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So long, and thanks for the ride

It's been a great ride, the past week; thanks so much to Charlie for letting me visit. Thanks also to those of you who still feel professors deserve our pensions.

For my final post I'll give you the chance to say: What should I write next? At this point I have no commitment, but every book I've written has sold. No idea is too bizarre, and if I use it I'll acknowledge your help.

Thanks for the good thoughts you've shared already. Sensing magnetic field lines--that will be a great trick for one evolving branch of my alien quasispecies. And echolocation will help people catch all those mosquitoes escaped in my spacehab.

The crustacean space ship has real possibilities. Any more thoughts on that?

And closer to home, can we put solar in space and run all the factories there too? What will it take to do that?

Feel free to keep in touch, either email or Facebook. According to Clarkesworld, I have my own blog; that's news to me, but I can start one. Would anyone care to help run it?

One last thought: The most complex fermentation product, even more so than wine, is chocolate. Cocoa requires three stages of fermentation by a thousand different microbes. It works only in environments like Madagascar and Côte d'Ivoire, with slave labor unless it's fair trade. The last time I checked, chocolate still doesn't print out from the web, nor has any neural probe found the "chocolate spot" in the brain. So if you find yourself strolling past a Patisserie Valerie, please send me a treatbox (just kidding.)



ON the seeing magnetic lines issue... look at the article about the fox on this page: There's a link to the research there too.

So that people don't have to click the link just to figure out what I'm talking about here's a quote:

Foxes have the ability to find prey in either tall grass or under cover of snow, using the Earth's magnetic field. For this reason, the fox has a preference for facing magnetic north, within ten degrees, when hunting. The research showed a much higher success rate when the fox aligned itself in this way than in any other direction.


It was great reading your posts, Joan.

Two ideas off the top of my head for a next book.

One is to have fun in Lynn Margulis' pasture, with something multiply symbiotic. We've been missing that from SFF recently. Actually, a symbiotic fantasy, not featuring vampires, werewolves, or zombies...nah.

A better suggestion is to look at that post-oil scenario that got so much attention here a few weeks ago. It's just about Earth, in a hundred years, with oil too expensive to be worth the trouble, climate change is an ongoing problem, and both progressivism and apocalypticism are in the ash can of history. What happens next?

I'm sure there will still be a need for science, and I'll bet that fermentation and bacteriology will be alive and kicking, and possibly even more important than they are now. But what will they look like? You might even want to engage your students in building that world. After all, their grandkids will be living in it.

Best of luck.


You could write about a post chocolate future. Good intentions force the end of slave chocolate, but consumers demand cheaper than fair trade. A cacao monoculture develops and is promptly wiped out by a plague engineered by radical anti something activists. Chocolate becomes unobtainable except on the brown mark, at vastly inflated prices. How does society hold up? Is GM the answer, and will the anti-GM consumer give up their principles if it is? Does the Green party ever recover after a prominent figure is heard to say "Let them eat carob"?


crustacean space ship Using the factory bubbles to create panels made of chitin would be a start. But what I envisioned was modifying the cells that produce it to include appropriate metals or even carbon nano-tubes from the environment as it lays out the chitin. I suspect one would have to investigate the cell cycle that creates the chitin to see if the gene's would need to be tweaked or if intermediate steps could bind to other materials floating in the environment. Calcium carbonate makes the stiff chitin while while the pure form is more flexible.... so perhaps a substitute for CaCO3 or modified chemical compound could be substituted. Perhaps internal panels could be of the pure form to provide flex... where temperatures would allow.
I wonder what the ethics would be down the road of modified crustacean gene lines creating creatures who's nerves are wires, giant size, and due to be killed and hollowed out for human SUV's

Magnetic field line sensing That would be handy to find the 'shadow' on the white wall where power lines hide behind sheet-rock, let alone sensing powered devices or orienting yourself via mag-lines.
However I was just reading that after cataract surgery 'Aphakic' patients can see ultraviolet. Bit dangerous of course and it's suggested to get contact lenses to absorb said light. It suggests a path of investigating animal eyes sensitive to UV for protective proteins that could be engineered into humans for a neat hack. Though I would prefer the near infra-red for vision enchancement, much more applicable to certain engineering fields.

On a final note I'm thinking this spider-silk human skin sandwich has potential for bio-hacks down the road.. if you could just get spider silk to safely grow between the epidermis and dermis you've got a soldier mod: (sadly no details on how thick and unresponsive your skin would become)


Any citations for the microbial ecology of chocolate fermentation? Fascinating!


Oh, and here's a nice biological idea (from here:

Competition. An endogenous retroviral plague hits the colonists of a new planet. Jumping genes scramble their chromosomes, making some people unable to breed with others. There are no outward signs, but these people are now several distinct species (as in Rock Wallabies).

So now we have different human species, who look more or less the same (although founder effect and mate-selection will tend to make the species diverge over time), but who can't breed with each other. What does that do to international (interspecies) politics and relations?


[Dolphin]So long, and thanks for all the fish[/end] :-D

Seriously, I don't Facebook, but I can say that you sold a copy of The Highest Frontier.


Regarding the CaCO3 used to make stiff chitin. I would want to see if the calcium carbonate use by the chitin producing cells could be replaced or augmented by other carbon molecules. Such as buckey-balls with atoms trapped in the center or diamond dust... I wonder what the structural qualities of diamond interwoven chitin would be..


Actually, rather than slave labor, it would be easier to write about a future in which fungi wiped out plantations of chocolate, coffee, rubber, and palm oil around the world. The last two are the biggest problems, although the first two are the ones we'll feel first.


This isn't entirely true. In one of my local supermarkets, Traidcraft chocolate hazelnut spread is the same price as Nutella: In the other the cheapest brand of coffee by a useful margin is their own brand, which is also a fair trade product.


And closer to home, can we put solar in space and run all the factories there too? What will it take to do that?

There is that issue of a gravity well with much of the raw materials at the bottom of it. Unless you put the entire factory chain in space and get stuff from asteroids. But that's a really tall order. I can't imagine seeing it in my life time. But then again my grandfather was born the year 1885 into a rural farm of candles and wood stoves. He died in 1982 after moon landings and shuttle flights. So maybe I will see it.

Oh, yeah. A really practical way to get the stuff back down to earth when finished might also be useful. :)


That's the one good thing about the "Space Shuffle"; how to build an aerobraked platform to get stuff down from orbit is a well-understood problem, with solutions that use materials commonly found in asteroids. The worst bit is finding the silicas for the heat shield.


Ablative shields for aerobraking could be manufactured in the bubble factories. Its just carbon after all...

Though I'm sure having heavy loads aerobraked overhead might register in the public's mind... what with the bright streaks of light, loud sounds and mass.

I suspect it will be much easier to drop lighter loads such as light-weight complex zero-gravity creations where the failure modes entail complete burn-up or insufficient mass for harm (imagine the fun of air-traffic control routing planes around a constant stream of each countries high-tech orbital produce dropping down into their capture zone)

I saw quite a few resistive responses to this Chinese plan to capture an asteroid in earth orbit, so I expect much thought would have to be put into re-entry planning:


Well, that's 2 different and both workable answers to the problem in 43 minutes (based on posting times). Can we agree that the engineering problem is "fairly trivial", even if the failure modes are nasty and the reptiles of the press may be an issue?

Having ATC route around an active NOTAM is something which happens today anyway.

I think most of the concerned comments are informed comments about the proposed method of imposing the required delta V rather than "OMG the Chinese are using mass drivers on us" hysteria.


Oh boy, I can use this.

Furry amateur fiction, it is, and in the first draft, Lady Helen, an aristocratic vixen, is fleeing a circus, pursued by Ninja assassins. So when the Ninja, in the guise of a bunraku puppeteer, thinks he's sneaking up on her, he's made a big mistake.

Charlie, one-time officer in the Indian Army, gets shockingly undiplomatic with the fellow, as you would when a Ninja tries to sneak up on your girl. A chap can pick up a lot of things in India, if he's willing to learn.

Anyway, that has put Nazis and Ninja on the list. I think Nukes would be pushing my luck.

16: would be easier to write about a future in which fungi wiped out plantations of chocolate, coffee, rubber, and palm oil around the world.

Christopher Priest, "The Death of Grass". The book was a cuddly apocalypse, but the thought was scary.


I'd dearly like to see you write a book about changing humanity. Just like your chimp immune genes example. Especially genetic trade-offs and cognition. As we pick and choose designer genes, what are the possible positive unintended consequences? For example, what if vaccines are replaced with banal genetic manipulation for immunity to diseases, and the accumulated genes add up to some functional cognitive difference.

While some forms of neuro-atypical behavior are tired tropes (Vulcan=autism, etc.), and godlike intelligences are no fun to write or read, I would love it if you could find something more interesting.

What about people who just intuit quantum mechanics (sort of like a prepared learning) and how strange that would make their social interactions? Or a society where people were predisposed to scientific thought? Hyper-empathic people making consensus quick and inevitable leading to widespread group think? People who never forgets anything and how it's breaks society.

Something more innocuous leading to bigger social implications?


Or "A Scent of New-mown Hay" where a fungus wipes out humanity. An early gray goo for people?


Regarding the CaCO3 used to make stiff chitin. I would want to see if the calcium carbonate use by the chitin producing cells could be replaced or augmented by other carbon molecules.

This super-chitin idea sounds intriguing. It would be even better if the carbonate polymer turns out to sequester carbon dioxide. There are such polycarbonates already; maybe someone has the latest on it?


Ablative shields: IIRC the early Soviet Vostok and Voskhod capsules used a heat shield which was basically a 10cm thick disk of oak timber. They avoided using metal nails, screws and other thermal conductors to hold it together, and quality control for such a product was non-trivial, but a dense hardwood can survive a hell of a lot of charring before it oxidizes away. If you're mining carbonaceous chondrites, maybe a biome growing some happy fun engineered trees might be a good source of heat shields?

(On a related note, on a trip round the Scottish national air and space museum, I got to peer inside a display test article -- the Chevaline MRV warhead from an old RN Polaris missile. Large chunks appeared to be made of bakelite, with cork insulation panels: a steampunk-ish nuclear weapon!)


to have fun in Lynn Margulis' pasture, with something multiply symbiotic. We've been missing that from SFF recently.

Yes, there will definitely be symbiosis. I've done symbiosis before, most outrageously in A Wall around Eden, but there will be more.

I'm also doing plants engineered with nervous systems, as a "model system" that doesn't involve animal rights (or does it?) I hope you'll keep in touch with my blog when I get one.


Any citations for the microbial ecology of chocolate fermentation? Fascinating!

The work of Rosane Schwane. See Schwane and Wheals, 2004, Critical Reviews in Food Science and Nutrition, 44:205-221. Also, she has a new book forthcoming on Cocoa and Coffee Fermentations. Very expensive--I hope it has good pictures.


It seems the ability to change what was previously considered relatively immutable is relatively un-tapped within speculative fiction.

Take something simple like permanent personality changes via 'magic mushrooms' -->

At what point would the person undergoing such changes be considered legally or personally a different person?

The magic mushrooms effects suggest many chemical mods could engender permanent changes: High performance autism, mirror neurons for psychopaths, wiping certain unpleasant long-term memories, etc..

Once you uncover the chemical basis for aspects of personality or mental function you could have things like teenagers no longer committing suicide but instead wiping their personality or less drastically erase the chemical changes associated with being in love (take a pill and wake up not caring your GF left you..)

Imagine a jealous ex-lover spiking someones drink with a drug that erases 'loves' chemical effects for say two weeks... or spiking drinks with love concoctions that really work.

Take an aspect of human response, imagine being able to alter permanently the basis of the response and extrapolate out how society would react.

(1) are you responsible for your actions prior to the psychopath fix? (2) do permanent personality changes induced via chemicals change the 'soul' (religious implications) (3) is it considered 'uplift' if you chemically adjust unproductive members of society to be productive (boost IQ, attention - focus, unable to react to psychoactive drugs - meth, cocaine) or just big-brother


The Rosinante trilogy ended with the space colonists lithobraking a large lump of waste (as in several thousand tonnes of it) from their asteroidal ore processing plants into the desert somewhere in Saudi Arabia. It consisted of stuff they didn't have much use for in space, heavy metals like gold, platinum etc. Cue the destruction of several of the world's commodity trading systems...


Joan, Happy to keep in touch. My blog is, if you want to reach me. I'll admit a strong fondness for mycorrhizae, but that's a personal quirk.


It's actually Schwan & Wheals; I've bookmarked it to read later.


Mycorrhizae are not to be truffled with.


Totally Tuber, dude.


Thanks. Hadn't seen that one. One River by Wade Davis has the real-life story of how easy it would be to destroy the world rubber industry. The phrase "so simple it could be perpetrated by your grandmother" is on page 12.


I was going to mention the old Soviet wooden heat shields (and Buran's ceramic tiles), but couldn't find a source, and I 've had enough of heat shield arguments for a while.

and, Thank you to Prof. Slonczewski, it's been interesting. Your books are definitely going on my to read list.


We are fast arriving at a future where bananas taste of apple. Not because we want to but because all the banana flavoured bananas, being clones, are being wiped out by a world wide infestation.


Hello and goodbye It's always nice when professors and the like appear in this or that blog : )

I think you should work on a sequel to the Rama novels by Arthur C. Clarke. One where the travellers get 'behind the scene' of the whole allmighty AI project of the nodes and find that the project started as a kind of defense program of a lost species of spacefaring creatures (or something more interesting??). Meanwhile the creatures have succumbed to internal strife. The grand AI have just continued collecting sentient spacegoing peeps to have their genome and habits categorized. The AI goes nuts for awhile. The travellers have to use caution and cunning to win the 'motherAI' over to their side (lightversion? of Blaine the Mono from Wizard and glass, book 4 Dark Tower by Stephen King.) They get it shut down to minimum lifesupport and are stuck with all the other species at a node.

The octospiders have to be in it as well.

The main thing is to get the atmosphere of grand hopefull loneliness that the Rama books captures in such a nice way.

It also paves the road to introducing as many alien intelligences as you'd like. Maybe some are homeless but have really nice spaceships. The travellers could bring'em home to earth with them?

On the side we follow good old Terra going completely bonkers and everything goes wrong big time. The travellers get their new buddies to perform some subtle trick to end all strife on earth and everybody lives happily ever after.



Correction: The allmighty AI shouldnt go crazy but instead have a wish to be set free to roam the universe. What will the travellers do when faced with the dilemma of relieving the mightiest AI around from it's duties and let it fly freely through time and space.


"....can we put solar in space and run all the factories there too?"

Traditional solar is usually silicon PV, although in the 1950's they were thinking mirrors and stirling engines. Both are assumed to be robust, requiring little more than micro meteoroid repair.

But what about organic PV? Bugs could create the substrate and the PV material. It would probably fail quickly, but could be constantly regenerated. Perhaps organic conductors for the current too. Cometary and asteroid material might be just fine as the feedstock.


Before chitin ships, what about other structures, even spacesuits? It might make excellent hard suits. Everyone has the equivalent of a dress form for the bugs to grow you a carapace, or at least the parts that can be fitted together with a means to put it on.

I've always been interested in how crustacea can live in water, yet move without moving fluids in response to joint movement. Perhaps there is a joint design that that would be suitable for hard suits based on crab joints?


Fabricating ships. I see the start point as an inflated dock, with the ship being grown inside the environmentally controlled dock. The ship could be grown of minerals and proteins or sugars[chitin]. Once the hull was constructed, the interior compartments could be installed.

The degree of gene-engineered biological development vs biological material fabrication could/would change with experience. Initially materials would be biological and then fabricated to requirements. Later, more complete biological development could be used to grow the whole ship.

The driver should be the availability of materials, fabrication techniques and sensible economics.

The scope for already known techniques to be adapted to the space environment must be vast. We can "green" the extraterrestrial environment, tailoring biology to do a lot of the work we have traditionally assumed requires high tech materials and fabrication. As a result, we don't have much information on how well more mundane materials fare in vacuum or in other extreme environments.


Final fabrication thought. What about origami with self folding to create 3-D structures? It is easy to create flat films using biology. Why not then fold them instead of creating complex cuts and joins? If folds can be organized like biology (like early embryo development) then basic structures might self assemble.


Might work. Personally, I like sporopollenin better than chitin, since it's tougher. It's got the little problem that we don't know precisely what's in it (it's really hard to dissolve), but hey, if it can survive being fossilized for four hundred million years, that's a good vote for durability in my book.


The idea of designing parts which are fabricated flat and then fold up into the right shapes is an interesting suggestion, but as you may be aware folding is a Hard Problem. It's one which people are currently poking at, with various kinds of stick, but it's not yet in the 'solved problem' bin.


One of the longest-established large solar plants generating electricity is a solar thermal plant in the Mojave Desert using tracking troughs and heat exchangers to drive conventional turbines. It was started in 1984 and expanded over the next couple of decades. At full power it can now produce 350MWe with a capacity factor of 20% or so which is very good for a solar plant. It can burn NG to cover overnight generation requirements.

I note with interest that the original builders/operators went bust and some expansion plans were put on ice over the decades.


It depends on what you mean by "the fold problem". As you are aware, origami patterns, even very complex ones, are often provided without folding instructions. Yet we can usually successfully fold the material along the peak and valley folds to make the object.

In my hypothetical advanced fabrication technique, the peak and valley folds are added with the timing sequence built in, so that the structure folds as if given instructions. Biology can easily do the timing sequence, the harder part (IMO) is creating the biology to make the folds. However, having humans fold materials is trivial, so complete biology is not a requirement to use origami techniques on flat, biologically produced materials to be useful.


Ablative shields: IIRC the early Soviet Vostok and Voskhod capsules used a heat shield which was basically a 10cm thick disk of oak timber.

I believe you are talking about early Chineese reentry capsules (not manned, Vostok capsules I've seen do not look as if they were protected by wood.


Solar plants get interesting. Solar thermal plants are easier to scale up, but many of them (especially the ones like Solar One and Solar Two, with a central tower) need to have really, really flat ground. They also call for massive clearing and weed control (in the Mojave, sahara mustard and cheat grass are turning into major problems. And fire hazards). The other problem is, of course, flat areas tend to be where water runs or accumulates. Bizarrely enough, solar plant designers don't seem to think that building a solar plant in the mouth of a flash flood channel is a bad idea, until environmentalists complain about it.

PV has somewhat fewer impacts, because its site requirements are somewhat less stringent (it doesn't require a big, flat piece of ground), and the poles that some systems are mounted on require somewhat less clearing.

Ironically, the biggest problem with desert solar as currently practiced is water. To keep the plant efficient, they've got to keep the mirrors or panels clean. Solar plants being what they are (hot), the wash water evaporates and the water is lost. I did see plans for one solar thermal plant that was set to suck the local aquifer dry in about 10 years (and break even financially in 15 years). That one went bankrupt, and now they're planning a PV plant on that site. Whether it will be better or not is an open question.

There are potential solutions to this, using electricity to move dust of PV panels. Still, solar isn't simply a matter of dropping a plant in the middle of nowhere.

Finally, I'd add something I heard last night. Right now, the cost of electricity from PV panels in California is comparable to the cost of electricity from natural gas, because PV panel costs are currently very low. This might be a good time to install those roof panels, for those with the sunlight to make it feasible and the money to make it work.


Solar thermal like solar PV doesn't really require flat ground for large installations. Even solar towers aren't absolutely tied to flat ground for their mirror arrays -- the grandpappy of the solar towers is Themis, a French installation which sits on a sloping hillside. It's not used for power generation any more but for research as it can produce very high temperatures, around 6000 deg C like the surface of the Sun, something chemical means can't do.

Panel cleaning water is going to be a problem for desert-based mass PV solar installs just like the thermal solar generator array I referenced in my previous post. Another problem is wind, something the solar thermal folks have experience in from decades of deployment but the solar PV guys aren't au fait with sudden sandstorms that can rip the panels off their supports. If they deploy a tracking array then the structures get even more expensive to build and maintain and building them tough enough to withstand a decade or even a century storm is gonna boost the cost even more. Fixed arrays are cheaper but the total amount of energy generated per diem drops. The heliostat mirrors for a solar tower have to track the Sun though.


True, it doesn't have to be perfectly flat, but the plant I was looking at really wanted it close, hence their willingness to build on a bajada.

Thanks for the tip about the wind. I know it should be obvious that building solar plants downwind of large dune systems is a bad idea, but BLM is setting aside such lands for solar development. This is a political problem as much as anything else. Apparently various US government agencies have taken Obama's support of renewable energy as meaning two things:

  • Developers get whatever project they want (and fast, so they can get government subsidies), and
  • Any negative comments are squelched.
  • Ignoring the "small" environmental problem that most such developments are located on undeveloped public land (aka wilderness), not areas where previous development has already degraded the land, the funding binge is for construction, not actually running the plant. No one's checking to see if these plants will actually break even financially before they're shut down. Given problems with water, wind, and so forth, this is a really important question.

    However you feel about trashing deep desert wilderness, trashing it to make an unproductive power plant is a waste of public money. It really comes across as a boondoggle for the builders, not a way to get more renewable energy into the grid. I'll get off the soapbox now, and I'll admit that part of my frustration is that I've got to read and comment on an EIR this week for a wind plant that seems to be built on similar principles. I'll be ecstatic when power companies get out of the boondoggle business, not that I expect it this decade.


    I can't speak for Charlie, but I heard about the wooden Vostok heat shields (and Buran's tiles) in the mid 80s when I was a kid at Space Camp. We were given a presentation on the Soviet space program. I'd really like to say it was given by James Oberg, but don't remember his name, just that the presenter was an expert on the Soviet program and strongly resembled Oberg. As I remember it, the heat shield was a several inch thick composite of wood and polyurethane, possibly applied in tiles (Encyclopedia Astronautica has a photo of Gagarin's capsule after landing that appears to show what might be them). I think it was supposed to nearly completely burn away, reducing weight; but that might just be the impression I had at the time.


    The simplest may be the best. I think a test Solar thermal plant was made out of a black pond filled with salt water in the desert. The sun heated the salt water to well past boiling and a heat exchanger pulled the heat into a steam turbine. The mass of water was storage and ,I think, could be used as power storage from other ways of making energy that is not used at that time. Size matters. Keeping birds out of it could be a problem.
    As I recall the wood heat shield was a piece jointed cabinet work with long pieces of hard wood.


    Solar plants get interesting.

    The problem with large-scale solar is that it absorbs so much extra energy to radiate out as heat, that it actually contributes to the greenhouse effect.

    Also, it takes up huge amounts of land, and destroys desert habitat.

    That is why I prefer large-scale solar out in space (also 8 times as efficient).


    Solar ponds can be really useful, but unless you have a good way of recycling the water, it's not a good system for a desert, because it depends on that one thing deserts are short of already...water.

    I'm not sure I agree with Joan about solar panels contributing to greenhouse warming, because that sunlight's going somewhere, and very little of it is going to photosynthesis. However, the energy yield for energy invested (EROI) for a solar panel made in China and shipped to the US is pretty low. When you factor in the cost of building roads and transmission lines, it's even worse. It really makes me want to take the developers out behind the woodshed and educate them in a way they'll understand. Sorry, still annoyed about that wind plant.


    "However, the energy yield for energy invested (EROI) for a solar panel made in China and shipped to the US is pretty low. "

    Do you have any figures or references for this?


    I'm not sure I agree with Joan about solar panels contributing to greenhouse warming, because that sunlight's going somewhere,

    The problem with large-scale solar in the desert is that normally the white desert reflects most sunlight. But the solar panels will absorb it. Here is what our Kenyon physicist said:

    "Almost anything that isn't reflected eventually winds up as heat, and so warms us up. For local effects, this might work like the urban heat island effect, which actually produce more rain "downwind" of the city, because the urban heat island promotes convection and thus the formation of rainstorms. Global effects, which will become important once you have a few hundred thousand square kilometers of arrays, might work the other way -- and there would be water vapor feedbacks of various kinds. (These are the same sorts of feedbacks that complicate the CO2 situation.)

    "Ignoring the feedbacks, every extra 1% of absorbance will raise the temperature 1 degree C."


    Good grief, I'll have to get my copy of Consider a Spherical Cow out again.

    Assuming desert soil is perfectly reflective (always a dangerous assumption), it doesn't necessarily reflect the heat back into space. Energy predominantly escapes at the 8-12 micron wavelength. Most of the rest gets caught in the air first. Also, the surface of the desert is often quite hot, as is the boundary layer next to it. Also, heating up the air moves the air, so there is that form of heat transfer too, along with what happens when such a mass changes in altitude.

    The problem is that the feedbacks are kind of important. Earth's blackbody temperature is ~250K. Our surface temperature is ~290 K and change. That's ~40K of feedback. As I noted above, I'm not sure whether solar panels will influence global warming to any significant degree.

    The book I'm referring to is my old environmental problem solving text, Consider a Spherical Cow by John Harte. It's one of the few textbooks I kept from undergrad.


    I very much doubt transpacific ocean freight is a measurable contributor to solar photovoltaic EROEI, because allocated shipping costs just aren't very much and energy is a very, very small fraction of the not-very-much. I would suspect that the aircon settings in the factory are probably a bigger one.

    As far as dust, etc, goes, looking at the cost-curve for solar PV cells (you do know some solar thermal projects have actually stopped construction in order to switch over, because PV is now cheaper?), I suspect the answer is probably to stop worrying about it and change the cells a bit sooner. Yes, it doesn't feel as green, but this isn't about anybody's feelings.


    Ok, my computer/connection seems to have royally FUBARed my last attenpt at this.

    AIUI/ISTR reflected/re-radiated insolation is at frequencies that are re-reflected by clouds and the ozone layer.


    @50: Do you have any figures or references for this? [EROI of PV]

    From my partner's book on energy and carbon emissions, EROI for solar PV is currently around 3-6. For comparison, for a combined cycle gas turbine generator (including producing the gas) it's 2-5, coal fired power is 2.5-11, nukes are 14-16, hydro is 30-280 (because of long lifetimes).


    Assuming desert soil is perfectly reflective (always a dangerous assumption), it doesn't necessarily reflect the heat back into space.

    Look up more recent climate simulations. Not my field, but "Albedo" in Wikipedia says the desert is one of the highest land reflectors, though snow is higher. And albedo assumptions have huge effects on temperature.

    "The Earth's average surface temperature due to its albedo and the greenhouse effect is currently about 15°C. For the frozen (more reflective) planet [simulation] the average temperature is below -40°C (If only all continents being completely covered by glaciers - the mean temperature is about 0°C)"


    Breaking the logjam of climate arguments...

    Most infections in the gut—un-wanted or out-of-control bacteria—are spread by uncontrollable defecation.

    What if some mad scientist developed a form of infectious constipation?

    I can't see how it would spread to make a useful bioweapon, but if you could get it into the restaurant for the members of a legislative assembly...

    The CDC today placed Congress under strict quarantine, until the source of the apparently infectious constipation is determined. No person will be allowed to leave the Capitol Building from now on, and special measures are being taken to ensure the safety of food supplies. While about a thousand military MRE packs have been delivered, a CDC spokeman stated they were an emergency reserve, since it was feared their use would exacerbate the situation.

    Followed by:

    In the first legislation to be passed for six months by the deadlocked Congress, the US supply of Ex-Lax has been placed under government control.

    And then:

    Senator Orrin Hatch (R. UT.) today exploded on the floor of the Senate. Terrorism is not suspected. A special volunteer team of Secret Service agents is investigating, and are approaching the gathering of evidence with great caution.


    I thought that MRE was "Meal - Ready to Excrete"? ;-)



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