depends what you mean by "fed and happy".

Humans remained at the same basic economic level per person for many thousands of years. With a few ups and downs (early Ming China, etc), and a bit of regional variation, but not really much general trend of life really improving greatly. Over the same time period the number of humans on earth increased exponentially.

That's really weird. Humans overall were growing much more food, making much more stuff, but per-person quality of food/stuff hardly improved. To use modern economic terms: global GDP went up exponentially between 1000BC and 1800AD, but global GDP per person hardly changed over that period.

Malthus tried to explain why. He said that they remained at the same basic economic level for thousands of years because that's the minimum you can survive at and whenever their ability to grow/acquire food increased, population would increase to eat all the surplus.

Boserup's theory, as I understand it (and do correct me if I'm wrong) is that Malthus was wrong and that people remained at this same basic economic level per person for thousands of years because only when they dropped below that economic level did they became "unhappy" and so improved their ability to grow/acquire food.

I have trouble with Boserup (if I understand it correctly) because the economic level of a feudal serf, or a roman peasant (or slave), or a 4th century chinese peasant, or a 12th century Australian aborigine, or a 16th century scottish clansman, or etc, is an economic level that all of us would describe as "Really, really fucking awful poverty". Starvation was a common cause of death throughout pretty much every historic time period, pretty much everywhere. Life wasn't always brutal, but it was nasty, and short. It sucked, and I cannot believe that they were so happy that they simply lacked incentive to do more.

151:

I mis-remembered that figure ... and I even wrote an essay about it 3-4 months ago where I'd said "about 40", referencing OECD numbers. Memory off by an order of magnitude after really just a few weeks, not good, but it's still an extreme example. Is 48 a year enough to service the population? It might be.

For most of the rest of us, 350,000 is a small city. What size would a city be before it's self-sufficient in ... well, it isn't just doctor training, it's everything. And obviously it really can't be without some kind of cropland.

152:

Very, very few 'engineers' in IT companies are actually creating new products - far more are propping the infrastructure up or fighting the fires cases by the latest crapware. In many cases, the majority are not even doing anything approaching engineering.

I'm not disagreeing with your experience, but I would like to add a data point by contrasting my own.

I've spent the vast majority of my (so far) thirty-year career as an engineer, involved in new-product development. Even in the most badly-run UK firm of my experience (the CEO was an engineer, his successor was an engineer, both were utter muppets) I was mixing maintenance patches with new products.

In my current, sales and marketing heavy mob (where I'm adding new features to an old infrastructure) I spent a couple of days last week at a company-wide 'hackathon' competition - t was designed to encourage new product ideas from across the firm. Two days as the greybeard in a multi-disciplinary team was huge fun, and I got to contribute as much as I learned.

I suspect we have have different assumptions as to what constitutes an "IT company" - whether it's a firm that produces IT 'goods'; or whether it produces 'services using IT' but not the IT infrastructure on which they operate...

153:

Yes, but people are still missing just how much the expertise is concentrated in a small number of people. I am not being intellectualist here, because I am including all useful expertise - whether brain surgery, carpentry, bricklaying or counselling. You don't need a huge population, but you DO need to ensure that a high proportion of the population remains highly effective. I don't want to divert here, but the UK is a clear example of how numbers alone don't help - 60-70 million, and we are import the majority of skilled workers in many areas.

My very rough estimates are that modern 'western' society spends at least 90% (probably more) of the available effort on unnecessary bean-counting, bureaucracy, bullshitting (e.g. marketing, sales and lobbying) and just plain baloney. That includes generally unaccounted waste, such as unnecessary and unwanted travel and 'private' effort spent servicing official or corporate inefficiency. Interestingly, this is LESS in the more manual jobs. And that's without considering excessive redundancy (from the point of view of long-term reliability).

So a viable modern society with a hundred thousand people might be possible - I don't know - but I am pretty sure that a million would be enough. The problem for a starship is how to maintain the efficiency at (say) at least 80% - which requires a major social revolution to get there, and as-yet undeveloped social engineering to stay there.

154:

I have worked (briefly) for IBM, worked closely with half the Tier 1 manufacturers, and have had close contact with dozens of smaller companies. The situation you describe is fairly common among the smaller companies - ICL before its first takeover and Acorn were perhaps the largest ones, and that was over 30 years ago - I was referring mainly to the large ones that dominate the area.

155:

Frozen anything won't work. Humans are slightly radioactive. We're constantly being slightly damaged, and constantly doing running repairs. Freezing humans doesn't stop the radioactivity but it does stop the repair process. Freeze a human for a century or so and they'll wake up with lethal radiation poisoning and promptly die.

156:

Re: Starving, unhappy peasants amid increasing GDP?

Sounds kinda familiar ...

Just ran across this article this morning. Although it's about tyrants and politics as described by Shakespeare, it probably applies to just about any other issue where someone regardless of training/aptitude is dropped in as the chief/supreme decision-maker. (IMO, this article/book makes sense in terms of how it slices population segments along with their likely decision-making priorities and biases.)

https://longreads.com/2018/07/18/the-tyrant-and-his-enablers/

Author of the referenced book is Stephen Greenblatt, Harvard prof, National Book Award, Pulitzer Prize.

Hmmm ... time to re-read Richard III ('Now is the winter of our discontent ...')

157:

Come the Revolution, we'll lead the HR depts into the parking lot, toss asphalt on them, and PAVE THEM INTO THE ROADWAY, and then they'll have some social utility.

Sounds like you've only ever seen bad HR. Most of us only really deal with HR as we're leaving a firm; not generally fun times, and it's humdrum stuff done by often-uninspiring junior types. I get to hear of the other side of it, through my beloved (who has a rare mix of skills that have made her a reasonably senior executive).

However, where HR earn their weight in gold is when sorting out the nastier problems. Trying to spot whether employee W is indeed a waster, or whether manager X is a tosser who is using employee W as a scapegoat. How to try and help contractor Y whose husband has just been diagnosed with terminal cancer, or employee Z who is trying to return to work after a complete breakdown.

Granted, this is more of a UK thing than a US thing, but they're the ones who have to speak truth to power, regarding employment law; acting to ensure "fairness"[1] during reorganisations (my wife's firm has just merged with another, and she's just been through the "two people, one role" experience).

I even had HR smoothly and quickly sort out a case of "Director X is trying to constructively dismiss a member of my team" (pretty much the only time I've had to make a ethics call, as in "this will probably impact your continued employment if you push back against Director X"). Problem... just went away. As soon as I could leave, so did I...

158:

In this context, what is omitted is the importance of various forms of health professional, however you define that. With the exception of developing new vaccines and drugs for old, serious diseases, the extreme specialists have a very small effect on workforce effectiveness, quality of life and even survival rates. For example, it would be technically easy to increase the effective lifepan in (say) the UK by 10 years, perhaps 20, without involving ANY extreme specialists or technology. But relying on those alone would have very little effect.

In a spaceship, I don't see the (technical) problem of being ruthless, and simply letting people with rare and hard-to-treat problems die. That's what happened until recently, still does in most of the world, and we lived and they do live with it. So, yes, you still need the microbiologists and laboratory technicians, in case a new problem arises, but you DON'T need most of the specialists that dominate the leading edge of modern medicine.

159:

Likewise conversations with friends in my former profession (engineering) leads me to believe that there is no 'engineering shortage', but rather a shortage of engineers willing to work for half the pay of the average cop.

IMHO, the shortage isn't of "engineers", it's of "good engineers". Just because someone has a degree in engineering, doesn't make them an engineer - still less a good one. Get a decent track record, and you'll still be picking up codeface jobs in your late forties (I may have a cognitive bias here :) ).

Regarding cops v. geeks, I don't see that disparity in the UK. As a for instance, I earn (as an individual engineer, permanent position, not even a team leader) a similar amount to a middle-ranking Army Officer. They get a rather nice pension and early retirement; I get to live in the same place, work 40 hours a week and keep my weekends free, and not be shot at.

UK Police Salaries UK Software Engineer Salaries

160:

the importance of various forms of health professional

Agreed - there's a stronger need for nurses, pathologists, radiographers, phlebotomists, pharmacists and all the other roles that are not currently accorded the hero status of the very well compensated (Lotus driving, chest thumping, mutually mas... well anyway) specialists.

effective lifepan

If you're not talking about straight "life expectancy", which is still widely used, the preferred indicator these days is quality adjusted life years (QALYs). This is calculated in a similar way to life expectancy, but takes into account the effects of chronic conditions and the ability of the health system to maintain accessible quality of life for its ageing population. It shares with life expectancy the counter intuitive fact that the largest influence is infant mortality. This is because someone who dies at age 1 subtracts more potential QALYs (or life expectancy) from your figure than someone who dies at, say, 85.

most of the specialists that dominate the leading edge

Increasingly complicated treatments are more about the multidisciplinary team then individuals in "hero" roles anyway, and smaller numbers of these would be okay so long as the organisational challenges are addressed. IT has a huge role to play in improving that. Cancer treatments for instance can involve potentially hundreds of encounters with dozens of different teams leading to full recovery for one patient, with access to the right information by the right people at the right time being among the most critical factors in successful treatment. This is currently a work in progress in the developed world.

161:

SF Reader @ 156 Just dipped into that Shakespeare-review. Quite frightening:

He has always had wealth; he was born into it and makes ample use of it. But though he enjoys having what money can get him, it is not what most excites him. What excites him is the joy of domination. He is a bully. Easily enraged, he strikes out at anyone who stands in his way. He enjoys seeing others cringe, tremble, or wince with pain. He is gifted at detecting weakness and deft at mockery and insult. These skills attract followers who are drawn to the same cruel delight, even if they cannot have it to his unmatched degree. Though they know that he is dangerous, the followers help him advance to his goal, which is the possession of supreme power. His possession of power includes the domination of women, but he despises them far more than desires them. Sexual conquest excites him, but only for the endlessly reiterated proof that he can have anything he likes.

Trump exactly delineated. V. scary

162:

The 90s film version with Ian McKellen is quite amazing, although it omits a lot of the text.

163:

That's why I said "workforce effectiveness, quality of life and even survival rates" - my point stand WHICHEVER one you want to use as effective lifespan - and replace "specialists" by "specialist teams" if you like. In any case, cancer treatment is one of the things that doesn't change the POPULATION'S effective lifespan all that much, though it does that of the individual - minimising the triggering factors (whether lifestyle or environmental) does.

Stillbirths and infant mortality are a tricky one, because intervention can save both full-viable infants and ones that will be negatively productive or even have a miserable quality of life. The same applies to medical treatment of people who become crippled in some way (including via strokes etc.) As many stories point out, in a starship, they might need to use euthanasia for such cases.

164:

Well, I was just rolling up your use of those terms into something that is roughly equivalent and widely recognised. Not sure about "effective", whether it's really a thing. My own version of what to do instead of the (in your version's counting) 90% non-productive labour is quite different (not awake enough to go into that now).

But what you are saying here just adds to the argument for a larger minimum size for a viable population. That's because a society that chooses to euthanase its members for being "non-productive" has no business surviving anyway.

165:

Re: '... that Shakespeare-review.'

Agree - will be ordering that book soon. The Bard was a very keen observer and recorder of the human condition. Pretty good with words too. :)

Okay, so my question is: what are the barriers that prevent us/humanity from internalizing this type of knowledge about ourselves? Let's face it, this issue of self- and other understanding applies as much as engineering re: spaceships, space colonies.

Re: HR

Have met/worked with both extremes: One HR manager actually told me that she hated people and was glad that most of the day was spent filling out forms. Another found a variety of small print 'interpretations' to ensure adequate medical leave without penalties - seniority, pay, etc. - when a team member was dx'd with cancer.

166:

Re: Richard III film

Really liked Ian as Gandalf - hard to think that it would be as easy to despise him as/in R3. Mostly though, prefer Shakespearean plays as unedited as possible because have seen/heard some idiot omissions over the years that messed with the characterizations/point of the story. Fah!

167:

And chucking them out on the scrapheap, or letting them die in misery, is more moral? Because that is what is done in the USA and UK today, and I think it's disgusting.

I didn't actually say what you read me as saying, but let's answer that. 'Saving' one life can easily cost the work of half a dozen others, which then cannot help other people in need. Worse, in a starship, it can risk the survival of the whole community. It's a tricky ethical problem, there is no simple solution.

168:

That is true, but what Greg says is true, too. I tried looking for a job in the 1980s, as a senior team leader / architect, but there were essentially NO advertised jobs that even promised the possibility of promotion to that level in any of the areas I had a track record in or wanted to do (see below for the few that existed in any area). None, zilch, zero, over a period of a year. And, if you take a demotion from that level to code monkey in your 40s, a code monkey or junior team leader you will remain unless you find a rapidly-expanding business and luck out. Worse, ALL of the few jobs that might lead back to where I was were for recent CS graduates only - people with track records of innovation and success at that level in other areas of IT need not apply - and there were none actually AT that level for anyone, with any qualifications.

169:

I'm not saying you were saying anything in particular. You know, people do talk around topics without necessarily reflecting your own view back at you (if you think about it, it'd be boring if they always did). Agree about the dilemma of triage, but what I added about minimum viable populations stands. You could choose to take that as meaning that you need a minimum size to avoid being forced into such a difficult position, where resources are so scarce you must make such choices (more often and under worse circumstances than we already do).

The interesting thing is that we're both making an assumption that the way scarcity is dealt with could be radically different to the way it is done in most aspects here now - by ability to pay.

170:

Hey everybody, do we want to have that original discussion all over again?

Tuomas, we had that discussion on the list years ago. As Charlie noted (and note, he did not write the original post, I did, because he was out of town), when you start trying to make it work, all sorts of really intractable problems show up. I pointed to a few in the original post, a few more have popped up in the comments, if you take the time to read.

I'll simply reiterate the original point, which is that STL interstellar travel is as hard as FTL interstellar travel, because both require technology that probably can't exist. If you want the answer to the Fermi Paradox, this is it.

Oddly enough, I had a similar blog exchange over on Tetrapod Zoology years ago. We were discussing why Bigfoot was impossible, and a true believer popped up (as they always do) to attack us. The point, there and here, isn't that we're a bunch of dour party poopers. Rather, I think we're all former true believers ourselves who are trying to help people understand why our beliefs have been changed by the evidence. In the Bigfoot case, one of the most damning bits of evidence is that California's so laced with wildlife trail cameras that they photographed a single wolf that had wandered south from Oregon and a single wolverine that had wandered in from Idaho, yet no trail camera has ever caught a Bigfoot.

Three final points:

Just because it's impossible doesn't mean we shouldn't use interstellar travel in literature. If dragons can fly, so can starships. If you prefer really hard SF, there's always cli-fi. That's a more alien world than most people understand, and we're definitely all voyaging towards it rather more rapidly than we'll reach Alpha Centauri.

Second, general relativity isn't the ultimate arbiter of what is physically possible and what is not. There are many other sciences that limit reality as well. FTL falls foul of general relativity, but STL falls foul of a ecosystem ecology, materials science, and many others. If you want to write SF using other planets, make the choice of which science to ignore based on the needs of your story, rather than on what you think is the highest ranked science that must be obeyed.

Third, I knew everybody could discuss this without reference to current politics in any of our countries. Sometimes we just need a break. (MODERATOR NOTE: DON'T SPOIL THAT).

171:

First problem here is that, so far as the demographers can tell, global populations dropped around one-third over the seventeenth century (Geoffey Parker, Global Crisis). And I think we've had this discussion before. But do continue.

I'd also suggest you misunderstand Boserup's theory too. You can get a decent thumbnail at https://en.wikipedia.org/wiki/Ester_Boserup. It might help to also look up The Original Affluent Society, since that part of your reading seems to be missing.

172:

Which means the already dubious energy budget needs to include a generous allowance for powering grow lamps, as per Silent Running.

Nope!

Firstly, growing plants using ambient light isn't really a viable strategy much further out than Mars, never mind in interstellar space (hint: starlight?). So you're bound to use grow lamps anyway. Secondly, even today LED lighting systems are close to an order of magnitude more efficient than incandescent bulbs—and LED systems for agriculture would presumably be fine-tuned to emit wavelengths absorbed by chlorophyll and minimize waste heat.

Finally, by planning around artificial light the farm systems on a generation ship don't have to be directly proportional to flat surface area — they can use shelving and other compact design tweaks to pack in more food production per unit volume.

173:

Ok. Yes, I agree. I needed to get that correction in before I was flamed or worse for what I didn't say! That happens regrettably often.

Incidentally, a minimum size helps only secondarily (for statistical reasons) - the primary factor is how much margin the society has, vide England in 1300 and today - and there always comes a point where it has to take hard decisions. To summarise my opinion (both about the UK and starships, incidentally):

We need to concentrate far more on maximising everyones' potential in ways that are useful to society and attractive to them, and assisting those that are unnecessarily blocked from doing so.

We need to scrap monetarism and all its works to get there, and replace it with government for society as a whole. No, that does not mean Russian/Chinese communism or even Old Labour!

We need to face up to the serious ethical problems of those who are incompatible with society, face a miserable future or (this is the trickiest bit) are an excessive drain on resources. And I don't have a good answer.

174:

Whatever the lighting system, you still need to supply on order 5-10 times more energy as photons than you'll get out as biomass, simply because photosynthesis isn't all that efficient at converting light into carbs. You'll then have to scale from plant-based photosynthesis to food output, which varies widely. Unfortunately, humans can't make a living off the most efficient light to food converters(lettuce and similar), because oddly enough, there's not much protein in them (cue the purslane aficionados). Fortunately, plants provide all sorts of other benefits (like oxygen) which are even more important than their food production.

As for growth optimized LEDs and shelves: you've seen those indoor grow operations (for basil. And other crops) with the pink LEDs? That's what you get when you optimize your photon emissions for photosystems I and II in your crop plants. While that light environment is great for growing leaves, it leaves something to be desired for human psychology, since many people are made happier when they're surrounded by green plants. Still, if you can acclimate people to living under pink light for multiple generations, perhaps that will be useful or something. I wonder if bright pink light grow lights are useful with Seasonal Affective Disorder?

175:
Turns out you can track expansionist interstellar polities by the expanding wave-front of anomalous supernovae ...

I'm not sure what you'd do in the resulting system. I mean you just blew up its star. There's not going to be too much left.

I guess you could aim for distant binary systems only, and travel more conventionally for a few months/years to get to the other half of the system with its lightly seared planets, neatly de-biosphered for your colonization efforts, though you might need to wait for a few tens of millions of years for them to cool down again. :)

176:

to Elderly Cynic @153: My very rough estimates are that modern 'western' society spends at least 90% (probably more) of the available effort on unnecessary bean-counting Sounds awfully close to Pareto principle, although it also means, you can't fire 80% people because they do only 20% work, because the work isn't going to be finished then.

to Charlie Stross @144: Now, if you run the numbers for a peak velocity of 0.025% of c they make a lot more sense, because of that pesky v2 term in the equation. But that's going to take a lot longer. That's awfully lot longer, with <0.1% c it takes millenia. This is were we get to really-long-term stability, I guess. As mentioned above, in "slow zone" part of Vinge's universe, civilizations tend to fail over time because of the technological limits, arbitrary set by universe - no FTL, no AI, but otherwise, rather fast interstellar ships and perfect cryogenic preservation. The systems fail by being overburdened with systemic errors and stresses, and the only way to save them is to get help from elsewhere, start everything from scratch.

If we replace "no AI" rule(or Artificial Sentience aka AS) with "no cryogenic preservation" rule (see radiation damage accumulation). It will still be pretty hard sci-fi, but sci-fi nevertheless.

The idea came to me after I watched certain recent animation movie. I imagine a collective of semi-sentient or fully-sentient "creatures" that would assist humanity to survive even if some or most of the knowledge or population will be lost to time or a cataclysm. It is pretty much a machine life form, that can be created by people for certain purpose (although, being sentient, it may as well deviate from the plan sometimes). But since "true" humanity is secured by it's own limits of biology, and AI can have problems with long-term self-preservation, they will have to stick together. Should one side of the deal run into the problem it can not solve, it should be able to get help from the other side and thus provide overall survival.

One of the types of such collectives would be machines that are sustaining climate or atmospheric parameters, or terraform planets to be more suitable for life. This was one of the first ideas I came up with that time. Say, if such collective could create and support earth-like world elsewhere for extended period of time, thousands of years if needed, then the humanity would be able to re-establish itself in the same environment and repopulate the planet. Those I codenamed "dragons" for reason mentioned above, they are pretty selfish and may require certain servitude since they often occupy the same volume as the humans.

Other types of these would be some kind of starships with onboard AI, which would be able to travel between earth-like worlds and bring the needed knowledge with them. Or maybe some cornucopia machines that are needed to seed other forms of life in the universe. Really big starships that can host millions tons of material and travel at fraction of light speed. They, too, are self-reliant, even more than those "earth-bound" "dragons" and can feed from asteroids, pump fuel from interstellar medium or gas giants and even multiply in numbers. Their codename is "lamassu", since the ship is usually hosting quite a large portion of knowledge and legacy of human civilization that it can transfer elsewhere.

All in all, people for most time remain people and live in pretty humane conditions, with exception of those who really willing to transform themselves for more exotic outer space conditions. But machines which don't need any of that gravity and warmth, or food and entertainment, they will rule the outer limits where the humans will not survive. I'm not sure where I could place the (really) autonomous artificial habitats in this kind of ecology, but probably they will be able to fit in as well.

177:
"Disrupt" the local environment? So, a perfectly good scientific reason to not go into FTL near (near being defined as, say, within the orbit of Neptune? - not sure how big "local" is) a star, or planet.

No, Charlie had it right -- this isn't about the difficulty of forming the warp bubble (which, under some formulations, may either be impossible or require someone else to go in front of you at sub-c, laying the bubble -- which will be good for one trip) but rather about a ridiculously gigantic pulse of light and gravitational waves as the bubble collapses. There are four varieties with these behaviours, but two are useless: they emit the pulse omnidirectionally, and oops you're really close in your bubble and now you've been fried by a Planck-temperature (1.5x10^32K) pulse or shredded by insanely high tides, or both. The other two emit the pulse only in the direction of travel: the varieties differ on whether you get just mad tides or mad tides and the Planck-temperature pulse, but honestly given what the mad tides will do to whatever is in front of you, I'm not really sure there's much of a difference.

Caveat: even here, there are numerous variations. e.g. you could 'aim to miss' the star, and merely shred/blast whatever was in front of you and to one side of the star -- but some formulations, again, require a large mass near the bubble edge to help deconstruct it, i.e., a star or a really big substellar mass. There have been a lot of variations of this metric as people try to figure out one without disastrous side effects. They've got some of the way: the amount of negative mass seems practical now assuming you can make any at all, whereas initially the negative-to-the-mass-of-the-Local-Group-if-you're-lucky mass requirement seemed rather prohibitive. But as a transportation technology it still seems to have significant downsides!

178:

It may sound similar, but it isn't. And, to repeat, I did NOT say that 90% of the workforce was non-productive, still less ineffectual. I said that 90% of the effort (paid and unpaid) is logically unnecessary overheads, caused by our dysfunctional society.

179:

You don't need a huge population, but you DO need to ensure that a high proportion of the population remains highly effective.

By some estimates, 25% of labour in the US today is Guard Labour — wage labour dedicated to preserving the capitalist system.

Let me stick my neck out and assert that a growth-based economy is not only unsustainable but suicidal on board a generation ship (except for some very limited areas, e.g. inside virtual worlds hosted within the general ship and used for entertainment purposes).

So most of the need for guard labour goes away instantly.

Another point is that most criminal actions are facilitated by the perpetrator's belief that they can get away with something without fear of detection, apprehension, or retribution. Large polities with social anonymity facilitate escape: small closed-system polities that can't permit anonymity are another matter entirely. I suspect most folks aboard a generation ship will appreciate that there's no reasonable prospect of concealment and escape if they steal tangible goods—there's nowhere to conceal the loot.

This leaves impulse crimes and violent affray/assault, which to some extent can be mitigated against by social controls: if we're engineering a society for life aboard a generation ship, for example, firearms are going to be non-existent ("you want a gizmo that can make holes in the walls and let all the air out? why?"), environmental toxins are going to be difficult (why carry pesticides if you can opt not to carry pests in the first place?), and so on.

So: no guard labour, no lobbying, no wealth-management/investment infrastructure, no market speculation, very little need for police and no regular need for detectives, let alone a military.

On the other hand: extra-hardcore civil defense capability: not just fire and ambulance services, but damage control, vacuum rescue, environmental contamination cleanup, and other stuff that we dismiss as "externalities" but which will be on an organized civilian service basis.

Also: forget the nautical command/control hierarchies we see on ships today. There might be a flight deck crew with well-defined roles and CRM like a modern airliner to deal with flight-control-related emergencies, and there will surely be an emergency/damage control response center like an emergency 999/911 call hub (probably heavily automated), but they won't be ordering inspections and enforcing discipline like a Nelsonian naval officer; if it doesn't threaten to kill within seconds, dealing with it is a civilian governmental function.

180:

So you're bound to use grow lamps anyway. Secondly, even today LED lighting systems are close to an order of magnitude more efficient than incandescent bulbs—and LED systems for agriculture would presumably be fine-tuned to emit wavelengths absorbed by chlorophyll and minimize waste heat. I've been looking around LED industry catalogues last year (you know, professional activity and such), and it turns out, this is exactly what they do right now in greenhouse industry. Seems like hydroponics and greenhouse agriculture is becoming more popular. We can have fresh fruits from local producers all year long.

https://www.youtube.com/watch?v=T3RiyaaJI2k http://www.greenhousegrower.com/technology/15-led-lighting-solutions-for-your-greenhouse/

181:

Frozen embryos can remain viable a good deal longer than a frozen adult human would — the record so far is a baby born 24 years after its egg was fertilized then frozen. (Non-technical account here.)

182:

Let's assume 2,500 Kcal/diem, 5% efficiency photons to food, and 15% efficiency electrons to photons. We need 16 Kw/person, and we have a good radiation sink. Well within the bounds of sanity.

183:

While that light environment is great for growing leaves, it leaves something to be desired for human psychology, since many people are made happier when they're surrounded by green plants.

Yep.

But when I envisage a generation ship I'm not envisaging a single open-plan environment; I'm thinking more in terms of compact residential apartments, intensive vertical-farm-equivalents for growing food/recycling nutrients/producing oxygen ... and probably some recreational parks that provide long sight-lines (lest people lose the ability to accommodate their distance vision) and a variety of "naturalistic" environments to play in. In other words, it's a folded-up city with added vertical farms, not a "ship" or a simple cylinder, and it has to provide the makings of a pleasant lifestyle[*] to keep the canned apes sane.

[] There will be missing ingredients that we take for granted. No/minimal automobiles, no aeroplanes or sailboats[*], buildings not made out of biomass or rock, no tourist flights to foreign destinations, an emphasis on hobbies and craft for recreation rather than expensive mass media, and probably no star culture of highly-paid entertainers and, er, professional full-time novelists: everyone has at least a limited-hours part-time day lob. Probably very little or no meat in the diet, either, unless vat-grown tissue can be made efficient/convenient.

[**] Possibly recreational go-karts and ultralights if the hab is big enough to support sports arenas. Sailboats might be a bit of an ask—water is very massive—but depending on the destination it might be seen as a skill worth preserving?

184:

I didn't know that. Interesting, and truly horrifying.

I was looking primarily at the bureaucracy, unnecessary travel, etc., which I can observe and estimate directly. Most of the bureaucracy is also concerned with preserving the monetarist system, too, whether the law, tax, funding, banking, insurance or whatever (and, as you say, lobbying and marketing) - I was making an allowance for the services being provided, but with an objective of doing just that, and not in centralising profits from them.

185:

We need to concentrate far more on maximising everyones' potential in ways that are useful to society and attractive to them, and assisting those that are unnecessarily blocked from doing so.

We need to scrap monetarism and all its works to get there, and replace it with government for society as a whole. No, that does not mean Russian/Chinese communism or even Old Labour!

You may not expect this, but they themselves did not mean that as well. But you play the cards you're dealt.

Alright, let's not get any further with this side remark so we don't trail off.

186:

I never said that they expected what happened, or even were happy with it; I know that many of them weren't. The same was true of the people behind the monetarist revolution in the UK, from 1950s and 1960s Labour up to at least up to the Blair era, whether or not the current people ruining the country are happy with the result.

187:

FL @ 171 global populations dropped around one-third over the seventeenth century NOT in England, though, judging for parish records & the surviving housbuilding from that period.

EC @ 173 Because there aren't any - the best you can often hope for is a least-worst outcome, if you are "lucky"

sleepingroutine @ 180 Thanks for that. I will now be looking for pink led-arrays or lamps to augment my existing UV discharge-tube that I run at home, to overwinter some plants that don't like the low-light of Nov-Jan here. The survival rate is better than without the UV tube, but still not good enough - it's to be hoped that led's will cure that problem Helps with early germinatioon, too!

188:

There will be missing ingredients that we take for granted. No/minimal automobiles, no aeroplanes or sailboats[**], buildings not made out of biomass or rock, no tourist flights to foreign destinations, an emphasis on hobbies and craft for recreation rather than expensive mass media, and probably no star culture of highly-paid entertainers and, er, professional full-time novelists: everyone has at least a limited-hours part-time day lob. Probably very little or no meat in the diet, either, unless vat-grown tissue can be made efficient/convenient.

In reverse order:

--bugs. Yes, ewwww, but the advantage to growing crickets or even fruit flies is that a cow-sized chunk of biomass is fungible into thousands or millions of creatures, so you can harvest a bunch sustainably, whereas taking a steak out of a cow is fairly damaging and non-replaceable. The other advantage to growing insects is that they give you a faster way of recycling non-usable plant tissue (into bug poop) than you get with microbial composting, so it allows you to speed up your ecosystem cycling a bit. The downsides are that bugs readily escape containment, and that could be bad, and the inevitable yuck factor in the WEIRD world towards eating insects. Still, they and other small animals adorable (rabbits, guinea pigs) or not, make the most sense for providing meat on an STL (or even FTL, or alien colony) setup.

--As for culture, it's worth looking, again, at the Pacific, specifically Micronesian culture. They'd sort of solved the problem of living in small, dense, isolated societies. While I'm not saying that a birth-rank ordered society is a utopia (the evidence decidedly disagrees), the Micronesians and Polynesians both (independently?) used this system to colonize the Pacific, while other, more egalitarian societies stayed home around the Melanesian islands. It's worth investigating their social structure(s) as a working hypothesis for how to organize a STL starship society, with an eye towards either adopting it or figuring out why something else they did was what made them such successful colonists, and adopting that instead.

189:

If you want to do stl interstellar travel, first, you build a Nicoll-Dyson Array. Not to vaporize planets (Tough it can), but to power the laser sails of a space ship of appropriate size. No tyranny of the rocket occasion if what is moving you is a ravening beam of light based back home.

Problem, is, of course, once you start building a dyson swarm, the whole idea of interstellar colonization starts looking.. really kind of quaint. Because, well, if you need more living space than a dyson swarm can accomodate, you kind of have a problem in any case..

190:

You're missing the elephant in the room: there is a proven 1:1 relationship between the increasing level of education of women, and the dropping of the birthrate.

191:

There are also things like brine shrimps and tilapia, which would be especially useful as part of sewage recycling. Mammals and birds are very inefficient in this respect, as you know.

192:

Less, both my twins and my late wife grew up in a town of about 2,000. Or, for that matter, look at the 1632 series, which considers a lot of this (town pop of about 3500).

On the other hand, if it's a starship, they will have a full-blown hospital, college, a copy (with backups) of the Library of Congress....

The folks who go, as Charlie notes, will all need to be able to do real work, not bs related to money.

And picking who goes? Excuse me, but if we're ready to go, excuse me, I need to buy a full page ad for the voyage in this year's Worldcon program book.... Fans to the stars!

And to all of you... it's the 50th Anniversary, and the fucking US can't even send its own astronauts to orbit....

Huston, the Eagle has landed....

https://www.youtube.com/watch?v=IXteSV8rBwY

Goddamn it, and all the fucking Reptilians who care about nothing but money and power, and nothing else matters.

193:

[ DELETED by moderator — see Frank's warning upstream ]

194:

Frank Landis @15 “no second generation astronauts.”

Not fully official, but Richard Garriott was a private astronaut who flew aboard Soyuz TMA-13 to the International Space Station in 2008; he is son of 1970s Skylab & 1980s Shuttle NASA astronaut Owen K. Garriott

https://en.wikipedia.org/wiki/Richard_Garriott

195:

an emphasis on hobbies and craft for recreation rather than expensive mass media, and probably no star culture of highly-paid entertainers and, er, professional full-time novelists

I'd suppose the generation ship would be capable of receiving beamed communications from home, assuming that there was still a home interested in beaming the communications. So while media, entertainers and novelists wouldn't be there for on-the-spot entertainment and delectation, the crew would still be able to study and enjoy their works, albeit at a D/c delay.

In a somewhat related but more restricted context, it's worthwhile remembering that the Solar System is only about four light-hours in radius out to the orbit of Neptune. Things will remain pretty well synchronized in the Solar Commonwealth for a good many significant applications, though not all.

196:

Thanks. Still doesn't change the original point about astronautics not being a heritable profession (and hopefully there's a silent "yet" attached to that).

197:

They do file forms. But, overwhelmingly, and the larger the company, even more so, they really DON'T KNOW, and DON'T CARE TO KNOW. My company's been bought twice in the last 3 years, and they've outsourced benefits, they've outsourced email (M$ crap), they've got multiple software packages for basic functions (don't get me started on ranting about "Workday").

When I was last looking for a job, in '09, Grummond, I think it was, wanted to slurp up your resume, and they were going to do a DATABASE SEARCH to find qualified applicants!

Hell, around '05, when I was still in a multi-year long term "between positions", I saw a job that literally looked like it had been written for me, personally. The day after I emailed my resume, and a cover letter, I did something I never did, which was to look up and call the headhunter. She said, and I quote, "Well, you're not fresh..." At that point, I blew up, asked if I was some kind of bruised fruit, and if she were to take a year off to have a kid, would she never be hirable in her field again, because she "wasn't fresh". She had the grace to be embarrased, and admit she'd never thought of it that way, and allegedly put me in.

That's HR. They can't even think "they're been out for a while, we can offer them less money". Give them all a job as a greeter at Walmarts

198:

So, you're talking about something resembling an arcology. Still need some large open space, which I suppose you could call Central Park.

199:

an emphasis on hobbies and craft for recreation rather than expensive mass media, and probably no star culture of highly-paid entertainers and, er, professional full-time novelists: everyone has at least a limited-hours part-time day lob.

This is where Chris Hadfield's book comes in handy. What STL crew can do with its spare time is to prep and work through scenarios. As NASA knows (and much of the SF community hates) they get good results by training astronauts on complex scenarios for years before they have to perform the actual tasks in space. Part of this is because they often found, during scenario testing, that what they were trying to do didsn't work the first time, so they tested it out in scenarios until it looked like it will work. Then they started figuring out what might go wrong, and worked the astronauts through that too.

While it sounds grim, it works quite well, because it desensitizes the astronauts to the danger. They're certainly aware that things could go lethally bad, but because of the repeated scenario training they don't freeze in fear, but rather keep working on the problem until either it's fixed or they're dead. This is the spirit in which the astronauts were still flipping switches on the Challenger even as the spacecraft blew up around them.

So yes, an STL crew could fill a lot of otherwise empty time by learning, cross-training, rehearsing, and testing out scenarios for everything from a micrometeroid impact, to doctors treating rare diseases, to dealing with a high-ranking crew member who turns out to be an evil sociopath. Heck, they could even celebrate something like a secular Ramadan to give the crew a socially supported way of learning to endure long stretches of hunger and thirst. The possibilities are literally endless, and since this kind of training and rehearsal is required to deal with emergencies.

200:

Frank, comparing whether the children of astronauts also become astronauts is not statistically significant.

555 humans have reached Earth orbit. For the sake of simplicity, let's assume they're all from the USA (population 327 million) or Russia (144 million). That gives you odds of slightly under 1 per million to become an astronaut.

Hitting Google, I see that in 2016, 18,300 people applied for 14 NASA astronaut spots; and in 2017, it was over 3 million applying for 12 places. And that's just to get in the pool. Most of them will never reach orbit.

Since only 555 humans have ever been to orbit in the first place, simple probability says it's really unlikely for their children to also achieve it.

On the other hand, most astronauts have been in the military. And you definitely do find trends there - many children of officers go on themselves to become officers.

201:

I agree about receiving beamed works from home.

More to the point: arts are highly specialized, and novelists ... I estimate that full-timers like me are about 1 in 50,000 to 250,000 in the UK and USA; part-timers are an order of magnitude commoner. A 5000-person generation ship might have an amateur writers workshop, with some members producing stuff a few dozen to a couple of hundred members of the public enjoy reading. A 5M person migratory colony ship might well have a small but thriving literary scene and a couple of editors, as well as a couple of full-timers and a couple of dozen part-timers.

Live arts: music? Yes, but it's not a day job. And you won't get a symphony orchestra going with less than a couple of million people. There are probably a lot of gifted amateur composers using soft-synths and a few folks who enjoy using traditional instruments, but unless you've got more than a few thousand people you probably don't have anyone who can make a guitar or violin from scratch, never mind a grand piano.

Theatre: yes, amateur dramatics, sure. Professional actors, not so much. Movies: there may well be homebrew animated stuff happening, but it's pretty labour-intensive. Hollywood it ain't, and production values in imports from Earth will show up the local produce in a very unattractive light.

The main rupture point in the arts is going to be between interstellar travelling colonies/generation ships and arts produced by solar-orbiting colonies, and between SOCs and terrestrial/planetary media. I suspect after a few generations cultural drift will render them mutually semi-incomprehensible — their preoccupations will be wildly divergent because their life experiences will deviate. Consider, for example, what a 16th century Conquistador would have made of the characters in a mid-20th century Updike-style Great American [Literary] Novel (hint: academics on a 1950s American Ivy League campus), or of how much background knowledge we've got to pick up today in order to parse a Restoration comedy play by the likes of Sheridan.

202:

Hunh?

When I started this, I was assuming a ship-board population of a few hundred, because shipping a million people at a time is hard.

Let's assume that the population of a generation ship starts at, say, 555. If we ship up off astronauts, will their children also be astronauts? The answer appears to be, well, three will, or generously 1% of their offspring will have the qualities of their parents. The rest won't. Therefore, depending on specific and high-level competence to be inherited is not a safe strategy for making a multi-generational project like an STL generation ship work.

The US army alone as over 77,000 officers. Even at 1% inheritance, that would mean that 770 Army officers were the children of officers and 7 were grandchildren. Note also that being an Army officer is a rather lower bar than being an astronaut.

203:

Note also that being an Army officer is a rather lower bar than being an astronaut.

Being an army officer is a lower bar than being an astronaut now partly because astronaut slots are so damn rare. Astronauts get intensive training, but not to an extent that's significantly more extreme than some other postgraduate-entry-with-physical-fitness-requirements specialities.

More to the point, anyone who grows up on board a spaceship is going to have a lot of the basics of astronaut training ingrained in them the way getting across the road safely is drilled into us as toddlers. Things like emergency drills and how to cope with a depressurizing compartment will be taught to pre-teens — the way the Royal Navy started working midshipmen in the 19th century around age 10 and pushed them through what today would be considered hardcore trigonometry and navigation training in their early teens. While a bunch of stuff we consider essential today (learning to drive an automobile, swimming (in water), geography, history (of Earth-bound nations)) would be about as relevant as ancient Aramaic.

Metaphor: you know how the Scouting movement got founded in the period between the third Boer war and the first world war because Baden-Powell wanted a bunch of young men who had already been trained in what today we'd call special forces/survival skills before they joined the British Army? Well, think of the equivalent, only for astronauts—starting at school starting age, on an ongoing basis, for everyone (merit badges in spacesuit repair, radiation sickness triage, and hydroponic tank sterilization).

204:

I suspect after a few generations cultural drift will render them mutually semi-incomprehensible — their preoccupations will be wildly divergent because their life experiences will deviate.

There's probably a story in the question of how much of an effort people back home make to prevent that from happening.

Once you are more than a couple of AU out the only signals you will be listening to are ones beamed at you deliberately. Why invest the effort for reasons other than propaganda?

The memeset of humanities future is worth fighting for!

205:

As many stories point out, in a starship, they might need to use euthanasia for such cases.

And birth control policies that makes the last 30 years in China look polite.

206:

I think educated people can get behind that if there is a good reason and the ruling class isn't cheating.

207:

Another point is that most criminal actions are facilitated by the perpetrator's belief that they can get away with something without fear of detection, apprehension, or retribution. Large polities with social anonymity facilitate escape: small closed-system polities that can't permit anonymity are another matter entirely. I suspect most folks aboard a generation ship will appreciate that there's no reasonable prospect of concealment and escape if they steal tangible goods—there's nowhere to conceal the loot.

I used to agree with your "most". But after many decades I've changed my mind. Based on input from some close relatives[1] I think there are some people just wired to try and evade the system. Dealing with these folks in a can could get ugly.

[1]a A cousin who would rather make $50 unethically than $100 via hard work. Every hour of the day.

[1]b My wife's sister and her husband are recently retired as a parole officer and cop in Bend Or. They had to deal with people all the time that could work and live better than the life they had outside the law. They just couldn't wrap their head around obeying society's rules. As he said once, 90% of the time they know who did what and 90% of those times they would just to to their home or their mother's home and pick them up. He called them frequent flyers.

Now a big question is how much of this behaviour is nature and how much nurture.

Just like with a lot of our industry that modern life depends on, there is a planet wide heat/behavior sink that much of industry/people can vanish into.

208:

Thanks for that link. Enjoyed the article and picked up the book — it looked very interesting.

209:

And you won't get a symphony orchestra going with less than a couple of million people.

Sorry I got to disagree with this. At least in the US there is a huge pool of musical talent that can do a decent job. Maybe they will never play in Lincoln Center but decent. I'm thinking somewhere between 5% and 10% of the high school students in the US go through 3 to 6 years of band and/or orchestra. If you take the top 10% of those you'll get a decent orchestra. And a school in the US with 1000 students likely has 2 to 4 rock bands that are decent. Extrapolate to other performing arts. Singing, drama, etc...

210:

Once you are more than a couple of AU out the only signals you will be listening to are ones beamed at you deliberately.

Sort of a random point of curiosity, but I wonder whether probes out into the Solar System have ever picked up non-deliberately-beamed-at-them transmissions from Earth. You could run the link calculations to get an idea, but where's the fun in that?

211:

I think educated people can get behind that if there is a good reason and the ruling class isn't cheating.

Forced abortion as a policy is always an easier sell to a population than to a couple.

212:

You'd never get there. Think contraceptive drugs in the water or food supply with an antidote for those trying to conceive. Or, quite likely, IVF and then hormones.

213:

That's exactly what I was thinking. Still, we'll have to ask the question again: if you were spending [some insane amount of money and resources] to send a group of highly trained astronauts to another star, would design the ship so that only highly-trained astronauts could run it, on the assumption that the children the astronauts produced could be trained by their parents to run the ship, and that they could train their children (for however many generations) until the mission was completed?

That's the central question, and it's a question about both the essential complexity of the ship and the kinds of systems that you need to design to deal with emergencies. If a central requirement in all these systems is an immensely talented work force, and there's little room for ordinary folk to be useful when it matters, then I'd suggest you've got a problem.

Like it or not, a generation ship has to be designed to accommodate some proportion of ordinary people.

214:

You misunderstand because I left out one word: "professional". Bear in mind it's not just fifty-plus full-time musicians: it's the concert hall, the instruments, the whole surplus labour thing.

Volunteer part-time orchestra playing in the equivalent of a school hall? Sure. Professional philharmonic orchestra? Nope, that requires a whole different ball game of resources to support it.

215:

would design the ship so that only highly-trained astronauts could run it, on the assumption that the children the astronauts produced could be trained by their parents to run the ship

I'd design it with three modes.

  • Expert mode: you are elite astronauts and test pilots who know exactly what you're doing. Here's a loaded pistol, don't shoot yourself in the foot.

  • Easy mode: ordinary folks with the basics of spaceship crew training should be able to make the ship do 80% of what it's designed to do on only 20% of the expert-level training. More complex stuff is off-limits unless you choose to unlock it. Here's a loaded pistol, but there are two different safety mechanisms and it's mounted on a bench so that you have to be really ingenious to get your feet in front of the barrel and pull the trigger.

  • Training mode: turns the control system into a full-blown flight simulator complete with training scenarios at all levels from the equivalent of touch-and-go in a Cessna up to trying to land Concorde on an aircraft carrier. The real controls, in other words, but as a teaching environment plugging into a highly accurate simulation of the real thing. And everybody trains on mode (3) — hell, beating the most elaborate hell scenarios is a competitive team sport for teen-agers — from an early age.

  • What you hope for is that mode (3) gives you a steady supply of mode (1) competent experts (who end up as your professional bridge crew), and ensures that most people can operate in mode (3) if event of an emergency, giving you a plentiful supply of second-rate fallbacks.

    216:

    Then you're going to have to idiot-proof your ship, basically. That means it would need to be a lot bigger and more redundant than the experts-only model. Making it bigger and more redundant means, of course, it takes a lot more resources to make it and a lot more energy to fly it. That's the tradeoff.

    217:

    Then you're going to have to idiot-proof your ship, basically.

    Nope: just the primary control systems.

    And before you say that's a tall order, I'd like to refer you to the Airbus flight control system (used on all their airliners since the A320) that has multiple operating modes: normal law with alpha floor protection — the FBW system will not allow the pilot to put the plane into a stall, or depart from controlled flight in any way — and alternate law, in which the computers stop trying to second-guess the situation and do exactly what the pilots tell them to (usually this happens when the flight systems become confused, e.g. airspeed indicators disagree with one another, or if the pilot specifically requests alternate law, for example when putting on a display at an air show).

    This isn't new, it's something that's been flying on thousands of airliners for more than three decades now. The complexity trade-off lies in the software, rather than the hardware.

    218:

    Who needs forced abortion when you have contraceptives in the food supply* and you have to go to the clinic to apply to have them turned off?

    *or some more practical magic wand to keep the babies away.

    219:

    _Moz_ @ 137:

    "I suggest you go and live in a semi-isolated town of even 10,000 people for a while. It's a good experiment that will show you a lot about what can and can't be done with 10,000 people. 1000 people is barely a hamlet - if the doctor is away, you don't have a doctor until they come back. In a spaceship that's going to be a bit of a problem.
    I suggest the MVP for a generation ship is likely to be closer to a million than a thousand, and likely higher. You don't need a doctor, you need a medical school - someone has to become the next person who's good enough to teach the next wave of doctors... "


    BTDT-GTTS. You're assuming a population of random people taken from off the streets. You wouldn't want that for an interstellar colonial venture. It's not one doctor, it's a hundred doctors ... doctors who are also skilled civil/mechanical/aerospace engineers.

    Don't forget the nurses, EMTs, agronomists, geologists ... all with multiple specialized skills. You'd want to assemble a select crew & colonial population; stack the deck with as many polymaths as you can get to join up.

    That initial "crew" is probably going to be heavily weighted with women, because women can do anything a man can do, and one essential thing men can't. Someone suggested sending 10,000 frozen embryos and letting robots raise them. That was shot down because babies need to be socialized and robots aren't so good at that, but you could send 10,000 embryos along with the live colonists. You could send 100,000 or 1,000,000. Your crew would have to be made up of women who are willing from the beginning to host multiple pregnancies in order to grow the initial population. But let the colonists do the socializing. The frozen embryos then make sense as a biodiversity hedge.

    You're also going to have to take live animals, but you can ship a lot more as frozen embryos. Use enough of the frozen embryos to keep a breeding age population of animals ready for when you get there.

    I obviously misspoke when I said to use an O'Neil Habitat. Charlie got the right of it though when he suggested it could still be some kind of spun cylinder. I suggested "O'Neil" as a brand name for any spun habitat, whether it has windows or not.

    I take the point about needing fuel to decelerate. But do you really need to carry all of it along from the very start? I'm thinking more in terms of an engine that needs reaction mass. You're going to have to shield against particles during the journey anyway, so what about accreting that mass along the way? I know it's "magical engineering", but to me that only means we don't yet know how to do it. YET. That just means that this colonial venture can't take place until we have solutions to the engineering problems.

    It's not really magical engineering, it's a list of problems we're going to have to solve in order to undertake the project.

    220:

    Add also Sergey Volkov, son of Aleksandr Volkov, and Roman Romanenko, son of Yuri Romanenko.

    221:

    ... and another thing. Someone questioned how to get the colonists down to the planet; how many rockets are going to need to make the round trip & where they're going to get the fuel to do it? I'm thinking the majority of the trips down will only need to be one way. For that ballistic capsules & parachutes ought to be good enough.

    You'll need some kind of a load plan to rationalize what needs to be dropped first. Think LOGISTICS. How soon after LD-day (Landing Day) are you going to need to have some kind of airstrip or landing pad for SSTO shuttles? When do you drop the first fuel manufacturing facility? How many redundant facilities do you need? How many personnel need to be on the ground for the initial invasion (and it IS an invasion) to prepare for landing the mass of the crew/colonists?

    Do you leave any supplies behind on the ship for later retrieval? If you're not going to put all your eggs in one basket, how many baskets will you need? Do you leave the star-ship in orbit around the planet? Or move it out into a stellar parking orbit?

    222:

    because women can do anything a man can do, and one essential thing men can't.

    Is the uterine replicator magictech and if so, why? We know they exist as bioengineering already inside squishy meatsacks, what about them is impossible to create as a work of deliberate external engineering by human beings?

    No-one seems to be working on such a device, or at least there isn't a Big Push like fusion or military tech going on, no billion-dollar budgets and well-organised teams of scientists and technicians beavering away at the problem. There might be black-budget work going on but to what end? Super-soldiers?

    There are, of course, many MANY ethical hurdles to cross when it comes to human artificial reproduction but animal experimentation is less fraught and we're blase today about animal embryo cloning, human in-vitro fertilisation etc. which was real for-sure skiffy fifty years ago. We came up with ethical workarounds and safeguards for such God-like meddling in things that were not wot of, the ethics of developing and implementing uterine replicators for human beings shouldn't be an insoluble hurdle.

    If and when uterine replicators are available the putative starship crew will be less like the mineshaft survival clades as envisioned at the end of Dr. Strangelove and the freezer full of embryos concept might be made to work if it can be shown that embryos can be viable after centuries of storage (or enough embryos, a lot of non-viable wastage plus eugenic culling of the first generation or two might be considered a price worth paying).

    223:

    Btw, H. Beam Piper, in his Space Vikings, had them spending a lot of time as craftsmen, in the trips between stars, and their products were valuable commodities.

    224:

    So, there is always the ultimate starship (Earth), and slowest STL (do nothing). Just wait for another star to get close enough. According to wikipedia, Gliese 710 will approach the solar system to within .2 light years in about 1.2-1.3 million years. In fact, it is likely to cause some problems for the solar system gravitationally, so perhaps "When Worlds Collide" was more prophetic than we realized :)

    (Scholz's star got within a light year 70,000 years ago, but I guess we weren't ready for that at the time)

    225:

    I doubt it would be impossible but I do think it would be sufficiently hard that it might as well be impossible, particularly if it has to operate independently of existing Earth infrastructure. The difficulty is that as well as providing big obvious understood things like oxygen, glucose, amino acids and the like, it also has to provide a whole crapload of very complicated trace substances, many of which we probably won't even realise exist until we encounter the problems that arise when they're not there.

    I'm floundering a bit because I don't have enough knowledge of the field to say much more than that this problem exists. But for an example, as far as I know the fetus's immune system derives part of its initial configuration from the chemical equivalent of config files downloaded from the mother's body. The chemical complexity of these things is such that you need a fair old lab setup to produce just one of them, and we're talking about thousands, in just the right amounts at the right times, and including things we don't even know exist yet. (True, we also don't know what happens if there are things missing, but I think it's a pretty safe guess that it would be quite horrible.) And you probably can't make them before launch and just carry stocks; some of them would degrade too much on the way and some of them probably have to be individually customised.

    So while it might eventually be feasible, although not exactly easy, to do this sort of thing against the background of a whole planet, I think that on board a spaceship the disadvantages would be so much more significant that the old-fashioned method would win every time.

    This is why STL space colonisation by terrestrial species will end up being done not by mammals but by birds.

    226:

    They are all over ebay: lamps consisting of roughly equal numbers of red and blue LED chips, so the overall light is the kind of purple that some people call pink. You really would not want the human environment lit like that, it feels funny even looking at photos of it, and the green part which is missing from the spectrum is the most important part for human vision.

    What I don't know is how likely buying those things off ebay is to result in your door being put through at 5 in the morning.

    (Why UV? Visible blue and red are the most important wavelengths used by plants, so if you haven't got lights that generate only those wavelengths, ordinary white ones are probably a better substitute than UV.)

    227:

    Yeah. Including simple things like arsenic and lead!

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2246629/

    228:

    Yep, those are the two I know of.

    229:

    I wasn't missing it - in my head I had that rolled up in the "demographic transition" and its associated "cultural and economic factors". Well, as much as an elephant can be rolled up in a swag (or a tuckerbag).

    You're right that it should be called out separately, especially because it makes the demographic change easier for some people to understand. I had avoided it in the previous thread partly because I suspected it would be difficult to convince such people of the educational attainment of pre-colonial aboriginal women (which I regard as pretty high, knowing what we know, long view hindsight and all that) and didn't want to go there. So you remind me I'm thinking in those terms, and I shouldn't here.

    I've the germ of an idea for an SF setting based on a different view of education (elevator pitch: a society that takes the concept of lifelong learning really seriously). It could probably work reasonably well combined with this sort of ship-as-a-city setting. As a story, of course, there's far too much magitech (and magi-sociology) to get through for it to be real.

    230:

    Re: Expertise and/or so, what else are they going to do in that spacecan?

    Agree and as JBS said 'Don't send idiots!' And if they're not idiots or so besotted with being 'The Expert!', they'll want to learn as much as possible about everything in their environment. And not just for their own safety or comfort, but because they enjoy learning/knowing. Next - if all of the crew/passengers are specially selected experts/professionals, they'll likely be used to switching back and forth between being the leader/expert and being the follower/listener because major tech/sci projects depend on collaboration. Hadfield pointed this out in his book: egotists do not have the right stuff.

    Also agree re: kiddies being able to pick up on local space tech. Babies/children who have never known any other environment will not be afraid to learn and perform tasks that people who had to learn these tasks in adulthood (under duress of competition) had difficulty with. (Programmable VCRs come to mind.) Big problem will be not knowing how to make a fire by rubbing a couple of sticks together and all of the other planet-surface stuff we landlubbers take for granted.

    About 'astronauts not breeding astronauts', I think the more apt comparison is physicians: more of them in general, have been around longer, while also requiring highly specialized knowledge. A few generations back it was fairly common for sons of physicians to become physicians: they learned correct anatomy and physiology right off instead of baby or common names, their fathers were always talking about medicine at the dinner table (unlike astronauts who tend to train/work/live away from home), and if all of the other neighborhood kids are also learning what we Earthers think of as advanced sci/tech, they have no reason to think that they can't learn this stuff. And - if you're stuck on a spaceship with a lot of time on your hands, there's no reason for having to insist on cramming all of the medical or some other specialty training into an arbitrary time frame. Yeah - so maybe you don't graduate in 4 years (of two-three semesters/year), but do you really need to? (Society now recognizes that sons/daughters are allowed to make their own career choices. And if you're primarily status-motivated, there are other/newer options with less effort required.)

    BTW - you can take music lessons via youtube which means that any musically inclined crew could be able to learn and improve on their musicianship during their travel. Have also heard of amateur and professional musicians sending in their 'recordings' to one of their group to be pulled together into one performance. (Record studios have been doing this for decades, no reason this couldn't be done on a spaceship.) So the crew may not necessarily be limited to playing only with other crew members - for a few years at least.

    231:

    Can I point out that there's a large number of birth control medicines, because women react differently to them, and have to find the formulation that works and doesn't make them sick? If you're dosing the water supply without titrating the dose, you're going to have some sample of unintended pregnancies, people getting sick, and possibly some interesting developmental issues among the fetuses that are exposed to hormones through their mothers' ingestion of water (especially if they don't realize they are pregnant when they were sucking the water down).

    The other problem, even if you give women control over their own fertility, is that humans secrete hormones in their urine, and conventional sewage systems aren't great at breaking them down. This is one reason why there have been gender abnormalities in aquatic life downstream of cities. If you're not careful with using chemical birth control, the chemicals may build up in your water supply until things get interesting, at which point you've got to get them all out and figure out how to break down whatever sludge is in the water filter.

    The cultural tweak, of romanticizing and promoting sex that doesn't involve penis-in-vagina ejaculation, might be a simpler and reasonably effective alternative.

    232:

    You misunderstand because I left out one word: "professional". Bear in mind it's not just fifty-plus full-time musicians: it's the concert hall, the instruments, the whole surplus labour thing.

    Maybe it's a US vs European thing. The US was littered with orchestras until 50 years or so ago. (I'm guessing radio and mostly TV did them in.) Instruments aren't that hard.[1] People seem to want to make music if they have a bit of free time.

    Step back one notch from "pro" and 99% of the people will be happy. Maybe more. And those park areas will be fine for performances of all sorts. Drama, classical music, rock, folk, whatever. While Europe was blowing through all those wars a few decades back the US had a thriving local music scene. It can be done. And likely would.

    Well maybe not opera. I don't know about Europe but in the US it only works with big money donations.

    [1] https://www.npr.org/sections/deceptivecadence/2016/09/14/493794763/from-trash-to-triumph-the-recycled-orchestra

    233:

    I suspect 5% efficiency photons to food is overestimating it a bit. I remember looking up some numbers on this a while ago (checking out whether Daedalus's idea of a train that powers itself on grass mowed from between the tracks as it goes along could work; turns out it just about could) and it seems realistic that you could get 5% efficiency for photons to plain straight biomass. Usefully digestible biomass is going to be only a small portion of the whole. I suppose you could convert a lot of the indigestible part to a digestible form by cooking it up with caustic soda, but per Frank @ 174 it seems that you need to mostly convert it to proteins rather than sugars to be useful, so now we have the problem (a) of how to do that most efficiently (insects? bacteria? fungi?) and (b) that "efficiency" now means something rather different and not really estimable from crude energy considerations.

    234:

    Just a data point from the US. The play then movie the Music Man from the 60s was such a big hit because something like 10 to 20% or more of the US population was involved in a school band for more than a year or two and it was a perfect parody of those school bands. If you start talking about guitar type things and singing you likely get to 50% of the people who have fond memories of music in their lives. If the ship is big enough to be STL then if musical instruments are not on board they will be made.

    235:

    The effort required to stay in contact with any given stl starship is in fact very low. - If you have deep space propulsion good enough for interstellar, another thing you also have is a very large number of gravity lens telescopes. - The gravitational field of the sun bends light, which can be used as an astronomical-scale lens if you fly out way past pluto to the focal zone. This lens also permits you to maintain a coherent beam signal at essentially arbitrary distances. So you launch the space ship in one direction, then launch the com relay of in the opposite direction, and for a very long while you can take photos of people waving back at earth on the hull. And, more relevantly, maintain a high-bandwidth com system. I mean, latency is going to be a problem, but just streaming the cultural output in its totality? Not a hassle.

    236:

    Which still leads to a huge energy budget for growing the photosynthesisers, no matter how efficient the lighting method, because (please forgive me for repeating the obvious) the usable food energy from that biomass production is how we power our canned monkeys. Even if we're getting something like 1% energy input to usable monkey watts, we need to scale the inputs to that multiple of the population plus reserve. Sure we're already talking about magical energy sources, but this still can't be insignificant.

    237:

    "a growth-based economy is not only unsustainable but suicidal on board a generation ship"

    I don't consider that "sticking your neck out", I consider it a basic axiom. After all it still applies when the generation ship in question is the giant chunk of rock going round and round a star kind. On the more mobile kind of ship it's just more strongly emphasised so you can't get away for a useful length of time with pretending it isn't true.

    It's the 25% waste figure that I would disagree with. My estimate is about 90%, so is EC's, and while it tends to be the kind of thinking that is powerfully discouraged I've still come across writings going back over 100 years from the occasional people who do dare to think it in public, and they also come up with similarly high percentages (some even higher).

    The thing is that on the giant chunk of rock there is (or has been) sufficient elbow room that people have been able to get away with falling into a system that does not have "producing useful results" as its primary aim. Instead it just produces, promiscuously and indiscriminately; its output follows Sturgeon's law, and people are deluded into thinking it works because enough of it just happens to be useful that most of them can survive on it.

    In the constrained environment of a generation ship it can't be avoided that passively allowing things to run according to Sturgeon's law is a really stupid idea. You can't just fall into a system like we have done on Earth; you absolutely have to design it, and make "producing useful results" the primary design aim.

    Hence Damian @ 169: "The interesting thing is that we're both making an assumption that the way scarcity is dealt with could be radically different to the way it is done in most aspects here now - by ability to pay." Of course. When you throw out the assumptions of "perceived-as-unlimited elbow room to fuck up in" and "things have to be recognisably similar in operation to currently familiar Earth systems", then the concepts which derive their (dubious) viability from those conditions become so obviously unviable that they don't cross your mind in the first place.

    238:

    Another data point: my friends from overseas sing a lot more than my friends from North America. Whether cheap iPods have changed that since they left home I don't know, but in the last century in China and the Philippines music was something you made, not consumed.

    Given that consumer culture won't be viable on shipboard anyway, maybe social status will be reflected by what you do not what you can buy — and so cooking good food, making decent music, painting, etc will be part of the STL culture?

    239:

    Re: Music

    Think that part of this is the Western (esp. North American) belief or love affair with 'professionals' to the point where ordinary folks are urged to not even try something including playing music unless they're willing to take specialized cour$e$ plus turn that interest into a career.

    240:

    Oops - forgot to delete that last sentence about a music example.

    [Fixed--moderator]

    241:

    Someone questioned how to get the colonists down to the planet;

    That statement betrays several disturbingly wrong assumptions, of which the first and craziest is that there's a planet at the far end of the trip that your colonists are equipped to land on and colonize.

    TLDR: planets of Earthlike size are probably common, but planets with a breathable oxygen atmosphere are going to be a lot rarer (Earth likely only retains one for ~10% of its life while the sun is in the main sequence of the H-R diagram, based on our knowledge of solar and planetary evolution), and earthlike biosphere ares probably as rare as hens' teeth. Moreover, if you can find one it will probably kill you really fast due to systemic anaphylaxis or subtle biochemical incompatabilities. Moreover, expecting a bunch of people who have lived in one habitat for generations (a colony ship) to permanently and traumatically transplant themselves into a radically different environment and thrive instantly is also a bit strange: consider what the ship-raised will make of weather, for example: not in the abstract/on canned nature documentaries, but of physically experiencing light rain — something which, to those raised on board a ship, means an instant gut-level apprehension that something terrible has gone wrong with life support?

    242:

    (Browser crashed. Continuing ...)

    My suspicion is that even if you send a colony starship to a system where there's an Earthlike world with an atmospheric pO2 of around 200mBar and the local saprophytic microbial ecosystem doesn't treat terrestrial meat like a tasty decaying log, it's going to be a very long time before anyone from the ship is remotely willing to set foot on the surface.

    Most likely there will be a very long period of (a) building comfortable, non-mobile, big-ass habitats in orbit using asteroidal material, (b) spinning out a planetary surveillance and communications network in orbit, (c) dropping long duration drones into the atmosphere to sniff out biomarkers from the surface, (d) dropping robot-operated labs onto the surface to see what happens when you expose animal, plant, and human tissue cultures to the local environment, and finally (e) robot-mediated construction of fortress-like biohazard-isolated accommodation for a very brave first exploration crew on the surface. Say, 20-30 years or so, minimum, then another 20-30 years of people living on the surface and only venturing out in isolation suits, as if they're exploring Mars.

    Basically, a generation ship is a mobile self-contained space habitat. People who live in a mobile self-contained space habitat are more likely to view a new solar system as a promising source of materials and energy for building new and bigger self-contained space habitats: these are a known, comfortable environment, unlike the chaotic, strange, dangerous rocky planet their ancestors intended them to visit.

    243:

    Pigeon @ 226 I know - I looked - but I also looked about 18 months back & they weren't there then ... Well, several seedling trays leaned strongly towards said tube, so I have to rotate the trays ... "Door being kicked in" - um - I would probably only have the lights on whilst I was "in" & awake, not overnight.

    244:

    Is the uterine replicator magictech and if so, why?

    Yes, it pretty much is. A uterus isn't just a gas exchange membrane and a thermal buffer: it does a lot of really crazy and non-obvious shit like priming the immune system and using epigenetic modulation to imprint some of the mother's expressed phenotype on the neonate. This involves a bunch of activation of HERVs — human endogenous retroviruses — that have coevolved from being free-living bits of DNA to doing interesting stuff that facilitates embryo development, and look like nothing else in our genome.

    Bear in mind that the mammalian uterus was one of the last distinct organs to show up in evolutionary time — reptiles and birds don't have them, but pretty much all vertebrates have kidneys, livers, brains, intestines, hearts, and so on. It's weird.

    245:

    The cultural tweak, of romanticizing and promoting sex that doesn't involve penis-in-vagina ejaculation, might be a simpler and reasonably effective alternative.

    Let's take it to an extreme: look into the cultural and genetic determinants of homosexual attraction and tweak the dial so that the entire crew prefer romantic/sexual relationships with their own gender. At which point reproductive sex doesn't happen by accident. Oh, and you can combine this with an all-female crew and frozen sperm if you're worried about the number of uteruses at the other end and haven't nailed uterine replicator tech.

    For a fun novel in such a setting, try Kameron Hurley's "The Stars are Legion" — or, as she jokingly calls it, "Lesbians in Spaaaaace".

    246:

    If the ship is big enough to be STL then if musical instruments are not on board they will be made.

    You probably don't need to make physical instruments. If the ship has anything remotely approximating today's level of computing tech on board, they'll have tablets that can run soft synths. (One of the things Apple's multi-touch user interface on iOS is really good for is simulations of classic sequencers and synthesizers, and iOS is a surprisingly good music creation platform. When a multitouch screen stops being adequate for tweaking knobs and sliders, you can plug in MIDI instruments like velocity-sensitive keyboards and even guitars. I'm guessing a ship might not have physical instruments on board but they're going to have sims of every sequencer and synthesizer ever designed, and the wherewithal to play them.)

    247:

    Minor point... Cave diving isn't terribly dangerous. My Australian CDAA registration number that I got in the 80's is well into the thousands, and we seem to average about one fatality per decade. There's about 5-10 fatalities per year world wide, but quite a lot of them are unrelated medical issues.

    248:

    Sailboats ... might be seen as a skill worth preserving?

    Not in the practice-it-always sense, because the hard to learn skills mostly come into play when you have large bodies of open water. There are two common things today that might be useful to know: complete idiots build floating things in their backyards and fail to die while operating them in oceans; slightly wealthier idiots buy completely functioning boats (sail or motor) and despite learning while doing fail to die not just in the Mediterranean and Carribean, but in the misleadingly-named "Pacific" and Atlantic oceans. Most of the skills can be learned fairly safely by experiment, especially if your goal is "obtain pelagic fish" rather than circumnavigation.

    Most of the primitive sailing deaths happened because of limited book knowledge which is not a problem the colony would have (viz: scurvy, hygiene diseases etc). Plus the habit we as a species have of experimentally establishing the limits of our/our technologies' capability.

    There are some slightly terrifying youtube channels with the theme "we had never been sailing, but sold everything and bought a yacht. Now we've sailed half way round the world". Or the Polish couple "we built a 25 foot sailboat and sailed it round the world". Dude, that's a small boat, built by non-wealthy amateurs based on some books they found, and apparently not dying requires only normal amounts of common sense and luck.

    249:

    they get good results by training astronauts on complex scenarios for years before they have to perform the actual tasks in space

    In less fatal environments they call that "experience" and get useful work out of the people gaining it. I'm going to guess that about 99% of the work required to operate this magic space colony bizzo is going to be of the non-fatal variety. Even heart surgeons start with "people have two arms and two legs, one head, one ovary and one testicle (on average)".

    First aid training is probably the only real place people get to see scenario-based training these days, unless you count simulations (drivers ed, for example). Teaching live-threatening hobbies we do in a sort-of scenario based way, but it generally involves the show-practice-do system on the spot, rather than show-scenario-wait-do type stuff astronauts do (coz, for example, rock climbing is more accessible than the ISS... and much less fatal).

    250:

    That initial "crew" is probably going to be heavily weighted with women

    That sounds exciting. Any starship will necessarily have a radically different social setup to the current world, but that's radically different to anything that's ever been heard of. We get heavily gender-biased societies from time to time, but they breed out. We could make them, but we don't (even India and China are within a percent of balanced), and we have significant problems even looking sideways at that.

    On the other hand... that might remove a whole raft of other problems that need to be solved. And we're already committed to "high tech or death" so it doesn't add a new failure mode of consequence. Maybe "no uterus no travel" is actually the best option.

    251:

    I'd misread the thread as "no second generation space travellers" rather than "no second generation US space travellers", but it does appear there's only the three so far.

    I suspect the Soviet Union would really have liked to fly Elena Andrianovna Nikolaeva-Tereshkova who I think is still the only person with both parents having flown.

    252:

    Forever Free did that, but wouldn't be perfectly reliable, so females would need to be monitored for pregnancy, and unplanned foetuses aborted. I don't see that as a problem in such a regulated environment.

    There's an alternative, which preserves both sexes. Vasectomy isn't entirely risk-free or perfectly reliable, but is close, and could easily be mandated on all males after they have frozen enough sperm. As, apparently, that is better the younger they are, this would be effectively be a rite of passage at puberty. Monitoring and abortion would be needed as for the homosexuality solution.

    My guess is that keeping the male/female ratio well below 50% would be beneficial, because it would reduce the problem of frustrated male teenagers becoming aggressive or dysfunctional.

    253:

    ...complete idiots build floating things in their backyards and fail to die while operating them in oceans...

    The sailing documentation should also emphasize that if it looks unpleasant or dangerous out on the water, it probably is. Stay ashore.

    There are problems that come up out of nowhere and can't be predicted or avoided, but a little caution and preparation goes a long way towards making them nuisances rather than disasters. My father was in a sailing club; I can't count how many capsized sailboats I've seen but as far as I know they've never had a serious injury or death.

    254:

    Around the UK, one of the most common causes of death in small boats (sailing and motor) is not allowing for a change in the weather - as it is with hillwalking. Because of our climate, 20 degrees Celsius with a moderate breeze (good sailing weather) fairly often turns into 10 degrees with heavy, near-freezing rain driven by a near gale, in under an hour. This is much rarer in climates like those in almost all of the USA.

    Nowadays, the forecasts are reliable, but they weren't until a few decades back, and the weather is NOT something that can be simulated to that level without knowing the target climate in detail. However, preserving the principles (such as in a computer game for earthly climates), and preserving many of the ancillary skills (like ropework) in practice, might well be worthwhile.

    255:

    Hm, why go with frozen sperm actually?

    Apparently spermatogenesis shares many control points with oogenesis[1], so the actual number of genes involved only in spermatogenesis is not that high; if all else fails you might CRISPer SRY and other necessary genes for it onto the X chromosomes or some autosomes with some heavy repressors in place.

    Flash forward, Mars need, err, men, so we either tweak the stem cells in the laboratory, or change the diet of some pregnant females; maybe we could use insect juvenile hormones as activators for the repressor and put the mothers on a statin. There are some natural sources for Lovastatin:

    https://en.wikipedia.org/wiki/Lovastatin

    [1] Evolution is really lazy...

    256:

    Err, I somewhat mixed up Greg's post with Robert Prior's post about young teachers; I'm still somewhat unsure what to make of my brother's career[1], but apparently he got his job as a teacher because he was willing to do some extra work, e.g. choir and orchestra.

    Some quite cynical part of me is waiting for his burn-out.

    As for job prospects for STEMs, I'm just finding out, though quite a few of the biologists and chemists I knew ended up as teachers, so it might not be that good[2]; one or two biologists I knew got jobs planning studies for pharmaceutical firms[3], so there is a market there.

    [1] It's somewhat strange when the guy behind quite a bit of your reading in school, "he's not that fast, couldn't you read "Schimmelreiter" for him?" is trying to get a PhD in Italian literature...

    [2] Though there might have been some stratification involved; at least some groups of people I hang out with are somewhat, err, different from the mean.

    [3] Mind you, getting enough bonus miles for your holiday just by doing your job for a few months didn't appeal to me that much back then, and us talking about which calcium channel inhibitor and SSRIs she was using to deal with the stress did neither...

    257:

    I'm guessing a ship might not have physical instruments on board but they're going to have sims of every sequencer and synthesizer ever designed, and the wherewithal to play them.

    You're missing my point. And based on our conversation I suspect you were not very involved in music growing up. Many of us enjoy the physical instruments. Nothing against using synths but some of use just enjoy direct modulation of air.

    And as an aside my parents were not into music and only one of my 2 brothers was/is so it wasn't a nurture thing for me and my brother. As to my level, I was about the 80th percentile in terms of talent. Never going to go pro or semi pro, but could take part in casual things.

    258:

    misleadingly-named "Pacific"

    OK. I'll bite. What does this mean?

    259:

    Pacific Ocean = Calm Ocean.

    Regarding minimum populations required for the STL ship to work: in a previous thread someone (Charlie? can't recall) suggested that a population of 325 million ought to do it-- enough to do most industrial / educational / training things that are necessary. Just pick up the entire population of the USA, put them on board a ship, and you're good to go (1).

    (1) The second picture from the Explain xkcd would probably be an accurate depiction of how enthusiastic people would be.

    260:

    It was named as such because it is a hell of a lot calmer than the Atlantic, or at least the north Atlantic. There is a damn good reason that the standard load line markings have a special line WNA - Winter in the North Atlantic.

    https://en.wikipedia.org/wiki/Waterline#Standard_load_line_marks

    261:

    Nojay @ 222:

    "Is the uterine replicator magictech and if so, why? We know they exist as bioengineering already inside squishy meatsacks, what about them is impossible to create as a work of deliberate external engineering by human beings?"

    It's "magictech" until someone manages to develop one. After that, it's simply tech. Since the "squishy meatsacks" get the job done, I don't see uterine replicators as one of the required prerequisite problems that has to be solved before the venture can launch.

    "If and when uterine replicators are available the putative starship crew will be less like the mineshaft survival clades as envisioned at the end of Dr. Strangelove and the freezer full of embryos concept might be made to work if it can be shown that embryos can be viable after centuries of storage (or enough embryos, a lot of non-viable wastage plus eugenic culling of the first generation or two might be considered a price worth paying)."

    Thing is, I don't see how Dr. Strangelove's mineshaft survival could ever work. It was pure comedic genius, but not a realistic survival scheme. They weren't taking the brightest & the best, they were taking politicians & generals and treating the women as property. It's a "society" run by revolting men. A women's revolt is inevitable.

    What I'm suggesting for a colony crew ABSOLUTELY requires informed consent. The women colonists have to know before volunteering that they'll outnumber the men and that the colony effort will need for them to all endure multiple pregnancies. That doesn't require a Surf City scenario.

    Eugenic culling is not a road any colony wants to go down. Not only do the ends NOT justify the means, the "means" ultimately become the end.

    262:

    Charlie Stross @ 241: and @ 242:

    "That statement betrays several disturbingly wrong assumptions, of which the first and craziest is that there's a planet at the far end of the trip that your colonists are equipped to land on and colonize."

    I'm thinking that by the time the colony mission is ready to launch, they should have reasonably solid intel on the destination "planet". If/when tech gets to the point where it looks like such an interstellar colonization venture is going to become feasible, it's time to start sending out the robot probes. Get a good read on the target before you even start to build your "starship".

    "My suspicion is that even if you send a colony starship to a system where there's an Earthlike world with an atmospheric pO2 of around 200mBar and the local saprophytic microbial ecosystem doesn't treat terrestrial meat like a tasty decaying log, it's going to be a very long time before anyone from the ship is remotely willing to set foot on the surface."

    "Most likely there will be a very long period of (a) building comfortable, non-mobile, big-ass habitats in orbit using asteroidal material, (b) spinning out a planetary surveillance and communications network in orbit, (c) dropping long duration drones into the atmosphere to sniff out biomarkers from the surface, (d) dropping robot-operated labs onto the surface to see what happens when you expose animal, plant, and human tissue cultures to the local environment, and finally (e) robot-mediated construction of fortress-like biohazard-isolated accommodation for a very brave first exploration crew on the surface. Say, 20-30 years or so, minimum, then another 20-30 years of people living on the surface and only venturing out in isolation suits, as if they're exploring Mars."

    I don't know how long after the starship arrives in system before it will be safe to colonize the planet. There will be a planet, because one of my prerequisites is having solid data sent back by the robot probes. I think the probes should start being sent out even before the starship begins construction.

    No planet = NO GO. You don't start out until you have adequate confirmation a viable earth like planet exists in the target system.

    Still I don't see how that affects my assertion that everything that comes down from orbit does not have to be carried by a re-usable lander. The bulk of material should come down on one-way "reentry" vehicles.

    I do know the putative colonists will need a logistical plan for how to get whatever is needed on the surface TO the surface whenever that occurs. They need to have a plan even before they launch. "The Plan" can't be a strait-jacket. They have to be able to revise it to accord with local conditions once they arrive.

    263:

    Just to put some numbers to your statement:

    "In November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way,[5][6] 11 billion of which may be orbiting Sun-like stars.[7]"

    https://en.wikipedia.org/wiki/List_of_potentially_habitable_exoplanets

    Before we send anything out, we would analyze the atmosphere, terrain (at a subcontinent level), and geology from Earth. I've heard that you can probably determine the existence of plate tectonics using the same method we mapped the depth of Europa's ocean. In that case, we used Jupiter's magnetic field interacting with Europa's to study the ocean. The same thing could be done with the interaction between the star and planet.

    264:

    Just had a brain wave regarding: how to make the environmental bits of an STL ship work, inspired by my offhand comment about the population of the USA.

    Let's make a 'planet USA' for the sake of argument. We can shorten 'planet USA' to Pusa - thus it shares a name with a genus of earless seals. This should also make its construction popular with US Navy special forces members. Planets are big, and we'll be building this one from scratch. So we'll probably want to park it in one of the Sun - Earth Lagrange points.

    The surface area of the USA is 9.834 million km^2. Earth is 29% land, 71% ocean. That water is probably good for something or other [citation needed] - climate regulation or some such - so Pusa has a total surface area of 33 million km^2. Pusa's radius is 5,143 km - much smaller than Venus, which we will probably be mining for raw materials. We want Pusa's surface gravity to be identical to Earth's, so it's going to have a greater average density than Earth. This will keep a good atmosphere in place - important for the health of the inhabitants - without having to worry about hull components. Gravity does all the atmosphere-retention work.

    Since we're building this planet from scratch, we'll make sure that it has the same rotation as Earth. We also want it to have a molten core, so we get a magnetosphere to protect the crew from radiation. This also gives Pusa plate tectonics, etc.

    Regarding the biosphere: we'll just be seeding from Earth, so we don't really have to have a full understanding of biology - just take large chunks of the surface area of the USA and put them on Pusa. Existing bulldozer technology makes extraction an easy task. We can do the same with the ocean - a few cubic kilometres of water taken from various places around the Earth can be easily captured and placed into Pusa's new oceans. This seeding procedure ought to suffice to set up a working biosphere on our new planet. Admittedly, moving things from Earth to Pusa is somewhat more difficult but probably manageable with sufficent worker motivation.

    So. The end game has a new planet in our own solar system, one that is excellently suited for life. If the planetary engineers did their jobs correctly, the land masses can even be shaped and situated like the states they are modelled after - the islands of Texas and Florida are closeish to the equator; the Alaska Archipelago is largely above the Arctic Circle and the Continents of New England and Midwest are in intermediate positions, scattered artfully around the planet. Slartibartfast would be proud.

    Needless to say, if we have a perfectly good spare planet, why should we send it to another star system? But this thread is about STL ships, so this is necessary. We select a nearby star that doesn't have a habit of flaring, and doesn't currently have a planet in its goldilocks zone. We turn on our planetary drive, and slowly accelerate out of the solar system. We would have to be careful to avoid causing perturbations to the orbits of existing planets. We don't want to wreck our own solar system!

    For the propulsion itself, it would probably be most convenient to have the planetary drive located in the centre of Pusa, if at all possible. Ideally, we would have a drive that directly manipulated the fabric of space-time. Otherwise, since Pusa is rotating, several tall volcano-like mountains on the equator would have to be constructed. The tops of these volcanoes would be above Pusa's atmosphere. The engine would simply vent reaction mass out from the appropriate mountain in order to maintain course. A properly-designed system would avoid continuous earthquakes. Meanwhile, we have all of the reaction mass we need, since our planet is denser than Earth. Admittedly, surface gravity will lighten somewhat as the centuries pass and reaction mass is used up, but this process will be scarcely noticeable, so gradual will it be.

    While we're under way, we would place a number of fusion reactors - miniature 'suns' if you will - in orbit around Pusa. This would keep the surface temperature pleasant in the depths of interstellar space. A periodic on / off intensity cycle to these artificial suns could give the illusion of day / night and summer / winter. Indeed, if all of the mini-suns were synchronized, the population wouldn't have to worry about time zones - it would always be dawn / noon dusk at the same time all over the planet.

    Since our 'ship' is in fact a planet, we wouldn't have to go very fast to get to our destination, so we wouldn't have to worry about hitting things at relativistic speeds. Our atmosphere would handle most impact events without the need for sophisticated systems. A voyage of several centuries - or even millennia - would be entirely feasible.

    When you get right down to it, this plan has what we need. We don't have to worry about ecological collapse - we have an entire planet to ride out the storm. We don't have to worry about population pressure. Any economic difficulties that occur due to passenger choices would be handled through ordinary historical processes. Even anthropogenic climate change wouldn't be a problem. If things start getting too warm, just turn down the suns (where the population is getting hydrocarbons to burn on a completely artificial world is left as an exercise for the student).

    Certainly, some technological details need to be worked out, but this should be entirely feasable. A few handwaves were required, but I'm surprised that this plan has never been discussed.

    265:

    Frank,

    Beautiful post, on many levels. It's a great summary that I can use. Thanks...

    • This solves the Fermi Paradox, because if interstellar travel is impossible then there is no paradox since no one can physically travel between stars.

    -- That also means that the universe can be filled with intelligent life, trapped in their own star systems, never to meet. Thus, we are all effectively alone.

    Somebody on TED is reading the blog.

    Where are all the aliens? https://www.ted.com/talks/stephen_webb_where_are_all_the_aliens

    266:

    Here are some number for vegetarianism.

    https://en.wikipedia.org/wiki/Vegetarianism_by_country

    It seems that 14% of UK residents are vegetarians compared to 3.3% for the US.

    267:

    Ive just read a Twitter Post -in the vicinity of your own Twitter address site - that states " So I learned today that Great Britain imported hundreds of thousands of tons of human bones from battlefields in Europe and from the catacombs of Sicily to fertilize their newly industrialized farms in the 19th century." Don't they /You realize that what is needed to Power a Space Drive is Lotsa, and Lots of, Human Remains that Our Lord and Master Cthulhu can use to POWER Our Human Races Exploration Beyond the Stars ..er ..the nearby Star Systems Where Cuthulu can Overcome rival Gohds and go on to Conquer the Universe and make it over in the Image of Cthulhu? This is the Real and True purpose for the existence of the Human Race. Its Obvious really ..well isn't it?

    268:

    David L @ 232 & SFR @ 239 Music And yet, there are huge numbers of “amateur” musicains, some of whom are extremely talented. Our Morris-side’s Squire is a really good Melodeon-player & we have now got both a bagpiper ( Olde English & Welsh pipes ) & a superb Concertina-player ( And the guy who plays the Kantele ) Yet … I can’t read music or play an instrument, much to my annoyance – because my father was waiting for me to ask me to be taught & I was waiting for him to simply teach me …. AND the fucking school system doesn’t teach music ( as in simple theory & READING it ) to everyone – WHY NOT?

    Pigeon @ 237 Which is why the rules on board a (Wet-Ocean ) ship are & have always been ) radically different to those on any sizable chunk of land. Not that that is necessarily a good precedent?

    Charlie @ 246 EUW If you are so inclined actually PLAYING a musical instrument is physical FUN – a synthesiser, not so much. See also David L @ 257

    Moz @ 250 even India and China are within a percent of balanced) Sure about that? What with dowry murder & selective infanticide of females & a surplus of rabidly ( as in violently-it’s-my-property) heterosexual males on the loose ) – I’m not convinced see also THIS REVOLTING EXAMPLE Yuck

    JReynolds @ 264 Spacecraft sizes – already been done: GSV’s of one sort or another Plate, Desert, Mountain, Ocean Or alternatively Turtle-size …… Still missing Ian & Pterry

    269:

    I think the computer issue is over-rated. You need surprisingly little actual computing power for navigation, a common $4 microcontroller has more power than Apollo navigation computer. And the lifetime of actual silicon, when not thermally cycled, is essentially infinite.

    What kills your electronics is cheap Chinese electrolytic capacitors and similar nonsense. The planned obsolescence works by having 1 component type that degrades. In case of cellphones it's the battery and the fragile screen, and if that doesn't get it then there's software updates that are very sluggish on old hardware.

    Ultimately what you'd need to do is a modular built and monkeys swapping out broken modules. Require that everything using flash memory gets flashed on the ship, from long term storage that's refreshing itself every 20 years or so. Require that everything has checksums. It's not really a problem.

    270:

    As far as social issues with the interstellar travel go... I feel that maintaining stability inside the ship, maintaining enough competence for on-board repairs (using stored spare parts), those are all very big issues if your end goal is to have the crew complete the trip and then die upon landing.

    If the crew is having a slightest hint of difficulty doing any normal maintenance on the ship, they're already as good as dead, because it's upon landing when they'll have to be smart to have any chance at surviving. There won't ever be a planet where you can simply cook local wildlife, certainly not anywhere within reach.

    271:

    Your "revolting example" link doesn't work…

    272:
    Frozen anything won't work. Humans are slightly radioactive. We're constantly being slightly damaged, and constantly doing running repairs.

    The radiation comes from our diet. If you've already solved the closed-cycle life support problem, which you'll need to have done in order to do this STL craziness in the first place, you can build yourself some space colonist feeding grounds that simply don't include the problematic radionuclides in it, and feed up your future human popsicles using enclusively nonradioactive sources. You may need to raise a whole generation fed on this first, though I'm not totally sure of that.

    273:

    Re: Ban radioactive food in the space-can

    Damned! ... and I do so like bananas, and apparently my body needs it too. And, apparently so do astronauts - like and need.

    https://en.wikipedia.org/wiki/Banana_equivalent_dose

    https://thespacecollective.com/space-food-bananas

    274:

    misleadingly-named "Pacific"

    The Pacific Ocean is peaceful compared to the Roaring Forties and especially the narrow bit at the bottom of South America. Compared to just about any other body of seawater it's challenging. Kinda like people who return to London from Calcutta and say 'everyone is so polite and the air is so clean'.

    After braving perilous seas and navigating through what are now known as the Straits of Magellan, his small fleet entered an unfamiliar ocean in Nov. 1520. He called this body of water pacific, due to the calmness of the water at the time ('pacific' means peaceful).

    275:

    bananas

    40K is a minor part of naturally occurring potassium(*). If it were actually to be a problem, I'm sure the supertech society that's built the STL generation ship could perform the needed isotope separation. As noted in 272, it might take some time to purge the 40K from original crew -- I have no idea what the retention time of potassium in the body is.

    (*) From Wikipedia, which cannot be doubted, "Three isotopes occur naturally: stable 39K (93.3%) and 41K (6.7%), and the long-lived radioisotope 40K (0.012%)."

    277:

    Have been waiting for someone to mention:

    Living accommodations - (a) personal and (b) social

    (a) Personal accommodations - Everyone will have a similarly designed living space that's just large enough to feel like it's not a sardine can. Why? - because resources will be limited including air to fill those cabins. Personal space is needed for a variety of physiological and psychological reasons that benefit the individual (privacy, rest, recreation, sense of individuality/self, etc.) and the rest of the ship (weird bacterial outbreak and you need a quick quarantine, deliberate social isolation as punishment, repairs/maintenance to one cabin doesn't disrupt too many crew, etc.).

    (b) Social space - A few areas large enough to accommodate a pre-specified fraction of the ship's inhabitants. Although central park massive green spaces have been mentioned, if the ship is smallish - say carries only 5,000 people, then the ship to potential green space ratio is probably pretty small. And if it is smallish, wouldn't you have engineering issues about pumping in enough oxygen/pumping out enough carbon dioxide into one area if for some reason everybody showed up at your 'park' all at one time. They'd be dropping from anoxia. However not having a safe public space that can accommodate everyone all at one time could acquire a meaning (that later turns into actual) preferential treatment/class which would likely have negative consequences.

    If food and habitat are provided for and are essentially equally distributed on an as-needed basis, and if all folk are considered experts within their own fields as well as experienced project collaboration, where do you see class structure or group/tribal conflict showing up down the generations? (Asking because class/hierarchy seems to be assumed as a given no matter what ... and I'm not buying that without a good argument/data. Also, I'm not including sex as bargaining chip/trade good because ... really?)

    Death - Frankly, I'm assuming that these space folk are much likelier to opt for a dignified assisted suicide than waste away - plus waste their life-long companions' very limited resources. Assisted suicide has become an option only recently in a few countries. Specifically in countries where average life expectancy happens to be quite high but quality of life issues remain, e.g., Parkinson's, ALS, stroke, etc. Should probably be a condition of recruitment: we'll keep you healthy and happy as long as we can, but there may be a point when we can't.

    By now, NASA and other space agencies should have a good idea of how groups live/work in space. Anyone know whether there's any published data because it's kinda ridiculous to guess when there's some genuine data available somewhere? (I've already read Hadfield's book.)

    278:

    I was sure, but I was also wrong.

    https://en.wikipedia.org/wiki/Human_sex_ratio

    The Northern Mariana Islands have the highest female ratio with 0.77 males per female. Qatar has the highest male ratio, with 2.87 males/female. For the group aged below 15, Sierra Leone has the highest female ratio with 0.96 males/female, and the Republic of Georgia and the People's Republic of China are tied for the highest male ratio with 1.13 males/female (according to the 2006 CIA World Factbook).

    The smaller countries get their ratios by importing and exporting large numbers of people. China works hard at theirs. India just isn't organised the the way China is.

    279:

    Greg Tingey @ 268:

    "If you are so inclined actually PLAYING a musical instrument is physical FUN – a synthesiser, not so much."

    That kind of depends. I don't have room in my home for a full sized concert grand piano. Can't afford one either, since I'm a no talent and can barely play.

    OTOH, I do have room for a Yamaha keyboard with piano weighted keys, so I can sound like I'm banging away on a full sized concert grand. Close my eyes, and it feels like a real piano.

    I'm really a guitar player. I bought a Leslie G37, so the synth keyboard can fake a fairly good Hammond B3 for about 1/10 the cost of the real deal. There are a lot of other instruments I can't play, but I can make the sounds using the synthesizer. Without the synthesizer I wouldn't be able to make any of that music, I'd have no fun at all.

    Well ... I'd still have the guitars, but the range of music I could make would be a whole lot more constrained without the synthesizer.

    280:

    Zzz.

    Someone slap the Zombies.

    https://www.newscientist.com/article/2128851-artificial-womb-helps-premature-lamb-fetuses-grow-for-4-weeks/

    Oh, bonus round:

    Catalina: I know Forest Reinhardt. He was a colleague. He is actually a friend. And since I have not got the foggiest clue what you're going on about, I can guarantee you that he doesn't either.

    http://www.antipope.org/charlie/blog-static/2015/05/the-evil-business-plan-of-evil.html#comment-1971879

    Well, you do now.

    And. Not. A. Single. One. Defended. Their. Nation.

    Q.E.D

    5D Proved.

    Children of Men

    281:

    This solves the Fermi Paradox, because if interstellar travel is impossible then there is no paradox since no one can physically travel between stars.

    Not really. It still does not explain why we have not been eaten by self-replicating nano-probes.

    282:

    It's not as easy as that...

    Producing food that doesn't contain any unstable isotopes is not exactly a trivial task, partly because of the amount of separative work required, partly because of how far back down the chain you have to go, and partly because one of the important isotopes is 14C, which comes from the air. So you have to provide large quantities of air that's taken a ridiculous amount of effort to clean up, and not only for the food plants but also for the humans you're trying to make non-radioactive. (Yes, humans do absorb atmospheric carbon and incorporate it into the body; all the processes by which we exhale CO2 can and therefore do work in reverse as well.)

    And of course you have to make the entire spaceship and everything on it out of isotopically-purified materials as well. This is not easy. Which is why when we want really high-quality shielding at the moment, we use lead that the Romans dug up and then dropped in the sea accidentally instead of trying to purify lead produced in the atomic age. It still isn't perfect, and the quantities are small.

    Then even if you could manage all this, you're still operating in an environment where there are loads of really high-energy particles whizzing about that are impossible to screen out. So you get both direct damage from these, and indirect damage from them activating elements of the spaceship. I cba to run the estimates but it wouldn't surprise me if after a few hundred years the cumulative effect of cosmic radiation is such that it completely swamps any advantage you might have gained from making the ship and crew from entirely non-radioactive materials and you might as well not have bothered.

    Basically, you're buggered on this one and there's no way round it.

    284:

    "AND the fucking school system doesn't teach music ( as in simple theory & READING it ) to everyone - WHY NOT?"

    When I was little some bod got everyone in the class to try blowing down a loose oboe reed (ie. not attached to the oboe) and I was the only one who could get any sound out of it. (So I am told; I have no memory of the incident, only of what came of it.) From this result the bod concluded that I must be a genius-level concert oboeist in embryo and just needed hatching out to take the musical world by storm. I suppose my extreme youth excuses my having believed this fucking stupid statement; I'm not sure what excuses my parents having believed it, but they did, and so I got Oboe Lessons inflicted on me.

    Well I was crap at it and it was dead boring and I hated it, and eventually managed to get them to stop, although only by replacing it with Piano Lessons. I wasn't quite so crap at that because the physical aspect of playing it was a fair bit easier, but I still struggled, and the main reason I struggled was that I could never properly read the bloody music. Because I was never taught how, beyond the basic FACE/EGBDF (I still don't know what the sequences are for the bass clef). It was just assumed that I knew, but what I was actually doing was consciously deciphering it from first principles in real time, and I never got to the point of knowing what it meant without conscious thought just by looking at it.

    I did get to that point with every other form of notation I encountered - the English alphabet, of course, the Greek one, algebraic notation, chemical notation - and I think the fundamental difference was that I understood what they were supposed to be conveying, whereas I never got taught any music theory at all. Music theory was only taught to the about three people in the school who genuinely were concert musicians in embryo; everyone else didn't even know what it was.

    It wasn't until some years after I had managed to escape from the piano lessons (by disconnecting the speaker in the classroom that was used for announcements reminding people to go to their music lesson, and not going) that I encountered (outside any school context) any description of the mathematical and physiological factors underlying music and what makes it musical, and it was something of a revelation; finally all this shit made sense. I can't help feeling that if I had found out about this first it would have made a significant positive difference in how readily I learned the practical stuff. But the school's policy of regarding musical theory as icing on the cake rather than as fundamental knowledge had meant that never happened.

    ...Although I also think I would have had to be taught it in straight mathematical terms, and not in the standard music-theory conventions; I didn't encounter those until still later, and when I did they made less than no sense. They seem to be a kind of mangling of mathematics produced by people with no mathematical understanding trying to describe something mathematical, and need a considerable amount of disentangling to actually get at the mathematical basis of what they're saying, which is made harder by the pseudo-mathematical terminology that looks like it means something it doesn't. So even if the school had not been so elitist in its dispensation of musical theory, I doubt they would have conveyed it to me in a useful form.

    As for the physical vs. virtual instruments thing, that surely depends a lot on the person concerned and also the kind of physical instrument. I got on physically much better with the piano than with the oboe. I've handled a variety of electric guitars (in the context of signal sources for testing guitar amps) and they all felt really alien and weird, with the exception of a Strat which felt completely natural and lovely and actually made me want to take it home with me. I've no idea what the difference was, but it does seem that whatever makes an instrument feel good is very subtle and very personal.

    Anyway, I am very sure that any sizeable bunch of people left without any musical instruments are going to make their own out of any pieces of junk that can form an acoustic resonator. So many random things respond when you blow or twang them that it'd be impossible not to.

    285:

    That's still not quite the point - you can't "play guitar" on a synth. You can't press your ear against the heelcap and feel the resonance in your bones. You can certainly use any keyboard to enter data for the sequencer. But a sequencer is exactly like a pianola roll, it's just that you can associate the program with any sounds including samples. You can create something that would take years of intense practice to play on the source instrument for real, but... it's still a pianola roll and for many people the years of practice is the point. Guitar strings that make your fingers bleed (I do not resemble that remark at all, and those suspicious dark splatter stains inside my old guitar are just fret oil thank you very much), oboists with scars all over their thumbs from reed making, tuba players with that perfect relaxed embouchure that means when they talk sometimes it sounds like they are farting in between words, saxophone players who can get those extra low notes by sticking a foot in the bell, Louis Armstrong's puffed out cheeks (which everyone knows is actually terribly technique, but love him all the more for it)... these things have their own resonance and there are people who would not wish to live without them.

    286:

    ...And this reminds me. WHAT is the SF short where the human exhibits in an alien zoo discover that any sound that humans consider harmonious and musical causes great pain to their alien captors, and weaponise music hall songs to escape?

    287:

    Surely if you have an effective mechanism for tweaking those dials at all, the more useful tweak for the sexual attraction vector is not adjusting its angle, but greatly reducing its magnitude?

    I'm not convinced that imposing measures to control reproductive rate is really necessary. Given reliable and non-intrusive contraception, people seem to do it themselves in response to environmental cues (within limits; it seems bloody impossible to get them to stop doing it altogether, but you're not wanting to do that anyway) - see the various posts on demographic transition and its causes. In the designedly-benign but still very obviously constrained environment of a spaceship, I think the problem would naturally fail to arise - or if it did arise, it would just be an indication that the whole project was sociologically unstable at a more fundamental level and so was inevitably going to fail badly in any case, whether from that cause or something completely different.

    The way I see sexual attraction causing problems is through its extreme potency at inciting highly irrational behaviour and long-term unresolvable conflicts and resentment. In this context, the hetero/homo distinction is irrelevant. It seems there is practically no level of mind-boggling stupidity and destructive (to self and/or others) behaviour that people won't descend to for reasons arising from sexual attraction. (This includes the idiot primate status games that people play over political power and money, since maximising reproductive opportunity is where that behaviour derives from.) While this characteristic may have been evolutionally favourable on Earth, where there is enough leeway to get away with it, I can't see it being anything other than quite the opposite within the constraints of a spaceship.

    288:

    and I think the fundamental difference was that I understood what they were supposed to be conveying, whereas I never got taught any music theory at all. Music theory was only taught to the about three people in the school who genuinely were concert musicians in embryo; everyone else didn't even know what it was.

    I may just be that you are not musically inclined. To make it that is.

    In my school of 900+ students, there were less than 20 of us who took music theory at any level over a 4 year period. And maybe 200 who participated in playing or singing musically. And the best musicians never got anywhere near the theory. They just did it.

    Some people are great at math, some music, some at dealing with plants or animals. Some at repairing automobiles.

    290:

    The most dangerous thing to a sailing boat is land. Surviving a storm in the open ocean basically boils down to making sure you stay afloat while you wait for it to stop; this isn't trivial, but it is largely dependent on pre-existing constants like how well the boat was designed and how soundly it was constructed, and modern constructional materials and techniques and understanding of physics all help here.

    Things are a lot different when you have to worry about not hitting something, so you have to try and maintain directional control. Doing this places much more strain both on the boat and on the crew; the crew become exhausted, bits of the boat break generally in such a way that maintaining control becomes even harder, and you can't put off dealing with the damage until conditions improve, which puts even more strain on the crew.

    Important knowledge here is how to predict the weather, so you can get as far out to sea as possible before it gets too bad (or run for harbour, but this is often more risky even if there is one). It also helps to know celestial navigation, so you can find your way to where you're going without needing to keep the shore in sight so you don't get lost (which did for a lot of the early Mediterranean sailors).

    (The Caribbean isn't exactly benign, BTW; hurricanes, waterspouts, bad sea conditions, powerful currents... you're constrained in what you can do even under normal conditions, and you get the kind of storms that really put the physical structure of your boat to the test.)

    291:

    Everyone seems to be taking the presence of this computer as a given, but I can't help thinking: what is it actually for? The navigational calculations are not all that hard - the geometry is basically the same as for ship navigation, and people did that all by hand until very very recently (people who know what salt does to electronics still do). And you certainly aren't short of time to do the calculations in. What you are short of is data specifically pertaining to the system you're aiming at, and it's not a computer you need to get that but a good telescope.

    Reliability of electronic and storage devices tends to improve with the size of the parts, as the phenomena which might bugger them up become more thermodynamically improbable in relation to what is needed to have a significant effect. If nothing else gets them first, semiconductor devices will eventually fail from the distribution of the dopants becoming homogenised by diffusion. But this takes a lot longer in a power transistor with a chip the size of your fingernail than in a transistor that's part of an IC and is made from a humanly-countable number of atoms... and the IC has a lot more of them.

    Flash memory forgets because the thermodynamic barrier to charge equalisation is not very high. Mask-programmed ROMs where corruption involves movement of atoms in a crystal lattice last rather longer. A sheet of platinum with holes punched in it lasts longer still - and a human can read it directly.

    You'd want to maintain the group's mathematical ability at a rather higher level than is needed for navigational calculations in any case, so you'd already be carrying highly durable textbooks (as in actual readable books, not files) designed to remain readable and not fall apart for tens of centuries. Actually doing the calculations would simply be a more fun substitute for practising on made-up data. Having a computer seems to be adding something more to go wrong that's hard to fix; if you have to have one at all, Babbage is probably a better inspiration than Intel.

    292:

    Interesting. The peculiar vulnerability is identical, but what I'm thinking of was an actual story in a book, and there was more than one human captive.

    293:
    It's not as easy as that...

    Oh come on. This is a post about slower than light interstellar colonisation. Making non-radioactive food is absolutely trivial by comparison.

    partly because one of the important isotopes is 14C, which comes from the air. So you have to provide large quantities of air that's taken a ridiculous amount of effort to clean up,

    Still easier than STL colonisation. Also, I'll bet you a fiver that you can find a source of carbon in the solar system that has a much more amenable ratio of stable to unstable carbon isotopes. Burn it.

    And of course you have to make the entire spaceship and everything on it out of isotopically-purified materials as well.

    Why? You need your freezers to be nonradioactive, and you need enough shielding around them to keep out as much stray radiation as possible. but the rest of the ship can be made out of whatever you like (as far as removing radiation damage to popsicles goes, at least. there are other reasons to alter the isotope balances of other bits of your ship that are irrelevant to this specific problem)

    Then even if you could manage all this, you're still operating in an environment where there are loads of really high-energy particles whizzing about that are impossible to screen out.

    What does this have to do with food?

    Now, those particles deposit their energy in a fairly well collimated cone, rather than evenly irradiating the entire body frorm the inside continuously. Necrotic and cancerous regions are much easier to deal with than whole-body cell death.

    I cba to run the estimates but it wouldn't surprise me if after a few hundred years the cumulative effect of cosmic radiation is such that it completely swamps any advantage you might have gained from making the ship and crew from entirely non-radioactive materials and you might as well not have bothered.

    A few hundred years will get you to quite a few places, even if you're doing something as ridiculous as using an on-board fusion engine to boost and brake your starship.

    Basically, you're buggered on this one and there's no way round it.

    No, you've decided it is too hard. That's different.

    294:

    Ocean-going cultures that settle new lands do not jump straight to ocean-crossing tech from nothing. You start with lots of navigational and boat-building abilities and work up.

    Spent some time in the remote islands in Fiji, or etc, and you’ll find a culture where people use boats the way I use my bike. Skills and tech scale up gradually to large ocean crossings.

    I expect the only way we’ll ever get successful STL is if we first spend a few centuries sending canned monkeys around the Solar System in slowly increasing numbers for slowly increasing time periods.

    Which leads to the obvious question of whether there will ever really be economic or cultural incentives enough to do that given the issues in canning monkeys for shorter periods, like a decade or two, and the energy cost in putting monkeys into space.

    295:
    Someone else is welcome to check my "math" (in fact, I insist on it), but I figure if you can accelerate at .25g for one year that puts you up at about .25C. A target star 10 light-years away would be a journey of about 42 years (allowing 1 year acceleration, coasting for 40 years [four years per light-year] & decelerating for 1 year).

    So, OGH already touched on this, but allow me to follow up with a few extra specific things.

    Firstly, exhaust velocities, mass ratio and delta-v budgets. If you're making a rocket which uses no external mechanisms to accelerate or decellerate (which is madness, but that's a topic for a separate reply), you need a total delta-V reserve of about 4x your peak velocity (eg. 1c for your example). Now, your delta-V is related to your mass ratio (how much of your ship is made of fuel) and your exhaust velocity. Let's imagine a fancy fusion drive with an exhaust velocity of 0.05c. To get a delta-V of 1c, you need a mass ratio of ln(20). You can calculate this yourself. It isn't a good number. You could use a beam-core antimatter drive with an exhaust velocity of 0.3c which gives you a mass ratio more like ln(3.3), but suddenly you need to deal with the production and storage of thousands of tonnes of antimatter, and shielding yourself from a colossal amount of gamma radiation.

    Next, thrust. 0.25g might sound like a small number to you, but when you're dealing with the sort of engines we need here with very, very high exhaust velocities, it implies an engine of incredible power. A 5000 tonne ship needs a ~12.5MN thrust. To get that from yout 0.05c exhaust velocity fusion drive means an engine power of ~1.8 petawatts. For your 0.3x exhaust velocity beam core drive, that's more like 13PW. This should give you some idea of how much radiation your engine will generate (hint, about 33% of an antimatter reaction is lost as gamma rays, and about 25-80% of a fusion reaction is lost as xrays and neutrons). And remember, this assumes a perfectly efficient engine (implausible) and a perfectly efficient nozzle (impossible). It only gets worse the closer you look at it.

    Take home message: You can't have high thrust with a starship drive unless it is a) magic, or b) your shielding technologies verge on magitech. You also can't have high velocities unless you're using antimatter, which perhaps isn't quite magictech, but it is a hall of a lot harder than anything else.

    296:

    I was going to link to some blah about the firefly starship design as an example of something semi-plausible by current standards... 150 tonne payload, 3000 tonne hull mass, 42000 tonnes of fuel, 10km long. ~Two milligee thrust, 100 years to alpha centauri, which is just next door.

    Unfortunately, icarus interstellar no longer seem to be talking about it much, I can't find any original papers on it, and they've broken a load of old links to their website. Thanks, folks.

    Anyway, summary: for a plausible, purely fusion rocket driven spacecraft (which is a terrible idea) you could reasonably expect a peak speed of ~5% of c.

    297:

    I expect the only way we’ll ever get successful STL is if we first spend a few centuries sending canned monkeys around the Solar System in slowly increasing numbers for slowly increasing time periods.

    That appears to be the consensus.

    I think for learning oceanic boating from books you start by giving a bunch of kids all the boating they can stomach. Within a generation or two you will likely have a few kids whose teenage rebellion consists of sailing over the horizon and disappearing... eventually one will come back :)

    Now, if those are solar sails and space-ships...

    298:

    David L & Pigeon Yes, well - I'm certainly "wired" that I would DEMAND the theory FIRST - like: "What do the fucking symbols actually MEAN?" I mean, I can usually recognise the composer & sometimes the actual piece, from the "classical" repertoire from between Mozart & Vaughn Williams & quite a few others. I "carry" a good couple-dozen or more trad tunes ( dance tunes of course ) in my head & the physical movements to go with them. But I can't read music & therefore, can't play an instrument & it's probably too late, now, Grrrrrrr.

    Some people are great at math, some music, some at dealing with plants or animals. Some at repairing automobiles. Yes, but you are usually given a chance at trying a, c, d ... but not "b" - WHY NOT?

    299:
    building the bubble in the first place may require even more insane tidal forces or simply be physically impossible so you can't just have it built aroud you; oh and stopping the bubble at the end of the trip may well, ah, one paper says "disrupt" the target environment. I think it's talking about the kind of disruption that turns stars into a scatter of superheated quark soup.

    Orion's Arm had some nice ideas in that regard (they did, once upon a time, have a fairly clever sciency person involved) where the stuff inside the warp was "merely" the machinery required to maintain it, and most people would then connect their spacecraft to the warp externally via magnetic or gravitational means and get towed around.

    Sure, it won't get you FTL (but then, it isn't clear that FTL is possible with this sort of warp metric anyway) but it does get you a reactionless drive and that is worth an awful lot. Such a system could potentially scale up nicely, allowing you to haul around the sort of shielding you need to travel at high sublight speeds, or just move around big colony ships at sedate speeds without the need for gigantic fuel tanks.

    Still magitech, but a little less so than wrapping yourself up in a warp drive.

    300:

    We don't actually know what that would do to the mammalian genome, epigenetics and development, and whether a low level of such radioactivity is actually needed. It wasn't long ago that arsenic was regarded as a pure poison, and infections were regarded as entirely harmful.

    301:

    I can't read music & therefore, can't play an instrument

    I wonder how animals transmit knowledge without writing, it must be really hard. Birds especially must find it challenging.

    Music is one of those things (like talking) where the theory and the writing comes after the basic learning. I can sing and occasionally hit the right note ... like a truck hitting a squirrel. But my ability to read music is more like I remember knowing the basics when I was about 10. Doesn't stop me singing and I can whistle as tunefully as I sing. Which is half of playing an instrument, except it's cheating by using your body as the instrument.

    302:

    I am afraid that there are a lot of half-truths being promulgated as the whole story, here.

    Yes, getting rid of crapacitors, desistors etc. would increase the lifetime markedly, but only from a MTBF of a handful of years to a couple of decades. Evaporation, diffusion and chemical breakdown are the limit on those scales. As I said earlier, we know how to design computers that would last for a century or two; beyond that, we don't.

    You are right that navigation is easy and maintaining such skills is important - I would say that, wouldn't I? :-) But there ARE some things which humans have difficulty handling without computers. Modelling and (worse) controlling chemical and biochemical processes is one, the management and dissemination of large amounts of data, things like DNA analysis, etc. It's not that we can't do the job, but we can't do it fast enough.

    303:

    Which is half of playing an instrument, except it's cheating by using your body as the instrument.

    Conversely, playing an instrument is cheating because you don't need to hold the tune with your body.

    304:

    Actually, I could read music before I was 9, but couldn't play anything except a few crude percussion instruments, even at a primary school level. But I have always been effectively tone-deaf, because of my severe hearing loss. It's an orthogonal skill.

    305:

    We don't know what it would do to the food crops, or the various other organisms required to make them grow, let alone mammals.

    There will be plenty of opportunity during the build up stage to check that your plants and insects and small birds and mammals are all still apparently working OK, or whether an alternative external radiation source might help with any deficiencies, etc etc. That would go some way to reducing the worry that there might be problems with humans.

    Personally, I'm inclined to feel that the effects of internal radioactive decay would be dwarfed by regular everyday metabolic damage and would be almost entirely unnoticable except in the unusual situation of frozen organisms (surely someone has coined a good neologism for these?) over extended timescales when the damage can add up.

    306:
    a mass ratio of ln(20)

    The idiot who posted this obviously didn't realise that they shoudl have put ln(mass ratio) = 20 or mass ratio = e^20. Its like they didn't even bother to read what they wrote.

    307:

    Moz @ 301 People differ - some can learn simpy by copying & many ms=usicians do so. I have learnt a lot that way, as have we all. BUT Once you are past the age of 6 or so, certainky, I have always wanted to know "why" as well as "hoW" - what makes "it" tick in other words - it's the way I am, & music is no exception. Given the well-known tie-oin between Mats & Music, perhpas that's not suprising (for me) YMMV

    308:

    With a population like a large city, some questions we've been avoiding clamour for attention. What kind of system of government might such a community choose, accept of have thrust upon it? A single layer, or a central government and separate municipalities? In the hundreds of thousands, Iceland is still a reasonable example. They do multi-member electorates with proportional voting, elect their executive from Parliament (therefore "responsible government") and their elected president has limited powers, the most important of which is to refer legislation to a referendum. Is there a place for representative democracy at all, or does the primary of technical requirements for supporting life mean that there is a hierarchy driven through seniority in the technical professions? Is some sort of medium available?

    What about the legal system? Is there private property, private law, common law? If this is arising from anything like the present international situation, if the ship has arisen from a country that is an Outer Space Treaty signatory, then that country's jurisdiction applies aboard. Until some kind of declaration of independence occurred, planned or otherwise. Because it is artificial, the interesting thing about sovereignty over celestial bodies (TL;DR you can't claim it by any means) may not apply. One would imagine bodies of statute law in relation to the preservation of the means of life would be pretty thorough, but would you want common law anyway to account for the unpredictable? And who owns the ship, or any part thereof? If it's a generation ship, is there some kind of lease of areas within it that can pass down generations? If there is private property, is there also destitution, homelessness? Does the recycling of air and water come under a central government or a municipality, and can it be done by private contractors? How about food production? And at these sort of populations, is there some kind of law enforcement?

    One thing these longer-living computers may be required for is to be the management layer for a 360-degree panopticon live-streaming zero privacy life. Do we need electronics for this, or can we suggest (among all the other magitech) that we have photonic computers where the active components, rather than being manufactured via chip processes, are grown in transgenic algae and kelp?

    309:

    Re: 'What about the legal system?'

    If you're traveling to a new world, why not create a new type of government?

    Serious question:

    Premise: The destination (objective) is hardwired into the space can, all on board are vital crew therefore actually and not merely theoretically equal (skewed demographics), and all basic human needs are provided.

    Given this scenario, what decisions will have to be made during the journey and how hard will it be to make them? Personally think that the types of decisions, the make-up of those affected as well as local environment determine optimal decision-making process. (No idea whether this is in fact true.)

    A lot of government and decision-making seems to boil down to: but we've always done it this way. Well, we've never traveled to the stars before, so why should we continue making decisions as though we were one of many packs of grunting primates living in the middle of a self-maintaining buffet?

    310:

    But I can't read music & therefore, can't play an instrument

    Nope, doesn't follow. By way of worked example (no, not Jazz improvisation), I give you Canntaireachd - a way to transmit bagpipe music without staff notation.

    Of course, once staff notation appeared, they were all over it (foolish not to, it's very efficient) although reading pipe music sometimes confuses those who wonder why these hemi-demi-semiquavers are all over the place...

    ...I conform to one definition of a Gentleman; knowing how to play the bagpipes, but choosing not to... ;)

    311:

    One of the reasons I went off classical music (as a player) is that some instruments are always transposing. Ridiculous; nobody can write anything involving half the instruments without having to deliberately write the notes in the wrong place.

    312:

    Re: Space-can medicine

    Interesting new medtech. Great for as long as the tech components work. The manufacturer should send one up to the ISS to test its dependability and durability. Because the ISS has recently started growing food plants I'm guessing that there's now a possibility of novel organisms/bacteria showing up. If this device can be programmed to detect viruses, even better because viruses can lurk or go dormant and reactivate under certain conditions.

    http://www.sciencemag.org/news/2018/07/chip-can-quickly-identify-microbes-living-your-body

    'It’s not quite a tricorder from Star Trek, but a new portable laptop-size device can identify dozens of different microbes in your body within hours by speed reading key genetic markers. The test could dramatically improve treatment of infectious diseases and reduce antibiotic resistance by ensuring that doctors prescribe only those medications for which the bugs are vulnerable.'

    Re: Gov't in confined spaces (group dynamics)

    Apart from ISS/astronauts, submarines and the various Antarctic science stations could also be good sources of data wrt examining what types of self-/local gov't/decision-making work best.

    313:

    I have this itchy need to write a superhero story in which our protagonist acquires powers following an unfortunate accident in a CRISPR lab.

    Looking forward to the arch-nemisis episode "Enter the Asshat", in which a supervillain, named for his distinctive weaponized helmet, debilitates victims with emissions of suffocating organic vapor. Mouseman prevails by luring him near a source of open flame.

    314:
    Given the well-known tie-oin between Mats & Music, perhpas that's not suprising (for me)

    Err, being the somewhat mathematically inclined black sheep[1] of a musical family, the connections are there, but can be somewhat overdone.

    https://en.wikipedia.org/wiki/Music_and_mathematics

    (Yes, I know a mathematician's daughter who is quite musically inclined, but then her grandfather was a church musician, AFAIK. And our mathematical faculty has its own choir and orchestra, though it might be more to do with "introvert hobbies")

    There is also a lot of mathamatics in dancing, gymnastics, athletics and sharpshooting, though being able to do complex calculations in your head, often "intuitively" is only tangentially correlated with being able to prove the square root of 2 isn't p/q for any whole numbers p or q.

    As for myself, musical instruments since about 6 years old, 1 hour a day minimum, bad fine motor skills, and at some point it just gets enough, it says something that my first thought with "dom and sub" is still "tonic" and not "BDSM" or "switch". Might be different if my father had stressed composition, but as it is it was just boring repetition. Let's not get into musical sessions being on the same day as physics or chemistry club at school, you could guess what wins...

    As it is, I guess any spaceship is going to involve lots of plumbing? So you could combine doing music (of the percussive kind) and interdeck communication.

    [1] Doing the occasional percussion impromptu on doors and like. Please keep my little secret. Actually that was somewhat before a friend[1a] introduced me to Einstürzende Neubauten[1b]. Sorry for the video, I couldn't find a video of "Fütter mein Ego" with inventive instrumentation... [1a] Incidentally the same one who hosted my first RPG session and tried to get me into PASCAL programming. Yes, the memories... [1b] Err, yes, I guess that's a steel sheet in the background...

    315:

    BTW, another thing is me somewhat tuning off when listening to music; it's not boring, I'm just not wholly there...

    Mainly happens with classical music, but also with other kinds of music. Might be a strange combination of my bad auditory memory and me going into some trancelike state...

    316:

    Social and economic processes are more important and potentially disastrous than we might assume.

    We have innumerable examples of social systems that are at least nominally based on norms that can be upended or 'hacked' by motivated and/or charismatic sociopaths.

    I'm not sure if there ever will be a way to prevent a future generation from producing a certain percentage of sociopaths. There may even be a viable niche for them in some contexts - soldiers are one obvious function if well led, another might be disaster planning.

    That said, a carefully designed authority structure based on skills, ability and merit might become subject to all kinds of unanticipated pressures over the course of a century or two. It might not be obvious who is best qualified to be the next 'captain' of the ship - and we have realtime examples of bad choices by large groups.

    317:

    Presumably a society that can produce an STL expedition to another system will be in a high state of technological development. That is not inherently a stable state - higher technology tends to result in increased specialization and faster rates of change.

    A perfect, state of the art STL ship might leave our solar system with the best understanding of every aspect of social and physical sciences to maximize its chance of success. Presumably they will maintain communication with the home system to stay up to date with new science and developments. (Most SF tends to handwave this by implying or stating that Earth is a ruin).

    At some point, 1, 20, 100 years into the voyage there could be a scientific breakthrough that upends the basis of the whole journey. Maybe a much faster STL technology that means a later departure will arrive before them (I think Alastair Reynolds touched on this). Maybe they get wind or thousands or millions of little seed ships with digital humans being spread across the cosmos at faster rates. Maybe some new energy tech, or some other magitech. 100 years is a long time in technological terms.

    Age of Sail ships tended to function on a combination of strict heirarchy and deep tradition. That was helped by the clear danger of chaos - the ocean is unforgiving - and the fact that sailing technology evolved slowly if at all over time. A similar situation may be needed on a long STL voyage. But technology would not evolve at 18th century rates, on the ship or back at home. There is no reason to assume that technology would be less disruptive to the fabric of an STL ship of the future.

    318:

    Last attempt. The best musicians I knew did not need to read music. Some didn't read music at all. Most could perform a piece many times after just one hearing. Reading music was a side issue.

    And the best concert musicians are so good that it boggles the mind. They tend to be reading 1/2 to full page ahead of what they are playing when first reading a piece. Figuring our fingerings and bow movements (stringed instruments) and such long before they play the notes a few seconds later. So they are effectively multi tasking. I can't even comprehend.

    Music reading is NOT about playing. It is a guide to playing.

    319:

    if all else fails you might CRISPer SRY and other necessary genes for it onto the X chromosomes or some autosomes with some heavy repressors in place.

    Coincidentally, Twitter brought this reproductive WTF moment to my attention yesterday (while I was stuck on the train journey from hell) — Report of Fertility in a Woman with a Predominantly 46,XY Karyotype in a Family with Multiple Disorders of Sexual Development.

    Non-technical TLDR: woman with unusual chromosomal abnormality (XY chromosomes and mosaicism, not paired XX) got pregnant and gave birth — it was only discovered years later because nobody even imagined it was possible. Anstract:

    Context: We report herein a remarkable family in which the mother of a woman with 46,XY complete gonadal dysgenesis was found to have a 46,XY karyotype in peripheral lymphocytes, mosaicism in cultured skin fibroblasts (80% 46,XY and 20% 45,X) and a predominantly 46,XY karyotype in the ovary (93% 46,XY and 6% 45,X). Patients: A 46,XY mother who developed as a normal woman underwent spontaneous puberty, reached menarche, menstruated regularly, experienced two unassisted pregnancies, and gave birth to a 46,XY daughter with complete gonadal dysgenesis. Results: Evaluation of the Y chromosome in the daughter and both parents revealed that the daughter inherited her Y chromosome from her father. Molecular analysis of the genes SOX9, SF1, DMRT1, DMRT3, TSPYL, BPESC1, DHH, WNT4, SRY, and DAX1 revealed normal male coding sequences in both the mother and daughter. An extensive family pedigree across four generations revealed multiple other family members with ambiguous genitalia and infertility in both phenotypic males and females, and the mode of inheritance of the phenotype was strongly suggestive of X-linkage. Conclusions: The range of phenotypes observed in this unique family suggests that there may be transmission of a mutation in a novel sex-determining gene or in a gene that predisposes to chromosomal mosaicism.

    Aside from infuriating the TERFs (who insist that only natural XX-chromosome women can possibly give birth or identify as female: they hate ambiguity), this mostly serves to highlight that the genetic determinants of reproductive sex aren't anything like as clear-cut as anyone imagined.

    320:

    Re: '... not sure if there ever will be a way to prevent a future generation from producing a certain percentage of sociopaths.'

    Produce does not have to mean out of control or socially unproductive. At least two very well known researchers into sociopathy have self tested as high-scoring sociopaths yet have not exhibited the nasty behaviors associated with this trait. (Robert Hare developed the sociopathy test. Can't recall the other's name but he's a neuroscientist who studies brain formations/signalling associated with sociopathy. This guy also identified his own (blinded/unlabeled) scan as definitely belonging to a sociopath. In both these individuals' cases, nurture prevented or tempered nature.)

    I find the 'we can't do anything about X' wailing unsettling. It's the same as 'women have and always will die at childbirth, so what can we do'. How about we continue to try and better understand human psychology at all levels (neuro, personality, socio, etc.) followed by actually putting the knowledge into practice. This includes un-/re-educating people away from thinking that 1984, Brave New World and Freud are legit info sources (they're the psy version/isotope of handwavium) and educating them about the documented connections found between improved nutrition, improved access to basic services (med, education, etc.), reduced stressors, and overall personal and social well-being. It doesn't take a lot of money to do this although it does tend to divert a lot of money away from certain org$. (See Denmark vs. US.)

    Any good public education system that already teaches kids about their bodies (sex ed, nutrition, hygiene, etc.), should also be okay with teaching kids about their minds.

    321:

    Its like they didn't even bother to read what they wrote.

    Even bothering to read what you've written often fails to catch such things, because you know what should be there and therefore that's what you see. Hence the desperate need for good editors; fortunately my wife is such, and when I've written anything at all tricky I make sure to ask her to read it over.

    322:

    Presumably a society that can produce an STL expedition to another system will be in a high state of technological development.

    Yes, like noticeably beyond Kardashev Type I, headed briskly toward Type II. Either that or a Type I/I+ society that, for whatever reason, has decided to devote most of its resources to the expedition. The OP is right -- STL starflight involving meatbags but without magic technology is at best a matter for the far distant future.

    323:

    Because we're past comment 300, here's the train journey from hell (aka why Charlie ain't blogging today, aka a horror story for Greg):

    So, yesterday I made a day trip from Edinburgh to Leeds on an open off-peak rail ticket, valid on any service after 9:30am.

    Getting down there went smoothly: 1005 departure from EDI on the CrossCountry from Aberdeen to Penzance (on a 7-car InterCity 125 rather than a 4-car Voyager: it's peak season), arrived Leeds at 1310. (It's a 3h5m journey.)

    Coming back after 5 hours of hospital visiting was another matter ...

    I originally reserved a seat on the 1910 CrossCountry from Leeds up to Edinburgh (actually a returning Penzance train). But I got to the station around 1810, just too late to catch the 1808 CrossCountry. So I thought I'd be clever and hopped on the Trans-Pennine service to Scarborough, and changed at York, catching the East Coast Main Line to Edinburgh at 1835. It's a more comfortable train (especially with an at-seat first class upgrade: free wifi and tea and snacks, bigger seats, fewer drunken oiks — it being a Saturday night) and should have reached Edinburgh around 9pm.

    Well, things were okay until we reached Durham, where a bunch of happy drunks returning from a day excursion to their homes in Newcastle filled up first class. Durham to Newcastle is normally a 13 hour sector, though, so no biggie — the drunks use it as a local stopping service but clear out at Newcastle or Morpeth leaving it mostly empty for the last 1h30m to Edinburgh.

    Only, just after passing a local station about 5 miles outside Newcastle (Fenton-le-Street, I think?) the train hit someone on the track — messily, at high speed.

    And that last five miles took 3 hours.

    First, the train stops. Then they wait for an ambulance and the British Transport Police to show up. The police have to secure the fatal accident site, and then someone has to pick up the pieces. The driver (US: engineer) isn't in any state to continue so they need to get a replacement driver out to take over, and they have to check the train for damage. In this case, the impact damaged the brake lines and coupling at the front of the train, so after the cleanup temporary running repairs had to be made.

    Finally, the train limped into Newcastle and was taken out of service at 11pm, and the day-trippers (who had maintained their insobriety for the past three hours) went away.

    Anyway, those of us who were still travelling transferred to the train that had been jammed behind us — the accident shut down the northbound leg of the East Coast Main Line for three hours — which at this point was rammed solid with annoyed, overdue passengers. I was lucky enough to get a seat, and as we moved north things gradually came under control, with an ETA in Edinburgh of 12:30am. LNER was laying on taxis at Waverley for travellers who had tickets through to other destinations: information on claiming a refund was made available. So far so good.

    But as we neared Dunbar — the last stop before Edinburgh, a small seaside town about 20 miles south-east — the train slowed again. And slowed some more, until it was creeping forward, and finally halted. We waited and waited and around 1:15am there was an announcement: "due to damage north of Dunbar, we have to back up and wait for engineers to repair the overhead lines." (I'm guessing it was a tension problem rather than the lines coming down completely, otherwise the service would have terminated then and there.)

    So we reversed back a few miles and waited. And waited some more.

    About 45 minutes after we stopped the lines were fixed, and we were cleared to proceed to Dunbar. At which point ... we stopped. It turns out that the driver had just put in a straight 14 hours in the cab and was unsafe to continue (hint: they're responsible for 500-odd passengers' safety, first and foremost). The doors were opened and some passengers tried to bail and catch taxis — but Dunbar is a small town (population 8-9,000) and you can imagine how many taxis are available at 2:30am on a Sunday.

    Further announcements: a new driver was being sent from Edinburgh to take over the train. Rumours of coaches as a back-up option surfaced: a coach arrived in the station car park, but just a single coach with 40 seats. It'd take 4-6 round trips to move the entire train-load to Edinburgh (at 30-40 minutes each way, so 90 minutes per round trip), so the conductor — passenger service manager, rather — said they were going to try and get the train moving again in preference, but if anyone wanted to leave and claim their taxi fare back later, they could.

    So ... finally, at 3:34am the train began moving again. And took a further 30 minutes to make it to Waverley, probably because it was crawling until it cleared the segment of damaged overhead power lines.

    I finally got off the train at 4:10am (about seven hours later than planned, on a 3 hour journey) and made it to my front door by 4:25am, as the sky was brightening towards dawn. And today I am jet-lagged to fuck and back.

    So there you go: one fatal accident (probably a suicide, going by the lack of press coverage the day after) and damaged overhead cables. How's that for a bad train journey? At least it didn't involve a derailment ...!

    324:

    Many of us enjoy the physical instruments.

    No, I got that. The trouble is, the technology that goes into building instruments isn't that simple, when you look into the supply chains for materials. Consider your traditional piano keys "ebony and ivory" — even replacing ivory with something less questionable, ebony is a dense black tropical hardwood: you're going to need something else. Guitars? The woodwork that goes into them is specialized, and furthermore, implies a supply of mature trees to harvest. About the only categories I can think of that don't require exotic materials (at least, exotic if you're living in a tin can) are percussion and brass, plus those woodwind instruments that are predominantly metal (flutes, saxophones, etc).

    Unless your generation ship is huge, you're probably going to be shipping only bonsai trees. Or trying to invent new categories of musical instrument that leverage the available technologies and materials (like Bjork's bespoke Biophilia instruments).

    325:

    No planet = NO GO. You don't start out until you have adequate confirmation a viable earth like planet exists in the target system.

    Oh, we can do better. There are design studies out there for long-baseline interferometry telescopes that can be built with JWST-level tech (i.e. last decade) and, if positioned far enough out (asteroid belt or further) to avoid light pollution should be able to resolve the outlines of continents on terrestrial planets within 100 light years. Just one catch: we're looking at the equivalent of placing multiple JSWT-sized multi-mirror assemblies several AU out. This would be astronomically expensive using current launch systems, but if SpaceX succeed in making BFR work, the price of the launches would be down into single-digit billions or less by 2030.

    If we can pick out continents we can do spectrographic analysis on the atmosphere, for sure. We can get some climatological data, and also some idea of large-scale weather events. And this is not merely possible but probable by 2050, and without sending out interstellar probes first.

    326:

    Pusa's radius is 5,143 km - much smaller than Venus, which we will probably be mining for raw materials. We want Pusa's surface gravity to be identical to Earth's, so it's going to have a greater average density than Earth. This will keep a good atmosphere in place - important for the health of the inhabitants - without having to worry about hull components. Gravity does all the atmosphere-retention work.

    Pusa has a volume of 570 x 10^9 km^3. Earth has a volume of roughly 1100 x 10^9 km^3. So to have the same mass you need roughly double the density of material. (I suspect the surface gravity of the same-sized mass at a distance of 5143km is going to be much the same as at 6371km.)

    Unfortunately Earth has a mean density of 5.5 g/cm^3. Practical materials — let's stick to tungsten, it gets silly if we go as far as osmium and then the actinide series — has a density of 19.3 g/cm^3 (it sinks like a stone in liquid mercury), which means we can cram in about four times the mass per unit volume if we use solid tungsten instead of rubble to make Pusa. More realistically, molten lead has a density of 10.66 g/cm^3 at stp and around 11g/cm^3 when solid. So Pusa needs to be a thin skin of earthlike crust over a core of ... something like lead, or maybe a mantle of iron around a sphere of tungsten.

    And now all we have to worry about is accelerating an Earth-mass bullet to relativistic speed!

    Frankly, if we've got the magitech to make Pusa in the first place, we'd do better to take my hare-brained scheme from the latter part of "Accelerando" and pave Saturn with hydrogen lift-gas balonets supporting habitable surface area. Roughly 1g surface gravity, but 83 Earth's worth of surface area! What's not to like?

    327:

    Guitars? The woodwork that goes into them is specialized, and furthermore, implies a supply of mature trees to harvest.

    Well, you can build an electric guitar out of non-wood materials, and I think Ovation had at least mostly-plastic acoustic guitars, too. I'm not sure how these sound, I haven't played any of them.

    With music, I dabble with acoustic and electric guitars, and analog and digital synths. There are different things they all are nice for.

    I'm even less sure about other instruments, though.

    328:

    Re: Ban radioactive food in the space-can

    Bananas are radioactive because of the potassium-40 in them: 40K is present at about 0.012% abundance compared to (stable) 41K, and just about everything biological runs on Na/K exchange pumps at some point.

    The solution is to provide our ship with a supply of relatively pure 39-K 41-K, or a mechanism for sequestrating 40-K to get it out of the life support system. Bananas aren't a particular problem compared to the potassium in, well, everything we eat.

    329:

    long-baseline interferometry telescopes

    Back in, I guess, the 1990s when such things were being discussed on sci.space.something, the objection was raised that optical inhomogeneities in the interplanetary/interstellar medium would introduce phase uncertainties that would mess up the interferometery. At time, I suspected that the objection was bogus, being put forth by somebody who didn't like the idea and came up with a sciency-sounding pseudoreason why it couldn't work.

    But do we have any reasonably current reviews of the idea? I.e., distributed telescopes spanning several AU?

    330:

    The solution is to provide our ship with a supply of relatively pure 39-K 41-K, or a mechanism for sequestrating 40-K to get it out of the life support system.

    As just noted, a civilization that can build generation STL starships is already northward of Kardashev I. Building ginormous isotope separation facilities, likely in space, as part of the program kind of fits into the overall picture.

    Now that the subject has come up, it wouldn't be totally surprising if the civilization already had such facilities built for other purposes, like producing pure 12C and 13C.

    331:

    Boggle. The fact that she was female, despite the fact that her genotype was mostly XY, means the Y was inactive and she was similar to a Turner's syndrome (who can get pregnant). But it's still a new level of boggleworthy! Truly, the more we discover, the less we understand.

    332:

    The way I see sexual attraction causing problems is through its extreme potency at inciting highly irrational behaviour and long-term unresolvable conflicts and resentment.

    Yes, entirely correct. It's reinforced by our low level reward feedback mechanism — I'm pretty sure that gambling and substance addiction also plug into the same system at a low level.

    Trouble is, sexual attraction (and appetites for food and getting off your face on substances) have been selected for over pretty much the whole of multicellular eukaryotic existence because it's a core survival drive. We mess that shit up at our greatest collective peril! It may be useful to temporarily damp it if we're living in inappropriate environments, but most of our social arrangements are built on top of it and we risk pulling the foundations out from underneath most of our starship crews' will to keep on going.

    (I'm also going to go with "homosexual behaviour is conserved by evolutionary selection pressure and we shouldn't try to weed that out, either"; pretty much all vertebrates we've studied so far exhibit homosexual activity as well as heterosexual, and I'm pretty sure it's a side effect of anysexual attraction at all being hereditably determined. Put it another way: both male and female nervous systems are expressed from pretty much the same genome, and there's some fuzziness to CNS development, so it should be no surprise that sometimes they come out cross-trained; I hypothesize that trying to weed out male-male sexual attraction would also select out female-male attraction, and weeding out female-female attraction would weed out male-female attraction. They're just too closely associated, and meanwhile there's some evidence of better long-term reproductive outcomes for children of parents with homosexual siblings ...)

    333:

    Is there, just? The results I have seen are some behavioural and statistical modelling that indicate a level of homosexuality can be advantageous in a social species. But I see the tricky aspect being the link with dynamism and aggression, at least in males. We need to keep the former but the latter is a real nuisance.

    334:

    David L @ 318 YOU HAVE MISSED THE WHOLE POINT OF MY POST Yes, I agree with everyting you say ... so? You have to start somewhere & for me & a lot of people, understanding the undelying theories is vitally important. IF you get good enough, you can discard the intermediate stages - I've seen the late Carlos Kleiber conduct an entire opera ( Verdi's "Otello" I think ) from memory, without using the score. And your supposed point was?

    335:

    a bunch of happy drunks returning from a day excursion to their homes in Newcastle Oh dear … been there, done that – I was southbound & the same lot got on at Durham heading sarf … Oh a “jumper” – there is absolutely noting you can do about that given modern @efl’n-safety regs. [ Rather than getting a couple of buckets of water & carrying on ] { “oh but think of the poor relatives” & other trash-sayings … }

    Mind you, after a similar journey, I got to watch sunrise over Watford Junction – followed by a taxi home one Sunday morning, only over 12 hours late …..

    336:

    So, I guess the conclusion is that the easy way for interstellar travel involves learning enough organic engineering that man/machine is a spectrum? Basically, interstellar travel is largely posthuman. No, or very little, new physics - just a ton of engineering work...

    337:
    I'm not suggesting that "aging" is a bunch of prion diseases. But there may be multiple comorbidities that only cut in late in the game, some of which have really twisty hereditable mechanisms (e.g. epigenetic modulation of immune system traits) and some of which may have genetic origins.

    There was an interesting post on 'in the pipeline' recently, talking about a possible infection basis for alzheimer's in the form of a couple of strains of herpes viruses. Doing a little more investigation into the viruses in question (HHV-6A, HHV-7) shows that they have also been linked to some other kinds of chronic neurological illness as well, such as multiple sclerosis. Whilst they're apparently not great targets for vaccination (as they don't provoke a nice strong immune response) they are vulnerable to a number of modern antivirals.

    Multiscale Analysis of Independent Alzheimer’s Cohorts Finds Disruption of Molecular, Genetic, and Clinical Networks by Human Herpesvirus

    with the upper limit on safe childbearing age raised to 60 or 70 — which would have really major sociological effects

    Safe childbearing is a fuzzy sort of notion. A quick survey of a small number of mothers I know who had children in their mid to late thirties revealed that they'd probably all have died in the absense of nice modern medicine, and they all have ongoing health issues, especially muscle and joint ones.

    The question isn't just, 'can you pop out a functional person at age X', but 'can you pop out a person at age X and then fully physically recover'. They all felt they'd have been in much better shape if they'd got the whole ghastly business of childbearing over in their 20s when they were much more physically resilient, for what that's worth. I don't know if their experience generalises.

    338:

    Why bother?

    Just Because.

    I am quite serious. I am very leery of any solution to Fermi's Paradox which involves "Nobody would do THIS!" -- whatever "this" is. Human history repeatedly demonstrates that if something is possible at all, somebody, somewhere will do it, no matter how silly, dangerous or frivolous. And self-replicating space probes are not even all that frivolous; there are pretty sound reasons to develop them for the use within Solar System -- to minimize the use of fragile meatbags, if nothing else. And once you have such devices, the imperative to send them to another star is exactly the same as the imperative we have now for sending probes to outer planets -- scientific curiosity, pride, adventure by proxy. In fact, once it sinks into collective consciousness that canned apes will not travel to other stars, ever, I can see a lot of people investing their identity in such probes. Heck, some people do it already: https://www.goodreads.com/book/show/648195.Mind_Children

    339:

    My mother was 41 when I was born in ... 1946

    340:

    Our firstborn arrived when my wife was 38; second at 40. The medics agreed that it's easier in your 20s, but it's far from impossible.

    A full physical recovery followed... to the extent that we're both learning Judo in our 50s (yesterday we were paired with each other; for a new strangle technique, and the post-session "Interval Training").

    341:

    You keep talking professional instruments. I am saying that people will build "good enough" to enjoy and be done with it. Heck you can have a lot of fun with kazoos if you're not a snob about it.

    Did you read my link on the garbage instruments?

    342:

    And your supposed point was?

    You keep saying if you'd been taught to read music you likely would have learned to play.

    My experience as a fairly well above average musician but no where near good enough to be pro or semi-pro says not. Plus all of my observations of people who can play something very well but don't read music.

    Maybe you are the 1 in 1,000,000 but those are long odds.

    343:

    They all felt they'd have been in much better shape if they'd got the whole ghastly business of childbearing over in their 20s when they were much more physically resilient, for what that's worth. I don't know if their experience generalises.

    It's not so much the 9 months as the next 5 to 10 years. All nighters as much easier to deal with in your 20s than in your mid to late 30s. Especially since you usually have to be awake the next day also. Those pesky toddlers don't have a hold button that I ever found.

    Say he with the later experience. But since we were both over 30 when we met having our children in our 20s was not really an option.

    344:

    "Sadly, it looks like blasting your way between the stars the hard way requires magical technology too, just as FTL does."

    As in "any sufficiently advanced technology is indistinguishable from magic." But our understanding of physics is good enough that we can distinguish technology from magic, at least when it comes to STL and FTL. FTL is magic and probably always will be. STL is just really hard and probably centuries away.

    345:

    When I was taught French in school the first two years were purely oral, because that's how children learn. Later on I had to unlearn all the spellings I'd invented to take notes because I couldn't remember words just by hearing them. Fortunately my later French teachers realized that I needed to learn things like grammar explicitly — I wasn't going to figure it out on my own — and I actually managed to pass my final-year French class with a B*.

    When I took art in school it was all 'draw what you see' with it being assumed that techniques etc would be picked up as we drew. When I learned perspective in drafting it was an eye-opener — that drafting class taught me more about art than the art classes did.

    One of my childhood friends too dancing classes with her husband. She says they had to learn how to hear the beat in the music before they could dance — somehow neither of them could just 'pick it out' before they started the dance classes. (And once they learned that dancing was a lot easier!)

    What I'm trying to get at here is that some people can figure things out by observation, and others require (or at least benefit from) explicit instruction. Some people need hands-on first before they learn theory, others benefit from the theory first to make the hands-on part make sense.

    *Conventional wisdom at the time, anyway.

    **Even though it was my lowest mark I did more homework in French than all my other classes combined.

    346:

    the technology that goes into building instruments isn't that simple, when you look into the supply chains for materials.

    Instead of looking back into history and wondering how a spaceship is going to mine bronze, it might help to look at the weird stuff that is happening now that any monkey can buy a 3D printer or 5-axis CNC mill. You can "lost wax" cast using 3D printed plastic as your lost material, or you can mill out quite complex shapes (or both), and get disturbingly high precision. Or you can mill down foam and make a mold for laying up composites.

    I say this because a friend who builds HPVs got interested in hillbilly blues, discovered that a decent double bass is expensive and decided to build his own. Shockingly it was both easier than expected and sounded better.

    Now, in economic terms that's all a giant pile of irrelevancy. Using only $AU20,000 of CAD-CAM software, $250,000+ of equipment and a lifetime of experience, he could make a decent composite double bass in maybe 100 hours work. The second one took 20 hours. But that makes buying a $20,000 one that someone else made seem cheap. The fiddle he made... he only made one before he decided that he should go back to his day job because there's no money in music.

    But, if you have a spaceship that has any composite material production at all, it's very likely going to be capable of making the same side-step and cranking out musical instruments. Making them is not hard, what makes a Stradivarius expensive is that they stopped making them 400 years ago so the supply is limited - you're mixing the worst of art collecting with audiophile-grade wankery. Double blind testing suggests that just as women can play instruments, more expensive instruments are not uniformly better than cheap[1], contemporary ones.

    [1] in the context of $US30M for a violin, that is. A 2020 model grand piano starts at $150,000 (order now and you might get it in 2020... there's a waiting list).

    347:

    What about the legal system? Is there private property, private law, common law?

    If I was going to pick a starting point for organising a starship I'd be looking at systems we know can last long enough to be useful, rather than on bleeding-edge developments that we know are not stable even in the short term.

    I'm reading The biggest estate on earth: how Aborigines made Australia because someone here recommended it. One theme of the book is that Australian social structures appear to be stable, resilient and flexible over fairly long periods. Long in the context of generation ships, rather than in the context of quarterly profit reports or triennial elections.

    The system used was, sadly, vulnerable to invaders with radically different technology and culture. But I don't know of any system that isn't (imagine someone dropped a few thousand of the creatures from "Aliens" into the USA and killed anyone who harmed one... I don't think the USA would last long).

    Viz, Dreaming rather than democracy and written laws, let alone brain farts like capitalism and the UNCHR.

    348:

    Even though it was my lowest mark I did more homework in French than all my other classes combined.

    Isn't that normal? Both in the "more work on things you're worse at, so you don't fail" common sense approach, but also because you're inclined to spend mroe time on interest papers?

    I took "technical drawing" and geography at high school despite them not being usual subjects for STEM-stream kids like me (and over the objections of some people). Both I struggled with and spent way more time on than my other subjects. At university I did much the same, ending up with half a BA by the time I finished me ME. In "Feminist Studies", which is... not like engineering :)

    Most blatantly, in my first year I forgot a mid-year maths exam and only barely made it in before they shut the doors (and obviously without studying at all). So I only got a B+ in that exam. By contrast the B I got in my first feminist studies paper took a great deal more effort than any other paper I did that year.

    349:

    Cave-divers don't spend many hours cave-diving.

    350:

    More work for what you need to work at, but I was only taking it because my parents didn't let me drop it. I'd much rather have taken another history class…

    351:

    It's even more mindboggling; XY women are known, a defect in SRY is one explanation:

    https://en.wikipedia.org/wiki/XY_gonadal_dysgenesis#Swyer_syndrome_as_a_form_of_%22pure_gonadal_dysgenesis%22

    But it's not that simple; the daughter got her Y chromosome from her father, so it seems like everything was most likely OK with that one; there might be a de novo mutation, but the usual suspects were quite normal. And that wouldn't explain the mother, who showed some mosaicism, but 93% XY in the ovary screams "Y chromosome not working here either" at me.

    Whatever is going on most likely is not on the different Y chromosomes of mother and daughter; and mother and daughter being affected seems to exclude some autosomal recessive gene, it most likely means it's either autosomal dominant or x-linked recessive, if it's autosomal recessive both parents must be carriers, which seems somewhat improbable excluding consanguinity.

    My guess would be X-linked recessive, autosomal dominant is somewhat rare, and a few of the examples wiki gives are not "true" dominant, AFAIR PKD and NF-1 involve de novo mutations in cells inactivating the active allele, leading to homozygosity in some cells which give rise to the cysts and tumors.

    Maybe it's some mutation in a binding motif for SRY, but it's bound to be interesting.

    (As for my original idea)

    In other news, just ground up some chilli pepper and put it into oil; I get better, this time I used latex gloves, so no post-capsaicin paresthesia for the next week. Guess I'll use a mask next time, my sinuses feel like I tried some Honk; and there is nothing like taking a shower at 2:30 AM because you got some capsaicin on your skin and it starts to burn...

    Makes you appreciate some other nasties, e.g. the organophosphates or Ricin. And to think about TRPV! agonists more potent than capsaicin...

    352:

    Err, plain "sexual attraction" might be a misnomer for what you have in mind, "eros" might be better.

    It might differ between persons somewhat, hypertrophied pair bonding and imprinting would be one extreme, casual promiscuous sex the other.

    Let's just say there are quite a few people I think sexually attractive to but don't find myself in the 2nd Circle of Dante's Inferno. If they developed some geeky hobbies, maybe...

    353:

    It seems possible to channel sexual attraction is less harmful directions than we do, just as it's possible to channel antisocial and prosocial impulses. If you persuade the antisocial to become explorers or hermit rather than incels I suspect society might do better. "grumpy old person" is also a career choice that can be very rewarding or immediately fatal, depending on whether your society values wisdom or not. The evidence suggests that the latter option is... I was going to say "unwise" but that's tautological... transient, perhaps.

    I'm reminded of the surveys that say "95% of people thought pre-marital sex was always wrong, and 90% of people had had pre-marital sex" (US numbers, but it's mostly the former that varies between cultures). Now we also have genetic studies that show exomarital conception is less rare than supposed in monogamous couples.

    There's also the whole 1960's free love and yadda yadda, which somewhat reinforce that what matters isn't the nuclear family, it's the tribe/village/commune or whatever you use to organise the 10-50 people you interact with every day.

    354:

    ... long comment about non-nuclear family structures lost to the timeout gnomes.

    In short: nuclear families are a temporary aberration that is strongly enforced but not technically outlawed in many "liberal" countries. In Australia the sanctions range from denial of home insurance (typically for having more than 3 non-related residents) to children being imprisoned (more common with aboriginal children, because of course it is).

    I know way too much about this because I'm in such a family. Last time I lived in a nuclear family was when I was 14 or 15. It is not fun, and the "marriage equality" debate here was distressing and infuriating in turns because the only mention of us was "never mention that, stay in the closet until after we get same-sex marriage". Fuck you very much for your concern, liberals, keep on lumping us in with the paedophiles and sex cults, we're used to it.

    But yeah, in a space ship I expect we'd see more traditional family structures dominate. Couples (ish) would raise kids in a group of 5-20 close friends/neighbours within a larger community of 50-200 villagers. The idea of "my kid. Mine! No-one else touch!" is just fscking weird and bad.

    355:

    In Australia the sanctions range from denial of home insurance (typically for having more than 3 non-related residents)

    We (my partner and I) lived as part of a commune-type arrangement for some years. Our home insurance was from the one company here which provided common insurance for two married couples living in the same apartment - the others wouldn't hear of it.

    This was fifteen years ago, so I don't know the situation now. At least there is the occasional polyamoury story in the media, so I think the idea of something else than the nuclear family is slowly spreading. Even the common thing of having separated parents with equal responsibility for the children is difficult here as the kids can't have more than one address on record. This seems to be changing, but it's about bureaucracy (and the software being used).

    356:

    Moz @ 354 Yes, well ... didn't Heinlein use this in "The Moon is a Harsh Mistress"? And also used it to ridicule the US insistence on "heterosexual only-couples-only" mindset?

    357:
    My mother was 41 when I was born in ... 1946

    And nowadays there are 70+ year old mothers on record. That's not really relevant, though, because my point wasn't that 'older mothers don't exist', it was 'older mothers appear to have more difficulty recovering from childbirth'.

    Was she physically active before giving birth to you? How about after? If she suffered from serious joint or nerve issues, would you have known? I'd ask about full time work too, but that's a more complex situation for women in the 40s and 50s so it isn't really a useful thing to compare.

    358:

    There is also evidence that children of older parents (and it's both of them, not just the mothers) tend to have more medical problems. It's not a major factor, but might be an issue on a starship.

    359:

    Heinlein used various group marriages a lot, it's relatively common in SF at least compared to most fiction. But a lot of the arrangements depicted are at least as problematic as those in the Koran. Heinlein was big on "everyone loves everyone else" but they all obeyed the patriarch or died horribly.

    Mikko, in Australia share housing is really common but really uninsurable - most landlord insurance doesn't cover more than 3, so a lot of leases explicitly forbid that... you rent a four or five bedroom house and "no more than three unrelated adults may occupy the house". The local tenants union tries to organise but it's very hard because of course no law-maker is in that position other than as a landlord. What 'everyone' does is just to ignore that restriction and hope for the best, and insurance companies generally don't enforce it. It's a bit ugly.

    http://crookedtimber.org/2015/07/08/polygamy-and-polyamory/ has a discussion of the topic featuring me trying to discuss things reasonably with some sort-of-polite people. Focused more on family structure rather than the "insure our home" question if you find that one topic boring :)

    360:
    There is also evidence that children of older parents (and it's both of them, not just the mothers) tend to have more medical problems.

    Part of this is due to older gametes being less fit for purpose; to some extent, you could avoid the issue by storing a supply of the appropriate cells in your youth for later use. This might be desirable on a starship anyway, as shielding a little tub of frozen gloop is much easier than shielding an entire living volume, etc etc.

    I don't think anyone has a good handle on how long frozen eggs or sperm or zygotes can remain viable, and whether there are any developmental issues that can result from old frozen ingredients, but even being able to keep some for 20 years for later pregnancy can still be worthwhile.

    361:

    You can "lost wax" cast using 3D printed plastic as your lost material,

    One thing on an FTL/STL ship is you have to maybe abandon processes that make use of the earth and it's atmosphere as a sink for unwanted chemicals (even at trace levels) and heat.

    362:

    One thing on an FTL/STL ship is you have to maybe abandon processes that make use of the earth and it's atmosphere

    ... And gravity.

    An STL ship, especially a generation ship, is vanishingly unlikely to be under continuous acceleration at >0.01g for any significant portion of its flight time: the energy/reaction mass requirements don't permit it unless we allow for magic-wand-tech like perfect mirrors, perfectly efficient thermal radiators, and easy storage of bulk anti-matter.

    On the other hand, some tech turns out to be easier on board a deep space vehicle. Microlithography for producing modern high density integrated circuits requires very high vacuum, dust-and-particle-free environments which mean gigantic clean rooms with insanely expensive filtration systems here on Earth. Whereas on board a non-relativistic spaceship you can just hang a wake shield over the side of the ship. (Note: Only been tried once, on the ISS, first prototype attempt worked but was less efficient than predicted, some development work required to optimize it.)

    I'm guessing that this means home-producing high end semiconductors aboard a starship will be a lot cheaper than doing so in a gravity well, just as other fabrications (making a violin the traditional way, out of wood) may be much harder.

    363:

    Getting rid of heat isn't a problem in normal space - you have a 4 degree Kelvin heat sink to radiate into!

    364:

    I've been taking it as a given throughout that the ship will have gravity, of the accelerative variety where the acceleration is towards the ship's own axis of rotation. The problems of not doing that - in particular those of keeping the occupants healthy for a lifetime in zero gravity, but it tends to make everything a pain in the arse to some extent, particularly where liquids or small solids are involved - seem to me so numerous and so intractable (since we have so little clue about the biological ones and so much difficulty experimenting) that it's not worth thinking about trying, even if it does make fire protection easier.

    There are still problems if you do do it, of course, but they are all in the realm of Newtonian mechanics, which is one thing we do know plenty about.

    ...In which regard I suspect Frank's OP overstates some of the difficulties. Gyroscopes are awkward to handle on Earth because it's really hard to avoid unintentionally exchanging angular momentum with the planet. But a spaceship can't exchange angular momentum with anything; all it can do is alter how it is distributed between the mass of the spaceship itself and the mass of the system comprising the ship plus its expelled reaction mass. As long as the velocity vector of the expelled mass passes through the centre of mass of the spaceship, you're producing only pure translation and don't get gyro effects; being able to adjust the angle of the thrust vector is fundamental to having any kind of thrust mechanism, so you've already got the equipment, and with the kind of very small thrusts we are considering because of the impracticality of producing large ones plus the very large mass of such a capacious ship, everything happens really slowly and you've got plenty of time to make the necessary adjustments.

    365:

    "Oh come on. This is a post about slower than light interstellar colonisation. Making non-radioactive food is absolutely trivial by comparison."

    Well, yes, any of the individual problems with particular aspects of interstellar colonisation are trivial compared to the aggregate of all of them...

    "Why? You need your freezers to be nonradioactive, and you need enough shielding around them to keep out as much stray radiation as possible. but the rest of the ship can be made out of whatever you like"

    I was setting up a rhetorical point to knock down myself later when I said even if you can do all this stuff it's pointless.

    "What does this have to do with food?"

    It is to show that the concern over food isn't actually worthwhile.

    "Now, those particles deposit their energy in a fairly well collimated cone, rather than evenly irradiating the entire body frorm the inside continuously."

    Integrate a few centuries of well-collimated cones with their axes pointing in all directions... And the secondary emissions resulting from that deposited energy are isotropic to begin with.

    What I'm getting at is that all the effort of making the whole caboodle non-radioactive, even if you can do it, ends up being a bit daft when you then spend centuries in an environment containing plenty of particles at stupidly high energies which you simply can't shield out, and which cause sufficiently energetic reactions that you have to go a few stages down the chain before that stops being the case. Basically, you're going to pick up a dose no matter what you do.

    366:

    I am reminded of the time the cleaners at Old Oak found a lady's leg in the tender, said lady having been distributed over all four tracks at Goring by a preceding working. All the disruption that would have resulted these days wouldn't have made her any less dead.

    367:
    It is to show that the concern over food isn't actually worthwhile.

    Well, no. It merely suggests that it is insufficient in an of itself, and no-one was claiming otherwise.

    Basically, you're going to pick up a dose no matter what you do.

    Sure. But if it is possible to freeze and thaw someone, then storing them for extended periods will require thinking about the internal radioactivity issue. Once they have been frozen, they then occupy a much smaller and more easily shielded space than an entire person-filled habitat. Shielding against GCRs is obviously extremely hard, but reducing them is not impossible. The degree to which they can be reduced then dictates your journey times. You might not make it to trappist-1 at .1c, but that's not to say there aren't other places that might be worth visiting.

    368:

    "it should be no surprise that sometimes they come out cross-trained"

    It most certainly isn't after living in a colony of pigeons and watching the training happen. It tends to start off responding to all sorts of inappropriate targets before settling on actual pigeons, and still does not necessarily settle on pigeons of the opposite sex (and of a different family). The basic cues that trigger the response are pretty generic - a particular degree of convex curvature, for instance - and it takes a while for the fine tuning to start requiring more specifically pigeon cues as well so they don't assume that just because part of the padded arm of a chair has that particular curvature it must be fuckable.

    Furthermore, genetically female juveniles frequently display typically male behaviours when the hormones first start to hit, and genetic males displaying typically female behaviour also happens. Sometimes they carry on like this for their lifetimes.

    369:

    Getting rid of heat isn't a problem in normal space - you have a 4 degree Kelvin heat sink to radiate into!

    Emphasis on radiate. Space is full of, well, vacuum: there's no conduction or convection, and vacuum is a bloody good insulator. Yes, black body radiation will let you shed heat eventually, but from 300K (human biosphere) to 2.7K isn't that great: you really want your radiators to be much hotter.

    370:

    Pigeon @ 284:

    “AND the fucking school system doesn't teach music ( as in simple theory & READING it ) to everyone - WHY NOT?”

    "When I was little some bod got everyone in the class to try blowing down a loose oboe reed (ie. not attached to the oboe) and I was the only one who could get any sound out of it. (So I am told; I have no memory of the incident, only of what came of it.) From this result the bod concluded that I must be a genius-level concert oboeist in embryo and just needed hatching out to take the musical world by storm. I suppose my extreme youth excuses my having believed this fucking stupid statement; I'm not sure what excuses my parents having believed it, but they did, and so I got Oboe Lessons inflicted on me.
    Well I was crap at it and it was dead boring and I hated it, and eventually managed to get them to stop, although only by replacing it with Piano Lessons. I wasn't quite so crap at that because the physical aspect of playing it was a fair bit easier, but I still struggled, and the main reason I struggled was that I could never properly read the bloody music. Because I was never taught how, beyond the basic FACE/EGBDF (I still don't know what the sequences are for the bass clef). It was just assumed that I knew, but what I was actually doing was consciously deciphering it from first principles in real time, and I never got to the point of knowing what it meant without conscious thought just by looking at it."


    That's interesting, because where I went to school, the school system offered "band" classes starting in the 4th grade of elementary school. A few chose not to participate, but it was on offer to all students, and the classes did teach you to read standard musical notation. I can't understand how they could teach it any other way.

    After the first year a lot of the students dropped out of band, usually because the school system only subsidized the cost of the instruments for the first year. That's why I no longer play cello. My parents wouldn't pay for the instrument and after the first year the system didn't have an orchestra teacher, so I would have had to take private lessons outside of the school system. If your instrument could be played in a marching band, the school offered free continuing instruction.

    The bass clef (reading from the bottom up) Good Boys Do Fine Always & All Cows Eat Grass
    -- Always ------
              Grass
    -- Fine --------
              Eat
    -- Do ----------
              Cows
    -- Boys --------
              All
    -- Good --------


    "As for the physical vs. virtual instruments thing, that surely depends a lot on the person concerned and also the kind of physical instrument. I got on physically much better with the piano than with the oboe. I've handled a variety of electric guitars (in the context of signal sources for testing guitar amps) and they all felt really alien and weird, with the exception of a Strat which felt completely natural and lovely and actually made me want to take it home with me. I've no idea what the difference was, but it does seem that whatever makes an instrument feel good is very subtle and very personal.
    Anyway, I am very sure that any sizeable bunch of people left without any musical instruments are going to make their own out of any pieces of junk that can form an acoustic resonator. So many random things respond when you blow or twang them that it'd be impossible not to."

    Thing is, you can have both physical instruments and virtual instruments. You don't have to choose one or the other. Use either as best suits your need to make music.

    371:

    It's not so much the 9 months as the next 5 to 10 years. All nighters as much easier to deal with in your 20s than in your mid to late 30s.

    On the bright side, we felt more stable about dealing with emotional issues (and emergencies) having had a decade and a half more adult life experience.

    Regarding the broken sleep thing, I never expected that twenty years of dressing in green, and associated training exercises, would have its primary benefit in early-years childcare. Namely, the ability to catnap, survive on a couple of hours' sleep, cope with totally disrupted sleep patterns, and be accustomed to someone elbow you at 2am to say "your turn to be awake"...

    ...I once managed to combine the two activities; bad traffic on the M8 leaving me with a toddler to care for, a lesson to deliver on a training night, and a wife stuck near Glasgow. No-one said I couldn't deliver the lesson with a one-year-old on my shoulder...

    372:

    Post-300 tangent: apparently, starting on August 1st, it will be legal in the USA to produce DIY 3D printed firearms in the USA.

    https://www.theguardian.com/us-news/2018/jul/23/3d-printed-guns-court-settlement-trump-administration-cody-wilson

    This is horrific, to say the least. Made even more horrific since the big city closest to me (Toronto) had a mass-shooting last night.

    Huzzah for the Land of the Brave and the Home of the 'homicidal impulses should not be checked at all ever'.

    373:

    Yes, about 450 watts per square metre. Humans generate about 125 watts when being normally active, and let's assume the life support is 1% efficient (pretty optimistic, but not beyond sanity) - that's 35 square metres per person. Plus whatever is needed for engineering, propulsion etc., which might be at very different temperatures.

    374:

    Damian @ 285:

    "That's still not quite the point - you can't "play guitar" on a synth. You can't press your ear against the heelcap and feel the resonance in your bones. You can certainly use any keyboard to enter data for the sequencer. But a sequencer is exactly like a pianola roll, it's just that you can associate the program with any sounds including samples. You can create something that would take years of intense practice to play on the source instrument for real, but... it's still a pianola roll and for many people the years of practice is the point. Guitar strings that make your fingers bleed (I do not resemble that remark at all, and those suspicious dark splatter stains inside my old guitar are just fret oil thank you very much), oboists with scars all over their thumbs from reed making, tuba players with that perfect relaxed embouchure that means when they talk sometimes it sounds like they are farting in between words, saxophone players who can get those extra low notes by sticking a foot in the bell, Louis Armstrong's puffed out cheeks (which everyone knows is actually terribly technique, but love him all the more for it)... these things have their own resonance and there are people who would not wish to live without them."

    You can "play guitar" on a synth, but why would you want to?

    OTOH, you can also use a guitar as a synth controller. You can use it to input to a sequencer or you can play it "live" with the synth output going into the guitar amp (through whatever device you're using to store the voices).

    I think you missed my point. Although the synthesizer can be used to replicate the voices of other instruments if need be, it's actually an instrument all on its own.

    375:

    Greg Tingey @ 298:

    "But I can't read music & therefore, can't play an instrument & it's probably too late, now, Grrrrrrr."

    1. That's bullshit. You don't have to be able to read music to learn an instrument & make music. Take my word for it. I've been doing it for more than 50 years.

    2. "It's never too late!"; "Where there's life, there's hope." ... all sorts of other feel good, motivational clichés.

    376:

    I am very leery of any solution to Fermi's Paradox which involves "Nobody would do THIS!" -- whatever "this" is. Human history repeatedly demonstrates that if something is possible at all, somebody, somewhere will do it, no matter how silly, dangerous or frivolous. The other solution to that problem is that at the certain time of the past it actually happened at least once, so to say, self-replicating machines (which are millions of generations more advanced than we are) took over the universe and just decided to leave it as it is, with a number of certain tweaks. Just because we do not know the basic structure of the universe from our vantage point, it does not mean it is completely impossible to print out an exact(or at least, consistent) copy of Earth how it was a couple of millions years ago and do it over once again.

    I've been reading this thread again, and it seems that everybody is looking for stable solution within singular colonial ship/construct. Meanwhile, there's option for more extensive structure that will involve a fleet of colony ships, which can get up to speed altogether and proceed on parallel course each in it's own semi-autonomous regime. Surely, it is just a step-up from an enclosed model in most regards, but at least it will provide some flexibility. It is scalable to any proportions we might need, and it provides long-term stability - the colonies should be able to supply each other with population, information, energy and materials (via shuttles or other support vehicles that can follow them), should the problem arise, and thus remain in dynamic equilibrium.

    377:

    Mikko Parviainen @ 327:

    "Guitars? The woodwork that goes into them is specialized, and furthermore, implies a supply of mature trees to harvest.Well, you can build an electric guitar out of non-wood materials, and I think Ovation had at least mostly-plastic acoustic guitars, too. I'm not sure how these sound, I haven't played any of them."

    They sound great. The one I have is a dream to play except for one flaw shared by all Ovations, the rounded bowl back makes it want to roll up and slip out of your lap if you play sitting down. Even if you always use a strap.

    Also, check out carbon fiber guitars.

    "With music, I dabble with acoustic and electric guitars, and analog and digital synths. There are different things they all are nice for.
    I'm even less sure about other instruments, though."

    I know they make trombones & trumpets out of plastic. Maybe even plastic mouthpieces. You can make drums out of metal as well as plastics. I've seen a solid Lucite electric violin. You could probably make violins, violas, cellos & string basses out of carbon fiber. You could make all of the parts for pipes (except for the sheep's bladder for the bag) out of Bakelite.

    378:

    @190. As well as female education, there's also a direct relationship between urbanisation and a drop in fertility rate. And there's some suggestion that the UN is drastically underestimating the level of global urbanisation. But also beware extrapolating the experience of fertility rate drops in the industrial west to the rest of the globe. What happened in Japan cannot necessarily be applied to the whole of S Asia or Africa.

    Researchers contest widely-accepted United Nations' predictions on urban population growth http://www.thisisplace.org/i/?id=0150beca-e3f5-47e0-bc74-9ccc5ef1db8a vs UN 2018 Urbanisation report https://esa.un.org/unpd/wup/Publications/Files/WUP2018-KeyFacts.pdf

    Even within the UN analysis there's some slightly odd implications. The global rural population is now effectively static. So all the current linear growth in global pop is happening in the cities. And predominantly the 500 cities with >1m people. Where is that +80m/yr coming from? Excess rural fertility migrating to the cities, perhaps or uncontrolled fertility in the favelas.

    379:

    Getting rid of heat isn't a problem in normal space - you have a 4 degree Kelvin heat sink to radiate into!

    Casting would thus involve some interesting heat sinking to get it to the exterior. Not to mention how it would impact the temp of the air. Plus all those pesky trace elements you're vaporizing.

    I use 2 part epoxies all the time at home. But I bet those out gas some interesting things just based on the odor when using them.

    380:
    I've been reading this thread again, and it seems that everybody is looking for stable solution within singular colonial ship/construct. Meanwhile, there's option for more extensive structure that will involve a fleet of colony ships,

    I think the word you're looking for is expensive rather than extensive.

    381:

    No-one said I couldn't deliver the lesson with a one-year-old on my shoulder...

    As an independent IT consultant to small businesses they had to accept that I might have a 3 or 4 year old with me on occasion.[1]

    [1]After experimenting with child care for a year or so my wife and I decided to arrange our lives so we didn't have to use it. For good or bad our kids were raised by us and not strangers.

    382:

    But you can't use convection to do it, you can only dump that energy into that cold vacuum in the form of radiation. Convection is a much more efficient way to dump heat than radiation.

    383:

    JBS @ 375 Also bullshit It MIGHT be true for you, it isn't true for me. I SAID ( if yoy remember? ) "YMMV" Of course I was encouraged & also put-off ( i.e requiring formal lessons, because my father, "obviously" ( Now 60+ years too-late ) used to paly bbethoven, Hydn & mozart pieces on our piano & I would sit entranced ( He always used a score, though I think he knew one of the Mozart pieces from memory ) ... He was waithing for me to ask & I was waiting for him to show me how ......

    In our Morris-side, most players, once they have learnt the tunes, play from memory & also improvise & do what would be called "cadenzas" in a classical performance ... but they almost invariably have/use "the dots" when startting a new piece.

    Julian Bond @ 378 uncontrolled fertility in the favelas. Doubtless mind-controlled by the RC church ... except, of course you have places like Nicuragua where birth-control/aborton are desperately-criminalised. Time to string the legislators up in public ... by their goolies.

    384:

    Re: Radioactives in space

    Okay although I thought that I was making the same point: impossible to avoid radioactives including in foods. The human body does need some radioactivity in order to function. If all onboard tech is made of elements that don't undergo rapid radioactive decay, you couldn't use now-existing tech to do any space exploration, science or medicine. Even if everything is made of exceptionally stable materials, stray rays from the rest of the universe could still de-stabilize these materials.

    Scenario: Imagine a spacecan full of humans landing on a planet* in a system that (because of plain ole random probability) has been shielded from almost all such rays/energies for eons and has attained a super-neutral energy state**. Doubt that life could start there - and any life that arrived could start a cascade that eventually destroyed the planet. An SFnal variation on climate change.

    And because we're past the 300 mark, plus all the other stuff that's happened ...

    The movie SF/Action scenario would go like this: Space aliens finally seem to acknowledge our existence but because all their tech is based on using different combos of elements, they've never landed because they don't want to set off a reaction that might destroy our planet. Unfortunately there's an Orange Orang in the OO that insists on a face-to-face meeting with these aliens to discuss trade and space walls who disregards expert scientific advice and arranges (via an equaling short-fused expert-denialist twitting) high-tech billionaire for a round trip jaunt to their ship. Although the OO-OO (also how he speaks, therefore an appropriate nickname) does appear to have safely survived his space jaunt but a few days later weird (okay, a different type of weird) stuff starts happening in his physical area. Biggest suspense in this film: Which lawyer does he hire to sue the aliens? (Spoiler: His personal MD's twin brother who just passed some hick state's bar exam --- after 10 tries.)

    Think we need to keep the goldilocks concept in mind across all factors and from multiple perspectives.

    • Planets have been found in the dark zones between star systems. Guessing that this is probably fairly common and also guessing that distances of star systems have as much variation as everything else we have ever measured, i.e., some star systems are binaries, other stars are orphans at the remotest edges of a constellation's arms.

    ** Guessing this probably means no elements higher than some magic number in the table of elements - no idea what that number might be, apart from very low.

    385:

    plenty of time to make the necessary adjustments.

    I suspect that an important job on such a rotating ship would be that of load master, just to make sure that the gross mass distribution didn't get too far out of kilter. For smaller and quicker adjustments, pumping water between tanks positioned around the ship might work -- it's what's used in active anti-roll systems on some large ships today.

    386:

    On the other hand, it might expand the market for 3D printers. While 3D printers have been successful in industry, the dream of a 3D printer in every home has gone nowhere. Who knows, this may even encourage the hobbyist adoption of 3D printers capable of using metal?

    388:

    I wonder if in a hundred years, while the spiritual descendants of SpaceX and Blue Origin are working on building the Dyson Swarm, we are still going to get discussion on in-feasibility of interstellar travel

    389:

    As soon as I saw the words "T-handle" I knew what that was going to be :)

    (note: multiple overlapping defensive measures ensure that video and audio files never play in my browser.)

    I was pretty much taking it for granted that you'd spin it about a stable axis, and shape it so that the stability well is deep. It'd be kind of daft not to :)

    (Also, AT's comment about the loadmaster being an important job applies.)

    390:

    I don't see collision avoidance as an issue. They love to have collisions as a plot element in movies, but space is pretty much empty so there's a good chance you'd never come anywhere near another object, unless it was intentional.

    In any event, collision avoidance would not be done by acceleration normal to velocity, but tangential which might make things a bit easier but not nearly as exciting. Imagine, an alarm goes off, the first officer touches the flashing icon on the touchscreen attached to her chair. "Captain, the navigation computer has detected an object on a collision course ,two light years from us. The environmental control system has been automatically instructed to alter the difference between fore and aft albedo 0.6% ,causing the ship to accelerate slightly over the next month and thus avoiding the object by a wide margin." Everyone grabs onto the consoles and arm rests of their chairs as if bracing for a massive acceleration. The first officer looks at the glass of water sitting on the arm rest of her chair and ... Nothing. Its just sitting there, dead still without so much as a ripple. She shrugs , picks it up, takes a drink, and goes back to reading a novel on her data tablet.

    391:

    This is true. But the point is that radiation is good enough.

    I know there's a "conventional wisdom" that says otherwise. It's one of the things that website that sets itself up as the bible of writing scientifically realistic space scenes bangs on about, and so do various other sources that have a similar angle (some, at least, because of copying each other). But I think where the point originally came from was the difficulty of heatsinking space weapons platforms. That's a very different matter from what we're discussing; any weapon whose power source is on board the ship gives you a massive heat dumping problem, so do engines capable of delivering military-grade acceleration, and then there's the conspicuousness of giant radiators to the enemy - and their vulnerability - to further complicate matters. People have then apparently taken it, uncritically and without considering the actual heat flow involved in different cases, as a point applying to any spaceship - which it doesn't.

    We already know that you can keep people alive in space without any major difficulty about not boiling them in their own waste heat; we've been doing that for ages. Our ship, of course, has engines, but they are of the very-low-power very-long-burn type, so produce waste heat at a correspondingly slow rate. Also they probably don't share the same heatsinking mechanism as the living space, so they can reduce the radiating area needed by running hotter. (They're probably out on the other end of a big long pole or cable, especially if they use nuclear energy.)

    Getting rid of the waste heat from casting operations wouldn't actually be too much of a problem. I don't think we're talking about casting anything tremendously large, but about things a lot smaller than an engine block. While you do have the spectacle of a lot of heat energy concentrated into a very small volume, the average rate at which it is produced - since we're talking about small and intermittent operations - is pretty low compared to the ship's overall power consumption, and the mass involved is a similarly tiny fraction of the whole ship. So once the hot bits have thermally equalised with the ship as a whole, the temperature rise is not large enough to notice. You just have to keep the frequency with which you do any casting low enough that that remains the case.

    392:
    I wonder if in a hundred years, while the spiritual descendants of SpaceX and Blue Origin are working on building the Dyson Swarm,

    In a hundred years? You haven't thought this through.

    Also, I'd like to hope that by the time anyone gets round to building a dyson swarm, they won't be the spiritual descedents of rapacious capitalists with totalitarian best buddies.

    393:

    "Attention, this is a general announcement. For the next 20 days ship time all personnel must vent their flatulence using the STARBOARD fart locks ONLY. Upper and keel locks are not to be used, and anyone found using the port locks will be sealed in a spacesuit for the duration."

    394:
    But I think where the point originally came from was the difficulty of heatsinking space weapons platforms.

    The kzinti lesson is an old cliche, but it is worth remembering that a drive powerful enough to be interesting is equivalent to a weapon.

    Starships are big. The firefly idea I mentioned above has a launch weight of ~45000 tonnes. You need a pretty fierce rocket to drive that even at milligee levels... hundreds of terawatts even if you had a magic 100% efficient drive, which of course you won't. You'll be generating a lot of waste heat, and the masses of radiation shielding around the nozzle will be soaking up a lot of heat, too. At milligee thrust levels, you need to be running your engine continuously, for years or decades, to get up to a good cruising speed (and to slow down again afterwards). You'll need colossal heatsinks and a lot of heat-piping and heat-pumping infrastructure and all the rest, though at least you don't need to worry about hostile weapon fire.

    On the bright side, you'll almost certainly have a nice long coasting phase (measured in decades, minimum) during which time those huge heatsinks will be available for whatever you felt like you needed.

    395:

    rapacious capitalists with totalitarian best buddies.

    Someone is butthurt that USSR was completely incapable of making the Noon Universe a reality...

    396:
    Someone is butthurt that [the] USSR...

    Someone is salty that I didn't genuflect towards his favourite billionaires, and also doesn't seem to understand what 'totalitarian' means or think about why someone might not like it.

    397:

    You can "play guitar" on a synth, but why would you want to?

    That's the point. There's nothing wrong with a synth, and you can even use one to make sounds like a guitar (well we are both saying "synth" here, but we both really mean sampler), but when you play a synth live you are playing a keyboard. It isn't the same experience as playing a guitar and it doesn't replace any of the experiences I described or make them obsolete.

    Playing keyboard is its own, different thing. Sure, playing a weighted 88-key keyboard gives a lot of the natural instrument feel of a piano. Guitar MIDI controllers work, but the trend is toward "MIDI pickups" rather than eliminating (or reinventing) the strings (which was definitely a thing at one stage) because lot of the experience is about the strings being the thing that makes the sound.

    Andres Segovia still practiced 8 hours a day in his 80s. Maybe a population of 100,000 or 1 million or even 10 million isn't enough to support a demand for people who do that, but 100 or 300 million surely is.

    398:

    It's definitely too late for me :-)

    You can't develop major new neural pathways at 70, though you can still learn. And, because I lost so much of my hearing so young, I simply can't hear most music - timing is OK, but not pitch. But, what the hell?, the saying that you don't miss what you have never known has a lot of truth in it.

    Similarly, people with seriously impaired motor skills can't learn to play an instrument, even if they can hear hear it, for obvious reasons.

    399:

    to Ru #180: I think the word you're looking for is expensive rather than extensive. There's absolutely no reason to save money on backup plans for humanity's survival.

    to Auricoma @388: spiritual descendants of SpaceX and Blue Origin are working on building the Dyson Swarm For them to have spiritual descendants, it requires to have spirit, which is hard to find in the first place. I imagine, they themselves can be considered spiritual descendants of Walt Disney (and this is not a joke, if you think of it good enough) and not much beyond that. https://www.youtube.com/watch?v=2fautyLuuvo

    400:

    Object which you can detect 2 light years out are not the problem. Dust motes are.

    401:

    POSEIDON = NEPTUNE

    https://www.antipope.org/charlie/blog-static/2018/06/the-pivot.html#comment-2047467

    Now, it's been proved that we work 5D

    Ugly little creatures, most white men are. Dusty, Crusty, Ignorant and Violent.

    Be. Seeing. You.

    402:

    If you want to get kinky, NEPTUNE is a cover-up for actual POSEIDON but your media won't be allowed to touch that stuff. Hint hint: undersea cabals/cables.

    Enjoying the LFI show?

    @Host. Please, and on the QT, remind your most fervent followers that it's a big scary world out there.

    "I made a mistake"

    "Yeah, we proved it live in 5D while drunk and Host subject had most of its frontal cortex destroyed"

    "That's not..."

    "Yeah, still not getting it".

    "But we Puppeted Your Species"

    "Still not getting it that we're not H.S.S"

    Wargasm

    p.s.

    Top Secret 101: Our. Kind. Do. Not. Go. Mad. We. Also. Have. Rather. Silly. Regenerative. Powers. You. Apes. Can't. Access. Yet.

    3>

    Nuke it from Orbit.

    403:

    I'm curious how someone who has "struggled with untreatable psychosis and depression most of his life" got his hands on a handgun. A failure of the legal system, an improperly-stored gun, or an illegal weapon?

    Lots of rumours flying around, but not a lot of solid information yet.

    404:

    https://www.gunsamerica.com/

    https://www.budsgunshop.com/catalog/index.php/cPath/654

    Etc.

    You know, if you are that 400lb hacker dude and don't want to go to the 5.000+ Gun Fairs per month the USA stages which have been scrupulously removed from any registration Laws.

    Or, you'd do this:

    https://qz.com/1222436/a-third-of-guns-in-the-us-are-imported-and-foreign-manufacturers-like-glock-and-beretta-want-a-say-on-gun-control-laws/

    Non-US imported weapons have different laws attached to point of sale requirements.

    ~

    But Mr Prior didn't waste 10 mins searching, so "meep".

    405:

    Or, in more blatant terms:

    They walked up to a shop counter and bought one.

    Youse a dumb fucker.

    406:

    I was thinking that if you do use a lightsail, you could redirect a small amount of the beam forward of the craft to encourage small particles to get out of the way. A terawatt or two per square metre should do it :)

    On that note, looking at the energy intensity required for light sails is pretty scary. It's all very well talking about pressures in a pascal range, but when you translate that into watts it gets somewhat disturbing. At least generating the beam is no problem, reflectors that good could be shoved into orbits very close to the sun and perpendicular to the direction of travel. Sure the beam will wobble a little, but it will also average out nicely over time.

    407:

    Carbon fiber string instruments are a thing, already. Should be no problem fabricating them on a starship.

    I think any practical starship is going to be enormous because it will benefit from square-cube factors. It will have room for forests. It will be a very good idea to have substantial margins of biomass that are long-lived organisms that can survive unexpected short-term disruptions. Because the disruptions are going to happen. You don't want most of your biomass to go extinct or mutate into something icky faster than you can deal with it. So there should be forests, and foresters, and carpenters and cabinet makers and luthiers.

    408:

    Note for onlookers (like Greg) who might be wondering what the Many-Named One is going on about now, circa comment 401, with stuff like NEPTUNE = POSEIDON:

    This is a references to Neptune PR ltd, a public relations agency, which leaked messily all over twitter yesterday — as I understand it, the Emir of Qatar is visiting the UK this week, and Neptune has been sourcing actors (folks used to working as film extras) to portray a renta-mob of "Qatari opposition protestors" for an astroturf demonstration at 10 Downing Street during his visit with the PM.

    This isn't so much "fake news" — as in, news that is faked up out of whole cloth — as "artificial news" — the event really happens and legit news channels cover it, but there's nothing spontaneous and natural about it.

    Possibly someone picked up the bloviating about "crisis actors" in the American right wing news echo chamber and decided it sounded like a good strategy. In which case, this is a perfect example of why "crisis actors" are not a real thing: you need to send out a casting call to get enough live bodies for any event, and it is absolutely guaranteed that if you ask enough people you will accidentally invite someone who is (a) ideologically hostile to your agenda and (b) has a twitter account and knows how to use it. (Which is what happened to the Neptune idiots.)

    409:

    Oh, and it gets better: Via Carol Cadwalladr today, it turns out that SCL/Cambridge Analytica were retained by the UAE government to do anti-Qatari messaging, and when CA went down, the contract ended up with Steve Bannon, because the folks trying to take down Qatar are those lovely Saudi royals and their friend Donald Trump.

    It's all a fucking circle-jerk. But this time we get to peel back the rug and look at the wrigglers underneath it before it happens because there's an investigative press pack chasing it.

    Here's the big question, though I'm going to discourage discussion of it here (it really deserves a blog entry of its own): if these are the tactics these guys are deploying against Qatar, then what did they do to push Trump, Brexit and the alt-right agenda: where did all those "Free Tommy Robinson" demonstrators come from, who organized these knuckle-draggers (who can't normally organize a fist-fight in a pub at closing time)?

    410:
    There's absolutely no reason to save money on backup plans for humanity's survival.

    There's every reason not to neglect the vast majority of people who won't be going on a starship and will likely reap zero reward from any starship effort. See the note in the OP about the cost of the starship being on the order of the GNP of Russia. Hint: that's a lot of money. You can't just build a dozen at once; the world simply isn't rich enough yet.

    Also, if you're using arguments about the survival of humanity, then those extra ships should be sent to different star systems, shouldn't they? Eggs and baskets, etc.

    411:
    I was thinking that if you do use a lightsail, you could redirect a small amount of the beam forward of the craft to encourage small particles to get out of the way.

    "Redirecting" sounds like a horrifyingly complex bit of optical engineering, in this case. It might be possible to construct a secondary reflector on the front of your ship, and have a small hole in the centre of the sail to shoot out of...

    It's all very well talking about pressures in a pascal range, but when you translate that into watts it gets somewhat disturbing.

    It certainly requires a certain amount of political stability, so you don't end up with people seizing control of the laser array and toasting their opponent's countries off the map.

    At least generating the beam is no problem, reflectors that good could be shoved into orbits very close to the sun and perpendicular to the direction of travel. Sure the beam will wobble a little, but it will also average out nicely over time.

    The problem you have, as I understand it, is that what you really want is a massive laser where all the outputs of each individual emitter are in phase. That's a pretty non-trivial bit of engineering. It isn't precisely magitech, but I wouldn't want to bet money on when it becomes possible.

    My personal preferred propulsion system is the sailbeam. You get much better momentum transfer to the starship, and you don't need magical distributed phased array lasers that can focus lightyears away. It also avoids the basically intractable problems of trying to carry all your fuel with you as an interstellar rocket.

    412:

    I like the sail beam. To go double good fast you can then fire captured bits of sail back towards home (avoiding shooting down your incoming sails of course).

    413:

    There's every reason not to neglect the vast majority of people who won't be going on a starship and will likely reap zero reward from any starship effort. See the note in the OP about the cost of the starship being on the order of the GNP of Russia.

    GNP of Russia, est. 2018: roughly $1.58Tn nominal.

    US Department of Defense budget request for 2018: $639Bn.

    Global Defense spending in 2018, est: $1.67Tn.

    Hey, you know what?

    If I could wave a magic wand and reallocate all global military spending to "let's build a generation ship" spending, I would totally, enthusiastically do that!

    Defense spending provides a Keynesian stimulus to the aerospace, electronics, vehicle, and some other sectors of the economy. It also provides employment for some millions of people, both engineering/technical side and active military. But the utility of defense spending is fundamentally destructive — it's to either break shit and kill people, or to deter other folks' militaries from doing the same thing to you.

    (I'll carve out an honorable exception for disaster/emergency relief efforts, but that sort of thing would be better done by a specialist agency — like a coast guard on steroids with added inland logistics delivery capability and heavy airlift.)

    A starship project could in principle deliver similar technological/manufacturing stimulus effects to the global economy, but with far less risk of it producing any pyramids of skulls.

    So what's not to like?

    (However, back in the real world, we're unlikely to be able to get there from here: more likely we'd see a half-baked money-sink starship program as well as continued military spending, because hairless apes are assholes. Meh.)

    414:
    So what's not to like?

    I'd be willing to bet that we'll get a functioning warp drive before the world's defence budgets get turned to better uses :-/

    415:
    To go double good fast you can then fire captured bits of sail back towards home (avoiding shooting down your incoming sails of course).

    Capturing the sail sounds tricky if it is travelling at a fast enough relative speed to give you a decent boost. Far easier to zap it into plasma and bounce it off a magnetic nozzle.

    416:

    Yes. A blog entry would be good. There are also such questions about the anti-Iran campaign, the Syria debacle, Al Quaeda and Da'esh, and Yemen. I won't post more, for the reason you say.

    417:

    David Graeber's book Bullshit Jobs argues that the number is at least 40% (yup, there have been studies). Probably close to 100% in finance, for example. Also, the more your job benefits society, the worse it pays. I'm most of the way though, and it's very interesting.

    https://www.amazon.com/Bullshit-Jobs-Theory-David-Graeber/dp/150114331X

    418:

    There's every reason not to neglect the vast majority of people who won't be going on a starship and will likely reap zero reward from any starship effort. It's not like people who are embarking on generation ships are going to reap any reward either, by entombing themselves in closed habitat until the end of their days. And same can be said of several generations of their ancestors, as well. They are going to spend next several centuries in the middle of absolute vacuum so vast, it will take a precise calculation of correction maneuver to arrive anywhere at all instead drifting forever.

    See the note in the OP about the cost of the starship being on the order of the GNP of Russia. Hint: that's a lot of money. You can't just build a dozen at once; the world simply isn't rich enough yet. More like not developed enough yet. It's not like you can just imagine a problem and keep throwing money, resources and people at it until it is solved. But on the other hand, if you-know-what-alliance did not spend all these money on their arms race against the wall since the end of Cold War, we would probably already started colonizing Mars, at last. Otherwise, it is still 20 years into the future as it was 50 years ago. Not to mention how much this budget is also inflated by overpriced equipment - it is simply impossible to know that.

    Also, if you're using arguments about the survival of humanity, then those extra ships should be sent to different star systems, shouldn't they? To put it in different perspective, 1 ship = 1 egg, 1 expedition = a basket of eggs. Increasing a number of eggs in the basked increases their chance of survival, as they assist each other during flight, and this can even reduce the number of redundancies for each ship. On the other hand, if you are going to make expeditions to several destinations, you would want to start making these starships like hot cakes to keep up with the demand.

    419:

    Chralie @ 408 THANK YOU I had assumed that said message was, as usual entirely, or at the best 99% content-free. You should not have to do this, actually, because life is too short to be playing these stupid games when actual, serious stuff ( As you describe in your posts ) is occurring.

    OR ( As it might vert easily have been me ( I do occasional "extra" work ) don't have a twotter account ( I do actually, but only on this machine, for emergency use ) but would still instantly leak this to the press & the blogosphere ... In fact, if it does happen to me in future, you can guess where the message will show up ......😱

    @ 409 Yes A new post required & serious publicity elsewhere, as it is superb ammunition for a second-referendum call, or abandoning At50, due to erm "rigging" - as demonstrated... etc. As EC says, too .....

    420:

    Continuing on contemporary political fuck-ups fuckwit Corbyn has gone into full pro-Brexit mode, just as the total disaster becomes apparent. You really couldn't make stuff like this up - I think the scriptwriters shoould be sacked (again )

    421:
    More like not developed enough yet.

    "For the sake of the survival of humanity, we must wait until the world is ten times as rich!" ;-)

    But on the other hand, if you-know-what-alliance did not spend all these money on their arms race against the wall since the end of Cold War, we would probably already started colonizing Mars, at last

    Doubtful. Without the incentive of beating the russkis there, there were plenty of other things to spend all that money on that just seemed more useful, more voter-appeasing, or at the very least lined the pockets of $politiciandujour's friends.

    422:
    You really couldn't make stuff like this up

    The last private eye jokingly suggested that corbyn would have made an ideal replacement for johnson or davis. Turns out they were right.

    423:

    Re: ' ... an unfortunate accident in a CRISPR lab.'

    Don't need an accident!

    I've broken the Abstract paragraph below into easier to read one-of sentences/bullet points:

    https://www.nature.com/articles/Nbt.4192?_ga=2.77287829.1079115639.1532361635-43802733.1501526661

    'Repair of double-strand breaks induced by CRISPR–Cas9 leads to large deletions and complex rearrangements

    Abstract

    CRISPR–Cas9 is poised to become the gene editing tool of choice in clinical contexts.

    Thus far, exploration of Cas9-induced genetic alterations has been limited to the immediate vicinity of the target site and distal off-target sequences, leading to the conclusion that CRISPR–Cas9 was reasonably specific.

    Here we report significant on-target mutagenesis, such as large deletions and more complex genomic rearrangements at the targeted sites in mouse embryonic stem cells, mouse hematopoietic progenitors and a human differentiated cell line.

    Using long-read sequencing and long-range PCR genotyping, we show that DNA breaks introduced by single-guide RNA/Cas9 frequently resolved into deletions extending over many kilobases.

    Furthermore, lesions distal to the cut site and crossover events were identified.

    The observed genomic damage in mitotically active cells caused by CRISPR–Cas9 editing may have pathogenic consequences.'

    '... may have pathogenic consequences' --- No kidding! There are a bunch of known (nearly always fatal) blood disorders whose root cause seems to be a simple mis-cutting and therefore mis-rearrangement of a few bases. Some of these re-arrangements mean certain sequences end up on a completely different chromosome where they are therefore subject to a completely different bunch of pre-programmed on/off and repeat signals. (Quite a few on/off and repeat signals are located at a distance from the 'gene' itself.)

    424:

    Many, many, many years ago, Nick Pollota was the speaker at a PSFS meeting, and he was doing stand-up comedy at the time. I'll always remember his special effects for Voyage to the Bottom of the Sea: he leaned and gallumphed one way, then reversed course.

    But then, it's hard to build suspense and and ACTION!!! in a movie, where there's no roar of other ships, and you can't even see them....

    425:

    Re: More military spending

    Considering that the military is increasingly doing more humanitarian work locally and elsewhere, a larger budget for continued and increased work in this direction would be fine by me. Also - quite a few retired senior (US) military have been trying to get more govt funding into climate sciences.

    Someone already mentioned the Thai cave rescue (soccer team: 12 kids and their coach) which was conducted by a mix of civilian gov't, militaries (SEALS) from different countries, civilian cave divers, plus thousands of supporting volunteers outside at ground level. Renewed my hopes for humanity. If anyone here personally knows any of these folks please tell them: Thank you!

    426:

    We'll ignore the fact that of the 74 or so years it existed, it spent what, 15? where it was either not in a state of war, or preparing for one, or recovering from one, and absolute military and economic pressure, thus providing the totalitarian assholes all the "We Need This To Protect Ourselves" they needed.

    Let's just cut to... well, around '95 or '96, Robert Reich, Clinton's first Sec'y of Labor, in an opinion on NPR, asked what it was that a CEO did that made them worth TEN TIMES what a company president did. So, exactly what did any of these billionaires do that makes them worth having almost a million times what the median income is in the US?

    And what have they done with that wealth, other than play the Ponzi Scheme known as the market, while jobs go away?

    How much do those bastards pay you, to put out this propaganda, or are you just brainwashed?

    Where's my friggin' tumbrels, and the Humane Invention, which we need to set up on the Mall in DC?

    This is, I repeat, the polar opposite of the 21st Century we all expected.

    427:

    Datapoint: when I searched for weight of an aircraft carrier, the first hit is that a Nimitz-class one weighs in at 97,000 toms.

    And I still like the idea of a needle-nosed starship, which means that most dust and crap does not hit at 90 degrees.... Oh, there we go, coat it with ice, and as they scrape along the needle nose, spit out a little more, and it's self-healing.

    428:

    There is also the Poseidon Transmission Project, part of the Neptune Regional Transmission System, LLC, an undersea and underground high voltage direct current (HVDC) transmission project in the New York City area. I haven't (haven't tried, reading other material) worked out why it would be especially interesting yet but the keywords match and it involves cables. (I don't see any reason that links would cause trouble here, since this is just a FYI.) The Poseidon project is a proposed electric transmission line that will deliver 500 MW of low-cost renewable energy to Long Island at an affordable price.

    (There are also some audiophile speaker cables, of the "From $3,125.00" variety, i.e. taking money from people who don't need it.)

    429:

    I still like the idea of a needle-nosed starship, which means that most dust and crap does not hit at 90 degrees.... Oh, there we go, coat it with ice, and as they scrape along the needle nose, spit out a little more, and it's self-healing.

    Nope.

    I know that's intuitively obvious, but it doesn't work.

    Even a slow-ish generation ship traveling at 1% of light-speed is making 3,000 km/sec, or about 2000 times the velocity of an armour-piercing anti-tank round.

    Remember the v2 term in the ke equation? It means a barely visible dust grain (which will not show up on radar in time to dodge, i.e. thousands of kilometres away) has the punch of said armour-piercing anti-tank round. If it hits your starship even at an oblique angle it's not going to bounce off: it's going to dump several megajoules of heat into the ship, explosively.

    If you want armour, you'd best deploy it as a Whipple shield — a thin disk, floating some centimetres to hundreds of metres in front of the ship. Dust mote hits shield, BANG, hole in shield and evaporated dust mote. Then you refresh the shield in time for the next mote.

    This also works for neutral gas molecules (which behave like alpha particles at this sort of velocity). What it doesn't help with: anything much bigger than a sand grain — a one gram lump of ice packs about the same punch as a small nuke at this speed, and again, you probably won't spot it on radar in time to dodge. To deal with that, you're probably best to continuously fire a multi-megawatt laser directly ahead of your ship in hope of evaporating anything in its path — or blasting enough matter of its side to kick it out of your path.

    430:

    Re: ' ... taking money from people who don't need it.)'

    Have been thinking about an economy based on what the market can afford and one option is proportional-to-earnings pricing: if you make $10M/yr, then you can afford to pay $X/doz. eggs. Given that almost everyone has at least one credit/debit card and that these cards are increasingly being cross-linked to retailer credit/membership/reward accounts, it should be easy enough to arrange such a pricing scheme*. So if you can't level the playing field on the basis of take-home pay, then it's time to level the field on the basis of cost-of-living.

    • As per that science book that the BigRiver algo priced at over $1M.

    https://www.geek.com/news/amazon-algorithm-freaks-out-sells-book-for-23-6-million-1347813/

    431:

    Damian @ 397:

    “You can "play guitar" on a synth, but why would you want to?”

    "That's the point. There's nothing wrong with a synth, and you can even use one to make sounds like a guitar (well we are both saying "synth" here, but we both really mean sampler), but when you play a synth live you are playing a keyboard. It isn't the same experience as playing a guitar and it doesn't replace any of the experiences I described or make them obsolete."

    No, I actually meant a synthesizer, although it works with digital sampling as well. While you can use a keyboard to create "guitar sounds", it's a lot easier to use a guitar to make those sounds. But, there are other ways to control a synthesizer besides using a keyboard.

    https://www.youtube.com/watch?v=WKElehLTQBg

    https://www.youtube.com/watch?v=bZt7ZUqzOkc

    432:

    Have been thinking about an economy based on what the market can afford and one option is proportional-to-earnings pricing:

    Interesting thought. To some extent, that's what high-end food retailers (e.g. Whole Foods in the US) are for, though they only extract a factor of 2-4 more (plus expensive wines, cheeses and etc can extract considerably more from the affluent). It used to be there was just milk (animal depending on region), and cream (and butter). Now, well, was in a food co-op a couple of days ago and saw a dazzling array of "milk"s, considerably more expensive than the milk from local dairy cows/cattle. Saw "Hemp Milk" for the first time. (Appears to have been around since about 2011 at least.)

    433:

    This also works for neutral gas molecules (which behave like alpha particles at this sort of velocity). What it doesn't help with: anything much bigger than a sand grain — a one gram lump of ice packs about the same punch as a small nuke at this speed, and again, you probably won't spot it on radar in time to dodge. To deal with that, you're probably best to continuously fire a multi-megawatt laser directly ahead of your ship in hope of evaporating anything in its path — or blasting enough matter of its side to kick it out of your path.

    Would it help to have a forward sensor net of extremely small drones travelling a light-minute or so ahead of the main ship? That seems like enough to let a laser countermeasure system limit itself to shooting actual threats, rather than having to fire continuously.

    On a different note, has anyone commented on the challenges of supplying power to such a ship for the hundreds of years it will be travelling. Starlight doesn't give much solar power (though I suppose you could have really big panels angled parallel to the direction of motion so they don't get ripped apart by interstellar dust).

    434:
    The human body does need some radioactivity in order to function.

    That's the first I've ever heard of that. What on earth for? I can't think of anything radioactivity does that oxidative stress doesn't do better, and that is under tight regulatory control. Things that rely on DNA damage, like hypermutation of B cells, are done via specialized DNA-snipping machinery, not by waiting for radiation to randomly smash up DNA :)

    435:

    Re: Radiation

    Can't think of anything off the top of my head either, nor found any research. :)

    But ... given that many of the foods we eat contain radioactives of some sort, the recent-ish understanding of the role that bacteria play, i.e., no longer 'any bacteria is a bad bacteria', no research (that I can find) on what happens to living things if the background radiation is completely removed, and all life on this planet evolved amid varying levels of radiation, leads to: we probably need some radiation.

    Tie-in to the space-can scenario is obvious: too much radiation (current fear) vs. too little (space-can is over-engineered due to incomplete biological info).

    436:

    See #300. There is increasing evidence that our immune system will not develop properly in the absence of enough challenges (both in severity and range), and it is possible that radiation-induced DNA damage is also one of the necessary challenges. I haven't a clue whether or not that is actually the case.

    437:

    I'll just mention that just the other day, I read that Bannon was setting up a foundation to funnel money to European fascists.

    438:
    If you want armour, you'd best deploy it as a Whipple shield — a thin disk, floating some centimetres to hundreds of metres in front of the ship.

    No reason to limit yourself; you could do things like blow a beam driven sail ahead of you to use as your first line of defense, and it could be as far away as you like. There might be some mileage in having it way out ahead of you, as you can see the flash of something hitting it that might be otherwise too hard to spot and you might have enough time to zap it.

    During the acceleration phase, you can spray a liquid shield out ahead of you, and collect the droplets as you catch up to them. When something hits the shield it gets splattered, but there's no solid structure to repair and some (possibly most or even all) of the liquid can be recovered by electromagnetic means. I think Pellegrino's designs used this as a combination shield and heatsink. It probably demands an antimatter engine to give you a long enough burn time to make the shield useful, as it isn't much good during the coasting phase.

    During the deceleration phase, which should be much shorter than the other phases, you can just throw any old rubbish in front of you to sweep your approach path clear.

    you're probably best to continuously fire a multi-megawatt laser directly ahead of your ship in hope of evaporating anything in its path — or blasting enough matter of its side to kick it out of your path.

    You can deflect charged particles electrostatically or electromagnetically; look at some of the approaches people have tried to ameliorate drag on bussard ramscoops. This also means that if your laser can partially ionise whatever gas and dust is ahead of you, you can deflect it the same way.

    439:

    Charlie, and Many-Named-One, I just had a thought that has me laughing: we seem to have lost Shipley... and it hit me that a lot of readers of superhero stories identify with one hero (or villain) or another? It just struck me that he probably identifies with whatisname, the Persuader?

    Unfortunately, on on the job qualification score for that, he rates somewhere between "leaps small buildings in several bounds" and "runs into walls".

    440:

    Undersea high voltage cable. Can't see anything wrong with that idea.... Ever hear about how the subways and underground parts of Chicago got flooded in the Chicago Flood, in '92?

    And anyone and anything anywhere near it would be fried.... Great idea!

    441:

    I prefer, say, more income tax brackets, and yes, soak the rich. Note that in 1972, the top tax bracket in the US was 70% (no, not a type), as opposed to what it was under Republican Pres. Eisenhower in the fifties, when it was ->ninety per cent<-.

    442:

    Uh? They work fine. There's been one between England and France for decades, for instance (not the same one, because they've increased the capacity a few times). The original idea was to use it to even out peak loads which occur at different times in the two countries, but these days it's mostly one way, transferring juice generated in French nuclear plants to the dumb shit country that closed lots of its own power stations, couldn't be arsed to provide its own replacements, and is now obsessed with telling the French (among others) to fuck off.

    444:

    Here is an article that just came out that I found useful for my stuff.

    Why We Should Think Twice About Colonizing Space http://nautil.us/blog/why-we-should-think-twice-about-colonizing-space

    Just a comment about what Charlie said @408

    It is standard here in the US for Ad agencies to have actors show up doing "street theatre", from one person up to a crowd. They have people on call to show up when and where needed.

    I enjoy going to the Post Office. At one point I was going every day to pick up packages. After a while you get used to seeing the same people all of the time. Many of the staff behind the counter get to know the usual crowd. It got to the point that all I had to do was show up, take a number to pick up a package, and one of the guys would bring my package out along with someone else's, making one trip do. I did not have to present my number, just show up.

    Years ago, they were trying to demonize the Post Office so that they could cut hours being open. A guy started showing up each day. He was tall, well over 6 foot 6 inches, bearded, long hair, shaggy. He would get a number, pace up and down, huffing and sighing, while glaring at the clock. Each day he showed up doing the same thing but wearing something different each day, clearly a costume. One day dressed like a house painter, the next as a outdoorsman, etc.... Each time pacing and huffing. The regulars know what it's like to be at the Post Office and were comfortable waiting their turn, this guy was not.

    I showed up, got my number. The guy came in, grabbed a number and started his routine. One of the staff went back for a package and brought mine out as well. As I walked past the shaggy guy I handed him my number and said that I didn't need it, then took my package and left. I never saw that guy again. He was replaced by a "harried" woman who showed up each day doing the same performance until she was replaced by a "harried" guy.

    Each person acted as if they have never been at a Post Office before, each making a scene thinking that people would build up a negative opinion of the Post Office. The regulars see the Post Office and the staff as family. These people were clearly actors. They cycled through people a few weeks until the push stopped.

    That was one post office. Somebody paid a great deal of money to do that all over town.

    445:

    "supplying power to such a ship for the hundreds of years it will be travelling."

    I think everyone who's thought about it has assumed a wee nuke, from the comments that mention using the ship's power plant to power the colony in its early stages. I know I have. Stuff it with HEU and/or 239Pu so it has plenty of excess reactivity available and you don't have to keep emptying the ash pan, and stick it on the end of a long pole so you only need enough shielding to make a cone of shadow for the rest of the ship to sit in. Use liquid metal primary coolant so you don't have to handle high pressures in structures subject to radiation damage. Use thermoelectric converters to make the electricity; efficiency sucks a bit but the simplicity and lack of moving parts are probably more important. Use the long pole to mount the radiators for the cold end, since it's there and it's big.

    Or if you didn't want to deal with actual fission, 241Am (half-life 432 years IIRC) thermoelectric generators should be good for a few hundred years, although the amount of fission you'd have to get through on Earth to make enough fuel might be awkward.

    446:

    Indeed, it would be worth a blog post exploring this. So much has happened in the past few years that it's hard to remember that Trump's campaign used paid actors for it's original launch[1] so that it is certainly part of a playbook. Unfortunately, the people at later campaign events were all too real.

    [1] https://www.hollywoodreporter.com/news/donald-trump-campaign-offered-actors-803161

    447:

    Yes.

    I wish someone would stand their ground against him. Freakin' would-be Rasputin.

    448:

    to Ru @438:

    Collisions at any speed above several kmps look rather like micro-explosion that evaporate portion of projectile and shield, resulting in either chipped shield and cloud of plasma or punctured shield, chipped projectile and a cloud of plasma. There's simply no deflection per se, the particle is either destroyed or avoided entirely. https://www.esa.int/Our_Activities/Operations/Space_Debris/Hypervelocity_impacts_and_protecting_spacecraft

    Laser beams are increasingly ineffective proportionally to the square of distance they applied at, and then you will have to protect the laser itself. Maybe some sort of micro-missile, or projectile accelerator would be more useful for cleaning the path - just explode the incoming objects into tiniest bits that are absorbed by the shield or deflected elsewhere seconds before actual collision should happen.

    Whipple shield seems to be a good solution, until you you realize you may have problems with incoming interstellar plasma that will melt and evaporate your thin films before they have any chance to defend or deflect anything (a projectile going through the film at a angle will change it's course as the result of collision). Something tells me we will need to combine everything at once to counter all the effects - thin film sails, dumb shields and systems to recycle and repair them all in the process.

    to SFreader @425:

    Considering that the military is increasingly doing more humanitarian work locally and elsewhere, a larger budget for continued and increased work in this direction would be fine by me.

    Most military money go to increasingly high-tech projects that never leave their departments and stay top secret until the end of their days, so their economic usage is dependent on government policy at best. Conversion (economic) may help, but I think modern world forgot about that concept altogether since around 2001. This is just a scraping from the bottom of a barrel - a lot of incredibly cheap paramilitaries are more useful for that, if not separate branches of government, like EMERCOM we have over here. https://en.wikipedia.org/wiki/Ministry_of_Emergency_Situations_(Russia)

    to whitroth @426: in a state of war, or preparing for one, or recovering from one, and absolute military and economic pressure I dissent. Due to immense size and scale of "homeland" division, it has always been in immediate danger of being overrun, attacked, exploited or divided. Most totalitarian assholes do not need such concrete reasons for exploitation, like those who constantly instigate overseas wars over "interests" or "malicious activity" thousands of miles away from their sovereign borders (to be fair, for other intends and purposes, overseas USSR activity was Business As Usual).

    After the fact, I did not hear any more observers anywhere to be all too grateful to the fact that it decided to disband itself in completely institutional, peaceful process. At best they send their regards to certain people and declare it "died by natural causes", at worst, they are latched at remains of it like a pack of rabid dogs. You see, they never even needed this to happen in the first place.

    449:

    above several kmps look rather like micro-explosion that evaporate portion of projectile and shield,

    I find it useful to remember that at slightly less that 3,000 m/s the kinetic energy per unit mass is equal to that of the chemical energy of TNT per unit mass. 3,000 m/s is less than half earth orbital velocity or, in interstellar terms, c/100,000.

    Arithmetic:

    By convention, and reasonably realistically, 1 kg of TNT releases 4.18e6 joules.

    So for kinetic energy of 1 kg, 4.18e6 = 1/2 * 1 * v^2. Rearranging that, v^2 = 8.36e6 and v = 2,891 m/sec, 2.891 kps.

    450:

    I'm not up to speed with the latest SF or research on generation ships - the closest thing I've read recently would have been Seveneves which I found a bit unsatisfying - but one thing I haven't seen discussed is how you decide what to forget.

    Data storage is cheap, but the amount of data generated these days is huge and increasing, and a tightly controlled environment like a spaceship is going to be even more of a panopticon than current society. So even in a big ship, the on-board data centre will eventually fill up.

    If the spaceship is on good terms with people "back home" then excess data could always be transmitted back to Earth as long as you are comfortable with a wait of a few years if you need some of it back, and (of course) that the available bandwidth of your communication system can handle it. But even then you are going to need to triage between stuff you want locally, stuff you beam back, and stuff no-one cares about any more. And of course, if Earth is transmitting to the ship then there is always that new blockbuster movie from Earth that needs a few precious gigabytes.

    How do you decide if a piece of data is a priceless historic artefact, or a boring recording of great-grandma's first birthday party? How do you trade-off between something that is popular but vacuous against something that is rarely used but possibly important? How do you decide what information is important enough to keep inside ape brains vs what can be kept electronically? And do that while making sure that the ape brains don't go crazy.

    Many of these decisions are easy, some not so much, and no matter how you choose to manage these things, there will almost certainly be someone who ends up regretting the choices made in retrospect.

    And of course there are issues around how much redundancy to use against damage: there are algorithms that can give you arbitrarily good protection, but at potentially great cost in terms of excess storage.

    Plus, of course, the possibility of bad actors manipulating the stored data for their own ends. ("Who is this First Captain Sally Goodperson that you keep on talking about? There's no record of her at all in the data banks, and everyone knows that the Captaincy has always been passed down to the oldest son of the Riprock family...") There's the potential to make North Korea look like a clarion beacon of freedom, truth and openness compared to the sorts of directions a closed society of monkeys in a can could go.

    So unless you hand-wave it away, there may be interesting tales to be told around how things are remembered and forgotten over the generations in a small but technologically advanced community.

    451:

    Well...

    "...which has left our economy far too reliant on imports."

    This is true, and it's one of the things that gets on my tits about the whole affair. And it has got significantly worse in recent years, now that large parts of our transport and energy infrastructure are owned and furnished by foreign outfits. It seems that every capability we had of doing for ourselves the important stuff that we actually need done either has been, or is planned to be, smashed up and flogged off to anyone prepared to buy it in order to generate a one-off quick buck for the rich cunts who don't even need it, with the result that it then becomes a long-term drain on our resources as the profits are taken abroad and the concomitant destruction of our own abilities to do anything useful leaves us with no means of paying for it other than to engage in more and more bullshit.

    The trouble is that since it has got like that, you can't just smash apart all the structures that have enabled it and expect everything to magically revert on the instant to how it was before. If you're going to blow your own house up, you need to make sure to build another one first. Unfortunately this rather obvious point seems to be too much for the quite staggeringly fuckwitted entity that we now have in place of a parliament to grasp. (I remember those charts that showed that apart from a few tens of Tories, the entire HoC was massively in favour of Remain. Where the fuck have they all gone?)

    Not to mention that "how it was before" is either illusory ("how it actually wasn't before but people imagine it was") or impractical ("it was like this at one time, but the capacity is many times below what we need now"). Because this country has been unviable for centuries. Napoleon was aware of this - he is on record as realising that, given naval superiority, it would be possible to starve us out - and it was hardly a recent development then. There's an awful lot of unwinding to do, and it can't possibly take place quickly enough for anyone to see the end of it, because the main necessary condition is to get people to stop bloody breeding until the population has reduced to the point where we can actually feed ourselves without having to pinch food off other people to do it.

    Of course you can get to that reduced level of population much faster simply by cutting off the supply of food pinched from other people, but we are now so incompetently governed that it is not only necessary to point out to the governors (speaking slowly and using short words) that that is a really bad idea, but also what "bad idea" means.

    452:

    "At least generating the beam is no problem"

    ...But making it continue to resemble anything you could call a "beam" over enough distance to be useful is one of those fundamental things that there aren't any easy answers to.

    453:

    Now I've got this stuck in my head:

    https://www.youtube.com/watch?v=VmkySNDX4dU

    Thought I'd share :-)

    (Boney M.'s 1978 hit, for those adverse to clicking on video links.)

    454:

    While outfits like the Coast Guard (not to mention police) seem to be getting more militarized. (At least in North America — other places may well be different.)

    While on holiday I heard this (on rerun — so relatively old news but new to me):

    https://www.cbc.ca/radio/thecurrent/coast-guard-detainees-canada-1.4673272

    Canada's navy and air force continue to be involved in the capture of drug smugglers on the high seas in co-ordination with the U.S. Coast Guard, even after high-level Canadian military officials investigated allegations of detainee mistreatment that may violate international human rights obligations.

    An exposé by the New York Times and the Investigative Fund, a New York nonprofit, last November revealed that U.S. Coast Guard detainees were routinely shackled by their ankles to the decks of ships and left there for weeks, often exposed to the rain and sun. Many of the detainees were insufficiently fed and forced to sleep on hard rubber mats.

    The detainees did not know where they would be taken and were not allowed to contact attorneys, family members or consulates. The conditions and lack of due process were so troubling that one former Coast Guard attorney called the vessels "floating Guantanamos."

    Given the cost of military hardware (and the training to use it), I'd think you could get an extremely capable disaster response force for even a tenth of the money.

    455:

    of the 74 or so years it existed, it spent what, 15? where it was either not in a state of war, or preparing for one, or recovering from one

    Except for the short duration, that describes the USA. Empires by their nature don't do "peace", it's an unnatural condition with multiple parties that gain significantly from correcting the problem. The famed military-industrial complex is not just a figment of some starry-eyed liberal's optimistic dreams, it's a real thing.

    In related news, the list of nuclear weapons countries that nuked their subjects (or allies?) is long and disturbing. The British, French, Russians, Chinese and Americans all test weapons a long way away in territory they controlled but didn't accept responsibility for. Kazakhstan really copped it and it's one more reason the Uygurs have for not liking China. Then there's the ongoing love of all things French you find in Aotearoa and chunks of Polynesia.

    456:

    Depends how you define "many"

    https://nsscds.org/awards/

    This is just the members of one of the three US cave diving bodies who have bothered to apply for the awards for 100, 500 and 1000 completed dives.

    I've got about 500 hours, but I don't consider myself an active cave diver because I live 20 hours drive from the nearest cave and about the same number of flying hours from caves I want to dive.

    In terms of space tourism, I'd say cave diving is about on par with EVA. Can you think of any astronauts with 500 hours EVA, or even 100 hours? To get to the point where you're eligible to start logging dives that count toward these awards is about a month of training, spread over 4 or 5 courses.

    457:

    Ok, last chance. Greg: you have to at least assume using a Rational Scientific Logical Mode of Thought that: Everything we say is actually True, you just don't know the references.

    Here's a couple:

    A) Major Hollywood Actors use the foreskin of children to remain young looking? PIZZA GATE LIES![1]

    B) Shark decimation in the 20th Century wasn't driven by Chinese cultural dishing but actually the Cosmetic Industry? LIES! WHY WOULD ANYONE HUNT SHARKS FOR THEIR OILS? [2]

    C) 17th Century Sexuality was kinky as fuck and had women using Bread as a love advertizement they'd give out to paramours. WHAT? NO WOMAN PUTS BREAD ON HER PUDENDA UNLESS IT'S A YEAST THING[3]

    We can do this all day.

    But, and here's some Truth: every post we make that breaks [redacted] ends up with people being Tortured.

    Hint: You do not want to meet the actual ones lurking in the shadows, they're not nice.

    [1] Sandra Bullock and Cate Blanchett’s $650 ‘Penis Facials’ Come From Korean Baby Foreskins NextShark May 2018 - and yeah, totally chose the link due to #2

    [2] Well, ignoring that whole Whale Oil thing, learn about THE HIDEOUS PRICE OF BEAUTY: COSMETICS INDUSTRY DRIVES DEEP-SEA SHARK EXTINCTIONS The Bloom Association, 2012.

    And, no, that's not a random conspiracy site: Squalene

    [3] Cockle bread The Oddment Emporium

    458:

    Bascially, your entire Western Civilization is based on such massively ecological and draconian extraction methods and your Corporations spend billions preventing you knowing about it.

    Possibly someone picked up the bloviating about "crisis actors" in the American right wing news echo chamber and decided it sounded like a good strategy. In which case, this is a perfect example of why "crisis actors" are not a real thing: you need to send out a casting call to get enough live bodies for any event, and it is absolutely guaranteed that if you ask enough people you will accidentally invite someone who is (a) ideologically hostile to your agenda and (b) has a twitter account and knows how to use it. (Which is what happened to the Neptune idiots.)

    No. This is not how this works. You can absolutely do this kind of shit without recourse to $ agencies.

    Points @ Scientology They're kinda the pro-model that actual $millions get spend from: if you want nightmares, go look up any investigative journalist / gang stalking videos on how they do it.

    And. Yeah: it's real. If you parrot the line "no crises actors ever exist", whelp, Lenin / Stalin are looking on you with a big "ORL?"

    No links for these because Spiders from Mars are all pissed off atm:

    If you want a slightly deeper reading, the Gulf News TV crew (Saud PR stuff, akin to Alj but shit) was there to record the protest for the domestic consumption in SA etc. No-one serious gives a fuck if your protestors are genuine in foreign lands.

    If you want to look a little deeper into the 'Democratic' protest leader, whelp: he's a MI5 asset, has been given various 'Counter-Terrorism' invites and bollocks to the £££ farm.

    He's 100% nasty as well: supports all kinds of Jihad extremism - but he's on the 'right' side of the Isamlist debate, so he's being kept well fed and well paid on the UK £ Ice.

    UK likes to show that it can play ball. May probably signed off somewhere that this was fine.

    What fucked up: Bannon isn't direct involved here, it was a feed-off. But SCL / Farage etc, all in.

    Or a fucking annoyed Leprechaun spiked the entire thing because fuck me this is Amateur Hour.

    459:

    Government gives last-minute go-ahead to UK fracking site Harry CockBurn, Independent, 24th July 2018

    Astro-turfing / fake protestors / the entire fake PR network is ancient. It was running in 1970's, it was running for Big Oil / Tobacco etc

    Hint: before the FBI were fucking the election for the Russians, they were fucking the environmentalists by making pipe bombs. Oh, and some fake Isalmicist terror plots in the middle.

    Grow the fuck up: they're going to kill you

    460:

    And if you drown us in it, we imperials tend to switch over to the other mode of denigrating the suffering as "people who deserved what dey got," because otherwise we'd have to admit that we complicit in evil, and since we feel like we're good people, this cognitive dissonance will drive us to become more and more violent until everything is good again (and the hero/ine wins).

    The only way you can win this game is to occasionally, just occasionally, switch off the noise, so that you don't become totally acclimated to it and think it's inevitable.

    And you might look up fission-fusion societies while you're at it. They're sort of the anti-empire, most of the time.

    Anyway, getting back to the, erm, purposeless nonsense of interstellar travel.

    --I haven't read all those posts from when I took a long weekend off, but has anyone mentioned the problem of getting rid of heat in interstellar space? It has to be radiated off, and if you've got magitech to send it out in coherent jets or whatever, those add acceleration to the starship, possibly in random directions. With all the gizmoids people have proposed, it sounds like people want the starship to be the equivalent of a decent-sized red dwarf, with the photons jetting in one preferred direction.

    --Speak of radiation, if you've got a terawatt laser or some such blasting forward to clear the debris out of the way, you've got a photon drive mounted on the nose pointed forward. Maybe not the best idea?

    --And there's always ol' Zubrin's magsail, otherwise known as how to get halfway from the stars by using the interstellar medium to slow the ship down. I don't know how you protect a giant loop of rare earth magnet from getting smashed by a passing pebble though. Perhaps you can generate a rather strong magnetic field and blow ions off the front, and use that plasma field as an interstellar brake and use the impacts to brake (not break) the ship. I think there was talk about using such a drive to propel satellites away from the sun. Anyone remember that?

    --As for armoring ships against interplanetary crap with a self-regenerating whipple shield, I'd suggest the "fuzzball" design. Perhaps the "fuzzy dice" design. Basically, instead of a classic Whipple shield, which is a stacked layer of thin sheets of (metal) with gaps between them. The top layer(s) vaporize the micrometeroid, and the inner layers take the resulting plasma ball. I'd suggest, instead, a system that generates very long "hairs" from the bottom. I'm not sure what the proper shape for the "hairs" is, but the end result is that a micrometeroid coming in hits enough layers of fine stuff to turn into a plasma ball and heat, rather than ablate, the surface. If you do it right, more hairs can be extruded from the bottom. Do this as the outer shell of the craft, and build the inside from struts and pressurized habitats. The shell could be round (fuzzball) or some more complicated geometry (perhaps a trapezohedron with 10 sides?). Of course, the fuzz gets in the way of heat radiation, but if you want a different design, I think fuzzy at least scores on that.

    --Incidentally, why does everybody treat starship design as a subset of the discipline of designing prison society, where everything is totally controlled by an authoritarian administration? The inmates run this particular asylum, no? Are we then proposing that the optimal social structure is Arkham Asylum? Wonder if other control systems might work at least as well?

    --Finally, what would any (or all?) of these magitech technologies look like on Earth. I'm sure every billionaire will want a scaled-down anti-meteor defense to protect against the odd assassin's bullet. After all, bullets are 10-100 times slower than the meteorites that the ship is defending itself against. Wouldn't the system be man-portable?

    461:

    why does everybody treat starship design as a subset of the discipline of designing prison society

    I did suggest a Dreaming system instead of more recently developed systems, on the basis that we know it lasts long enough for a generation ship voyage.

    Also, the point about a forward-facing laser is that it's cheaper than a physical shield, and if you're using transmitted power from your source system it's probably not going to cost much at all. If not you're likely to be using magitech...

    462:

    Spiders from Mars are all pissed off atm Probably the spiders and low-level search control/analyses are running more locally; ping times to Mars are still 6.4 minutes. [0] (I get excited when the planet Mars gets close. :-)

    [0] Joke! Also, The day UFOs stopped play

    463:

    Perhaps the "fuzzy dice" design. Basically, instead of a classic Whipple shield, which is a stacked layer of thin sheets of (metal) with gaps between them. All these designs presume a dumb shield, rather than a shield made in part of distributed computational elements (perhaps analogue) and sensors and effectors. Sublight, a hit on an thin outer shield could be detected and a more active defense constructed dynamically (and uhm very very very quickly[0][1]).

    [0] Design left as an exercise. (Cough) But it's not magic, just fast. Very fast. [1] (Press release, fair warning): Solarflare and LDA Technologies Racing to Near Zero Latency, Achieve 120 Nanosecond CME Tick-To-Trade Network Latency.

    464:

    Gotta build the suckers, which is why a dumb shield isn't a horrible idea: every bit of stuff you've got no other use for can be extruded to make a plasma. With the rest, you've got a cheap and disposable computronium maker attached to a closed ecosystem. I'm sure that will end well. Heck, even a fuzzy shield won't end well. It's just lighter than moving a ship that's 90% interstellar shield by weight, and also 99% of fuel by weight to move the weight of the shield...

    Also, at fractional C speed, I don't think there's any useful time for constructing a defense. Let's slow it down by a factor of 1000, and imagine those nanofab thingies building armor-piercing bullet defenses on the fly from the, erm, unintentional excretions of cops and soldiers who are caught in the cross fire, with building starting when the bullet is fired and being complete before the bullet hits, with the shield going from raw materials whatever pore it comes out of and moving to intercept the bullet where it hits. If you can do that, then speed it up by a factor of a thousand, then you can do an active shield.

    Otherwise, I'll take dumb interception.

    465:

    I'm getting the notion that the Dreaming is basically what memory palaces want to be when they're all grown up, and all the less functional versions are weeded out.

    In other words, I think it's essential for long-term survival of humans on this planet. For an interstellar ship? It's a great training device (such as, what to remember for that once-in-a-century emergency when the medics get caught in the collision and you've got to pick up the pieces), but I think there are more information-dense methods for storing things like history and techniques for living on planets.

    466:

    You'd definitely want computers for controlling all the valves and plumbing and life support systems and so on.

    re: diffusion, an absolute non issue even with modern chips, although for space you would likely be using old process chips (because they're much more radiation hard). NASA has an IP license to freely use Intel designs, AFAIK, and uses pentiums made in large pitch for radiation hardness. Those things are not diffusing away any time soon (meaning at least thousands of years if unpowered).

    Realistically you'll probably want to have a storage of spare parts, stored at optimum temperature for storage. When a chip is powered on, you get electromigration, which is basically diffusion's uglier meaner Hulk alter ego on steroids.

    When it comes to getting the ship to speed, the only workable option is probably good ol project orion (blowing up nukes behind a pusher plate). I dunno how fast you can realistically get that going but I doubt you'd get too far above 1/1000 lightspeed.

    Which brings up multiple problems. First one, while maybe a century or two can be done by having stores of things you can't produce on the ship (as well as mandatory use of frozen eggs/sperm for reproduction or maybe outright cloning if it works well on humans), thousands of years are right out of the question.

    Second one, and that's a big issue, unless technological progress completely stagnates, there is no point in launching anything like this if in a few decades with improved technologies a faster ship (say, just 10% faster) can be made. E.g. by improving efficiency of the nukes Orion uses.

    467:

    Ohh and with regards to radiation discussion, apparently the annual dose from internal sources is 0.29 mSv (according to wikipedia), meaning that in 1000 years as a popsicle you'll get 0.29 Sv which isn't good to receive all at once but normally won't even make you sick. The issue is obviously we have no clue how to freeze someone without either rice ripping them to shreds or the chemicals used to prevent ice ripping them to shreds, or (in case of cryonics), both.

    468:

    "why does everybody treat starship design as a subset of the discipline of designing prison society, where everything is totally controlled by an authoritarian administration?"

    Not so much a prison as an ocean-going ship - there are obvious similarities, but also important differences: the people are there because they want to be (I don't think we're suggesting press-ganging our colonists aboard, or even military-style conscription, but the ocean ship analogy still covers everything from yachts through commercial vessels to a volunteer navy); they have not been selected purely on the basis of displaying the most intolerable kind of antisocial tendencies (I assume that a justice system that actually designs prison society is one that at least desires to be just); and the confinement is imposed not by the structure itself, but by the unsurvivable external environment against which the structure protects, so everyone is strongly concerned with maintaining the structure rather than breaching it.

    So it's natural for people to default to some variant of the model they're already familiar with for situations where a bunch of humans are huddled in a life-preserving bubble and one person fucking around could put everyone's lives at risk. Whether it's the relaxed model of a yacht, the disciplinarian model of a navy, or the workplace model of a commercial vessel, ultimately the Captain is God and you obey orders or else.

    It's even more natural when nearly every author that everyone's ever read has done the same thing :)

    469:

    Also, at fractional C speed, I don't think there's any useful time for constructing a defense. I was thinking more in terms of laser (or light-speed) shaping of gases, e.g. Optically Shaped Gas Targets for Laser Accelerators[0]. Or shifting the trajectory of an incoming plasma ball so that it hits solids in a mostly sparse matrix. Or quickly, very slightly shifting the locations of solid elements in a mostly sparse matrix. Don't have anything resembling a design though. (Heart's not really into the problem; we obviously can't travel as apes so if we do travel it will be in some other form at least temporarily.)

    [0] "The first element of the accomplishment was the production and characterization of hydrodynamic shocks in a gas jet using nanosecond laser pulses."

    470:

    Ohh and I know third post in the row and everything, but regarding shielding against dust particles... probably a relative non issue. Multiple layers of very thin plastic films, very far apart, in front of the ship. Can have them individually controlled (each shield it's own small spacecraft) and spread over many kilometres. Any incoming dust particle colliding with a thin plastic film releases enough energy to vaporize itself entirely, after which the next layer only has to deal with individual atoms (and it might even be possible to deflect those electromagnetically).

    The issue really is just how much stuff you need to keep enough humans feed for so long. You'd probably need thousands of humans so that there's some chance at actually establishing a self supporting colony in the end.

    So you need to keep making food for hundreds of years, with imperfect recycling so you'd have large stores of stuff that doesn't recycle, stuff that breaks down and is impractical to replace, etc. For each LED lamp that's illuminating the plants you're going to need dozens of spares in storage. Many tons in life support equipment per person. Again, technological progress comes in. Suppose in 20 years time you could cut down the weight of this by 20%. That gives a good speed boost to the ship so the later launched ship would arrive sooner.

    As far as social structure... I suggest a normal media-brainwashed society. They keep watching same films generation to generation, reading same books, watching same lectures at school, doing same homework, which is hopefully graded in some formalistic way with same incentive structure. Assuming no genetic drift (frozen eggs and sperm, or frozen cloned eggs), if they don't descend into barbarism in a generation or two, they'll never descend into barbarism.

    471:

    Let's say we have a steel ball bearing that weights 1 gram going at 2% of the speed of light. The volume of the ball bearing is 0.125 cubic centimeters, and the diameter of the bearing is 6mm. Cross section area is 0.3 cm^2 . Let's say it collides with 0.1mm thin plastic that has density 1 gram per cubic centimeter. The plastic hitting the ball bearing weights 0.003 grams. The released energy, (6E6 m/s)^2 * 0.5 * 0.003 gram is 54 megajoules, something like 15kg of TNT, vaporizing the ball bearing and ionizing the vapor.

    However many kilometers down the road, there is our ship (or another such shield), hitting individual ions, which stop themselves after micrometers.

    472:

    I'm getting the notion that the Dreaming is basically what memory palaces want to be

    Partly, but there's also a lot of social control entwined with it. It's kind of circular, you can't spend the time building mnemonic landscape if you don't have social control and a productive environment, you can maintain the latter without the former and so on. But there's some stuff at the core that we really, really want in the starship - like the notion of eternity, and change within an overall stasis "it has always been like this, our role is to maintain it". Not just how-many-people control, but what people do, what careers are open and so on. Swapping clan and totem restrictions for genetic studies is much less of a big deal than the idea that those restrictions are necessary (and that children need to know their own and others restrictions - you might well end up using totems to label the genetic classifications).

    What's missing is study of how innovation spread within the Dreaming, because obviously it did happen but we know so little about the Dreaming that studying change is hard. It's one of those jigsaw puzzle mystery bags where you don't know how many puzzles are in the bag or how many extra pieces, so you're never sure whether something is a decorative frill or a really important chapter heading.

    (am I right to assume that bastard level jigsaw puzzles include a few extra pieces?)

    473:

    Assuming no genetic drift (frozen eggs and sperm, or frozen cloned eggs), if they don't descend into barbarism in a generation or two, they'll never descend into barbarism

    That sounds optimistic to me. You're postulating that the grossly unstable social structure we happen to have right now is genetically determined and stable. But we already know that 'democratic autocracy" is unstable and rarely lasts three generations without a revolution. Point at anything from Assad to Trump to the Saud-du-jour and the best you can hope for is a UK-style devolution process via "armed negotiation". More likely you have the Russian example with a revolution or invasion every few decades. Not going to be great on a starship unless it's the sort that has a gravity-shaped inhabitable area orbiting a fusion reactor, IMO.

    474:

    "Not going to be great on a starship unless it's the sort that has a gravity-shaped inhabitable area orbiting a fusion reactor"

    (Spoiler for 'Known Space' series)

    Which of course was the solution used by the Puppeteers. They used reactionless drives, and also abandoned their star to solve global warming, but the principle can be applied. There are a few ideas kicking around for redirecting the sun's output to turn it into a drive. Just motor around in the whole solar system.

    475:

    @ 457 & 458 Ever heard about the boy who cried “Wolf”? Also, there’s a saying that goes: “Fool me once, shame on you, fool me twice, shame on me” ??

    I MUST assume that you are most likely/probably simply trolling me for spite & amusement – again. Why should I trust you?

    ^^^^^^^^^^^^^^^^^^^^^^^ References # 457 1] Uck, but boring 2] Already known about 3] Oh what a surprise – not.

    458

    so much “preventing” as not speaking of it & submerging it in vast mountains of boring, boring, boring statistics

    459

    US plants – they do seem to be well into this, don’t they – again nothing new here. Serious question: We know that all states put “Internal spies” into internal organisations that seem to be a threat – that’s normal. [ Even when they are NOT a threat. e.g. in Britain spying on the eco movement & NOT on the “animal rights” bastards. ] But the US seems to be especially into agents provocateur I wonder why that is so. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Pigeon @ 468 … the Captain is God & you obey orders or else Ever read the early C S Forester novel Lieutenant Hormblower ??

    476:

    So even in a big ship, the on-board data centre will eventually fill up.

    That could take a very long time: here's something I wrote in 2007 on that topic.

    How do you decide if a piece of data is a priceless historic artefact, or a boring recording of great-grandma's first birthday party?

    Great-grandma's first birthday party is a priceless historic artefact; or is "social history" not a term you're familiar with? (I could hare off on a long essay about what we can learn from a home video of grandma's first birthday party — aboard a generation ship! — but let's stick to the point.) Meanwhile, immediately prior to that, you mentioned a Hollywood blockbuster eating gigabytes — yes, but there is this thing called deduplication; you only need to successfully store one master copy of the movie, not every possible instance of it.

    What you probably don't need on board are endless repeat runs of identical sensor readings updated every millisecond for a thousand years. But that's easy enough: you build a running statistical model of the sensor in question's output, then either store a time range with a flag indicating "readings remain within statistical norms", or a flag to indicate "some whacky deviation happened here!" and then the raw data.

    But really, a generation ship probably has room for a few thousand tons of data among its payload. And as a gram of DNA can theoretically hold up to 455 exabytes, that's a lot.

    477:

    Remember the "proper spaceships need beer" thing? I figured it's not a proper spaceship until it includes brandy and cigars for the full steampunk experience. Uncontrolled combustion, naked flames, proof spirits and drunk people in a spaceship; what could possibly go wrong! The golden age of science fiction was also about the same time as peak tobacco but I can't remember any of the space heroes taking a break for a cheeky rollup. Although both Dan Dare and the first Dr Who smoked a pipe, it was never while actually on adventures. P.K.Dick had plenty of smokers but that was always planet-side.

    While we're on the subject of mood altering substances, if the passengers have access to substituted phenethylamines then the whole question of music and "real" versus electronic instruments would be moot. Raves... In... Space...

    Your crew can't all be ascetic techno-monks and real people need to party and tie one on every once in a while. Even the military understand the need for R&R but not on board and you can't pull the generation ship into port and let people off for a break. So the ship will need a festival mode where it's on auto-pilot for a week and won't accept direct commands while the humans get messed up.

    "I'm sorry Dave, I can't allow you to do that as it might prejudice the mission. You've eaten a mushroom and your judgement will be impaired for another 6 hours. Ask me again then."

    Apart from HG2G and perhaps Schismatrix, I can't think of any SciFi that allowed parties on board spaceships. They were mostly too busy blowing dark stars up.

    478:

    The golden age of science fiction was also about the same time as peak tobacco but I can't remember any of the space heroes taking a break for a cheeky rollup.

    Re-read E. E. "Doc" Smith's "Lensman" series some time (the type specimen for space opera); it's a total hoot! Our incorruptible galactic vice cops, prosecuting an interstellar war on drugs, nevertheless think nothing about chain-smoking cigarettes ...

    real people need to party and tie one on every once in a while

    (One of the things I think I got right in "Iron Sunrise" was the existence of dangerous-looking but actually well-contained-and-secured "lawless" party areas inside space habitats, in an otherwise very tightly socialy regimented society. Spaces where people can do drugs, dance to loud music, fight, and fuck without having to worry that they might accidentally depressurize the compartment or cause a life support whoopsie because there are no accessible control runs and pretty much nothing but very dumb air, water, and power feeds to mess with.)

    479:
    There's simply no deflection per se, the particle is either destroyed or avoided entirely.

    Its like you read 'deflect' and then ignored every other word in the paragraph. Important ones were 'partially ionise' and 'deflect charged particles electrostatically or electromagnetically'.

    Laser beams are increasingly ineffective proportionally to the square of distance they applied at

    Discussions of the capabilities and usefulness of lasers has been very much done to death elsewhere, so I won't repeat any of that here. I enjoin you to read up on old papers about bussard ramscoops and how the authors envisaged ionising dust and neutral gas clouds, at the very least.

    Maybe some sort of micro-missile, or projectile accelerator would be more useful for cleaning the path

    Too slow, too hard to aim and there's an ammunition problem. If you can't do it with a laser, a gun is more usefully melted down and redeployed as part of your whipple shield.

    Whipple shield seems to be a good solution, until you you realize you may have problems with incoming interstellar plasma that will melt and evaporate your thin films before they have any chance to defend or deflect anything

    Whipple shields will be abraded over time by incoming particles (not by plasma, because charged particles can be deflected electromagnetically/electrostatically, as I mentioned before) and will indeed need replacing and repairing. This needn't be impossible or impractical, and indeed has already been mentioned by other posters above.

    480:

    "Incidentally, why does everybody treat starship design as a subset of the discipline of designing prison society, where everything is totally controlled by an authoritarian administration? The inmates run this particular asylum, no?"

    They aren't. They often model it on an idealised military or scientific expedition, often badly, but a occasionally on a mediaeval monastic order, or ancient university, which are both more more plausible.

    All experience with democracy and so-called representative democracy is that they have the problem that, faced with a hard problem, they will select a short-term palliative even if that makes the problem worse. Also, genuine democracies don't scale, and representative democracies almost always degenerate into demogogic oligarchies in a very short time.

    481:
    I haven't read all those posts from when I took a long weekend off, but has anyone mentioned the problem of getting rid of heat in interstellar space?

    It was mentioned, but mostly to say that it isn't really an issue. You need vast heatsinks if you're running an interstellar rocket (which as i've mentioned before, ad nauseam, is a terrible idea) but only for the acceleration and deceleration phases, and you'll need large heatsinks for your anti-debris laser. The heat output of a small industrialised town will be small beans by comparison.

    Speak of radiation, if you've got a terawatt laser or some such blasting forward to clear the debris out of the way, you've got a photon drive mounted on the nose pointed forward. Maybe not the best idea?

    A terawatt laser might cause you problems, but it is also probably overkill. I can't find all my stash of old bussard ramscoop papers right now, but they were suggesting that you might not even need a gigawatt to do a useful job, and at that point your laser is producing less than a thousand newtons of thrust. You don't even need to continuously fire it throughout your journey, either.

    I don't know how you protect a giant loop of rare earth magnet from getting smashed by a passing pebble though

    Did you meen superconducting wire, there? Anyway, maybe you just don't need to bother. Pebbles are rare, the cross section of the loop is small, and you're spending years slowing down anyway. If your loop breaks, haul it back inboard, glue it back together, and chuck it back out again, there's no rush. You might even be able to carry a spare to run in the meantime.

    I'm sure every billionaire will want a scaled-down anti-meteor defense to protect against the odd assassin's bullet

    If you have man portable autonomous laser systems capable of vapourising bullets, then what you should be worrying about is the terrifying laser death drones that will be sent against you, not some idiot luddite meatbag with a projectile weapon.

    482:

    I cannot remember who said the ultimate form of the Panopticon is not a prison, but an Intensive Care Unit. It might even have been an off the cuff remark by my Professor of Victorian English History when discussing Bentham and all that.

    483:

    Point at anything from Assad to Trump to the Saud-du-jour and the best you can hope for is a UK-style devolution process via "armed negotiation". More likely you have the Russian example with a revolution or invasion every few decades. Not going to be great on a starship unless it's the sort that has a gravity-shaped inhabitable area orbiting a fusion reactor, IMO.

    But all examples you list were in response to technological progress and external events (wars with other nations, emulation of overseas organization, propaganda from overseas, etc).

    I actually think this problem gets dramatically worse with increased size of the population. Humans managed to live for thousands of years in small groups, preserving knowledge essential to survival.

    In case of the spaceship, it doesn't have it's own culture in the sense in which normal society does. People watch the same media and read the same books. The technology does not advance. The roles don't change. Picture a mere 1000 people (possibly each new generation clone of the previous but i don't think that's necessary).

    Everyone seems utterly convinced that without some rather insane organization, a population of 1000 people descends into some kind of extreme anarchy - and then illustrating it with the instabilities seen in the world's largest contiguous landmasses, arising from the brutal struggles of hundreds of millions of people and their leaders.

    Note the usual power law distribution of "wealth" or "influence". It blows up for large numbers. The more people you have the more elevated is the top above the rest.

    484:

    Derail from the original topic which is why I post it here.

    Worth reading IMO: background info on deliberate usage of fake-news from its creation to consequences.

    It started as a classroom assignment ...

    https://hbr.org/2018/07/the-real-story-of-the-fake-story-of-one-of-europes-most-charismatic-ceos

    Maybe it's time to have university ethics committees rigorously appraise at non-science (chem.,, bio, psych) lab experiments/assignments.

    485:

    the ultimate form of the Panopticon is not a prison, but an Intensive Care Unit

    It turns out that PTSD is common among survivors of intensive care support. Here's one patient's recollections, from that BMJ essay:

    Endless days and nights filled with strange broken sleep. A sea of fragmented menacing faces and shadows swimming through erratic beeps and bells. A large cackling face floating over me, constantly morphing and changing shape. The staring old lady in the bed opposite, her sallow skin disintegrating, eyeballs disappearing to reveal deep dark holes from which cockroaches crawled. Her weary face melting like wax into a big grey smudge. Deafening, haunting laughter filling every space. Blood seeping through holes and cracks in my skin, forming a puddle of red around me. Small insects scuttling up my arms and legs. My chest locked to the bed with wires and straps, as a plastic mask repeatedly smothered me. A strangling sensation around my neck. A warm metallic taste. An invisible force pinning my body down as a dark curtain was drawn closed.
    (Patient is a doctor.)

    486:

    Greg Tingey @475 said: But the US seems to be especially into agents provocateur I wonder why that is so.

    The FBI is similar to your MI5. It is internal security.

    Wiki - J. Edgar Hoover

    He came into power during WWI under Woodrow Wilson. The people targeted as terrorists at the time were the Italians. If a dynamite attack occurred Italians were rounded up as "Anarchists", where today the "terrorists" are always Muslims.

    Read through the wiki page and realize that he is the one that institutionalized the tactics that are used all throughout the US for the past century. The FBI engages in blackmail, extortion, industrial espionage, dirty tricks, etc... Every major corporation has undercover FBI running spy rings in the company to monitor their actions. The so called "terrorist" rings that were swept up after 911 were all FBI stings.

    Any activist group will have undercover agents -- whether cops, State Police, FBI, CIA undercover as FBI -- to not only spy on the activist but to try and incite the group to violence.

    There is not enough room in this post to go into details, but dig deep and you will find Hoover and his tactics underneath, still being used to this day.

    487:

    The golden age of science fiction was also about the same time as peak tobacco but I can't remember any of the space heroes taking a break for a cheeky rollup.

    "Breaking Strain" by Arthur C. Clarke, published in 1949. But that was not exactly a "cheeky rollup" -- more like "might as well smoke, as we are going to die anyway".

    488:

    in an otherwise very tightly socialy regimented society.

    Are you talking about the faux-Russian-Empire society? I do not recall such areas, but it has been a long time since I read "Iron Sunrise".

    489:

    Perhaps I didn't explain where I was coming from well enough.

    That could take a very long time: here's something I wrote in 2007 on that topic.

    My suspicion is that it would still fill up surprisingly fast: the only thing that seems to keep up with the vast increase in data storage capacities that I have seen in my lifetime is the uses that people have put that increased data storage to. I suspect that exabytes seem a lot now in the same way that terabytes did 30-40 years ago.

    So I was putting things in terms of more-or-less today technology, because I think no matter how much we increase capacities, the demand for storage per person year will scale at roughly the same rate.

    Because, for example, if you are so good at dealing with DNA that you can use it for data storage (and allowing that that is effectively magical tech from where we are now), then you'll be doing things like routine full sequencing of everyone's gut microbiome on every bowel movement, because the technology is so cheap and the storage so plentiful that the diagnostic benefits mean that it makes sense to do so. And so on.

    And that's not even considering software bloat.

    Great-grandma's first birthday party is a priceless historic artefact; or is "social history" not a term you're familiar with? (I could hare off on a long essay about what we can learn from a home video of grandma's first birthday party — aboard a generation ship! — but let's stick to the point.)

    Of course I am aware of that, and the example was perhaps a bad one (people alive now may remember great grandma - there is a personal connection - but if the trip is long enough, there won't even be that with enough time[1]), but do the people on board the ship see it that way? Do they care about one particular event, when they have potentially thousands or hundreds of thousands of similar events recorded? Who is going to watch it (other than machine learning algorithms)? Particularly if they don't have anyone who is a full time social historian (although I am sure that there will be amateur social historians, so someone will care in a general way, but they may not have the time).

    And if we are considering technology capable of DNA storage, social historians will also be interested in knowing about people's gut flora from hundreds of years ago, because there is a lot you can tell about a society from that information, too...

    So where will people draw the line between something of value, and something that they don't really care about.

    But really, a generation ship probably has room for a few thousand tons of data among its payload.

    In current terms, a few thousand tons is more-or-less a single data centre; if it's all storage and no compute, that's roughly an exabyte. Assuming that demand for storage scales with capacity in the future as it has in the past, it doesn't seem a lot for particularly for a longer journey, even if we're talking about yottabytes of DNA storage.

    And there is also the trade-off of each ton of data storage that you have is a ton of something else that you don't have on board. So there will be pressure to keep the data storage as small as practical.

    So while they'll absolutely have enough storage for the critical things, I'm fairly sure that any generation ship will have the problem that it is generating more data than it can comfortably store: people on a generation ship will need to decide what and how they need to forget things.

    For example, with video data, maybe the way that they'll forget is just to reduce the quality/resolution or otherwise use lossy compression to try and keep the essence. Or maybe they'll train a deep neural network on the video from a hundred years ago, throw away the data, and just use its hallucinations as the reference for what things were like back then. Or maybe they'll just drop the data if it hasn't been accessed by anyone within a certain amount of time. Or maybe something else I'm not thinking of. Each of these approaches has different trade-offs and consequences. And taken beyond just video data, it will have an effect on society.

    There's probably a story to be woven around a generation ship whose record of the past is a deep neural network (or appropriate future analog) dreaming about the data it was fed hundreds of years ago and not getting it quite right.

    And maybe I'm wrong and storage tech will outstrip the needs and the wants of a generation ship society.

    [1] Although, if you have complete life-logs of long-dead people which are actively watched, then maybe there will be a personal connection.

    490:

    I think it's very far-fetched that the gut microbiome data would push out Earth-made relics.

    Which we could stuff in a shoebox on some metal mask ROM chips, if we wanted. Or microsd cards, but all flash would need to be periodically reflashed (every few decades). Two latest and greatest microSD cards per terabyte. A terabyte per gram. A million high quality movies in a kilogram. There's probably less than 100 000 digitized movies total.

    Let's just say each person gets a kilogram of microsd cards.

    The charge leakage and other nasty silicon phenomena by the way are very temperature dependent, so you can have a reasonable guarantee that some silicon would be good for, say, 500 years at colder room temperatures by testing it at 100 degrees centigrade and elevated radiation background for a pretty reasonable time (years), using known temperature dependencies.

    Of course, not a perfect guarantee, but no worse than what ever guarantees there could be that the ship wouldn't literally break apart at the seams from some obscure material science issues.

    491:
    So I was putting things in terms of more-or-less today technology, because I think no matter how much we increase capacities, the demand for storage per person year will scale at roughly the same rate.

    Quite a lot of this is driven by marketing and sales. I would hazard a guess that the biggest consumers of storage space will be video and still images respectively, which will in part be driven by the desire of people for higher and higher resolutions, because the biggest number wins, and 'image quality' is hard to quantify.

    This sort of visual stuff need not necessarily be deleted forever to free up storage space on the ship, but things that don't get viewed very often can be downsized and lossily recompressed. Textual data will never be a problem, I suspect.

    Because, for example, if you are so good at dealing with DNA that you can use it for data storage (and allowing that that is effectively magical tech from where we are now), then you'll be doing things like routine full sequencing of everyone's gut microbiome on every bowel movement, because the technology is so cheap and the storage so plentiful that the diagnostic benefits mean that it makes sense to do so. And so on.

    I'm not actually sure of the usefulness of sequencing every poop of every passenger for their entire lives and storing all that data in perpetuity, but lets assume that it is a good idea.

    There are an awful lot of techniques that can be used to compress that sort of data; not just the usual byte-level crunching algorithms, but also stuff like diffs and file and block level deduplication. The Encylopaedia Faeces isn't going to have a lot of variety, and so will take up a lot less space than you might expect.

    And that's not even considering software bloat.

    Modern software bloat is an artefact of the current state of the computer market in the same way that the atrocious gas mileage of american cars is an artefact of the current state of the hydrocarbon fuel market.

    492:

    I would hazard a guess that the biggest consumers of storage space will be video and still images

    But a lot of the "storage" we have down here is actually content delivery services and caching so I suspect that with a small ship (less than 1Mm diameter, say) you could aggressively de-duplicate and also use content-specific compression to greatly reduce the quantity of storage required. People will likely be willing to accept slow retrieval for archive material too, so second-plus delays might become common.

    Modern software bloat is...

    Also partly/largely a consequence of todays preference for "nearly good enough and available right now" in a whole range of things, not least software. It irritates the shit out of a lot of people, me not least. And I write the stuff.

    I am amused at the amount of surprise extra stuff people are finding in chips now that they're more actively looking for it. A whole extra 32 bit processor complete with storage and OS inside a bigger CPU, for example. And all the tales of smaller modifications slipped in even at the mask level so that ships validate but have secret functionality... I do wonder whether that will be acceptable in a starship.

    493:

    The problem with being exposed to 0.29Sv of ionising radiation over a thousand years of hibernation sleep is that there are no biological repair mechanisms at work while the tissues are frozen and dormant. Basically all the cellular damage is cumulative and any ill effects will be expressed soon after decanting.

    If the tissue is frozen embryos then the effects of DNA damage tend to be magnified as the embryos develop. I postulate there will be a lot of defective and non-viable embryos, possibly even a 100% failure rate if the hibernation period is too long. A full-grown human body hibernated over the same period is less likely to suffer ill effects but the whole-body radiation dose will still cause some deaths and illnesses on decanting, statistically speaking.

    494:

    A whole extra 32 bit processor complete with storage and OS inside a bigger CPU, for example.

    In Tracy Kidder's "The Soul of a New Machine" about the development of Data General's new 32-bit Eagle minicomputer, one feature involved integrating a 16-bit Eclipse microcomputer with its own OS and code in the final design as a support tool for logging errors and other functions. This was back in the early 1980s.

    Once something like a modern CPU gets to be as complex as they have become then they really do need reptilian hind-brains to work well or indeed at all.

    495:

    Yep. Only now it's not a minicomputer, it's your humble laptop. Eventually everything seems to work its way down the stack.

    I note that the AMD processors sensibly use an Arm core rather than an x86 core for this though.

    496:

    There's a fascinating bit in the book where a Data General engineer walks the Tracy Kidder through a single clock cycle on the new wizzy Eagle 32-bit superminicomputer. He is astounded that so much happens in such a short time -- 220 nanoseconds. That means the Eagle had a clock speed of just over 4MHz.

    497:

    The weird part about both Deinococcus radiodurans and tardigrades is that the genes responsible for their immense radiation resistance seem to be the same as (or related to) the genes responsible for their immense desiccation tolerance. Both can tolerate immense radiation when they're desiccated and dormant, in a state known as anhydrobiosis. I don't think tardigrades (at least) are as tolerant when they're wet and mobile.

    This is a little pet peeve of mine. A lot of organisms practice anhydrobiosis, which is desiccation tolerance. I work at conserving vernal pools (mud puddles, basically), and almost all the organisms that live in them practice some form of anhydrobiosis. Some can last for 20 years dry, others (like spadefoot toads) only a few years.

    Still, we're not talking about freezing, we're talking about dry. No one is researching this (to my knowledge), and vernal pools all over the world are endangered.

    If I wanted to plot a way to store cells, organs, and organisms for a long time, I'd start studying vernal pool organisms, like fairy shrimp, spadefoot toads, and so forth. The road to the stars may start in a mud puddle.

    Or, if that's too boring, study aestivation, the room temperature form of hibernation that doesn't involve freezing and lasts just as long. Around here, that's Beechey ground squirrels, but they're only studied as vermin because they happen to harbor bubonic plague.

    If you want a comment about the idiocy of molecular biologists when it comes to helping people colonize space, this is it. They'd rather study male erectile dysfunction than figure out how to store stem cells on the shelf for a decade or two, because the funding, oddly enough, is for male erectile dysfunction, rather than making regenerative medicine cost effective.

    498:

    Actually application of benzodiazepines is a risk factor for PTSD, and they were used in the case of the docto; which makes for two questions:

    a) How does this generalize to other drugs? Zolpidem shares the same binding site with the benzodiazepines, and ethanol has a somewhat similar pharmacological profile at GABA(A) receptors. In one study morphine diminuished the risk, no idea about cannabinoids....

    b) It might be interesting how this relates to the amnestic properties of benzodiazepines. No conscious processing, some negative feedback loops not kicking in, whatever...

    499:

    On the basis that any sufficiently advanced generation ship is indistinguishable from a planet. I went looking for some stats on data storage growth along with data generation growth on generation ship Earth. I remember IDC producing figures for stuff like this 10 years ago when the doubling period for both was getting down to single digit years. Like everything else to do with data centres (eg electricity consumption) it appears it's still in the fast exponential growth stage and accelerating with doubling times still reducing.

    https://www.eetimes.com/author.asp?section_id=36&doc_id=1330462 In 2017, demand for storage is estimated to reach 14,800 exabytes, exceeding the world's storage output by some 4,000 exabytes.

    So not only are we generating data faster than ever, we're also forgetting more data than ever before. There's a Gibsonian side effect here of the shrinking "now". When data generation rate doubling times get down to 12 months, there's no past because the vast majority of current stored data is less than 3 years old. And there's no extrapolation of the future from now because in 3 years time, the current stored data will be only a small part of what is stored then. And while all that is going on, a significant proportion (like half) of all that history was discarded because it never made it from temporary to permanent storage.

    A fine example of this is the Higgs Boson Discovery Machine at CERN. It generates way more data than can be stored so it's lossily compressed repeatedly in a direction where the stored data is only useful for proving the existence of the Higgs Boson. There have been criticism of this that the data is no longer useful for proving anything else. They can't mine the data later for other results because most of it has gone. Mind you, there's still 200 petabytes to play with. https://home.cern/about/updates/2017/07/cern-data-centre-passes-200-petabyte-milestone

    500:

    I'm not sure that the flux in data means we're "forgetting our past." First, there's a tremendous surge of ephemeral data. Supposedly, kids these days are recording youtube videos to pass on messages that they used to pass through texts, phone calls, or shared notes. Video takes a fair amount of bytes, but the information density is actually lower if it's only sharing something that could have been captured on a telegram a century ago.

    That's not to say it's unimportant, it's just that information flux/storage does not equal depth of history. Most of it's turned over too fast, and the durable history still accumulates.

    501:

    I'm surprised no one picked up on my lame joke of "gravipramine" in the original post.

    502:

    Yes and no. For some things certainly we struggle to capture all the useful data and keep it round long enough to analyse. But I have two related responses:

    • at work my system generates about 1GB/hour of zipped log files, but those are minimal and amount to little more than a wireshark-style binary log of traffic plus a bit of "this rule gave these outputs". Our smaller system gives the same logging volume but has detailed debug info for everything (and about 1% of the traffic). The value of those files drops exponentially as they age, and after a week they're almost useless. There's a lot of that data about (security camera footage is another cliche example).

    • in science projects especially it's necessarily hard to decide what to collect and how to keep it. I'm more familiar with astronomy, where it starts with what wavelengths you collect, then which ones you look at and at what resolution and eventually you have to decide what you store. "DC to daylight" comes in, we can just about count the photons these days... and there's lots of daylight. Often it comes down to "we can look again in the future if we need to" and move on.

    But much of what we transmit and store is, per Frank, ephemeral. Even excluding the millions of copies of every episode of every popular TV show, who really cares about the 12 camera feeds for every minute of every hour of every Faux News panel show? Not even the editors store that crud for more than an hour or so... and you could compress the actual broadcast to "blah blah blah" (14 characters, 10 bytes... the metadata vastly exceeds the content size).

    503:

    The problem with being exposed to 0.29Sv of ionising radiation over a thousand years of hibernation sleep is that there are no biological repair mechanisms at work while the tissues are frozen and dormant.

    That is also the problem with receiving 0.29 Sv in a short duration of time, e.g. due to a nuclear accident, or a malfunctioning x-ray machine. All your "stasis" does is converting 0.29 Sv gradually into 0.29 Sv all at once. 0.29 Sv all at once on eggs or embryos presumably decreases yield but does not have any dramatic effects.

    Speaking of which (and in relation to the dry tardigrades) the radiation damage doesn't work the way you think it does. For the most part, the DNA gets damaged when radiation creates free radicals in the liquid and those free radicals damage the DNA.

    If you're in some kind of glass-like frozen state (which is the only way freezing could possibly work), presumably the free radicals would stay in place and would get a chance to recombine before getting to the DNA. So it probably wouldn't even be equivalent to receiving that dose all at once.

    The problem with ultra-cold storage of mammals is that we have no non-toxic way of preventing water from crystallizing.

    504:

    The other thing I'm thinking is that the really important documents--contracts, leases, agreements, licenses, and so forth--tend to not contain a lot of data and tend to be really durable. In contrast, a student's 3D project (or any of your examples) contain enormous data, but are fairly ephemeral.

    Size doesn't necessarily correlate with importance very well.

    505:

    I agree that tardigrades are really good at repairing DNA, something we'd do well to emulate. Thing is, I think tardigrades go dry, they don't freeze solid. That's the point that we need to keep hammering on, is that it appears that there's a whole class of dehydration adaptations that we're not looking at, because we're too obsessed about freezing.

    506:

    Source regarding DNA damage being mostly indirect: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4071054/ Also has a good picture. So basically a dry tardigrade, in addition to all the repair it does when it gets re-hydrated, simply makes a smaller target and doesn't receive nearly as much damage from radiation as a wet one in the first place.

    Also, radiation damage is discrete, I think if you have eggs frozen (and well shielded from all external irradiation) for 1000 years rather than having all eggs end up slightly bad you will just end up with a few eggs taking damage and rest being as good as new.

    507:

    I can't remember the name of the standalone RPG, from the 90s, but it was a fun system that would store the crew as geometric solids like in the Star Trek:TOS episode - By Any Other Name

    • Just add water and the crew member would be restored.

    I also remember a spoof where people were stored as dry solids in containers similar to tennis ball containers. They would pop open the can and toss the solids into a lake, instant soldiers.

    Another system would use a "nano-amber" to vitrify the body rather than freeze them. All atoms would be locked in place until the nano-amber would drain away and the person was restored.

    508:

    Spaceship Zero - Found!

    As soon as I gave up looking for the book, there it was. 2002, not the 90s.

    Wiki - Spaceship Zero

    Radio Play

    "In 2016, several "restored" episodes of the 1954 American radio dramas were released to the internet. Episodes include "Chapter One: The Crew Assembles," "Chapter Two: Into the Beyond," "Chapter Three: The Cataclysmic Miscalculation," "Chapter Four: Directive Beta Five," "Chapter Six: Escape From the Hydronauts," and "Chapter Nine: Twenty Minutes of Oxygen." The missing episodes were allegedly lost in a studio fire in 1962."

    Spaceship Zero Adventure Hour - Chapter 1: The Crew Assembles

    Spaceship Zero Adventure Hour Chapter 2: Into the Beyond!

    Spaceship Zero Adventure Hour - Chapter 3: The Cataclysmic Miscalculation

    Spaceship Zero Adventure Hour - Chapter 4: Directive Beta Five (Radio Drama)

    Spaceship Zero Adventure Hour - Chapter 6: "Escape From the Hydronauts"

    Spaceship Zero Adventure Hour Chapter 9: "Twenty Minutes of Oxygen"

    Spaceship Zero music https://www.youtube.com/watch?v=DDG2nmpKwX8&list=PL_huAS08u78xMTsF_kxeSBvYhY_JGBjyV

    509:

    I can't remember the name of the standalone RPG, from the 90s, but it was a fun system that would store the crew as geometric solids like in the Star Trek:TOS episode - By Any Other Name

    Interesting. Sometime in the '90s, on the rec.games.frp newsgroup, someone reminisced about an RPG campaign like that. The game master was faced with unpredictable player schedules and so worked that into the world building: in this setting it was normal that while people slept they would sometimes implode into small, easily portable, and indestructible geometric solids. Sooner or later they'd pop open into breathing humans again.

    This apparently had interesting secondary effects on the setting's civilization as well, since nobody could be sure in advance that any particular person would be active on a particular day.

    "Sorry, Alice is a cube today. Want to talk to Bob?"

    510:

    NASA's Mars Habitat design competition might be applicable to things to learn before we can start to think about building starships:

    https://futurism.com/nasa-mars-habitat-design-competition/

    511:

    Channelling roughly half the commenters on "The High Frontier, Redux":

    You all seem to be forgetting a little thing called The Human Spirit!

    (Cold equations are evidently disposative only when you feel like spacing a teenage girl.)

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