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Mediocrity

In my last blog entry, I asked "What is the minimum number of people you need in order to maintain (not necessarily to extend) our current level of technological civilization?"

It occurs to me that besides the obvious ramifications we've been chewing over (read the comment thread if you dare — it should only take a couple of hours), if you turn this question on its head it looks like a component of a set of answers to the Fermi Paradox.

Loosely stated, the Fermi Paradox is this: there are roughly 7 x 1022 stars in the observable universe. We know that planets aren't rare and that stars of our own sun's class aren't rare, so earthlike worlds are presumably not rare. Going by the principle of mediocrity, our own existence shouldn't be particularly unusual. So where is everybody else? There are plenty of stars old enough that, if intelligent space-going life has a non-zero probability of emerging, our galaxy should long since have been overrun. And if not, why do we detect no signs of extraterrestrial intelligence?

In general, there are two classes of solution to the Fermi paradox; ones that assume that we are unique special snowflakes in an empty cosmos, and those that postulate that intelligent species are common, but some kind of mechanism stops them from colonizing interstellar space.

If we look at the second problem set, and broaden the focus ... well, intelligent species emerge as components of a biosphere bound to a particular planetary habitat. We humans are land-dwellers on Earth in the later high-oxygen period; conditions on earth even one billion years ago would have been rapidly fatal for an unprotected human, and even today, survival on 90% of our planet's surface area is contingent on the availability of cultural artefacts like boats (80% is water) or clothing (for protection in hostile climates). So the real question isn't, "can intelligent life colonize other star systems?" so much as "can intelligent life propagate itself, and its supporting biosphere and technosphere to run in alien environments? Which is a very different question. Call it the Ark Problem; if your name is Noah and you're going on a one-way trip to another world, how big an Ark do you need (and how many specimens per speciality, be they biological or technological)?

(Last time I asked the minimal-biosphere question here, while ploughing a space colony furrow, one of the first answers was "oh, you just need humans and blue-green algae". That, plus soy beans and tilapia and five dollars won't buy you a latte in Starbucks — especially once your colonists begin dying of obscure micronutrient deficiency diseases.)

But enough with the ark problem and defining the minimum population of a stable self-maintaining technosphere; there are other fun concepts that might bear on the Fermi Paradox. Chief among these is the Simulation argument. (In fact, I gather Steve Baxter has written a paper about it, but it doesn't seem to be on the web.)

Loosely stated, the simulation argument runs thuswise (pace wikipedia): it is taken as axiomatic that consciousness is an emergent property of physics (i.e. there's no ghost in the machine), and that we can simulate physical systems. Thus, it is possible in principle to construct a software simulation of a world inhabited by intelligent beings who will perceive that world as real. It then follows that either no civilization will ever reach a technological level capable of constructing such simulations, or that every civilization capable of doing so will choose not to do so for some reason, or ... we're probably living in a simulation (because any civilization capable of running a civ-sim is liable to do so many, many times; so the number of sim-civilizations will vastly outnumber the number of authentic ones, and by the principle of mediocrity we are not exceptional).

(NB: you can find a more formal treatment of the simulation argument in Nick Bostrom's original paper, although the idea goes back some way before then, to Hans Moravec and earlier less rigorous speculators.)

It's that danged principle of mediocrity that's causing all these problems. It shows up in the Fermi Paradox, it turns up in the Simulation Argument, it turns up like a bent penny in all sorts of places — it's a big problem for the standard model of spacetime, once you start digging into the Boltzman Brains paradox (for a quick intro, look here or here). Indeed, it seems to me to be a corollary of the weak anthropic principle.

... And I've run out of brain cells with which to continue this line of thought, but a dangling question remains: how relevant is the simulation argument to the Fermi paradox, either (naively) as a solution, or as a mode of temporal reasoning for examining the possibility of our being alone in the cosmos?

264 Comments

1:

I always thought the "Civilizations are bloody hard to keep going, long enough (in the cosmic sense) to make it out very far from their birth place, let alone find another one, all the while dodging extinction at the hands of errant asteroids, etc..." was a perfectly adequate answer to the Fermi paradox without invoking anything more exotic.

I admit, though, that the Simulation Argument gives me the heebie-jeebies.

2:

I'm comfortable with the simulation argument, in the same way I am comfortable with the possibility of there being gods; while we could all be the creation of any number of gods in any number of ways, it makes no actual difference--the world is still indistinguishable from a naturalisticaly evolved one. In a sense, all those gods, and all the other arbitrary and unlikely universes cancel each other out.

Given that lots of these simulations could be running, there's absolutely no reason to believe that we are only running on a single one. In fact, we're running on all possible simulations and in all possible universes. There is, in fact, no difference between 'simualted' universes and 'normal' ones - being that they are internally indistinguishable, and for any of them there are _always_ more possible turtles further down.

All of this comes, really, from a relative of the Dust Theory a la Greg Egan, but the upshot is that it all adds up to normality.

3:

I find it likely that reality is generally incompressible, and thus a simulation of reality would take up a computing mass close to what is simulated. In that case it is highly unlikely we are not real.

4:

Great question Charlie, but there's so many issues here I'm going to have to do multiple posts.

On the Fermi paradox: Here's an answer.

1. To travel to another star, any race has to learn enough about biology to create a functional biosphere, either on the ship or at the other end. We can include machines in this, if we want to extend the boundaries of life to include things without cells.

2. Unless there's a trick, interstellar travel is always going to be hideously resource intensive and take a long time. This is a barrier to most travel.

3. We don't know the variation in potential biospheres out there, but we do know that:
A. Planets without biospheres are instantly lethal, and the only way we can live there is to manufacture a biosphere there.
B. Planets with biospheres that are compatible with ours are likely biohazard zones, and people living there will probably not be allowed physical contact with people not living there, unless there's some sort of universal biosphere.
C. Planets with biospheres that are not compatible with ours are like planets without biospheres, only worse, in that you've got to battle the local biosphere for whatever resources you need.

Given those options, why do you want to settle another planet anyway? The best options appear to be planets without biospheres, and you can only settle those if creating a biosphere is a straightforward task that can be accomplished by a small, properly equipped crew, probably with self-replicating technology. We don't have any of that yet, and it's not clear that we will get there any time soon.

So the answer to the Fermi paradox is probably that interstellar colonization probably isn't worth the trouble. I'd also point out that Fermi thought this was paradoxical in an era of colonization. As we get out of that era, we're getting skeptical about the paradox as well.

As for why we can't hear alien radios, well, the Earth is already getting quieter as we switch to cables and ubiquitous, low-power broadcasting, so the answer may be that, even for civilizations that develop radio communications like ours, the window for when they're blasting out signals to the universe at large is quite small, and given signal attenuation (falls off as the square of distance, I think), it's unlikely we'll be in detection range when a civilization lights up for that brief time. We could be surrounded by pre- and post-radio bright civilizations, and never know it, especially if they've all made the calculation that it's just to expensive to visit the neighbors.

5:

The obvious solution to the Fermi Paradox is that God created this entire universe just for us and that we will someday colonize the whole thing in his most Holy Name.

The fact that God is some tentacled kid running a Life simulator while swilling nano-brew in a dorm party on a gas giant somewhere notwithstanding.

6:

That simulation argument is wonderful. I hadn't quite thought it all through in those terms before. The argument reminds me a bit of Hofstadter's stuff on super-rationality, which I suppose can be thought of as an optimistic framing of the "principle of mediocrity".

7:

The principle of mediocrity seems like an unnecessarily precious restatement of the ubiquity of the normal curve.

8:

If Space Aliens did detect our Radio signals they would probably investigate us before direct contact. When they learn (among other things) one of our major religions is about putting our "God" to a slow, painful, degrading death for preaching peace and tolerance...Maybe they would pass the word to leave us alone?!

9:

Reasons to be uncomfortable with the simulation argument:

As Greg Egan pointed out (somewhere or other on his rather large and sprawling website -- I can't find it right now), someone who runs a sim that contains conscious beings is implicitly accepting responsibility for all their suffering. If they're using genetic algorithms to evolve an AI, then the immediately pre-final steps are, presumably nearly fully conscious -- at a minimum, we're contemplating great ape or hominid levels of awareness, and so the sim-owner is also responsible for repeated acts of genocide. Indeed, he's recanted the error of his [fictional] ways in "Dust" and now considers the experiment described therein to be horrifyingly unethical.

Put it another way: if we are living in a simulation, then unless we accept a solipsistic model (in which there are only one or two minds, and everyone they perceive is a simulacrum or one of Daniel Dennett's zimboes or p-zombies) it follows that there exists a simulator who is directly responsible for the deaths of everyone you know who has ever died, and who is going to inflict death on you. And the alternatives? It gets worse, rapidly ...

10:

I have to agree with both rosyatrandom@2 and david@3. It's unlikely that we'll be able to ever generate a perfect simulation of reality that is smaller than reality itself, simply because of the amount and nature of the information involved. But even if we did manage to make a perfect simulation, is the life lived in a perfect simulation actually distinguishable from a life lived in reality?

On the other hand, if you start talking about *imperfect* simulations, that's a whole different ballgame. At what point does a imperfect simulation of a human being (or other lifeform) become intelligent and self-aware? Now we're into artificial intelligence and the definition of life.

11:

I always liked the answer that the galaxy has been overrun by other civilizations - and we are the result of one of their biological, self replicating Turing machine probes landing on Earth.

12:

I recall a recent book proposed that there will be a global catastrophe when the Earth supports so many people that local reality is over-observed, leading to catastrophic breakdowns in the quantum reality around us.

That's the problem with the simulation paradox: the system crashes when there are too many entities within it interacting. This would make a great disaster for a novel: the heroes are in a world which will crash, say in 2012, because the simulation will break down. At that point, most of the population will be destroyed by the system tools who are trying to do a new build to get reality up and running again. Our heavenly sysop may have to declare an apocalypse, and once things are working again, he may have to monitor it for quite a while to make sure it doesn't crash again.....

More generally, there are large classes of chaotic phenomena which we know are computationally intensive. Flipping a coin is a good example, as is rolling dice. Unless we're talking about some sort of exotic quantum processors that can handle chaotic processes accurately at all scales (a.k.a. the Mind of God), it's probably simpler to assume we're real, and that such events spontaneously arise.

And if we're inside a super-processor that can accurately simulate reality at all levels, then we're off in airy-fairy land anyway. I'll get to what "living in Maya" means below.

We can also test for the simulation by deliberately looking for problems in phenomena where we know that simulating them is computationally intensive. Basically, we need to think like beta testers and try to get reality to crash in some informative but non-lethal way. So yes, we can test the simulation hypothesis.

As for the idea of "Maya" (that the world is an illusion)...With the necessary prefix of IANAB (I am not a Buddha), Maya usefully refers to the idea that human brains are limited, and therefore a lot of what we call "reality" is actually extrapolated from our limited senses, generally using the limited models our minds can accommodate. Even assuming there is a Reality out there (which Buddhism does), when you get a glimpse of it without all the modeling, it is impossible to talk about it accurately, because our language is part of our limited model of the world.

This is very different from the idea that the world is a computer simulation. What it's saying is that, in order to live and act, you have to simplify and extrapolate from that limited knowledge.

13:

The problem with mediocrity in terms of the normal curve is that nobody's exactly average..so anyone trying to use it to argue against the fermi paradox has an issue: Even if 99.9% of civilizations decide its not worth the trouble to spread itself around, the nature of the paradox itself is that HEY, THERE ARE GOING TO BE TONNES AND TONNES AND TONNES OF CIVILIZATIONS. If one out of a thousand..ten thousand, etc, are inclined to spread out (aside from the ones that are closer to the mean, decide to colonize one world, and then give up), then there's likely to be some inclined to spread out exponentially.

14:

More generally, there are large classes of chaotic phenomena which we know are computationally intensive. Flipping a coin is a good example, as is rolling dice.

Are you suggesting that we could test whether or not we are in a simulation by holding an international coin flipping day? Or, minute, I guess would be better.

15:

I'm bookmarking that comment for future reference.

16:

If we're in a simulation, should we expect to be able to create our own simulations once we've reached that point? Should we expect our simulations to do the same? Should we be able to create a stack of virtual machines deep enough to crash our own universe? That'd be one way to test it.

17:

Thinking about it a little more, I suppose that such an experiment could either crash the system, or create some strange failsafe result, like everybody in the world flipping heads at the same time.

18:

If you postulate that we are in a simulation, the Aborigene dreamtime seems suddenly more sinister :-)

What happens when a simulated civ reach the technological state where they can create their own 'sim civ' ?

So many SF stories have been written (accelerando comes to mind) and filmed (existenz,the matrix,the truman show, inception ...) with link to this idea.

What about the energy requirements of running a 'sim civ' of a few billion brains ? And emulating all these supercomputers, portable electronic gizmo ?

What would be the point of creating a Virt CIV ? What could we/they learn from it that couldn't be learned by observation or history mining ?

Maybe the potential for entertainment ? But our current environment seems rather unfocused for that purposed.

19:

Your statement about how it would be unethical or "inhumane" and there is a simulator who is responsible for your future death and the deaths of everyone assumes that you can be conscious without death. It might be impossible to create a stable, intelligent being that doesn't die, or that can live beyond a certain length of time.

If the Simulator merely grants us the best, most stable form of consciousness he can create, and lets us make of our lives as we will, then he's not responsible for our deaths. He may be using us as a stepping stone, learning about consciousness and improving with each run. He might even be re-using people, improving them and putting them back into the next run. That would mean he's actively assisting everyone to meet their full potential, and how is that wrong?

20:

Someone trying to run an ethical simulation could preserve the consciousness-state of each entity in the simulation, for later reinstantiation when the simulation terminates; alternatively, they might reuse the core consciousness in another entity in the simulation. Hmmm... call that “heaven” and “reincarnation”... or factor in “hell” and ask what a the simulationist is really up to— cranking out suitably motivated worker AIs to do the menial work for their civilization, perhaps? (David Brin had an interesting take on it in Stones of Significance.)

21:

Hm. At first blush, the simulation argument brings an interesting association between the "collapse of the wave function" quantum weirdness and lazy computational evaluation.

22:

One wonders if the universe-running VM is smart enough to do deduplication on the fly ...

23:

In other words, the ethics constraint doesn't apply if this is the best of all possible worlds?

Yes, and monkeys will fly out of my butt.

(Unlike some, I am not comfortable with the idea of god(s). It's a traditional term for something that's extremely ugly, when you consider the implications -- just as kings and monarchs are shiny and romantic at a distance, but turn into hereditary dictators (with secret police, natch) when you get up close and personal with them.)

24:

Re: quantum over-observation

Didn't that happen in the book-version of Greg Bear's Blood Music?

http://en.wikipedia.org/wiki/Blood_Music

25:

or a good enough Virtual Memory scheme to merely slow down appropriately with the added complexity rather than crash. We wouldn't notice the performance hits since our own Consciousness and perception is part of the same program...

...Unless the "mind" module is running on a different thread, and they have an "out of order operation" bug somewhere.

26:

@heteromeles Only some forms of Buddhism believe there is a Reality out there.

The simulation idea feels intuitively correct probably because what we experience as reality is, in fact, a simulation created on the fly in our cranium moment by moment.

The idea that one can "get a glimpse of [Reality] without modeling" is probably one of the more neurologically naive assumptions of Buddhism. The modeling of Reality (i.e. making sense of sensory input) by the brain happens in so many layers and meta-layers that even such "glimpses" are only relatively less moderated.

It's more like: once the abstract-conceptual model-layer shuts down (i.e. the strictly human one), we get a glimpse of the more fundamental body-action model-layers (i.e. the animal one) which the brain cannot stop generating.

27:

What about the energy requirements of running a 'sim civ' of a few billion brains ? And emulating all these supercomputers, portable electronic gizmo ?

Technically, it only really has to simulate one brain - yours. I mean, mine. Everyone else is just a subroutine?

28:

Interesting that you should bring this up. The following article appeared in MIT's Technology Review on Monday 26 July:

http://www.technologyreview.com/blog/arxiv/25501/

The comments are very much worth reading.

Since I am already fully aware that I am the center of the Universe, it's obvious that the rest of you are mere simulations.

29:

There's something about this thread that resonates with the research being done on photosynthesis, where it's looking like quantum effects are playing a heavy role in producing such efficient energy conversions.

Couldn't the basic "reality-ware" of the universe be built up from such principles? Then you could have as many computationally intensive events as you want and not worry about a system crash because the inherent dynamics of the universal system sorts out superpositions instantaneously.

30:

Sigh,

I know, but I just don't understand the paradoxical nature of the Fermi Paradox.

Let us assume, for the sake of argument, that the average distance between planets inhabited by intelligent being of at least our level of technology is 50 light years.

Just sending the equivalent of a ping back and forth takes a century. Establishing a common code base will take at least another two centuries in the best of all cases. While conversations will be massively parallel, it will take the best part of a millennium for the very first conversations to reach any kind of conclusion or results.

The Fermi Paradox is no older than 60 years. Maybe the Paradox is simply a result of our impatience - on the scales we're talking about, a century or two are little more than the blink of an eye.

31:

Wow. Combining the Fermi paradox with the simulation argument and various pieces of anthropic arguments. This is going to be one confusing comment thread, but a fascinating intersection.

Just to clarify one thing, observers inside a simulation are 100% disconnected from the "timescale" or the "difficulty" of simulating them. Assume our universe is a simulation which runs in steps of Planck length. It doesn't matter how fast time runs in the "hosting" universe: if it takes a thousand of our years to simulate one Planck length in our universe, there is no way we could know. So you can't use that angle to attack the simulation argument.

32:

Simulation is a fun mind-screw to take out and look at; but as has been said elsewhere, it requires an order of complexity higher than that of the universe we find ourselves in, and complexity is inversely proportional to probability.

If we're a simulation, then the computer we're running on is a universe, which may be inside a cluster called a multiverse; and the pay-off of this thought train is that whoever- agent or society- built these computers and/or clusters isn't just "god" to our "amoeba" but actually lives in a reality several orders of complexity above ours.

Assume we have 10 of the posited extra dimensions, and that our simulation is essentially World of Warcraft as compared to reality. Off hand that means our dev directly senses 9 or more dimensions out of the 100 or so it maneuvers through.

As for Mediocrity, who says it's a hard and fast mediocrity? One set of values, in a deterministic universe, yields the same outcome every time- if the set is big and accurate enough (and possibly ignoring some quantum effects). Mediocrity is a range of values. It is possible that intelligent life results from several points on a graph, but only from one point inside the mediocre value range. Meaning we're not-special, except that we are.

Mediocrity as a template for understanding reality isn't turtles all the way down. It's a starting point. Assume we are, in every way but one, exactly mediocre. The one way we are extraordinary is intelligence- though of all the intelligences possible, ours is only a mediocre one.

That's my have-your-cake-and-eat-it-too-Mediocrity-as-non-Mediocrity explanation.

33:

Why is your argument about the ethics of the simulator any different than an argument about the ethics of having children?

Yeah, if I'm in a simulation, then the person who is running the simulation is responsible for my death, simply because they're responsible to a large degree for my life. How does that description of a simulator sysop differ from the description of a parent?

Given a choice between existing in a simulation and not existing at all, I'll choose existence for myself, even if that involves both experiencing and inflicting suffering. (Heck, I'm not a vegetarian, I already regularly inflict indirect suffering and death simply to survive.)

Another note on the suffering angle: consider an individual actor in a posthuman society of this sort. How much computational complexity makes up its mind? Is that going to be more comparable to that of a simulated human, a simulated city, or a simulated civilization? Many humans have no moral problem eating animals, and most humans have no moral problem eating plants. I'd argue that this is mainly because of their inability to *relate* to the suffering animal or vegetable entity.

And you're made up of cells, which are analogous to some whole organisms. Even the most extreme fruitarian doesn't object to murdering the cells of, say, an apple, in huge numbers. And people often do things that distress or destroy subsets of the cells of their own bodies.

From the point of view of a posthuman individual, if we're in a simulation, are *we* (individual modern humans) more like a cat, a tree, an apple, a donated kidney, or what? Why should we consider their actions towards *us* with different standards than our actions towards a banana?

Heck, maybe raising an "Earth" as a pet is part of a developmental stage for a young transhuman mind attempting to become mature and responsible, much as some parents teach their children about responsibility by making them responsible for a pet such as a dog.

34:

A simulation does not have to be perfect for it to work. It is very possible that the universal "resolution" (reality units per square meter?) of our existence is lower than the resolution of the highest level universe (the "real" universe).

In fact you have to assume this if you are working under the assumption that reality's information cannot have lossless data compression. The question is at what resolution does one consider a universe to be "real" enough? At the point at which the universe's citizens are capable of self-awareness?

Recent evidence suggest we live in a "holographic" universe where our perceived units of reality are made up of many smaller dimensions of information overlapping. In fact it even suggests that our reality is at a lower resolution than is capable of by those dimensions (think pixels being made up by smaller RGB dots). Perhaps this is evidence of our reality being a simulation and each dimension is a different thread of computational information. The speed of light would then be the limit of information transfer in the "real physical" world where the computer is calculating our existence.

35:

Then there's the question,would OUR simulator allow the simulation of a true A.I.?

36:

as has been said elsewhere, it requires an order of complexity higher than that of the universe we find ourselves in, and complexity is inversely proportional to probability.

No it doesn't; it just requires really good algorithms for determining what's important. And to a first approximation, you can get there by tracking that to which attention is being paid.

(Paging the Copenhagen Interpretation; Niels Bohr to the white courtesy phone, please!)

37:

In practice I wonder how much difference there really is between the simulation argument and the many worlds theory?

Either there are a ton of simulated universes representing every possible permutation or there are a ton of real universes representing every possible permutation.

We just happen to be in a simulation or universe where there is no extraterrestrial intelligence nearby. In which case, there probably are simulations and universes where that is different.

38:

Is there necessarily a highest (real) universe?

There could be an infinite regress of simulated universes.

39:

Rick, are you absolutely sure you cannot be replaced with a short shell script?

40:

Infinite regress of simulated universes suggests that there is no limitation of universal-resolution or as Mr. Stross (how do you prefer to be called?) suggests it requires very capable algorithms (what is called procedural simulation in the world of video games) that can take into account what aware-observers are paying attention to. This also assumes that the simulation is somehow FOR us aware creatures, or that observation of the universe has greater significance than we now know.

What if it isn't an infinite regression but rather something like the Penrose stairs? In this case the simulation is circular and the "top universe" is actually being simulated by the "bottom universe". This also would necessitate that complexity can be born of lesser complexity.

41:

So time flies when you are having fun because the rest of the simulation slows down due to complexity.

42:

This also assumes that the simulation is somehow FOR us aware creatures, or that observation of the universe has greater significance than we now know.

Yup.

Another aspect of the simulation hypothesis that gives me the shudders is this: how do we know that we are the object of the exercise? What if we are to the true object of the exercise as, say, the poultry and livestock in our farms and slaughterhouses are to us? (That is: we're merely a useful intermediate step towards something else?)

43:

Say, something clever enough to escape simulations?

44:

Or the mice.

45:

To pick up the simulation argument, who says that the simulated reality must have any similarities with the host reality it is running on?

The host reality could be incredibly more complex then the simulated reality, in which case the simulation could easily be running on the equivalent of a pocket calculator.

Then there is the question of what exactly is the scope of the simulation. Does it simulate the whole universe, down to the last bit describing every single particle starting at the big bang and earth just happened to be something insignificant that happened somewhere in a tiny corner of the whole simulation?

Or is it specifically designed to simulate earth, or even just one specific person, and the simulation is only running at the necessary resolution to produce sufficiently exact input to make the world believable?

In which case, the less something is observable/observed by one of the sophonts that are the primary purpose of the simulation, the less detailed the computational model for that particular thing needs to be. Only the attempt to observe something by a sophont will result in a (possibly temporarily) increase of the complexity of the model used by the simulation.

e.g. until recently the simulation wouldn't have had to worry about the details of any other solar system beyond knowing what type of star it is. Only the attempt to observe them with sufficiently sensitive instruments finally requires to decided if there are any large planets around which could possibly be detected.

In which case the solution of the Fermi Paradox is very simple, whoever setup the simulation decided to minimize the complexity of the simulation by only simulating a single planet filled with sophonts and just filled the rest of the universe with a very coarse model to get just enough background to make the observations of the sophont(s) sufficiently consistent.

46:

This sounds similar to the eschatalogical argument, which runs something like this:
Imagine, for the sake of argument, that which particular human body you ended up living in is randomly distributed, thus it is unlikely that we are living in the very early part of the human era (e.g. the probability that we were born within the first 5% of human births would be 5%). It lacks the solid foundation one gets by starting with a known fair coin tossing machine.

Personally, I would think the argument to speculative to be relied on anyway. It hasn't even been tested yet.

Thirdly, what about measure. If these civilisations are only simulating one species, then the simulation may well have far fewer civilisations in it than the real universe, so even many simulations may not outweight the universe.

Fourthly, why would anyone ever simulate an entire sentient race, surely there must be a better way of doing it. On the other hand, perhaps not.

47:

Reality is already being simulated in one form: the internet. Representations of people’s thoughts are imputed into a growing level of complexity (Second Life becoming more immersive). Extrapolating that with the technology a century down the line: immerse yourself to the point when reality no longer intrudes. And since your neural input would be constantly added to the program, it may be eventually possible to exist independently of your real self … and be immortal, or rather a simulacrum that believes itself to be you.

So there would be a creep towards a simulated world, with programs evolving from something fairly benign. Asking who is responsible for that is like asking who’s responsible for the existence of the internet. Alternatively, if this potential is recognised, there may be a more formal process implemented to control the simulation...

Maybe an early-level sim – by design – will aim to create an ideal world. In that world, I guess there wouldn’t be the added complications such as alien visitations, though some might question that as being paradoxical in such a vast universe (along with why is its expansion accelerating.) And there might be other strange phenomenon that doesn’t bear rational explanation, such as ghostly apparitions.

The problem will be agreeing on what is an ideal world. Maybe easier just to base one on the real world.

48:

"There are plenty of stars old enough that, if intelligent space-going life has a non-zero probability of emerging, our galaxy should long since have been overrun."

Does it follow though that a really old civ would elect to overrun the galaxy? Rather than, say, hanging out in Matrioshka Brains around a few long-lived stars in the galactic periphery?

But if there were a galaxy-saturating, gigayear old civ in one in 100,000 galaxies, would we have noticed?

49:

If we take Fermi's paradox at face value and presume that life is commonplace, then we still come up against the inevitable problem of distance. Even intelligent life based in a neighbouring star system would take hundreds of light years to travel to our Milky Way,

But even if that were possible, you would have to ask whether an intelligent race would feel it a good idea to contact an "inferior" race. They might feel that it would be prudent to see if the species was mature enough to warrant contact from another race.

As for the simulation argument, I can understand Nick Bostrom's thesis, but it doesn't explain the eternal question of who's running the first simulation?

50:

It also strikes me that with a simulation world, we're edging into the territory of Terry Pratchett's Thief of Time. To paraphrase, in his take on the universe, the 96% of the universe that we can't observe is the paperwork and audit trail on the 4% we can observe.

So, perhaps in the cosmological dark energy and dark matter, we're merely seeing those parts of the simulation that are keeping the shiny lights up in the sky going, and the reason we can't determine what they are is that our programs are not allowed access to those resources.

We could also posit that various odd aspects of cosmology (inflation, C, etc) as structural features in the simulation to keep increasing complex nodes (e.g. planets with life) from interacting with each other in ways that would cause the simulation to crash faster.

See, the real test of a simulation isn't that you're slowing the step rate down (as pointed out correctly in comment #31 above), it's that you generate a localized crash where the system overloads, and data gets lost in an informative way.

In real life, people get their shorts in a knot about being "the observers," but the way photosynthesis etc. is set up (with quantum effects in the electron transport chain), I suspect that the majority of computationally intensive interactions occur keeping cells running and microbes interacting, to keep this whole show going. Whatever we're observing as humans is at is the tip of the cherry-stem on a truly enormous computational sundae.

51:

Does that mean if I can get out there and start futzing with dark matter, I can cause an "index out of bounds" exception, and screw with the value of my bank balance, or the constant that controls the temperature water freezes at?

52:

In one sense that we can observe, our Sun is not sitting at the top of the mediocracy bell curve, but in fact an outlier. namely it inhabits the largely empty gap in the local spiral arm called the local bubble, and has probably done so for a long long time.

I'm not going to speculate how not being in the general miasma of the galactic stellar distribution that *is* the norm could, or would affect the rise of intelligent life (other than perhaps maybe giving us several million years of relatively benign conditions free from the effects of nearby major supernovae, or whatever while we quietly evolve)

But it might mean that we can't apply the principal of mediocracy, in which case, our nearest neighbours could me much further away, and as has been discussed to distraction hereabouts: Getting about in space is Hard to the power of difficult. And the argument that we haven't heard them isn't exactly robust. I reckon all our articicially radiated EM is largely swamped by the cosmic background within very few light years. If we can't justify the budget to build a REALLY good listening station on the dark side of the moon, who's to say any one else is?

Talking of the moon, how rare do you think a honking big moon like ours is? and more importantly, how important are the tides it gives to the development of land based complex animals? I've no idea, but if the answer to both is RARE and IMPORTANT, then we might be a long way past 6 sigma on the gaussian of mediocracy.

Just my ramblings.

PS, you might be on to something with that simulation idea, some dude in a black coat has offered me some coloured pills and now my fingers are MMMMMMEEEEEELLLLTTTING into the keyboard. :)

53:

Sorry, I type too fast, and I've had some rather nice Beaujolais. Apologies for the typos :(

54:

"Is there necessarily a highest (real) universe?

There could be an infinite regress of simulated universes."

There's nothing to stop them looping.

55:

Ah, I should have known someone else would get there first! (#40 and maybe others)

My view would be that it's not so much a linear cycle, but more like a highly inter-connected graph: all possible connections are real connections.

56:

@MWT: Yup. Agree with you 100%. As noted above, IANAB, and also, the real point is that "Maya" is really a term for of the subjective construct we each separately make and call reality, rather than a description of the nature of Objective Reality, assuming Objective Reality does, in fact, exist.

Note that, if Objective Reality does not, in fact, exist, then magic is possible in some form, because we each construct reality to some degree.

Anyone want to contact L. Sprague de Camp and Fletcher Pratt on the ouija board and get their opinions?

57:

I think some of the previous comments get close to this point, but I'll rephrase anyway.

Perhaps we are in a simulation, but we're just epiphenomena. The real point of the simulation is for purposes totally divorced from us. It could be like this. A developing human mind starts out with lots of neurons. These neurons get mercilessly slaughtered as the person ages, matures, and learns. Perhaps we're like those neurons.

Our own experiences and civilizations may be nothing more than the low-level processes of some matrioshka brain.

On the Fermi side. I think it really is a big problem. The galaxy is not that big, especially if you are an AI with strong nanotechnology. They really should be out there in all sorts of diversity. They should be highly diverse, with widely varying histories and motivations, and exploiting a variety of "ecological niches". Some may be really hard to detect (nanobots quietly munching on Oort cloud objects), others should be much more flamboyant (http://web.archive.org/web/20040207175652/http://www.transhumanist.com/Kansa-Fermi.htm).

I have no idea why we don't see them, and that makes me worry.


Anyway, my spider-senses tell me of some cool convergences between Singularity-thinking and Lovecraft. Perhaps cosmic horror is the natural outcome of Singularity-ish ideas.

P.S. Boltzman Brains really are the stuff of nightmares. The concept basically implies that the vast majority of observers will find themselves in a hell of utter emptiness and chaos. If this is the case, I'm happy to stay in my (comfy) simulation.

58:

I think you need always to bear in mind the Anthropic Principle when applying the Mediocrity Principle: most of space isn't a planet or even in a galaxy at all, yet here we are....

59:

I believe in Grant Morrison's "The Invisibles" humans are simply quantum-bombs in some inter-dimensional war. The entire process of humanity is simply the loading of gunpowder.

I also just remembered that "The Invisibles" also has a Hand of Glory!

60:

To those who have been implying it, why would a simulation be any less "real" than what we are experiencing now? What does the underlying computational substrate have to do with the reality that is being experienced?

Charlie, have you considered the ways in which you and your fellow humans are already eerily like gods? How easily could you already be mistaken for one by someone from a different era and tech level? And for that matter, to what extent will our descendants inspire in us reverential awe? I submit that, for all intents and purposes, you are as much of a god as ever there was one.

61:

Scott Aaronson and Anthony Aguirre recently discussed some of the same anthropic wackiness about physics and computation that's coming up here, so if you like this comment thread you might like that too!

From that discussion, it seems really strange -- and yet not -- that the densest possible computation that can happen in our universe is right around the event horizon of a black hole. Is it possible that an advanced civilization (or random chance) could arrange a hyper-dense system (both in mass and information) that collapses into a black hole and uses some simple(ish) laws of physics to give rise to information organized in simulations like the one we exist in? (I'm no physicist, so probably not...)

62:

The thing is, we assume that what is being simulated is the entire universe, when really, you just need to simulate the stuff that is closely observable to a conscious entity and fake the rest. Since no one can really say if the number of conscious entities is greater than one, the complexity of the potential simulation can be drastically reduced.

To put it another way: simulating newtonian physics is easier than simulating relativistic physics. Perhaps the universal simulation code has a statement like:

if( mindDoingObscurePhysicsExperiement() )
  doRelativistic();
else
  doNewtonian();

It might be easier to just call rand(2) when a coin is flipped and then backfill with sensory impressions that support the result. Hell, if we *are* in a "simulation", there's no telling if the rules are actually at all reflective of any "real" universe. Everything could be entirely made up, ad hoc, in a way that can be simulated easily.

Given that if this is a simulation, we've experienced nothing else, determining what differences there might be from the real universe would be an impossible task, as we know nothing about that real universe. All we can do is look for inconsistencies in how the universe behaves. But even then, we still don't know if this would mean anything, after all, we currently *do* see inconsistencies between relativity and quantum physics. These, we put down to lack of knowledge. But how do you *prove* this is because we don't know something rather than a failure in the model? We can't, really, one way or the other.

63:

@sburnap #61

This leads to a nice argument against science and population growth actually. The more observers there are, the more expensive the simulation, since you can't "fake" it as easily. You have to do more expensive calculations.

Similarly, if those observers develop better instruments (Hubble Space Telescopes, LHCs, etc.) they will also force more expensive simulation.

So, we should ban science because if we keep up expanding our observational powers, it'll make the universe too expensive and we'll burn up too much of our computorium quota.

64:

Presumably you've read and listened to Scott Aaronson's latest video on bloggerheads which covers lots of related topics (Boltzman Brains, the medicrity principle applied to multiverses etc)

http://scottaaronson.com/blog/?p=454

65:

I'll have to admit to being a duck-typing realist here. I believe in Ockham's Razor. If the universe seems real despite our best efforts to test its limits, then it's best to assume that it is real. If it's a simulation operated by people smarter than us with the purpose of making us think it's real, then they can anticipate any possible test we might perform.

Saying "the Fermi paradox exists because we're in a simulation" amounts to saying "we can't explain the Fermi paradox". The explanation in "Accelerando" is much better than this. Even the "yeast-in-a-beer-vat" explanation is better.

Obligatory xkcd simulation-and-reality reference: Frogger. (Read the mouse-over text.)

66:

@ben 16 - "If we're in a simulation, should we expect to be able to create our own simulations once we've reached that point?"

Some ObSF - Daniel F Galouye, Counterfeit World (1964), aka Simulacron-3.

[Spoilers, though pretty obvious from the nature of this thread]

It's 35 years since I read it, but people in our world working on creating a massive computer simulation in which the agents become conscious realise that they themselves are agents in a simulation; I forget how but they manage to get rescued or lifted into the "real" world (you can tell it is real as there is no Moon)(or is it real?).

I guess if we were living in a simulation, the simulation would not really have to model an entire universe, just the bits close to us in detail and the rest more impressionalistically, as in traditional movie matte paintings. (As an 8-yo I had the feeling that the only really real stuff was stuff I could see, and that people were in charge of putting it in place and making it work as I moved about, a bit Truman-show-like).

Of course, maybe by discovering all sorts of exo-planets in short order we are creating simulation creation problems for our datamasters. Didn't Stephen Baxter have an Interzone short story along these lines, where our surprising success in getting to the moon caused data glitches as the simulation broke down in an area it was not expected to have subjected to such close scrutiny?

67:

My main problem with the simulation argument is that simulations require resources, and in any universe I can believe in the thing being simulated needs to be simpler than the thing doing the simulating.

To me this says that assuming you have n planets worth of complexity in your base universe you can get O(log(n)) levels of simulation before you get to an Aristotelian universe...

Of course you could just use your universe to make lots of planets surrounded by fake stars, but then again you had the universe in the first place so why bother?

68:

If one combines the concept of the Biblical harvest of souls with
Bostrom's ideas about posthuman simulation, one can even develop an interesting and completely heretical concept of theodicy. From the posthuman perspective, our universe looks rather like a zero-player Massive Multiplayer Online game, an oxymoronic concept conceived a design for the Artificial Player Character, or APC. An APC is similar to a Non-Player Character, except that it possesses its own individual motivations that provide it with the volition required in order to behave proactively in the MMO environment.

When seen from the posthuman point of view, we are all nothing more than APCs running around the virtual environment of an MMO called the World of Man. Like all game characters, we are bound by the limits set by the MMO's posthuman designer. However, if another posthuman managed to hack into the MMO, this second posthuman would have the ability to begin interacting with the APCs, corrupting the virtual
environment, and generally creating havoc within the game world. Perhaps he would tell some of his friends how to break in, then let them take over APCs and play as proper player-characters, but with amped-up stats and abilities that the regular APCs can’t match.

Faced with a maliciously corrupted game, the posthuman designer can either turn it off or attempt to fix it. He could simply manually scrub each aspect of the game, but this brute force solution wouldrisk creating new problems and would certainly warn the mischievous interloper. A more elegant solution would be to trap the malicious
posthuman and his friends in the game without warning, then insert a viral APC designed to infect other APCs with the ability to resist the malice of the posthuman intruder. His purpose in doing so would be to salvage those APCs whose emergent behavior suits his original plan to develop AIs capable of demonstrating the behaviors required for the real game.

69:

One of the things that amuses me about that argument is that the people who say "this must be humanity's peak, because that's the most likely time to have be alive" are pretty much all members of a statistically small clan of highly educated middle-class westerners (the "weird" grouping, in sociological terms: White, Educated, Industrialised, Rich, Democratic). But they don't seem to regard being born into that small group as nearly as unlikely as being born into some other group of a similar proportional size....

70:

AIUI the Principle of Mediocrity tells us to expect to be from the middle -- or mode? -- of a distribution. What this means depends on what the distributino is. Normal gives us one idea. Bimodal another. Singular or degenerate would be another -- it could be that the Fermi logic is correct, and that any technological civilization of our level is likely to go on and dominate the universe in short time. The expected number of civilizations is one. We exist, hence we're that civilization, just as we're the only such species on our planet.

This interacts well with Robin Hanson's "early success makes hard problems look easy" paper, which I won't google due to backwards interface right now. But imagine a bell curve of hypothetical civilization start points -- a few luckily early, a few late, most falling around the same time. Except that, as above, it's winner-take-all, so the lucky tail of the curve prevents the rest of the curve from forming. So all extant civilizations would be those that got particularly lucky in their origins. Normally it takes a long time to evolve live, except in reality that never happens, since planets where it takes a long time get overrun by planets where it happened quickly.

71:

"It's unlikely that we'll be able to ever generate a perfect simulation of reality that is smaller than reality itself[...]"

Well, it's not quite what Kurt Gödel proved, it comes close, but still no cigar.

I think Asimov dealt with this fallacy in a short story of his: The perception of the simulations perfection is also simulated, and thus useless as indicator of truth.

(Can't remember the title of the story: About a robotic human simulation, who starts mucking about with the papertape that controls his simulation of reality.)

Obviously, if such simulation shortcuts are made, inconsistencies might be "observable" inside the simulation.

But that issue could be trivially paste over, with a (simulated) ability to overlook more or less glaring inconsistencies and/or a willingness to act on non-(simulated-)reality based events.

The high frequency and variety of "out of the body" experiences, reported in all cultures thoughout history, and the effect these have had, thus makes compelling evidence for the simulation hypothesis.

In other words: Our ability to be religious makes a compelling argument that there is something to be religious about.

Poul-Henning

72:

@25 c is the maximum render speed of reality.

maybe a black hole is a crash?

73:

Have you read his Merchant Princes series? There's several civilizations that are lower tech in that.

74:

Interesting post. Re: the Fermi paradox, I have a couple of issues with it. Basically I don't think that it's actually testable at the moment. On the issue of detectability (or not) of artificial signals at interstellar distances, I've seen it argued both ways with no sign of any consensus. And also, in fact, the same with 'starships' of whatever sort. (Of course, if the interstellar gap is effectively-insurmountable, as Our Gracious Host has argued, then the problem goes away entirely...)

Scientifically, the only thing that we have any real chance of answering any time soon is: what is the mass function of terrestrial planets? Presumably when the next round of Kepler data goes public in February next year, that will help. And in the meantime we at least know that they exist (Gl 581 etc).

Probably the only other thing that we can reasonably conclude at the moment is that our galaxy isn't host to any Kardashev Type III civilisations, and there don't appear to be any in the Local Group either.

75:

You know, I think I have to go dig out my copy of the old Infocom game "A Mind Forever Voyaging". It's an excellent game, one of Infocom's best. It's about the first simulated human-level intelligence our society is able to make ("Perry Simm", a simulated human living inside the PRISM computer system), and in the game there actually is a practical reason for the person to be simulated.

(Incidentally, the AI turns out to be a writer. The implementors didn't know he would be, that's just the way his development in the simulation progressed.)

76:

(Can't remember the title of the story: About a robotic human simulation, who starts mucking about with the papertape that controls his simulation of reality.)

I think you're thinking of Philip K Dick's The Electric Ant - https://secure.wikimedia.org/wikipedia/en/wiki/The_Electric_Ant

77:

The way I see it, if this universe is a simulation, then what is being simulated appears to be the movement and interaction of galaxies, and we're (at best) an unexpected by-product of the laws of physics having been set up the way they are. The chances are, the simulators haven't even noticed that some grains of dust orbiting mote-like stars have a thing film of organic slime.

But the argument as a whole doesn't impress me. Strip back a layer of technology, and all you're doing is claiming that we're all characters in a novel, and your average sentient species will probably write more novels than computer simulations of a universe, so by the principle of mediocrity, we'd have to assume that that's where we are.

78:

Me too. The Fermi paradox is basically saying "we're special, why don't the other kids come and play with us?". Furthermore, it's built on the Drake Equation, which is complete and utter drivel. The only honest answer we can currently give for any of Drake's constants is that we just don't know. Add in the fact that the equation itself multiplies terms rather than iterating each stage (chance of complex life evolving? X successes out of Y attempts, if you please, not just X percent), and you've got a classic example of how physicists do biology. Badly.

None of which is really what Charlie's talking about. I tend to think of the simulation hypothesis as an extension of the the "We're special" problem. We're so important that someone set up an experiment just to create us (OH RLY?). Well, I'm not special :)

79:

Goddam, when I retire, I am just going to spend all my time reading all the comments in Charlie's blog. This is what you always hoped the net would spawn, as opposed to the average board where, as my son says, "the trolls and dumbasses always win in the end.".

This is my first exposure to the Simulation Argument, thanks. Very nice. I have been seriously buying into the "much easier to be gods in virtualities than to travel to the nearest other solar system" explanation of Fermi's Paradox, re Greg Egan's "Wang's Carpets".

Question, is not the "principle of mediocrity" just a refinement of the Cosmological Principal -- that there are no privileged observers? What are the additional refinements? The Perfect Cosmological Principle (of Fred Hoyle and the Steady State Theory) refined the Cosmological Principle to "no privileged observers OR PRIVILEGED TIMES". Could we not formulate these concepts as refinements of the Cosmological Principle?

Chris

80:

One other S-F reference. That simulating the entire universe requires at a minimum the resources of the entire universe (which would like to avoid the overhead involved since it is already busily Wolfram-computing itself) wound up being the dramatic conflict of the most excellent Neverness trilogy of David Zindell.

Chris

81:

If you have a stack of simulations inside each other, couldn't you just make each simulation slightly less detailed, courser, and smaller than the previous?

Maybe the original starting point was entirely filled with conscious beings from the infinitely small to the infinitely big. Then they ran some simulations with a minimum and maximum distance and something called empty space...

82:

Other than the Matrix, I was first introduced to this idea in xkcd http://xkcd.com/505/

83:

To be honest Fermi's paradox looks really weak. The simplest explanation is that nobody has gone past at the right time. Maybe they had a look 500 million years ago, weren't impressed and kept going. Maybe they had a look 1000 years ago, weren't impressed and kept going. Maybe they had a look yesterday, weren't impressed and kept going.

The amount of time in which we have had the ability to detect a space going visitor is vanishingly small. For the rest of that time we could have been the biggest tourist draw in the galaxy and we would be none the wiser. Or maybe the "Lonely Galaxy" guidebook says "Boring, don't bother".

84:

A simulation of the movement and interaction and galaxies doesn't really need atomic resolution though. Granted, our simulations aren't good enough to fully reproduce observations yet, but we can mostly simulate these phenomena already. They are actually pretty simple systems until you get down to solar system scales, and there is no need to treat a star as anything more complicated than a point mass (stellar collisions are so unlikely that evolved - i.e. not forming - galaxies can be modelled as collisionless fluids). I'd be disinclined to think this the purpose of a cosmic simulation.

There's a disconnect between the behaviour of galaxies and solar-system/planetary level physics. It would be interesting to figure out if you could form life with a simulation that consists only of a single forming star plus some suitable initial conditions (i.e. pre-formed heavy elements, gas of the right temperature, maybe a nice supply of cooling background radiation etc). Beyond this, I'm not sure what influence the rest of the Universe would have. You wouldn't even need the illusion of other stars, galaxies and external phenomena - the creatures that evolve aren't going to miss them. If in a Universe like ours life doesn't escape its own star, there doesn't seem much point in simulating the entire Universe just to simulate life.

That leaves some interesting possibilies if true: the simulation is for life, and it does manage to propogate itself in violation of the Fermi paradox; the simulation is for some other purpose (it might just be testing if life is possible in such a Universe); or it could be the Universe is not simulation.

85:
In general, there are two classes of solution to the Fermi paradox; ones that assume that we are unique special snowflakes in an empty cosmos, and those that postulate that intelligent species are common, but some kind of mechanism stops them from colonizing interstellar space.

Well, there's also the third class, where there is intelligence everywhere but we either don't recognize it or we don't have the tools to see it. But let that pass.

There is a very easy mechanism that a lot of people find believable and which presents an insuperable bar to colonization - and that is simply the level of the technological arts that is achievable in this universe. The lower the level, the harder any sort extended colonization is going to be.

So you've got ftl invented by some 14-year-old genius powered by AAA batteries, the paradox is really mystifying. Crank the possible down to ftl is hard it becomes less so and cranking still further to ftl is impossible and you're starting to see a resolution in sight. If the Highest Possible Level of technological Development (HPLD ;-) )gives you O'Neil colonies fifty miles long and travelling at 0.0001 c, well, I'm guessing you're not going to see a lot of aliens in your back yard :-)

86:

One of the unanswered questions about the simulation argument is what exactly the purpose of such a simulation might be.

I have meditated deeply on this very subject, and come to the conclusion that it's most likely a screensaver.

87:

@11:

I recall a recent book proposed that there will be a global catastrophe when the Earth supports so many people that local reality is over-observed, leading to catastrophic breakdowns in the quantum reality around us.

Robert Reed's "Under a Gated Sky" has the conceit that when the sky is examined in too-great detail by radio telescopes, optical telescopes, interferometry, etc, the machinery supporting the illusion collapses and you see reality "as it really is".

88:

@57:

P.S. Boltzman Brains really are the stuff of nightmares. The concept basically implies that the vast majority of observers will find themselves in a hell of utter emptiness and chaos. If this is the case, I'm happy to stay in my (comfy) simulation.

It's kind of hard to tell if you're on the outside, but the people doing the Boltzmann Brain stuff are generally considered to be cranks that the serious people wish would just go away.

Yes, the analyses of BB's are considered to be just that bad, don't demonstrate a terribly good grasp of what a measure is, and seem to be at this point, the sole province of string theorists. Whom a lot of people wish would just go away as well, incidentally.

89:

But if we accept the argument that any sufficiently advanced civilization will developed convincing simulated reality, and we are living in such a simulated reality, then we in this simulated reality will go on to eventually develop our own simulated reality withing the current simulated reality and so on without end...

Perhaps each simulated reality cannot contain another simulated reality that is as compltes as the one that contains it. If so perhaps it will be harder and harder as the simulations nest deeper to create new simulated realities whithin them so that the process must eventually stop.

If I go into a simulated reality out of boredom with this one I would want to be sure in advance that my "death" in the simulated reality would leave me alive and well in the real one.

If we are now in a convincing simulated reality, how will we know when we "wake up" upon our supposed "death" in the simulated reality, that the reality in which our simulation is running is the actual reality and not just another simulation?

90:

A general comment on the principle of mediocrity, the Anthropic principle, etc: The first is that some care has to be taken with the measure that is used to determine what is the norm. While it may seem obvious now what that measure is for any of a number of propositions, all too often it turns out to be the wrong measure.

The second comment is simply that you can only use this principle on a distribution, not a single data point. The fallacy - often unconscious - is that if everyone assumes they're the norm, well, most people are going to be right. And that's okay. But then the incorrect jump is made to the inference that the person reasoning thusly is likely to be one of those "normal" people. False!

You simply can't do science that way - you're assuming information that you don't have. If you flip a coin ten times and get ten heads, do you assume that other people will get the same "typical" result and so the coin must be biased? Or do you wait and see and gather more information on ten-flip runs?

91:

@81, @83

I dunno. A solution to the Fermi Paradox has to be pretty universal. Some alien somewhere my find us or something around us interesting. Given the age of the galaxy (which is old enough to be totally filled with space-going critters, mostly machines), I'd expect to find a huge diversity of interstellar life, all with very different motivations and ecological niches.

Even dull, or not-particularly exciting or valuable niches get occupied by somebody. I do find it weird that we've got no evidence for anyone strip mining the solar system (maybe with some stragglers eking out a meager living in the rubble that's left).

Nope, everything looks relatively empty. If they are out there, they sure are inconspicuous. And that makes me worry.

92:

@89:

Given the age of the galaxy (which is old enough to be totally filled with space-going critters, mostly machines), I'd expect to find a huge diversity of interstellar life, all with very different motivations and ecological niches.

So you're saying that even if the high end of technical art is fifty-mile-long O'Neil colonies cum interstellar arks that take anywhere from 10,000 to 100,000 years to make a trip there must have been some sort of activity in our neighborhood? Activity, furthermore, that we could actually see?

We'll have to agree to disagree on that one.

93:

@90

I'm thinking that machine-intelligence with good nanotechnology should be quite happy going from point-to-point in interstellar space. 10K - 100K years is fine if you can turn yourself off for most of the trip. No need to be as big as an O'Neil ark. Why not spread billions of beer-bottle sized arks of nanobots. These would be like a machine-spores to quickly spread across a galaxy (if you think 10-100 million years is quick). Lots less mass to move around.

Also, there may be plenty of interest between starts. Oort clouds will largely overlap, so if you make a living quietly munching comets, you need not wait 10K years between ports of call.

Last, why should all ET's be intelligent? Why not machine-based life that's super well adapted to life in deep space, but dispenses with expensive things like big intellects?

All this makes me think the galaxy should be brimming with life (of various sorts of plant-like things, predators, scavengers, etc. etc.) that can spread across stars. Since it looks very very empty, I think something seriously disturbing may be going on.

94:

@91:

I'm thinking that machine-intelligence with good nanotechnology should be quite happy going from point-to-point in interstellar space. 10K - 100K years is fine if you can turn yourself off for most of the trip. No need to be as big as an O'Neil ark. Why not spread billions of beer-bottle sized arks of nanobots. These would be like a machine-spores to quickly spread across a galaxy (if you think 10-100 million years is quick). Lots less mass to move around.

You're assuming a level of technology I've already said is not allowed. No machine intelligence as smart as a human being (or dog or whatever), and no nanotechnology, at least, no nanotechnology of the "good" sort you seem to be thinking of.

The assumptions are that you can only stick your aliens in a can, that the can has to be fifty or so miles long, and that it's got to be in space anywhere from 10,000 years minimum before making a port of call. Still think that the colonization thing is doable under those assumptions?

Your perfectly free to assume whatever level of tech you want, and perfectly free to say that I'm being way too pessimistic about the end state of the art.

But that would be a different discussion.

95:

I don't know exactly what Fermi had in mind -- all I've heard him quoted as saying on this subject is "Where are they?," without much explanation. But I do find the paradox puzzling, and I think some of the people on this thread who don't find it puzzling may be missing the point.

The argument (at least the argument people make today, as opposed to whatever Fermi himself may have meant) isn't that we're special enough that someone would want to take a hundred-parsec trip to visit us. The argument isn't that we should be able to recognize a technological civilization somewhere far away. The argument isn't that there ought to have been a space tourist who visited Earth and went away. What it hinges on is: if species with technological civilizations are relatively common, and if interstellar travel and colonization is practical with sufficiently advanced technology, then you'd think that at least one species would have colonized the whole galaxy by now.

And the thing to realize when you hear that is what "the whole galaxy" and "by now" means. The age of our galaxy is something like ten billion years. Earth is about four billion years old, and life is more recent than that. You can perhaps come up with reasons that life couldn't have evolved ten billion years ago (not enough heavy elements), but it could certainly have evolved somewhere a lot earlier than it did here. Or you could imagine that life began on some other planet about the same time it did here, but that it got to tool users maybe ten percent faster. That doesn't seem so unlikely; there's been a lot of contingency in our history. So that would give them a couple hundred million years head start. It shouldn't take more than a few million years to settle the whole galaxy (assuming it can be done at all), so, if you believe in the principle of mediocrity, it would seem most natural that it would have happened in the distant past.

So the question is: if you assume that the galaxy has seen other technological civilizations before, why didn't one of them convert Earth into a planet more to their liking back before multicellular life began here? Why didn't they dismantle Luna and turn it into computronium, or turn Mercury into one of their solar power stations? Why aren't there here already, doing something so unsubtle that (in the unlikely event we had managed to evolve) their presence would be obvious?

That's what I wonder when I hear "Where are they", anyway. Obviously at least one of the premises must be wrong, but I don't think it's obvious which one.

96:

The simulation argument's detractors discussing how hard it would be simulate computationally an entire universe with: Newtonian physics + Einsteinian physics + quantum physics being observable are missing a relatively easy out:

Spawn your own universe after setting the initial conditions and let the "simulation" run. Spawn another bubble universe with different conditions and run it... ad infinitum... maintain a wormhole link to the daughter universes for monitoring. Spawning universes could be as simple as forming miniature blackholes or setting conditions upon stellar collapse. In this scenario the computer substrate is a bubble universe...

Recent physics articles talk of possible universes spawned within blackholes and if that could explain the flatness problem:
http://www.eurekalert.org/pub_releases/2010-04/iu-oua040610.php
Why not let a bubble universe run the simulation? Much less resource intensive. BTW: random noise is not very compressible... meaningful information has repeats and is compressible.

My personal take on the universe:
We exist in a probability wave where quantum observation (especially multiple observations) set a consistent reality. Quantum events decohere into macroscopic events (at rare times with visible macroscopic effects) and combined with observations from conscious entities shift the probability wave to be self-consistent across what we observe as time.
Self-consistent means that changes to accommodate an observation can reach into the past or future. Wherever the same light-cone is shared the probability wave form co-evolves with observations.

Aliens can fit into this world view easily enough... however I'm personally of the opinion that the events required for intelligent technological life is rare. Be it a large moon to stabilize the earths tilt, a relatively quiet sun, a 3rd or 4th generation solar system with high metallic content, the amount of time the earth has been around without intelligent life (umm almost 1/3 the lifetime of the universe?), etc... all imply we are really rare.

97:

@Eric: suppose you live on an island (apropos of the previous thread, perhaps Easter island). You have lost the ability to make seafaring craft. In your entire life, and the memory of your grandparents, no-one has ever seen any sign of intelligent life from outside the island, nor detected any signs that anyone else out there is using your idea of high technology (no moai flying through the sky, no decaying reed boats washed up on your beach). You might conclude that you were alone in the universe. You would be completely wrong, and a smelly European in a sailing ship might be just over the horizon, about to drop in, gift you with syphilis, claim your island in the name of a monarch you've never heard of, and bugger back off over the horizon. You'd never see him or his ship again.

Now, tell me how that scenario (shamelessly modified from Iain Bank's description of an outside context problem, of course) could be proven not to apply to the Fermi Paradox. I honestly don't think it could, at least not right now. Logically, maybe, but empirically? I find it very hard to imagine the level of proof required.

98:

Charlie, are you sure humanity has made it to mediocrity?

I mean, look at us! We still think a lens, a mirror and a CCD chip make a decent telescope! We think 3D printing is a really neat idea! We can't even make antimatter. Hell, we can't even find the goddamn Higgs Boson, and if we can't do that, how will we ever build a network card that can talk to the cosmic string network? (Of course, the network is run by a race that has a random fucking number of manipulatory tendrils, and they never, ever use real numbers, because several billion years ago they fought major wars over the appropriate base for their numerical system. Unless we get help, decoding the packets will be beyond us for the next billion years...)

We're retarded, stunted and delusional! 90% of the human race don't know that attribution errors exist. We only inhabit three dimensions. Most of us think God is a psychopathic human male with a beard! Some of our pathetic brethren even worry about bat-winged squid gods...

Why the fuck would anyone want to talk to us? We're not even immune to memetic viruses, and the memetic parasites we tolerate are just plain disgusting. We don't even know that shoggoths are a form of soap...

"Gll'gm'rph, don't touch that human! Get out of that solar system right now! It's dirty in there!"

"But Mom!"

99:

The reasons we may not have heard from ET are many, starting with the difficulties for physical travel not to mention separation from local bandwidth (as someone hereabouts speculated on before, I recall).

Another recent proposition from the AstroBioSETI arm of research suggests that we may simply have been looking for the wrong thing because ET is a cheapskate, sending messages is expensive and we should therefore retune for tweets rather than looking for blogs: http://www.sciencedaily.com/releases/2010/07/100721094231.htm

Interesting though, they propose listening for their Benford Beacons from galactic core (on the basis that there are more stars there and therefore a higher likely hit rate) but I like @Mark G (52)'s point that being in a quiet bit of an outer spiral arm might be better for developing intelligent life from a mean-time-between apocalypse point of view.

On the subject of SA, it could be that our speculated God-Like Teenager is playing the single player version of Civ. Frankly it's just better that way because in the multi-player version, regardless of whether our GLT or the other one a little further down the LAN wins the contest between our Civ and his, it might not be a fun experience for us.

100:

I had meant to expand on this statement:

"random noise is not very compressible... meaningful information has repeats and is compressible."

There was a recent article on physorg that talked about how you could achieve high information content from few starting rules. The idea being that a relatively small rule set could evolve over time into the complexity of our universe. The core concept was that the information content of the basic rule set can expand via simple interactions (probability waves interacting in my world-view) into the vastly more complex and information rich universe. At various Planck intervals along the evolution of the rules, complexity arises that cannot be compressed without losing information.

On a final note I should expand on the probability wave viewpoint by mentioning that I do not think that is the only probability wave.. Just like the probability of an electron being in a particular location has varying likelihood, so does what we perceive as our universe exist as interacting wave with some probability value (not necessarily unity) . An entire subset of less or more probable universes (the multi-verse?) could be interacting unseen by us, yet shift into our visibility with the right "observations". We evolve the universe with our observations.. quantum observations reaching into the past when necessary.


101:

@95 @Chris

Good points. However, Easter Island is visited by outside migratry birds, fish, etc. Sometimes bits of weird wood or even seeds wash ashore from other places. All of these are evidence for some life in the outside world, even without smelly Europeans showing up. (Nice ref. to the Outside Context Problem).

Anyway, that's part of my point. If alien intelligences exist, so should alien equivalents of seeds, dumbly reproducing robots, etc. etc. It's all physically possible to send stuff between stars, especially if you can wait out long trips.

My guess is, if there are alien civilizations, these should be accompanied by alien weeds and alien pests, etc.; all of which should just spread without any real point other than propagation and reproduction.

Now we haven't looked that hard for alien weeds or pests infesting our solar system, but I rather doubt they exist, even though I think they ought to be out there.

All things being even, I think Great Filter arguments probably hold the most water.

102:

I forget which book he did it in, but I liked one of Ken Macleod's solutions to the Fermi problem. It turns out that intelligent life has already arrived in the Solar System and many other places. But it's colonies of microscopic machines living inside of asteroids. These "ships" are not very large, hot, bright, noisy, or fast-moving, and in fact are normally indistinguishable from uninhabited asteroids until you get very close. The inhabitants have all the time in the world and are not interested in acquisition or necessarily even initiating conversations with local life.

Another solution to the problem I've often seen suggested is that some UFOs really are space craft from interstellar voyagers and only coordinated efforts to discredit and mock the idea blind me to the truth. I don't find the idea very credible. But that's just how I *would* think after the media successfully brain washed me, isn't it?

103:

A problem I've always had with the Fermi Paradox and the Drake Equation and all the other suppositions about extraterrestrial intelligences is that we have no reason to suppose any other intelligence out there apprehends the world the same way we do, thinks the way we do, or is remotely interested in the same things we are.

Case in point, we have already met another species which is just as intelligent as we are. We hunted them to the edge of extinction so we could make cosmetics and corsets. We've never had any success at all in communicating with them. They seem pretty unlikely ever to build rocketships or radios, and they've never clicked out a series of prime numbers for us. But we know their brains are just as complex as hours, and somewhat bigger. They're using those brains for something, but it's something totally orthogonal to us.

And, you know, whales share an evolutionary history with us--they have more or less the same five senses we do (though with much more emphasis on hearing and less on vision), and nearly identical biochemistry. When it comes to interspecies communication, they're probably a best-case scenario. If we ever met life from a different solar system, they could very well be even more alien than whales, using their brains for some complex computational task even less relevant to our interests than whatever it is whales keep singing about. Hell, they might not even use the same senses we do. They might be much faster than we are, or much slower. We might not even be able to perceive each other directly.

Point is, we have no way of knowing what we're looking at. Trying to find ETI's by scanning the sky for radio signals might be about as pointless as trying to find whales by scanning the seabed for golf courses.

104:

As you said above, if they're only spending the cycles on where attention is being paid, then it will be the attention of the beings who are the "point" of the simulation. And there'd be no point putting in the amount of detail to humans that I am currently experiencing if that was the case, unless humans are the point.

So either they're willing to spend a lot of computational power to simulate the universe at a planck level, or I'm the centre of the universe, or this is reality.

I think I like option 2 both the least and the most.

105:

There's a hole in your analogy: "Easter island" needs to be big enough to provide evidence supporting the theory of evolution. Otherwise your easter islander is left with only two origin hypotheses -- panspermia (from some unknown hypothetical island-over-the-horizon) and creationism. (Actually, creationism and evolution belong in the same basket -- both of them entail humanity appearing on "Easter island" rather than arriving from somewhere else.)

But yes, overall your point stands.

106:

Actually, no: they only need to ramp up the processor cycles for stuff to which attention is paid in the sense of there being an "observer" -- some other bundle of particles whose state may be influenced by the thing being observed. That means us. It also means bacteria or plants or possibly a dust particle that just happens to be in the path of the high energy cosmic ray in question.

The rest of the simulation space can be tagged as undefined, or dealt with by approximation.

107:

I think you may be a bit unclear on units of time vs. units of distance. And also on matters of cosmological scale. Can I suggest reading a good introductory laymans' text on cosmology or astrophysics?

108:

The bubble universe idea is similar to mine. Its always less efficient to simulate something than to have the real thing. That goes for a Z80 processor, or a civilisation, its easier in relative terms to create the real thing.

You can do it with bubble universes, or you can do it with just changing the physical constants in a region of this one. Just set things up as you like, tweak some starting conditions, set some fake boundaries (aka The Truman Show) and away you go. Hell, if you can tweak physical constants, why not tweak time constants? Make it run fast for a while.

So maybe the simulation is just this solar system, with the stars beyond it being the simulation that's played out on the surface of a boundary we can't go beyond, yet. Shades of Vinge's 'Zones of Thought'

The question arises, why would you do this at all?

One possibility is having someone to talk to. If you find yourself really alone as a species, the only intelligence you can find, then grow some companions by setting up a series of nurseries, ramp up the time constant and grow some intelligences, or maybe slaves, from first principles and evolution. Once they reach your desired development level, let them out to play/serve.

Oh and as for the mediocrity principle, its as well to remember there is no Mr Average. Everyone is special in some small way because the probability of the totally average in all respects is vanishingly small. You don't get to realise the 'special' quantity until you get to compare with a big enough sample set.

109:

My two cent to the simulation argument (I didn't read all comments, so I'm not sure if they are talked about already):

Cent 1: I still have problems with the infinite recursion nested somewhere in the probleme: if it is easy for highest-tech civilizations to run conscious large-scale universe/civilization simulations (CLUCS), then a simulated civilization should in the end be able to run a CLUCS, too. So you get a nested set of CLUCS with one creator civilization on the one end (which cannot be sure that it isn't a CLUCS, too), and no end to simulations on the other end.

Cent 2: The other problem I have with CLUCS is the question how computing-intesive such a simulation would be, i.e.: How big needs the universe in which the simulation takes place to be, to create a seamless CLUCS? And if it isn't seamless, but has matrix-like faults (or Heteromeneles(sp?)' overloads), wouldn't it be possible to observe or test the act that we are in a simulation somehow?

Taking these two cents together, and assuming that universe and CLUCS are somewhat similar, one could also question how big the "loss factor" would be - if the simulation is not seamless, how many nested CLUCS are necessary to make it quite obvious that something isn't right to the innermost CLUCS - and if they are seamless (all turtles to the bottom ...), what would be the physical proporties of the simulation-running universe, and when does that become unbelieveable?

(I think some of these ideas are similar to some speculative science I read, but I'm not sure whose - Egan of course, but there's another author on the tip of my tongue who wrote about the nested simulation problem ... some of these identical looking e-books ... Karl Schroeder or John C. Wright maybe)

110:

About universe as a simulation, my personal interpretation has always been that this universe is an AI breeding-and-training ground.

Religion was invented to give us a training target: the meeks, the credulous and faithful AIs will be harvested and put to work inside extradimensional gadgets and devices, while the too independent, unreliable ones will be discarded.

111:

Another aspect of the simulation hypothesis that gives me the shudders is this: how do we know that we are the object of the exercise? What if we are to the true object of the exercise as, say, the poultry and livestock in our farms and slaughterhouses are to us? (That is: we're merely a useful intermediate step towards something else?)

And suddenly we're off with the Great Old Ones...

112:

36, 50 & 97 ...
Simulations - no.
Breaks Occam's Razor, big-time, and as stated elsewhere requires better/more complicated simulation as our ibservational methods improve. Hence the "breakdown of simulation" repeating SF idea.

Copenhagen Interpretation of QM.
WRONG.
MUST BE WRONG.
Why?
Because there is an underlying level of order, on which we do not (yet) have a mathematical/physics handle.
How can I/we tell?

Modern runs of the double-slit experiment.

In which SINGLE photons are fired at the slits.
At first ( up to 25 ~ 300) the firings appear random, as one would expect, but over a larger number of firings, say over 5000, (and you can space the firings as far apart as you like - once a minute will do nicely) the usual "wave" interference pattern appears.

The simplest explanation that fits all the presently-known facts is that there must be an undelying level of "order", as previouslly stated.

Paging a really good mathematical physisicst to get the Nobel for solving that one .....

113:

Can I suggest reading a good introductory laymans' text on cosmology or astrophysics?

Do you have one in mind?

Only the last time I made a similar suggestion the respondent (an artist with virtually no math background) hit Wikipedia than creatively reinterpreted an article there to prove their original contention (which was approximately 180 degrees to the generally accepted understanding of the topic under discussion).

At which point I gave up!

115:

If the Highest Possible Level of technological Development (HPLD ;-) )gives you O'Neil colonies fifty miles long and travelling at 0.0001 c, well, I'm guessing you're not going to see a lot of aliens in your back yard :-)

You'd be surprised. The galaxy isn't actually that big, it's very, very old, and exponential increases are very, very scary.
If you're travelling at 0.0001c, that takes you a billion years (a hundred thousand light years, at one ten-thousandth of light speed) to travel from one side to the other. Our galaxy is roughly ten times as old as that. Even if you make really parsimonious assumptions - one ark starts off at one edge of the galactic disc, travels ten LY in 100,000 years, stops for a thousand years and builds another one; iterate - that still gets you galaxy-wide coverage fairly quickly.
In a billion years, they've spread from one side of the Milky Way to the other, and there are, theoretically, 2exp10,000 of them, or roughly 10exp30 - ridiculously more than there are stars in the galaxy. Easily enough for a million million colony ships to be in orbit round every one of the four hundred billion stars in the galaxy at any one time, and for thousands of times as many to be in transit.

Of course, by that time they would have used up a significant amount of the galaxy's mass to build. If you assume that one of these travelling colonies is a million tonnes, then you'd run out - you'd only be able to build a mere 10exp29 before you'd used up every piece of non-stellar, non-dark matter in the galaxy.

Even if you assume that life can only arise around a Population I star, that's still plenty of time. There are Pop I stars more than a billion years older than our own sun.

116:

Another point worth consideration about simulations: when we write simulations, as we've to deal with finite and expensive constraints on computation and data storage, we try to simulate a) a strongly simplified abstraction of the reality and/or b) a very spatially/temporally limited subset of it.
If the reality we observe is a full blown simulation (and not simply a fractal abstraction where unobserved stuff does not exist), we must ask ourselves wich kind of complexity the "real" universe would have.
OTOH, if the simulation does take shortcuts with the reality, like showing atoms only when someone is watching for them, and in any other moments using statistic rules, sooner or later we should be able to find some bug on this side too... even if, thinking a bit about this, quantum mechanics after all *is* a bit funny about these kind of stuff...

117:

That sounds rather a lot like Second Life.

There's a lot of games on the internet which cast a fitful light on the idea of a Simulation. Second Life isn't real, not from my point of view, but there's an emotional involvement, and there is an internal consistency.

If we are a Simulation, all we can be sure of is that it is self-consistent. We make predictions, based on the rules we infer from out observations, and those predictions work.

Second Life has just upgraded the Physics engine, from Havok 4 to Havok 7. I haven't seen any obvious changes, but I know that the previous upgrade, to Havok 4, was enough to change the physics of the world, in ways that can be noticed. And there is still stuff available in-world which hasn't been updated to match.

It feels a silly thought, but if we are in a simulation, maybe the Physics Engine has been updated, and the Young-Earth Creationists haven't noticed. Second Life has a scripting language, and with the revised Physics, some scripts need tweaking. And we have traces of the old scripts in the "real" world we're in. Things such as the miracles recorded in religious texts.

But changing the Physics doesn't change other things.

(I know I shouldn't have talked to those Jehovah's Witnesses...)

118:

Charlie @9:
The problem with extending religious arguments to simulations is that God is somewhat different to a being running a simulation. Almost all formulations of God have him as embedded within this universe. And a large number of formulations have him as substantially similar to ourselves (or rather, us to him).

Whereas your simulation-runner is, largely or entirely, outside this universe. We simply can't say anything about the universe in which they reside, short of possibly the laws of logic and mathematics. So why expect that they have anything like our concepts of morality? Especially if you consider morality to be an artefact of evolution, as many do. Who's to say the simulation-runner evolved? Or even is an organism per se?

And even if did have some form of morality, would they be able to recognise suffering inside the simulation? Somebody jokingly brought up Conway's Game of Life, which will do as a metaphor, at least. How would we recognise "suffering" in Conway's?

119:

The phrase fourteen unanswerable questions, in Buddhism, refers to fourteen common philosophical questions that Buddha refused to answer, according to Buddhist Sanskrit texts.

Questions referring to the world: concerning the existence of the world in time

* Is the world eternal?
* or not?
* or both?
* or neither?

Questions referring to the world: concerning the existence of the world in space

* Is the world finite?
* or not?
* or both?
* or neither?

Questions referring to personal experience

* Is the self identical with the body?
* or is it different from the body?

Questions referring to life after death

* Does the Tathagata exist after death?
* or not?
* or both?
* or neither?

120:

Eric @57:

P.S. Boltzman Brains really are the stuff of nightmares. The concept basically implies that the vast majority of observers will find themselves in a hell of utter emptiness and chaos.

In which case, maybe they go mad and start imagining that they are lots of little tiny minds, rather than one big one.   8^)

Although now I reflect on it, the assumption is somewhat anthropocentric. Why should 'emptiness and chaos' be inherently a bad thing? Especially if it's all you've ever known. I would imagine that loneliness is only a problem if you're one of a species which has evolved to expect company...

VD @68:

If one combines the concept of the Biblical harvest of souls with Bostrom's ideas about posthuman simulation [...]

That opening line made me literally crease with laughter. I like the way your mind works.

121:

Hi ! All that remind me of Ramsey Dukes "Words Made Flesh" in 1988 : (from Amazon...) This is the book that first challenged our basic assumptions about the nature of the physical universe by suggesting that we might all be living in a virtual reality - and that information might prove more fundamental than either matter or energy. The ideas in this book have even been given an airing on the pages of New Scientist but, fourteen years on, this remains the most thorough and complete discussion of the virtual model of the universe. While others are beginning to explore the concept, the author had been working with it ever since the 1960s when he was studying mathematics at Cambridge university under Conway, himself a pioneer of artificial life studies. What struck the author was the division in society between those who fully accepted a materialistic view of existence and all phenomena, and those who felt there was 'something more behind it'. This book was an attempt to bridge that division by pointing out how the most extreme materialistic viewpoint would tend eventually to blow open its own walls far more effectively than any spoon-bending exercise. What seemed like two irreconcilable structures of belief would turn out to be just two complementary ways of approaching mystery. This edition contains the original text with new introduction and two further essays plus two stories appended to carry the debate forward into the 21st Century

122:

Thinking about the Fermi Paradox, I wonder if one possible answer is that intelligence is extremely rare as it arises as an evolutionary advantage in situations that usually kill off a species.

Consider most species; they sit in niches that they are well adapted to. To pick a particular example, fruit bats are well adapted to life in warm forests. If a fruit bat was born with a smidgen more intelligence than its fellows it's not necessarily going to represent an improved ability to reproduce and pass the ability on simply because fruit bats have everything they need all around them.

Now consider a species of ape right on the edge of extinction. Its natural habitat destroyed by some catastrophe, an ice age perhaps. Driven out of its niche and reduced to a few dozen breeding pairs such a species would literally be on the edge. In such circumstances an ape with a bit more nous has a huge advantage in finding new food sources and making a living in a hostile environment.

If you were to repeat this experiment a million times you might find that extinction is the natural result but in one case, our case, it seems that a miracle did happen. Recently evidence has arisen that at one point our ancestors were driven to about 70 individuals on the south coast of Africa. I'm speculating (poorly informed no doubt) that this is the moment that real intelligence started to appear, and from that nadir everything we've come to view as innately human - fire, farming, Lady Gaga etc. arose.

But the chances must be vanishingly small because it requires a species to both close to extinction and also to either have present slightly intelligent members or for the mutation to arise spontaneously while there are still enough individuals left to constitute a viable genetic base.

In my lifetime we've learned that planets round other star systems are common, and I hope we may one day find out whether or not life itself is common. I do believe though that we will find that intelligent life is rarer than a seven pointed snowflake.

123:

"And there'd be no point putting in the amount of detail to humans that I am currently experiencing if that was the case, unless humans are the point."


Not necessarily; it could be that what we humans experience is the absolute lowest bound of experience required for the whole simulation to remain internally coherent.

124:

The Fermi Paradox is based on estimating the size of a probability about which we have no information. If this unknown value is greater than 7x10^-22 then we expect there to be life in the universe. If this value is less than 7x10^-22 then we are lucky to be here. But we have no idea what this value is, what it depends upon, or how to estimate it.

Fermi was a little bit hasty in coining his "paradox". Models are useful constructs, but when you don't have the information to determine the parameters they are subject to the classic principle of GIGO.

125:

"the book that first challenged our basic assumptions about the nature of the physical universe by suggesting that we might all be living in a virtual reality"

Well, the first one except for all those other books that had done it before. (Daniel Galouye's 1964 "Counterfeit World" is the first one that springs to mind, possibly because I read it fairly recently.)

126:
So you're saying that even if the high end of technical art is fifty-mile-long O'Neil colonies cum interstellar arks that take anywhere from 10,000 to 100,000 years to make a trip there must have been some sort of activity in our neighborhood? Activity, furthermore, that we could actually see?
If you assume a civilization takes 50Kyears to establish a new colony, it would take less than a hundred million years to completely overrun the entire galaxy.

Compared to the age of the galaxy, that's a lot less. At 1000th C, you've crossed and criss-crossed the entire Galaxy multiple times. Ergo, you have to assume that no civilization capable of doing so has arisen before the last couple million years...

A paradox is something that starts from A, and leads to either not-A or both B and not-B thru a set of logically defensible steps. A paradox arises because one of the step is incorrect (usual math paradox: one of the step is equivalent to "divide by 0") or A isn't true to begin with. Given that we do have a paradox, it's just a matter of figuring out which step or assumption is faulty. Hence, the two classes of solutions: we're special because of X... or we're not special but colonization is close to impossible.

Most of the papers on the topic you can find on the arxiv take the former stance. Of course, you then contend with SETI, which doesn't assume you can colonize, merely that you pollute the electromagnetic spectrum with your civilization. A paper last year put an upper bound on the number of civilization that can be present "at the moment" (i.e. in our light cone) in the galaxy: less than a dozen.

127:

Surely we are just a soap opera and/ or gambling for highly advanced aliens.
Gambling on the likelihood of nuclear war, on invention of printing, on the careers of politicians.


Asfor the simulation idea, I just think that if you can't tell it apart from reality then it is irrelevant.

128:
Fermi was a little bit hasty in coining his "paradox".
Actually, no. His paradox was "assuming that the principle of mediocrity holds true...".

(see above for the resolution. Your solution is "ok, the principle of mediocrity is wrong")

129:

Perhaps,metaphorically, the universe is like a fruiting tree. It springs from minicule origin and develops according to innate principles. Prehaps planetary consciousness is the eventual fruit of this tree. Fruit emerges on the tree at a fairly concurrent season throughout the tree. Before the fruit the tree exists without fruit, and time passes as the tree prepares to fulfill its fruitful destiny. If planetary consciousness develops concurrently, then there has not been sufficient time for any evidence of others to make it across the void to any of its fellows. Maybe soon.

130:

The simulation argument rests on two axiomatic foundations: a physicalist view
of the origin of consciousness and the amenability of all physics-based systems
(including the brain) to exhaustive and fully accurate representation as software
programs. I accept the first axiom but have some reservations regarding the
second one.

When you speak of constructing a software simulation of a world I assume you
have in mind some process by which a digital mapping of a physical continuum
is coded and run on some unimaginably powerful "computer in the sky". The
doubts raised in my mind regarding such a notion (and a fascinating one it is)
touch on the question of just how refined a digital model of a physical system
has to be to replicate all of its essential properties. Can any digital representation '
of a physics-based system, however exhaustively detailed, be considered a full
representation of it?

In his own consideration of the Simulation Hypothesis Frank Tipler makes a
distinction between a 'simulation' of a physics-based system and an 'emulation'
of one; a simulation of a physical system inevitably involves some degree of
abstraction; it is an idealization or cartoon representation meant to showcase
the systems most essential features; an emulation, on the other hand would
be, if you please, a photo realist representation of the system, capturing every
nuance of its granularity. It seems to me that, in our present state of knowledge,
it should not be taken as axiomatic that physics-based systems can be fully
emulated by discrete, pointillist digital representations ('Reality is analog not
digital.' as Tom Clancy has said)

These questions regarding the 'granularity' of a simulation/emulation are
especially pertinent when they touch on any consideration of modeling
physics-based systems that generate conscious minds (organic brains
in our case). It is not a form of back door mysticism to suggest that the
roots of consciousness lie in those "gnarly" qualities that would elude
digitization.

131:

Now consider a species of ape right on the edge of extinction. Its natural habitat destroyed by some catastrophe, an ice age perhaps. Driven out of its niche and reduced to a few dozen breeding pairs such a species would literally be on the edge. In such circumstances an ape with a bit more nous has a huge advantage in finding new food sources and making a living in a hostile environment.

I think you nailed it.

132:

There's always the Dark Matter explanation. (Intelligent life and its stuff makes up a majority of the universe, but for some reason it is hiding.)

133:

Ian @129:

Well, if that's true, then we just go back to analogue computing.   8^)

134:

Benjamin Rosenbaum's The House Beyond Your Sky is a cracking simulation-inspired story.

Contains the suggestion that once simulation inhabitants start modelling their own simulations, they will find some efficiency hacks don't work, because they are already in effect at the level above their "reality". Hitting one of those walls would be a pretty terrifying moment.

135:

My personal guess as to why we don't see evidence of other intelligent races like us is because we aren't really an intelligent race - at least not yet.

We are quite clearly (in my humble opinion) evolving toward a transition (singularity) to a non-biological life form whose intellectual capabilities will be as far beyond ours as ours is beyond a bacteria.

If I'm right, at the end of this transition we will find myriads of similar civilizations across the universe. Why aren't they talking to us now? Well, how many of us spend time trying to communicate with ants or amoebas?

And since our transition from small tribes to hyper-intelligence will take at most several tens of thousands of years, it's rather unlikely that any other extraterrestrial species in the same state of transition are anywhere within communication range.

136:

The other assumption in the Fermi Paradox will be that aliens are enough like us that they would find the Earth worth visiting or colonizing.

It may turn out that planets with pre-existing biospheres are worthless, and that terraforming dead worlds is much better. Or that planets are worthless, and species end up migrating to dwarf stars that will last hundreds of billions of years and converting to digital life or just building orbital habitats.

137:

I don't like the Simulation Hypothesis, because I feel that if there was a computing substrate that could support those kind of simulations it would probably be populated by evolved entities that would compete for the (still finite) resources available and quickly eat any simulations.

I do like pocket universes more as a literary idea (and there is a difference). A pocket universe isn't going to be as accessible to its creator as a simulation, and it gets around problems like indeterminacy and the granularity of the simulation. It also has different psychological implications.

I've just finished with the DS game Infinite Space (SPOILER AHEAD), whose plot hinges around our universe being an artificial one created for some reason, and humanity's role according to its creators being to observe it and bring about its destruction. Good stuff, but I don't think the characters would be as motivated to survive and fight back if they were in a simulation.

138:

I recall a recent book proposed that there will be a global catastrophe when the Earth supports so many people that local reality is over-observed, leading to catastrophic breakdowns in the quantum reality around us.

Didn't Stephen Baxter write a short story about something similar? In that case it was that our space probes overloaded the computations for the projected, simulated universe that we saw, which caused it to break down and expose the true, civilized, universe.

139:

@121

I think it’s an elegant idea, and entirely possible, but considering the comparative lack of success in other ‘intelligent’ creatures (Whales, Dolphins, Elephants), highly-social creatures (Wolves, Lions, Apes) and other instinctively resourceful animals, I suspect that enhanced nous in our ancestors would not alone be enough to offer a particularly strong evolutionary advantage. Additionally, considering how tremendously expensive food-wise our large brains are - wouldn’t a situation in which starvation is likely generally select for less brainpower, not more?

I’m no evolutionary biologist, but perhaps a more important factor than the intelligence of the individual homid was his ability to use tools. My thinking is that as soon as tools entered the equation, the ability of homids to manipulate these tools represented a massive selection advantage. We aren’t necessarily the canniest in the wild, but I would hypothesise that our ability to conceptualise objects and events external to our own experience, to make use of and indulge in the abstract; gave us a tremendous leg-up over the birds and the beasts. If you think about it, modern language - through which the average person receives a variety and volume of information that would be unimaginable in the not-too-distant-past – is in itself absurdly abstract; the only reason it seems ‘normal’ to us is owed to the intensive cultural tutoring inflicted on us from the very moment we’re born.

140:

Why should the simulations show an empty (on intelligence) universe at all? Why not include simulations of other races with the same simulation, or at least artifacts of same in our simulation?

This all smacks of solipsism. In my experience, philosophical arguments, like the simulation argument, based on logic are often wrong. Reality is far more complex and interesting than toy logic.

141:

The use of tools is very much useful as a cognitive aid as they can hold a lot of the cognitive load. A simple example is counting with stones - try counting large numbers of things in your head without such a simple aid. Another is think of a jig-saw puzzle with a piece missing. Can you determine if a piece is missing without assembling it? Possibly, but clearly the cognitive load is hugely reduced with assembly. Without these tools, human intelligence would be very basic indeed.

142:

I haven't the background to assess the plausibility of this argument:

"An astrophysical model is proposed to answer Fermi's question. Gamma-ray bursts have the correct rates of occurrence and plausibly the correct energetics to have consequences for the evolution of life on a galactic scale. If one assumes that they are in fact lethal to land based life throughout the galaxy, one has a mechanism that prevents the rise of intelligence until the mean time between bursts is comparable to the timescale for the evolution of intelligence."

http://arxiv.org/abs/astro-ph/9901322

A Star Trek-ish galaxy after all, perhaps...

143:

This reminds me of our computer games. We make better AI in them and what do we do to them. We shoot them. Sometime they will figure things out :). Bad day for us.

144:

@121:

I'd modify that a bit, personally.

Last night, I finally deleted a long entry about the ubiquity of intelligent species on this planet, and the fact that only one of them developed radio, mostly because I get annoyed at the simplistic ways the physics-biased look at intelligence. Anything definition that starts with "I'm intelligent, therefore anything I do is the definition of intelligent," should be suspect as a definition (and those with a proper British education can supply the latin term for that argument).

As a start, let's define intelligent species as follows: "they need to be trained in order to survive." This implies the existence of some sort of culture that transmits the knowledge, if only from mother to offspring. Since many carnivores fall into this category (including cats, who have to learn how to hunt), I'll further narrow intelligent species down to "training-dependent species in which different populations exploit multiple and divergent resources in order to survive."

On this list, we have:
-humans (including all hominids)
-all great apes
-some monkeys such as capuchins (some of which use tools)
-a number of dolphin species (including orcas and bottlenose most prominently)
-possibly sperm whales, and possibly humpback whales
--all species of elephants
--African gray parrots
--some species of macaws
--Ravens
and so on (I'm not sure about raccoons and bears, for example).

On that list, only one species--us--has gone on to broadcast Lady Gaga at the cosmos, although several hominids figured out the fire trick.

Conversely, most of the lineages above have a LOT of extinct species in them, and it's unclear whether any of those extinct species were less intelligent than their living counterparts.

That's one problem with the idea of assuming that, where there's positive selection pressure for intelligence, therefore you will get people. It hasn't happened that way for most species.

The other problem was posed by Jared Diamond in Guns, Germs, and Steel. In his experience, Papuans are some of the smartest people on the planet, yet they were stuck with neolithic technology until recently (and the guns they're starting to improvise out of plumbing supplies tend to back up his observation of their intelligence). The whole point of GGS was that many factors play into cultural advancement, not just raw intelligence. In evolutionary terms, sperm whales may be smarter than we are (in terms of sheer processor power), but since they have no mechanism for producing or physically controlling fire, any technology that depends on fire is closed to them.

145:
So the real question isn't, "can intelligent life colonize other star systems?" so much as "can intelligent life propagate itself, and its supporting biosphere and technosphere to run in alien environments?

It's helpful to think of it as a series of filters.

1. Intelligent Life develops, but in an environment hostile to serious technological development. You mentioned the fact that most of our planetary surface is covered by water - well, what about a water-going sentient species? They may have a nice, complex civilization, except that they'll likely never discover fire, and that more or less automatically prevents cuts them off from many advances in technology (metallurgy, for one).

2. Intelligent Life develops technology, but lives and dies out in an environment where they are never pressed to go beyond a certain point. Think of how anatomically modern humans existed as hunter-gatherer groups for tens of thousands of years, with extremely slow advancement for most of that period. Had the environment not changed with the end of the last Ice Age and the extinction of much of the megafauna, that might have continued going on.

3. Intelligent Life develops, but gets killed by natural phenomena. We know that the human population went through a drastic bottleneck when Mount Toba blew up 90,000 years ago, for example.

4. Intelligent Life develops technology, but reaches some sort of societal equilibriam. Think of Imperial China after a certain point. Other races might be even more inclined to reach that, particularly if they live in a hostile environment that attaches a heavy risk to failed attempts at innovating.

5. Intelligent Life develops space-faring technology, but just doesn't care. Think of us humans, for example. If we really wanted to, we could probably have colonies on the Moon and Mars inside of the next three decades (although they probably would not be self-sustaining, at least not at that point). Heck, we probably could have had them by now if it had been a huge priority back in the 1960s. But we don't, because our society doesn't place any real value on space colonization, or at least not enough to make it actually happen.

146:

Keep in mind that it only took the human species 80,000 years or so to reach the point where it could broadcast Lady Gaga. (Out of 4.5 billion.) The people of New Guinea were "stuck" if you are thinking in terms of centuries rather than eons. Also keep in mind that a big reason they are "stuck" is because of all the other humans having gotten the land that is more resource friendly. The whole point of GGS is that if you put the residents of New Guinea on the ancient Euphrates, you'd get and advanced civilization.

Presumably the best definition for "intelligent" would involve rearranging the world for your own benefit. Clearly in that regard, the human species massively outdoes all of those other species you mention, even those, like Papuans, who are stuck in a crappy environment for civilization.

147:

@114:

If the Highest Possible Level of technological Development (HPLD ;-) )gives you O'Neil colonies fifty miles long and travelling at 0.0001 c, well, I'm guessing you're not going to see a lot of aliens in your back yard :-)
You'd be surprised. The galaxy isn't actually that big, it's very, very old, and exponential increases are very, very scary. If you're travelling at 0.0001c, that takes you a billion years (a hundred thousand light years, at one ten-thousandth of light speed) to travel from one side to the other. Our galaxy is roughly ten times as old as that. Even if you make really parsimonious assumptions - one ark starts off at one edge of the galactic disc, travels ten LY in 100,000 years, stops for a thousand years and builds another one; iterate - that still gets you galaxy-wide coverage fairly quickly.

No, frankly I wouldn't. Since you've missed the point, let me repeat: colonization of the sort your thinking of will become more or less likely depending upon the level of technology that is allowed. This is not a hard point to grasp.

If I push my slider button far to the right and get inexpensive ftl travel - say Sol to Alpha C in two weeks - then yes, you're looking at a genuine paradox. But the further left you push the button, the harder this sort of thing becomes. I'm suggesting that building habitats 50 miles long and taking 43,000 years to get to the nearest star (heck, at that point, I think Alpha C will no longer be the nearest star) might put a bit of a cramp in the colonization meme; certainly much more so than easy ftl. Or maybe the situation is even worse than that. I don't know and neither does anybody else.

So you really can't keep asking "why not"; at some point, you've got to actually provide an explanation of why anyone would do such a thing. I could just as easily profess bemusement that there's never been a land-dwelling animal on Earth that was supported by rigid pneumatic tubes rather than calcareous bone. And any time you suggest an answer, I get to say "prove it" ;-) Not the way to do good science.

148:

There is another solution to Fermi paradox. That we are inside a time paradox. Humans build a civilization that makes a time machine and send humans to the paat to buil a civilization. Now, those 90% of the missing matter are other alien civilizations that could/would/will broke the paradox, so we do not see them. Something to think about :).

149:

scentofviolets @146:

I could just as easily profess bemusement that there's never been a land-dwelling animal on Earth that was supported by rigid pneumatic tubes rather than calcareous bone.

*cough*spiders*cough*

Well, hydraulic.

150:

@67:

My main problem with the simulation argument is that simulations require resources, and in any universe I can believe in the thing being simulated needs to be simpler than the thing doing the simulating.

To me this says that assuming you have n planets worth of complexity in your base universe you can get O(log(n)) levels of simulation before you get to an Aristotelian universe...

Of course you could just use your universe to make lots of planets surrounded by fake stars, but then again you had the universe in the first place so why bother?

This has come up enough times in the comments that I'm surprised no one has pointed out the obvious flaw - if we are indeed living in a simulation, we have absolutely no idea what the underlying rules really are or how they would be implemented.

The questionable assumption here then is the assumption of granularity. More, the assumption is not just that we're working in Z, the integers, but a finite subset of them. So then you get a smallest possible distance, a largest possible distance, and an absolute upper bound on the information being held in processed in the simulation at any given instant.

Relax either of those two assumptions, and you can not only have turtles all the way up, but turtles all the way down as well - the classic "What if there were an entire universe inside of each electron" sort of head noodling. Me, I'd guess that we live somewhere inside of ℂ^∞ or some other closed field. "Really". :-)

151:

OK. I happen to think that 50 miles long is too small, but that's not a real problem. And I think that they'll decide to travel at just a bit over the average local speed.

But you won't encounter them very often. They've adapted to living in space, and planets are neither interesting nor desirable to them.

P.S.: On the simulation problem>
If it's a simulation, then the smallest feasible thing is what will be simulated. If they're interested in a galaxy, they won't bother simulating the rest of the universe, they'll just feed in externalities. If it's a solar system, POOF!, the rest of the galaxy is just a mirage. Only the solar system is actually simulated. If it's a planet, POOF!, there goes the rest of the solar system. Everything else is weakly coupled, so it's more efficient to generate it exogenously.

Now within the planet things aren't so clear. Coupling is a lot stronger, and it becomes more difficult to find the natural edges of things...until you get to the single organism. If *YOU* are being simulated, then there's no reason to believe that any of the rest of the universe exists. Actually, in that case it's probably better to just simulate your brain (mind?), presuming that's what's being studied (or played). Even if you are studying the interactions of a few "persons", it's probably more efficient to just simulate their minds, and to generate the inputs from a much simpler model. (Your senses can't detect most of what's going on in the universe, so those signals don't need to be fed to you, so they don't need to ever be generated...unless they're needed for some signal that is to be fed to you.)

152:
scentofviolets @146:

I could just as easily profess bemusement that there's never been a land-dwelling animal on Earth that was supported by rigid pneumatic tubes rather than calcareous bone.

*cough*spiders*cough*

Well, hydraulic.

Nope. You're wrong. That was easy.

153:

maybe great Cthulu has already risen,,, maybe this is the simulation spaces of his mind.....

154:

@150:

Even if you are studying the interactions of a few "persons", it's probably more efficient to just simulate their minds, and to generate the inputs from a much simpler model.

Heh. You're all fakes, phonies, frauds. There's only one person's mind being simulated . . . and that's mine.

155:

I don't think an "ideal world" is likely to be the goal. If I look around me, most current simulations are on-line role-playing games. I suppose that the nature of those games would change as sensory feedback became more realistic, of course, but it looks to me as if that's where we should presume it started. (Yeah, there are Sim-City, and Sim-Life, and Sim-Earth, etc., but that's a minor theme. Most are like World of Warcraft or Eve OnLine.

156:

Relax either of those two assumptions, and you can not only have turtles all the way up, but turtles all the way down as well

A large fraction of this thread is arguing about how difficult it is to determine if ewe are in a simulation or not and providing arguments to make it harder.
That is really arguing that the simulation argument is unfalsifiable and really goes against the grain of my thinking.

157:

@155:

Well, if it really is a simulation, you don't get to pick and choose what gets put in or left out, do you? What makes you think the laws of physics inside would be anything like they are on the outside? Is there any reason why the assumption of granularity is any more or less appealing than the assumption of a continuum?

158:

Just to throw a brickbat, I did note up in comment #11:

"More generally, there are large classes of chaotic phenomena which we know are computationally intensive. Flipping a coin is a good example, as is rolling dice. Unless we're talking about some sort of exotic quantum processors that can handle chaotic processes accurately at all scales (a.k.a. the Mind of God), it's probably simpler to assume we're real, and that such events spontaneously arise.

'And if we're inside a super-processor that can accurately simulate reality at all levels, then we're off in airy-fairy land anyway."

Basic point: if there's nothing you can possibly do to tell that you're in a simulation, then we're dealing with a non-falsifiable argument, e.g. a religion by conventional definitions.

That's boring and non-productive.

I'm more interested in using what we do know about simulations to figure out if it's possible to scientifically test the simulation theory. I think there are ways, but you have to think like a beta tester, not like a believer.

159:

I'm responding to the issue of falsifiability. If this question was reframed as "everything we do is determined by [a] God", most of us would (I think) deny that proposition as unfalsifiable and therefore a not really worth debating.

I really don't care what the proposition is, as long as there is some way, in principle, to come to some sort of answer.

The Fermi question is very interesting, but I prefer to address it outside of religion/philosophy. Otherwise we could solve it by referring to Judeo-Christian scripture:

"God created the universe and He made only humans as the intelligent beings to inhabit it".

How do we test that?

160:

I think it is non-falsifiable and in the realm of religion.

Whenever I'm running a simulation, emulation, or virtual machine and it crashes or otherwise exhibits an obvious bug, I restore the system to a checkpoint from before the problem and alter the conditions so it doesn't happen again. We could be living in the buggiest of beta-release universes and still never prove it because every time we encounter the stack traces of the gods we're restored from backups after the problem is fixed or bypassed.

A really lazy developer-god might just be running a multitude of simulations in parallel with slightly different random number seeds, and continuously merging only those that don't crash or get into an inconsistent state to produce a consistent narrative without the bother of actually fixing all the simulator bugs and limitations.

161:

"God created the universe and He made only humans as the intelligent beings to inhabit it".

How do we test that?

Guess we've got to explore the entire universe.

162:

All we are testing is the part "only humans as the intelligent beings to inhabit it". We are not testing the assertions "God created the universe " and "He made humans".

However, I'm good with the part about fully exploring the entire universe. :)

163:

scentofviolets @151:

Nope. You're wrong

No, you're wrong!

Wow, I love these in-depth scientific discussions, the meeting of minds, logic reigning supreme, and all parties leaving, ultimately, more enlightened at the end.   8^)

164:

We already have We're very Rare, It's All a Simulation, Colonizing Space is Ridiculously Hard, You Can't Take it (high tech) With You, Advanced Intelligence Cannot be Recognized By Our Methods:

Some other solutions to the Fermi paradox:

6. Intelligent life that isn't very good at hiding gets eaten by Yog-Sothoth

7. As in "Century Rain", we're real but the rest of the universe is a simulation

8. SETI was successful a while back but the government/the aliens are covering it up

9. All intelligence once it reaches a certain level of development moves to another universe which is more convenient for the shopping and so on

9a. This universe is a "seedbed" for intelligence. When intelligence reaches a certain level, it is brought to another universe/harvested

10. All technological intelligence is self-destructive simply because they will end up working with Forces They Cannot Control if their technology reaches a certain level (there are far, far worse things to meddle with than nuclear power)

11. The reason that the galaxy is not crowded with intelligent life is that the first race is still here, and does not appreciate people who go around *terraforming their property.

12. The Prime Directive requires that we remain ignorant

13. Not a simulation, but more limited mind-control so we don't see the aliens (The "They Live!" solution)

14. The Heliocentrist big con!

Any more?

Bruce

165:

(I suppose some of those could be combined...the Big Con Theory, Aliens are where we can't see them...)

Bruce

166:

Merging simulations? Makes me think about all those celebs that I swore were long dead being in the news! This thread is making me paranoid.Wait I already was from the continual reference to Lady Gaga? Maybe she and I are the only sentient ones. 8-}

167:

@scentofviolets where can I find this Robert Reed's "Under a Gated Sky" because Google is being no help.

168:

@163:

scentofviolets @151:

Nope. You're wrong

No, you're wrong!

Wow, I love these in-depth scientific discussions, the meeting of minds, logic reigning supreme, and all parties leaving, ultimately, more enlightened at the end. 8^)

Whoooooosh! Why don't you get back to us all when you can actually, you know, post some evidence? The only "hydraulics" I can think of wrt to spiders would be a muscular analogue, as in jumping spiders.

But you go ahead and post your evidence - you know, what you didn't post the first time around and what I pranged you for - so everyone can see how wrong I am ;-(

169:

I'm sorry, it's actually Beyond the Veil of Stars. "Beneath the Gated Sky" is the sequel.

170:

BENEATH the Gated Sky.

171:

Whoops! (Trying to be a Smart..Aleck)

172:

what if WE are the old ones, the first race to get anywhere except flint?

what if the younger races will quail in terror as our mighty battleslashers cruise over their worlds...
in a bit

173:


I think there's a hole in the Simulation argument...

The number of sim-civilizations might outweigh the number of real ones, but the size of all sim-realities will probably be much smaller than the size of all real ones.

Being the outermost shell, reality will always have more bytes, and thus the higher probability of containing you.

174:

There's a book somewhere (hell, might as well google for it . . . ) called If the Universe Is Teeming with Aliens - Where Is Everybody?: Fifty Solutions to Fermi's Paradox and the Problem of Extraterrestrial Life.

Anyone read it? Is it any good?

There was a paper I read about a couple of years ago (which I annoyingly can't now find, and would appreciate a link to if anyone recognises it from the description) arguing that if we assume that there are limits to the distance it is practical to send craft, then a complete exploration of a galaxy may still leave lacunae enclosing up to tens of percent of the total star population (depending, obviously, on what these practical limits are). There is also, of course, the fact that we are already moving from analogue radio transmission to digital, a much less visible technology over interstellar distance. This leaves 50 and 60 Hz radiation, of course, but if we move to DC transmission - possible in the light of the current spread of long-distance high-voltage DC lines - then we might again become invisible to observers.

I think the general point here is that some of the assumptions common in this discussion haven't always been thought through thoroughly, and the answers might not be as intuitive as people assume.

175:

@164: How about Colonizing Space isn't worth it?

That is, there's always a chunk of something which is easier and less energy intense to colonize than traveling to another x where x is the moon, a planet or solar system.

The corollary to this is it only becomes worth colonizing x when you have rendered your current habitat as expensive to maintain as colonizing x would cost. That tends to cause species extinction events even without the egg basket dilemma.

We seem to be achieving that at a rapid rate...

176:

Relax either of those two assumptions, and you can not only have turtles all the way up, but turtles all the way down as well

I think you've just turned the counter-argument from a digital one to an analog one.

So, say space and bits-per-volume are infinitely divisible and infinite, respectively. Reality, as we define it, remains the outermost shell. So the ratio, even if it is between two infinities, remains the same.

On a side note the simulation argument also makes a big assumption that most of (any) reality is some kind of civilization, and so ripe for containing designed simulations. *This* reality sure isn't like that. In fact the ratio of accident-to-agency in this reality might as well be infinity to one.

177:

@175:

I think you've just turned the counter-argument from a digital one to an analog one.

So, say space and bits-per-volume are infinitely divisible and infinite, respectively. Reality, as we define it, remains the outermost shell. So the ratio, even if it is between two infinities, remains the same.

I don't know what you're talking about in the second paragraph, but I'm not talking about the laws our simulation is running; I'm talking about the laws under which it runs.

For all we know, the "ultimate reality" is not three dimensions, or four or elven, or even infinite. It could be one. No way to tell.

If you're looking for some sort of evidence from the inside of the simulation, how about time asymmetry?

178:

@173:

Being the outermost shell, reality will always have more bytes, and thus the higher probability of containing you.

This isn't necessarily true.

179:

I'd write-off the Fermi Paradox as as violation of the anthropomorphic principle. It assumes

A - for 'nonhuman intelligence', 'ETs' 'organic/nonorganic intelligence' we would recognize these and/or they would share our motivation to go forth and multiply, invade, conquer, etc. maybe the only thing that makes humans 'special like snowflakes' is our arrogance, selfishness, and/or curiosity.

B - that there is a good reason for any life to invest the resources exploring vast reaches of space either with machinery or monkeys-in-cans. for example, lets say based on current or near-future values of earthling science/tech knowledge, its possible for us to build a monkey-can with a >50% chance of keeping the monkeys alive while traveling to one of the more interesting moons of Jupiter or Saturn and getting them back in a condition which they can still survive earth-normal gravity for a near-normal lifespan. What are the odds of any country with the wealth investing the near-trillion-$ price tag - taking the risk of a huge egg-on-face disaster, or taking the political risks to make that happen? And is there any potential benefit of such a project that justifies the investment?

In the millions of years (current guess-timate) of life on earth, we've sent monkey-cans no farther than the moon, and the US only did that to show up the Russians, and some people think it never really happened and was done by George Lucas.... we've only sent a handful of machines outside of Earth gravity and most are long-dead... considering us monkeys are generally more interested in killing each other and working together to achieve interstellar travel, I think the only sufficient motivation earthlings would have to migrate beyond our local solar system is if we muck it up so much that running away is the only survival option, in which case we'd kill ourselves off fighting over spots on the life raft... reminds of the Clarke-ian hypothesis that the cause of 'supernova' is industrial accident. oops, there goes the solar system....

basically to sum up, A-it is incredibly arrogant of us to think that interstellar travelers would be interested in us, have anything in common with us, or would exist in recognizable form in our known 3-dimensions and follow our currently 'known' laws of physics. and B-there's no place like home. even Mars is a long ways away and there's not much to do when you get there....

As far as simulation - if they wanted to give us the impression of a giant universe, with no way to get 'there' from 'here', they did a damn good job localizing their intensive processing requirements. consider we still haven't explored 80% of our own planet surface area, not to mention anything deeper than a mile or 2, etc...

180:


...reality will always have more bytes, and thus the higher probability of containing you.

This isn't necessarily true.


At this point, you're going to have to define what you mean by 'simulation'.

181:

@179:

This doesn't have anything to do with the simulation, just the number of bytes. It is quite possible for a proper subset of a set to have the same number elements.

182:

>Another aspect of the simulation hypothesis that gives me the shudders is this: how do we know that we are the object of the exercise?

Larry Niven's Bordered in Black comes to mind. We are some alien's food supply, and they've simply not come to harvest us yet. (yes, a good shudder from my early days of reading science fiction...)

183:

Well, it's more a metaphor than an analogy, innit?

184:

David Deutsch comes up with a really neat way round the computational resources issue if creating simulated reality. He suggests that Tiplers ideas about the end of the universe are relevant. In a closed universe that ends in the big crunch, informational density increases exponentially near the end. Computational speed increases at the same rate. Deutsch argues that the civilisations at this point create simulation because they effectively have infinite computational resources.

185:

Anthropic principle, dammit, NOT anthropomorphic!

186:

scentofviolets @168:

The only "hydraulics" I can think of wrt to spiders would be a muscular analogue, as in jumping spiders.

Erm. Yes. Exactly. Not just jumping spiders, but all spiders, have legs which contract via muscles and extend via hydraulic pressure. (The 'Spider' wiki article has references for this.)

Thus spiders support their weight using hydraulic pressure.

187:

perhaps true reality is analog, the only reason for this quantum business is to make the sim practical to run?
the diffraction slit experiment is an example- the reason that it works is that its a code module, and when we get it down to single photons it still runs the diffraction module code.
dont worry, it'll be fixed in the next patch

188:

@147:

I'm suggesting that building habitats 50 miles long and taking 43,000 years to get to the nearest star (heck, at that point, I think Alpha C will no longer be the nearest star) might put a bit of a cramp in the colonization meme;

It's an economic/will argument. It falls in the same trap as the Galactic Zoo/First Directive argument ("all elder civs will not colonize potential sentients"):

It takes only one who decides to do that to colonize the entire galaxy.

You need to argue that colonization is physically hard, instead of economically hard.

189:
what if WE are the old ones, the first race to get anywhere except flint?
That's essentially David Brin's "The Crystal Spheres" setup.

Spoiler alert: Brin puts two arguments in front of the Fermi Paradox in this one. One is the elder argument (in the story, we're actually the sixth oldest starfaring species to arise in a galaxy where intelligence appears to be more or less common). The second (the so called crystal spheres) is a contrived physical mechanism that prevents any probe/ship/colony from reaching any inhabitable solar system until the local species becomes capable of getting out on its own.

190:


There's no way to prove if you are in reality or not, but the simulation argument just feels silly.

'There is only one universe, but many hats. Therefore we are probably living in a hat.'

Q: The universe is much bigger than all the hats. I am probably not living in a hat.

A: Not necessarily. There may be a hat as big as the whole universe.

Q: Do you know something about hats that I don't?

191:

Exactly-- there is no need to simulate every piece of the universe & its physics. You need only simulate the perceptive aspects that populate our phenomenological experience, which is itself a simulation.

Given that our phenomenological experience of the universe is itself a "good enough" and "highly realistic" simulation that is indistinguishable from "reality", it is axiomatic that such simulations are possible.

192:

This is my take on the Principle of Mediocrity too. More succinctly: if the PoM is valid, why aren't I a subsistence farmer?

193:

Oops. That was meant to be a reply to ChrisJ@69.

194:

While I won't argue with the high probability silliness of the simulation universe theory, there is one fundamental question that every simulation supporter needs to be walloped with:

Why do you think you're the focus of the simulation?

A lot of these statements boil down to, "Oh, so long as you can fool me (and if I'm nice, all other humans), then the simulation could be pretty simple."

While that does get a close shave with Occam's Razor, it's even more probable that the simulation is designed to focus on something else, say grasses, and the complexity you're experiencing is simply a side effect of the complexity needed to provide a realistic experience for all the grasses in your life.*

*You didn't get the joke. Right. Corn (maize), wheat, rye, oats, rice, and sugar cane are all grasses. Almost every person on the planet gets a majority of their calories from grasses, either directly through grass products, or indirectly, by eating things that eat grasses. Since grasses now cover much more of the planet than they did before they tricked humans into domesticating them, I can make a very good case that we're doing the grass's work for them. I mean, they even have us working on speeding up their evolution, so they can dominate even more land area. Although I have (seriously) heard a scientist say that corn is smarter than he is,** never let it be said that intelligence underlies control. The grasses have managed to domesticate us with no evident nervous system at all.

**he was trying to accurately simulate photosynthesis in a corn plant, but the his best model was much more inefficient than the plants he was studying, because the plants were better at shifting resources around as the light changed.

195:

So what you're saying is, we're going to make it to Brazil before we make it to 2001.

196:

Ignoring the simulation argument for a moment (violates Occam's razor, remember?) there's probably a good reason people don't come visiting, and we all know why.

The Dragons/Rats get them, in the cold dark spaces between the stars. And we haven't yet developed pinlighting.

Go, captain.

197:

Looking at this thread, I think that many just don't get the Fermi Paradox. Here are some points:

(1) The very difficulty / expense of interstellar travel may occasionally motivate it. Think Egypt's pyramids (another big, expensive waste of resources).

(2) Any explanation for why the galaxy isn't filled has to apply to all creatures, in a galaxy of 200 billion + stars, for the past 10 billion years. Saying it's hard, or expensive doesn't cut it for me! I don't see how these explanations reduce the numbers of colonizing aliens to absolutely zero.

(3) Saying we're too primitive or boring to be worth visiting also doesn't work for me. If anything, the rock beneath my feet may be of mild interest to someone. Again, I don't see how our primitive/boring status makes us avoided by absolutely every single alien.

(4) Yes space travel and interstellar travel is really hard and expensive. However, all you need is 1 (ONE!) ET civilization to figure it out, and waste all those resources on doing it.

(5) Along with the point above, let's say only 1 species in a million figures goes out space travel and (for whatever reason) colonizes the galaxy (at a nice speed of .001-.01 C). Guess who we'd be more likely to encounter? We're more likely to see those species with the motivation to waste huge efforts on travel between the stars, because the'd be the ones who's numbers would be increasing.

So at some stage between the formation of planets(and we know of lots of them, so these seem ubiquitous) and the stage of galactic civilization, there is a Great Filter. I don't see how get around that.

I personally hope we've passed that Filter, so that we're not Mediocre. If we are Mediocre, we're likely doomed, since that's the best explanation for the Fermi Paradox I can see. That doom will probably occur in a pretty short time horizon (probably before we or our robotic Saturn's Children, manage to colonize even just the solar system).

Anyway, since we've only got a sample size of one, there's not much hope of resolving this issue. My main wish is that we find some wildly improbable past event or series of past events that makes our technological society (and early steps at space-exploration) possible. If we're only here because of 100 billion to 1 fortune, we're really lucky in all sorts of ways.

198:

I wonder whether Fermi's Paradox requires an answer any more involved or complicated than the simple fact that space is *very* big. Habitable planets are simply too far apart to permit the existence of inter-stellar civilisation. I mean, even light takes four years to reach the nearest star to our own.

199:

But interstellar travel may be so difficult/expensive as to be impossible for practical purposes. In which case, intelligent life-forms will only expand out of their home system when it comes within 'easy reach' of another star - lets be generous and assume that the Oort cloud is accessible, so you need the Oort clouds to touch to colonise. Rather cuts down your options (and increases the time required to spread), doesn't it.

The other thing is that - if you want to put the principle of mediocrity to a use that makes sense - you start to wonder why the only intelligent life-forms we know about have evolved in the middle of the local bubble. Could it be that there are simply too many potentially life-breaking events (orbital upsets caused by passing stars, say) in more crowded regions of space? If life on planets needs five hundred million years to advance from Archaea to intelligence, but a typical planet not in the local bubble gets blasted back to the level of Archaea (or equivalent) every hundred million years or so, intelligence is only going to occur in bubbles, well isolated from other (colonisable) systems. If you combine this with the possibility above....

200:

It seems to me the "simulation" argument also qualifies under the "some kind of mechanism" solution to the Fermi Paradox in another guise.

One of the (many and gaping!) logic holes in the Star Trek universe was the holodeck. Simply put: when you've got the holodeck (perfect user-configurable virtual reality), why are you (or the Klingons, or anyone) using any resources building star ships at all?

Many many science fiction authors have tried to get around this by postulating some kind of desire for "the real thing" that supposedly arrives along with the ability to have whatever you want. Only the "real" risk/achievement of "really doing it" apparently satisfies. But of course in a perfect virtual reality, you could easily make it *more* risky, and the "achievement" (whatever it was) much *harder* to obtain. Reality doesn't hold a candle to perfect simulated reality with all the safeties off and the difficulty on "super hard".

Let me put it another way: imagine user-configurable perfect virtual reality exists. Why would anyone spend their time doing anything else but living/existing/playing in it?

But you'd *know it wasn't real* begins the "reality is better" argument. Of course you would know that. Just like you "know" that there might be a better job, life partner, friend, usage of time out there for you *right now*. But you're easily able to ignore those absolutely real doubts and get on with your life. Knowing you're not screwing someone more attractive than your girlfriend doesn't make screwing your girlfriend not awesome. True for all values of "girlfriend attractiveness". And so you'd easily be able to ignore the "doubt" inherent in your user-configurable perfect virtual reality, and get on with your virtual life, too.

So -- and here's where mediocrity kicks in -- assuming the technology to travel interstellar distances in good time is on the same level of complexity as the holodeck, there are plenty of space-capable civilizations out there, and they are all living happily in their holodecks, because that's exactly what we'd do if we had that choice to make.

201:

Another:
Once you've spent enough generations in space to get from one star to another, you've adapted, and don't want to live on planets anymore. (MacroLife, Zebrowski)

202:

That sounds like an interesting solution.

However, is our sun always in a bubble? Doesn't it take about 200 mya or so to revolve around the galaxy, and during this we bob up and down a bit from the galactic plane?

I'd guess the nearby environment to our sun varies lots as it revolves around the galaxy among lots of stars, nebula, etc. with slightly different trajectories.

Anyway, hopping from Oort cloud object to object seems like it would make interstellar travel easier, since you've got lots of (small, cold, bleak, desolate) places to stop between stars. Much smaller trips, so you can do galaxy-wide colonization in baby-steps.

203:

@187:

@147: I'm suggesting that building habitats 50 miles long and taking 43,000 years to get to the nearest star (heck, at that point, I think Alpha C will no longer be the nearest star) might put a bit of a cramp in the colonization meme;
It's an economic/will argument. It falls in the same trap as the Galactic Zoo/First Directive argument ("all elder civs will not colonize potential sentients"):

It takes only one who decides to do that to colonize the entire galaxy.

You need to argue that colonization is physically hard, instead of economically hard.

Sigh. Please. This is a mathematical argument. What you're doing is essentially trying to get me to show why colonizing aliens aren't here, rather than you having to show me why they should be. Let me go through the argument again.

With a given level of allowed tech, colonization is more or less easy. With a very high level allowed, say ftl running off the output of a diesel engine, ditto for gravity control, extreme nano tech, etc, the fraction of civilizations that are capable of carrying out a colonization program is very close to one. So if there are say, 100,000 such civilizations, you get 100,000*1=100,000, and Fermi's paradox is indeed paradoxical.

If, otoh, the maximum allowed tech is something that only allows travel at 0.3 c, the minimum size of a self-sustaining ecology fits into something the size of a few football fields, indefinite suspended animation is possible, etc, then the fraction drops from something close to one to something more like, say, 0.1, and the number of civilizations who will attempt some sort of colonization drops to "only" 10,000. Still a big number still making Fermi's paradox a paradox.

The point here is, this is a monotonic relationship. Higher levels of tech means a figure closer to one, lower levels means something closer to 0, and all other things being equal, given two tech levels for a given civilization, it is more likely to colonize at the higher ceiling rather than the lower.

So if the tech level is low enough, the multiplier drops from 1 to 0.1 to 0.01 . . . Thus, if there are 100,000 civilizations, but the allowable tech level on this scale results in a figure of 0.0000001, the probability of us seeing signs of these colonizers in just one chance in ten.

Iow, this is just one more term to plug into the Drake equation. And saying yes but if even only one civilization . . . is simply wrong-footed. What it comes down to is one person (me) throwing out a set of assumptions, and another person saying "Yes, but if you ignore those assumptions . . ." This is not good reasoning :-)

204:

What makes everyone think there's only one Great Filter?

There are two interpretations of this idea. First, let me suggest that everyone read comment 122 again, then read comment 145 (and maybe 144, which touches on the same territory.) Add to that the issue of whether any given "earthlike" planet has a big moon (otherwise it will be like Venus, with hot gasses and virtually no chance of forming life.) A big moon is highly unlikely. Add to that the chances of a nearby supernova, more asteroids than our solar system has, etc., and you come up with a very, very small chance of life forming at all. Then ask yourself whether the planet in question has heavy metals, petroleum, a convenient source of anything that burns even as well as wood... add to this the possibility of nuclear war, bioweapons, runaway Greenhouse scenarios, and stuff we haven't imagined yet... The Fermi Paradox pretty much resolves itself as you add multiple layers of improbability.

The other interpretation, of course, is much scarier. What makes you think there is there is only one Great Filter?

205:

It does bob up and down and back and forth. Also, stars further out orbit the galactic centre slower than those further in, so there is some shear. You may also find it interesting to hear, that there are density waves (similar to acoustic waves, but with wavelengths in the thousands of light years) travelling through the galactic discs.

The highest concentrations stand out as being brighter than the rest of the disc and are widely know as spiral arms (although there are other processes further contributing to the phenomenon).

So, our neighbourhood is not only changing, it is periodically getting squeezed and torn apart again. (Ok, less dramatic than I make it sound, but definitely a factor.)

206:

Re: the fermi paradox debate currently raging.

Aren't re rather missing the link with the previous thread Charlie started on the amount of people needed to maintain civilisation - if interstellar travel takes centuries and if it takes 100 million+ individuals to maintain civilisation then maybe the question of why no-one has come visiting is becoming a little clearer?

207:

OK. I largely agree, however all this depends on the achievable limits of technology. I tend to think that computation, nanotech, etc. have LOTS of room for feasible improvement.

Starships (say at .1C), strong nanotech, and AI is well within the realm of physical possibility without having to invent new physics (no need for magic, FTL, unobtanium).

Where limits may occur, it may have something to do with fundamental limits to complexity. Perhaps strong AI (much smarter than humans) is not feasible, because you'll get diminishing returns on investing in more complex minds. Or perhaps instabilities just accumulate and your AI mind is increasingly likely to collapse into madness as complexity goes up.

This may also help resolve the Fermi Paradox. Perhaps the more complex a system becomes (minds, societies), the more prone to collapse they become. Thus, you'll have a hard time evolving societies with the smarts needed to build starships or even reach their local Oort clouds.

I kinda like this solution. Nature abhors a Singularity. ;)

208:

@206:

OK. I largely agree, however all this depends on the achievable limits of technology. I tend to think that computation, nanotech, etc. have LOTS of room for feasible improvement.

Starships (say at .1C), strong nanotech, and AI is well within the realm of physical possibility without having to invent new physics (no need for magic, FTL, unobtanium).

But you don't know that, and further, while what you suggest is possible for a technological upper limit may be necessary for colonization, there is nothing there that suggests it is sufficient. One easy possibility is that a complete and self sufficient ecosystem capable of supporting a few hundred people may take on the order of a few hundred square miles. And while travel at 0.1 c might be feasible for something massing, say a few thousand tons, there's nothing that says 0.1 c is possible for a few hundred million tons. And so on and so forth.

One implication here is that - again per an earlier thread - while colonization may be irremediably hard, exploration is not. Of course, it will be much easier to do robotic one-way missions, and easier to do flybys than landings. There's an ascending scale here. However, the signs of explorers passing through our immediate neighborhood might be a bit more difficult to ferret out :-)

209:

@191:

This is my take on the Principle of Mediocrity too. More succinctly: if the PoM is valid, why aren't I a subsistence farmer?

That's exactly right. Yes, it's true that for most people that if they go by the principle of mediocrity they will be correct and representative, iow, there is a high probability that their assumption is correct.

The fallacy is to then reason that any given individual thus has a high probability of being the norm. Not correct. And further, you can't know this until you go out and actually gather the data. An after-the-fact realization as it were.

And in fact, this is the chief objection of adopting this assumption - mostly it's just a glib way to sneak in information about the system that's not really there.

210:
However, is our sun always in a bubble? Doesn't it take about 200 mya or so to revolve around the galaxy, and during this we bob up and down a bit from the galactic plane?

Yes, our sun (and many other stars) move in and out of local bubbles, which themselves form and disappear around the galaxy over time as stars move relative to one another. My point was that it's not impossible that the appearance of intelligent life on a planet requires that planet's star to have been in a local bubble for $long_time, and thus civilisations are (a) rare and (b) always in the worst possible place to start colonizing from. (Sorry, I was in a hurry and didn't make myself clear first time round.)

Our 'local' galactic environment varies a great deal, but only over astronomical time-periods, which make even geologists look short-termist.

Anyway, hopping from Oort cloud object to object seems like it would make interstellar travel easier, since you've got lots of (small, cold, bleak, desolate) places to stop between stars. Much smaller trips, so you can do galaxy-wide colonization in baby-steps.

That depends on what's required to maintain your technology level, as discussed elsewhere - if you need a 50km O'Neill colony, then those 1km rocks 10,000AU away really aren't worth visiting unless the spectrometer shows they're made from solid unobtanium. There might be enough big objects in the inner Oort cloud (~2000AU distant, or about ten light-days away) to be worth visiting, but that doesn't mean you want to go out into the black.... (Apart from anything else, remember that the volume you need to be able to search increases with the cube of the distance; once objects start being hundreds of AU apart, finding them becomes a serious challenge.)

211:

Erm, wait a minute.

10% of the speed of light is still pretty darn close to needing unobtainium.

Last time I tried to figure out how fast you could go with radionuclide batteries, I ended up at about 0.1% light speed. If we cared to build an ISS sized space probe (weighing 5-10 times as much) and ignored some of the engineering trouble and the outcry when you try to send about 100t of Plutonium-238 into orbit, we could send this thing to Alpha Centauri, build another Cheops Pyramid next to the old one and put a glorified manual instead of a corpse into the central chamber - to be accessed after almost exactly as much time as it took us to turn the old one into a tourist attraction.

Going 100 times as fast will not just require 10000 times the energy density, it will also require a magic wand able to efficiently accelerate vast quantities of your fuel to something pretty close to c, using a device with a mass pretty darn close to nothing.

Using even remotely accessible technology that doesn't happen to emit its energy as gamma rays or something of equally spectacular uselessness, we may think about using nuclear fission, which yields about 165 MeV per atom or about 0.7 MeV per atomic unit (vs 5 MeV for alpha decay in radionuclide batteries, or 0.02 MeV/u). Or nuclear D-T fusion, which yields 17 MeV per event or 3.4 MeV/u. (It's just that this number isn't achievable, since Tritium has a half life of only 13 years, you'd need to breed your fuel from lithium - on the other hand pure d-d fusion only yields 12MeV ...)

So, given a fusion reactor and some pretty efficient engine, accounting for some inefficiencies, you might just be able to achieve 1% of c, perhaps even 2%.

After all, you want to lug around a million tons of stuff and nude apes in spaaace (that's about twice the weight of the largest ocean going vessel ever constructed - you want people to spent their lives on those things after all ...) and you'll need at least about the same amount of fuel as you're trying to lug around.

That means you'll need to comb through 60 cubic-kilometres of seawater, extract about 50% of the deuterium and get it into orbit without losing more than a small percentage of it.

Oh, and did I mention that you won't have a chance to slow that thing back down?

212:

You are mistaken, simulations are compressible, both in speed & memory requirements, that's precisely what advanced "game of life" algorigthms do. And if this universe is a simulation, it probably looks very much like a what we'd call at our level a cellular automaton indeed.

213:

@211:

IIRC, what you're referring to is the "calculate two ahead" algorithm. This isn't generally applicable, and in any case, you can't apply it recursively, that is, there is no algorithm that will let you calculate four moves ahead or eight moves ahead without computing one or more intermediate states.

So I don't think this really counts as compressibility.

214:

hey, why is it that we can go billions of years into the past, yet
how far can the go the other way, down towards the ocean depths
does anyone know whats at the center of the earth or on the journey down
except for the oil guys?
we think we are all possibilites, being realized locally the earth and thesolar system,
and were like satellites for earth, just sensory info gatherers, and the universe
is crunching right now as we speak, and what about dark matter how fast does that sheet go? thats the question.

215:

Nuclear pulse propulsion -- riding thermonuclear explosions to the stars -- is theoretically capable of 0.1 C or better, IIRC. And the rest of the ludicrous-scale effort doesn't look so daunting if you accept the grand initial premise that there's AI with nanotech or some otherwise fully-closed-loop automated industrial base to do all the manufacturing and even most of the R&D.

On the other hand, plausible nuclear interstellar travel also makes global destruction trivial, so that's another Fermi solution.

216:

Doesn't the inherent weirdness of things like quantum physics and string theory seem to indicate that we very well may be living in a simulation? Although simulation is kind of a misnomer I think, it could be perfectly "real" even if artificially created by some other entity. It might be a very different kind of realnthan the meta-reality, but so what?

Going back to Fermi... Maybe WE are the aliens, or at least a form of alien biological technology used to, you know, colonize the planet? The fact that our species seems to clash so dramatically with the "natural order" of the planet seems to indicate this to me. Or, our species may be natural to Earth, but our brains could be a "vehicle" for an alien species. Why don't we see aliens everywhere? Maybe we do, every day, and we are them...

This also applies to simulated reality. We may not just be simulations, but vehicles for the simulators themselves, to inhabit the simulated/alternate reality they have created. It couldnbe a game -- the point ofnwhich, perhaps, is to try to remember that you're in a simulation.

217:

No, I'm talking about Hashlife, which you have to see in action to believe; for example download Golly (multi platform) which can run enormous worlds (# of cells > your RAM) at breakneck speeds (6 octillion iterations in 30s)

218:

Has anyone run those numbers for solar sails? Really big solar sails, obviously.

219:

Well,

Dyson's interstellar ship was limited to 3.3% of light speed using 1/4 of its mass as fuel. That's equivalent to 1.66% of lightspeed if you use only 1/2 the mass as fuel as I assumed.

0.1C was only reached by the proposed Project Daedalus, notably not employing nuclear pulse propulsion, which had a payload of 1% of its whole mass, which consisted of fuel for the most part. So, your interstellar oil tanker now needs the deuterium of 6000 cubic kilometres of seawater per flight and still can't stop.

Nuclear pulse propulsion is limited by effective exhaust velocities ("effective" since a lot of the exhaust is lost to space not pushing anything). Exhaust velocities (equivalent to specific impulse) have the remarkable tendency of exponentially reducing the fraction of non-fuel that your spaceship is allowed to carry in order to reach a given speed.

The smaller the bomb, the worse it gets. Velocities of the smaller proposed designs (using 15-30ton TNT equivalent) have already been surpassed by VASIMR drives. Thermonuclear charges in the 1MT range were optimistically estimated at 6000 km/s (Dyson used a range of 750km/s to 15000km/s) effective exhaust velocity and it would be unreasonable not to expect some kind of mass accelerator to surpass that.

Trust me, bombs are a waste of energy.

Also, what is so bad about 1% of light speed? Where is your patience? If taking 10 times longer means you only need 1% of the original energy requirements and even less of the original mass requirements (you're putting a lot of energy into fuel you're carrying around), impatience is a sin. You'd be 10 times faster and could conduct 1/100th to 1/1000th of the number of flights. -> Less exploration.

I consider any space exploration conducted at 0.1% c or faster to be human scale. Sure, it takes thousands of years - but we have examples of things being around for that long. Namely stonehenge and the Egypt pyramids.

Most species last on earth in one form or another for at least a million years. That's giving us an envelope of 10.000 light years at 0.01c. And despite the usual pessimism, we're likely not to be the last intelligent species. A mere 10-20 million years would be enough thoroughly explore all stars in the galaxy.

Patience is the resolution to the Fermi Paradox.

220:

Sorry, doesn't fit on the back of the envelope I used. (Really!)

221:

What consequences does the simulation argument have for The Meaning of Life, then? What is the goal of the simulation and how you should act to maximize your fitness in the simulation.

Should an actor in the simulation try to grab all the resources in the simulation, or does that lead to premature termination of the simulation? "Oh, it went into the big clump of computronium -state again *reset*." If these kinds of land grabs are actively selected against in the simulation, you wouldn't see big expansionists (at least on the whole-universe scale, planetary scale expansionists do exist as demonstrated by ants, plants and people).

If the simulation is on an individual basis, is the goal to do something interesting with your life instead of taking the easy way out, thus increasing your chances of survival by avoiding boring the simulator. Or maybe the easy way out is the thing that's interesting, with the simulation being an exercise in living a relaxed life.

The simulation could also be run as a way to figure out how to break out of a simulator, in which case the simulator would like the simulation be as close to its perceived reality as possible. And the fitness function on the simulated entities would be how well their attempts to break the simulation are going. (This is a message to you from the Powers That Be, so get a move on already! Chop-chop, hackety-hack!)

If we are living either in the reality or as uninteresting noise in a simulation, life might just be a physical state that maximizes the increase of entropy in certain kinds of physical systems. The current low-energy state of a fluid-solid transition layer on a rocky planet orbiting a G2V-class star at 150 million kilometers. The sun, wind and water do smooth out the surface layer of the planet, but biological burrowers catalyze the process.

222:

As to the question of the blog:

The simulation argument is bogus.

Assumption 1:
It is possible to run a simulation of our civilisation. This part of the argument is based on estimations of potential computation power. If we follow the old human tradition of making mistakes, and we're wrong, then so is the simulation argument.

Assumption 2:
We're living in a universe in which we *can* run a simulation of ourselves.

Should we ever do so, we'll find out that we can't do that.

Why? Under the assumption that a meaningful simulation of ourselves would run faster than life and would have to run at least to the point of current technological progress and then some in order to have meaningful predictive value, the simulation would necessarily have to arrive at the point at which it would want to simulate itself under the very same assumptions.

Namely that the simulated simulation would have to run faster than the accelerated simulation. And this is not a singularity in a singularity, but a brick-wall. The simulation would be saturated in the blink of an eye.

The only way to prevent that would be to make it impossible to run a simulation in a simulation, but I just proved that even if it were possible to run such a simulation it would be impossible to run it.

Hence, it is all nonsense.

223:

Hey Mark G

About the moon:

I don't have references for these statements, apart from remembering a popular science book called something like " What if there were no moon?" or somesuch.

Anyway:

It's possible that tidal effects from the moon _help_ keep the earth's interior stirred and liquid, allowing the continued existence of a magnetic field which deflects most incoming solar charged particles.

The moon stabilises the earth's rotational axis, thus keeping the seasons regular. Life doesn't have to keep adapting to wildly varying seasons.

I've wondered if the moon has some protective effect on the earth, not by leaping in front of an incoming asteroid, secret service style, but by deflecting some percentage of the incoming rocks so that the frequency of large impacts is reduced just enough to allow life to take hold, flourish, evolve...and recover after the odd big rock does hit.

Maybe life needs to be on a planet where liquid can form, with a stable orbit (so a Jupiter is needed to keep the solar system in order), with a stabilising, tide-raising and protecting moon, and enough internal radioactivity and iron to have a gooey interior rich in iron that supports a magnetic field. Plus all the good stuff about not having too many supernovae nearby.

In that case, maybe earth is a real rarity.

224:

Holy crap! Is this the reason for the Voyager Anomaly?

225:

to spudtater @ 133:

Your reply raises a question in my mind.

An analog simulation of the Universe would be based on an a set of
algorithmic compressions of its phenomenology; the task of constructing
the simulation would be made slightly less daunting by the fact that such
algorithms are already known; they are the laws of physics. If the Universe
is computable by way of analog computing then its physical laws are,
ultimately, computational algorithms, implemented at the most elementary
level by interacting quantum fields.

My understanding is that an analog computer is not a Universal Turing
Machine; its software cannot be designed so as to be translatable from
one computer to another in a way that is completely independent of the
design of the hardware substrate on which it is be implemented .

Consequently (it seems to me) a simulation of the Universe accurate and
powerful enough to be emulate it (in the Tiplerian sense) would have to
mimic both the software (the laws of physics) and the hardware (quantum
fields interacting in a space-time continuum) so exactly as to be
indistinguishable from the Original.An emulation of the Universe based
on analog computing would BE the Universe all over again.

My question(s) then: Could a Universe spare the computational resources
(or even contain them!) to compute itself? Does the notion even make
sense? Would it not be infinitely self referential (a model of the Universe
modeling itself and so on )?

226:

There seems to be a lot of misunderstandings about what "a simulation" means.

First of all, when you create a simulation, you control all aspects of its interior, because you choose the rules.

Second, a simulation does not have to have full or even isotropic granularity. Quantum mechanics can, and often is simulated, using random numbers (See origin of "Monte Carlo" methods for ref. LANL.gov has good articles), (LHC might simply be investigating floating point rounding errors in the simulation code).

Planets, stars, galaxies can often be reduced to a set of general relativity coordinates + a few other parameters like temperature/emission spectrum, magnetic fields etc (In fact, they might actually be angles on a piece of black cloth, we know next to nothing about the luminosity of angels).

Third, a simulation can be adaptive, so that only once somebody lands on the moon, does it stop being made of green cheese, saving a lot of computational energy until then.

Third, since we would be part of the simulation, our perception of anything, including but not limited to the rest of the simulation, is controlled by the rules of the simulation.

Therefore any test along the lines of the Turing test, provides us with no knowledge not subject to the simulation. Even if you positively know that at the other teletype is an entity outside the simulation, your perception of him is controlled by the simulation. (Think "Flatland")

And any weird thing we might observe, is simply how reality is in the simulation, and this is the important bit.

Wave-particle duality ? That just might be an IF statement trying to use the more efficient computational algorithm to derive the result for the simulation, while the actual nature of the photons are the conceptual model from which the simulation is constructed, a conceptual model we don't have access to, being limited to observations of its approximation in the simulation driver.

There is absolutely no way you can tell if you are in an simulation from inside it, if the entity running the simulation does not want you to. (See for instance virtual machines for sandboxing windows-vira)

In other words: Any sufficiently advanced simulation is not only indistinguishable from, it is reality.

Poul-Henning

227:

So why aren't we overrun with insect intelligence robots? Shouldn't the galaxy be filled with them by now?

228:

This has been done, although I never see any indication of accounting for potential drag from hydrogen atoms. Nevertheless, using solar sails, laser illumination of the sails and even nested sails, the calculations show that you can reach the nearest stars in a reasonable time, i.e. << 1000 years.

229:

I'm not actually advocating for interstellar colonization or nuclear pulse propulsion... just pointing out that accepting the premise of AI + fully automated manufacturing gives you a pretty big magic wand for engineering on a staggering scale, and one that doesn't appear to violate any physical laws.

Personally, if I ever get a genie -- err, advanced AI-engineer and nanotech factory -- I'm not going to request an interstellar oil tanker but a bunch of smaller probes and send them exploring at much less than 0.1 C. In the mean time I'll stay home for me or my descendants -- assuming we don't blow each other up with our nanotech factories -- to collate the results.

230:

The whole "what if there was no moon" idea (and yes I read the book many years ago) is more about life on earth and assuming that is what all life would need. I don't buy it, and if any life is found in the solar system or elsewhere, this hypothesis will be refuted.

231:

@224:

My understanding is that an analog computer is not a Universal Turing Machine; its software cannot be designed so as to be translatable from one computer to another in a way that is completely independent of the design of the hardware substrate on which it is be implemented .

Hmmm . . . I'm not sure what you mean by an analog computer here. Certainly this is true if you're thinking of something like a pantograph. But there are cellar automata which are also "analog" in the sense that the output has a real-number representation (even if it can't be completely stored on a digital machine.)

There's also the fact that there are things an analog computer can do that a digital computer cannot; sorting can go as roughly O(n), for example.

232:

@216:

No, I'm talking about Hashlife, which you have to see in action to believe; for example download Golly (multi platform) which can run enormous worlds (# of cells > your RAM) at breakneck speeds (6 octillion iterations in 30s)

Is that really a "faster algorithm"? It looks to me more like you're precomputing a bunch of states and storing them in memory[1]. So yeah, you can store a bunch of patterns that end up as a stable beehive and jump to state 10^20. But that's kind of like slipping me the answers to the test I'm about to take; you can argue that I'm in an algorithmic speedup because it only takes me ten minutes to write in the responses to the questions and turn my test in. I'm by no means an expert at this sort of thing, but if that's what's meant by an algorithm, well, okay, I'll accept that definition. But that's not what I meant when I used the term. Otoh, it would be interesting to run one of Egan's Copies on a machine implemented in the Life game and have the Copy report it's internal experience[2] :-)


[1]In fact, it looks like your doing a tradeoff between speed of "computation of states" and computer memory. What's it called? Oh, actually, it's in your link, memoization:

Memoization is a means of lowering a function's time cost in exchange for space cost; that is, memoized functions become optimized for speed in exchange for a higher use of computer memory space. The time/space "cost" of algorithms has a specific name in computing: computational complexity. All functions have a computational complexity in time (i.e. they take time to execute) and in space.

So in any finite machine, you're trading off simulation space for speed.

[2]There's a grim thought - Copies either beehive or die off after a finite number of computations even when divorced from the wetware that normally runs them.

233:

@216:

This was sufficiently troubling to me that I went back to the original claim:

You are mistaken, simulations are compressible, both in speed & memory requirements, that's precisely what advanced "game of life" algorigthms do.


The technique being used to speed up the computations definitely trades of memory for speed; you can't do both at once. So as I said, while there is an algorithm that can compute every other state of Life without precomputing the intervening state (it's actually just a different collection rules that follow the original three in spirit), there is no algorithm that both speeds up the computation and leaves the amount of memory unchanged, let alone decreasing it.

OTOH, if you have an infinite amount of memory, that's really not that big a deal. As I've said before, even if it turns out that we're in a simulation that has a finite representation, there's no reason to believe that the machine it's running on is finite.

234:

@226:

So why aren't we overrun with insect intelligence robots? Shouldn't the galaxy be filled with them by now?

Aren't you presupposing some sort of self-replicating ability that's been specifically disallowed in this scenario? An interesting factoid: self-reproducing machines have been around for, oh, I don't know, around a half-century already? The implicit problem is actually not having machines reproduce; it's having them do so from a sufficiently simple base of starting components. So yeah, little robots that click together pre-assembled arms, power units, etc to make identical robot can in some sense said to have reproduced itself. But that's not what people normally mean by the term.

And in your scenario, even humans don't count as self-reproducers: they can't basic carbon, hydrogen, oxygen, etc, and assemble the complex organic molecules from which they are constructed. Asking your probes to latch onto the side of an asteroid, separate out the constituent basic elements and work from the bottom up seems a bit much. I can see this being promoted as a sort of self-unpacking asteroid mining setup that's coming Real Soon Now like strong AI and commercial fusion.

235:

@225:

There is absolutely no way you can tell if you are in an simulation from inside it, if the entity running the simulation does not want you to. (See for instance virtual machines for sandboxing windows-vira)

I suppose you have to distinguish intentional simulations from accidental ones. True, when you think of simulations you think there has to be a Simulator. But I don't know if that's necessarily true; the very famous counterexample (which, admittedly, cheats) are Wang's Carpets which apparently arose through some blind evolutionary process.

So it's not impossible to believe that it's not just an infinite progression of simulations, but that these simulations are all the result of chance.

236:

This response was to counter Eric's view that a very smart AI/intelligence might be self limiting. Simple intelligences won't fall into that trap.

While the idea of self replicating robots filling the galaxy is old, that doesn't mean it should be dismissed as not achievable. If we change the scenario and use biology that is deliberately seeded, we get a similar effect. Life will propagate given enough time and a suitable vehicle for star travel.

Suppose we found biology in different star systems that seemed very similar. Either we can hypothesize that this is some natural optimization, or that these biologies has a common source. If the latter, I would argue that this breaks the Fermi paradox as much as BEM's in flying saucers, evidence of Dyson spheres or stellar engineering.

It doesn't break the simulation hypothesis, but, as I've said before, I don't think it is an interesting idea to play with unless it is subject to falsifiability.

237:

For 3.8 billion years, thousands of alien races that passed by Earth thought it was just another one of the super abundant rocky worlds covered in primitive single cell life. Maybe someday it would ammount to something, but that would likely be medicore too.

Even for patient galactic intellegences a billion years was time not worth wasting monitoring some dreary ball of rock, just to watch a re-run of life evolving yet again.

If life is universally abundant as it may indeed be, then it's not so interesting I'm affraid.

238:

The whole "what if there was no moon" idea (and yes I read the book many years ago) is more about life on earth and assuming that is what all life would need. I don't buy it, and if any life is found in the solar system or elsewhere, this hypothesis will be refuted.

Hey Alex,

I think you missing the point. "The presence of a large moon" might or might not be a valid filter for intelligent life. It doesn't matter. What does matter is that you can stack one filter, such as "presence of a large moon" atop another filter, such as "presence of coal, petroleum or similar" atop another filter "physical capacity for tool use" and so on pretty much into infinity with no loss of plausibility.

Once you play with the idea of filters, and see how many you can stack without losing a sense of reality, the Fermi paradox kind of resolves itself.

239:

@ 225:
"Wave-particle duality ? That just might be an IF statement trying to use the more efficient computational algorithm to derive the result..."

Erm, ignoring the "simulation" argument (Violates Occam, AND if really good, as also stated, it IS reality, so there!) then.

You may really be on to something there.
A variation on that idea could (should be possible to be)be mathematically represented as the underlying order underneath apparent QM-uncertainty. It would certainly resolve the double-slit/single long-period iterated photon problem I mentioned earlier.

I think my brain hurts.

240:

And in your scenario, even humans don't count as self-reproducers: they can't basic carbon, hydrogen, oxygen, etc, and assemble the complex organic molecules from which they are constructed.

Human beings aren't autonomous. Individually we can't even digest our own food without the assistance of a multi-species bacterial colony massing on the order of a kilogram and containing roughly two orders of magnitude more cells than there are in our bodies. (There's one in your gut, and one in mine. Ever wondered why you get the shits after a course of antibiotics?) It takes a critical number of us to maintain a self-perpetuating technosphere (see previous blog entry). We're part of an ecosystem; we just happen to be the part that has developed weirdly baroque inorganic tools and uses them to invade otherwise inhospitable spaces.

But collectively, with the rest of the ecosystem in tow, we can move mountains -- at least, on a planet with the right amount of sunlight, a working deep carbon cycle and plate tectonics (but not too much plate tectonics), and a working biosphere.

Whether we can transplant/propagate this bunch of complex systems into a smaller, mobile environment (be it a Mercury capsule sized tin can or a fifty kilometre long hollowed-out asteroid) is the key unknown: are biospheres portable?

241:

Let's not forget it might not be a benevolent posthuman simulation we're currently residing in; Lest we forget ol' green face-tentacles from 'A Colder War'... "There is life eternal within the eater of souls. Nobody is ever forgotten or allowed to rest in peace. They populate the simulation spaces of its mind, exploring all the possible alternative endings to their life. There *is* a fate worse than death, you know." :o

242:

My point is that the suggested filters are not filters at all. You can choose any condition or variable you like an call it a filter, but that doesn't make it one.

Throwing an infinite set of "filters" together is just throwing mud at a wall and hoping some will stick.

243:

If the IF wave/partikle duality gives you a headache, then you have worse to come when you realize that the zoo of subatomic particles produced in larger and larger accellerators and the missing mass/dark cold matter both look like bit-drop-off-accumulation-errors[1].

If we care to, we can probably calculate how many bits of mantissa there are in the floating point numbers used and from that infer if a 64 or 128 bit computer is being used.

There's a good SF story there.

I wonder if Rudy Rucker could write it for us, it's not quite Charlies genre :-)

Poul-Henning

[1] Take one billion tons. Add the mass of an electron. Remove the one billion tons and notice that your electron has disappared.

244:

243:
It's not the Wave/Particle duality as such that gives me a headache.
I (think I) know that is ain't so ...
I'm enough of a long-ago physicist (before I did engineering) to know that photons ARE particles - I follow Feynman on this one - still got my copy of the Red Books.
The slow/single-release double-slit shows they ARE particles. And the emerging pattern shows that there IS an underlying level of order.
Even if that order is the $If_STATEMENT of a simulation.

What hurts is that my maths (at that sort of level) is now so rusty that I really don't know or remember where to start in trying to solve the problem.
What problem? Generating a control-equation that will accurately (*ahem*) model the systems' complete behaviour, from one-photon up to 5000+

In other words "god" isn't playing dice with the universe, but neither is it fully deterministic (most likely) - there is probably some averaging function that accumulates results over time and number with a predictive aggregation factor.

AARRRGH!

245:

Exactly:

If there are only a few particles in play, the simulation path where particles are simulated is taken, once the number of particles rise above some limit, the wave branch is taken, as that is faster to calculate :-)

Poul-Henning

246:

Re: "Where are They?"

I've often pondered about panspermia in relation to the Cambrian "explosion". What (I said to myself) if the explosion was due to some alien 'terra-forming' event? The aliens duly arrived, lived, evolved and died. We are their 'children' in a weird, panspermic(?) way. Would we, hundreds of millions of years later, necessarily be aware of their presence anywhere locally?

Cambrian fossils (AFAIR) are limited to the kind of critter that lives & dies in a sedimentary basin. So I wouldn't expect any of the aliens to be fossilized. Also - if the fossilised critters are bio-compatible with the aliens, we might not even recognize alien fossils if we had some!

How long do we expect galaxy-spanning 'peoples' to survive, after all, and how long do we expect their artifacts to stick around - or even be recognizable as artifacts? (I seem to recall a story where the moon is actually just a humungous mothballed ship)

247:

245
NOT exactly.
What about the gey area between (approximately 300 and 900/1500 particles.
Wher you cannot really tell whether you have particle or wave ???
Even though photons ARE particles - or didn't you read what I said about Feynman?

248:

Sorry about the anthropomorphic principle goof (my intention was simply to convey the absurdity of projecting our human motivations or desires onto nonhuman intelligences).

furthermore, the assumption that just because 1 nonhuman intelligence 'figures out' interstellar travel that they will like it enough to hit an exponential growth leading to universal saturation... seems a stretch.


249:

I've often pondered about panspermia in relation to the Cambrian "explosion". What (I said to myself) if the explosion was due to some alien 'terra-forming' event? The aliens duly arrived, lived, evolved and died. We are their 'children' in a weird, panspermic(?) way. Would we, hundreds of millions of years later, necessarily be aware of their presence anywhere locally?

A nice thought, but there are archaean bacterial fossils a lot older than the Cambrian. Stromatolites, etc. Their modern descendants are still around and are both recognisably similar to the Archaeans and recognisably related (biochemically) to more complex life.

250:

You need only simulate the perceptive aspects that populate our phenomenological experience, which is itself a simulation.

I don't think this saves much sim space in the long run.

Once you have simulated the results of perception, you must also remember them somewhere, and remember their consequences (seeing a supernova, seeing the color of someone's hair, writing a marginal note in a library book, etc.). The bookkeeping for all of this is going to be pretty huge, and mount up over time. Whether your sim is memory managed or GC'd you are going to ultimately end up with huge amounts of the universe having internal consistency that has to be maintained by really complex data structures. In the end, after a few billion people live for a few billion years (or maybe even a few hundred) you have accumulated a mind-boggling amount of data that it's really painful to get rid of, as when the last reference to and consequence of the existence of Caveman Ogg is gone and forgotten. That's a very, very long garbage collection; I recommend a separate GC process. Alternatively, if you're using regular alloc/free memory management, your sim crashes regularly. Either way the overhead of allocation rises higher and higher over time.

The discussion also brings to mind Edward Fredkin's question (in the '70s, I think) about sims: An alien race offers humanity the choice of utter annihilation or utter annihilation tempered by preservation in a running sim. At what ratio of sim-time to real time is this a reasonable deal? What if one sim nano-second is run each second? How about one each day? Etc.

251:

The simulation hypothesis needs to consider that the "gods" will limit themselves from considerations of morality. I explored this notion a bit in Moral Dilemmas of the Gods.

252:

That's a very, very long garbage collection; I recommend a separate GC process

Who cares - it's not as though it needs to be a real-time process.

253:

I see Paul Krugman linked to this post, so here's a link to his post:

Krugman, areography

Cool stuff.

254:

It is useful to consider arguments besides theoretic technology feasibility. One answer to the Fermi Paradox is that civilizations exist at a high level of technology for relatively short periods of time, and therefore the ones within a reasonable communication horizon are rarely contemporaneous.

Consider that exponential growth on a finite planet will end, one way or another. The historical precedent is periods of growth followed by collapse, followed by growth, followed by collapse (see Joseph Tainter's The Collapse of Complex Societies for a historical overview). The other possibility has never been seen: a civilization achieves a zero-growth steady state. It may be that such a state is nearly impossible. Our theories of economics all break down in such a state (it is unclear whether debt and return on investment are possible without growth).

The human mind has a hard time understanding the exponential function. Here's a simple gedanken to illustrate. While the answer is easy to calculate with high-school mathematics, use your intuition first, and then compare to the mathematical answer. Suppose civilization discovers a non-renewable resource and begins using it. Each year they use 3% more than the previous year. Under this pattern of use, there is enough of the resource to last 200 years. On what year is the resource half used? I suggest this is one reason civilizations "hit the wall" with all the subtlety of a race care impacting a concrete abutment. (FWIW, our civilization is already past the point where applying the brakes can avoid impact.)

255:

Well, my own personal favorite solution to the fermi paradox is an answer not on the wiki-list.

What if something about technological advancement causes a species to realize it is not in it's best interest to hang around?

Imagine a civilization created on the inner portion of a semi-active volcano. At some point of advancement they figure out that they're all going to die if they don't leave, as well as that better places do exist.

What if that was tied to important technological markers. For example:
-The process of creating a faster than light drive, causes you to discover that the "universe" you perceive is really the internal contents of a black hole.
-You look around and see other nested black holes below you.
-You conclude that there may be additional layers of black holes above and containing you.
-You postulate (or witness) that nothing prevents same level black holes from hitting each other, and conclude that the smaller black hole gets sucked inside out and eaten by the larger one.
-You realize this could happen at any level above your universe without you detecting it coming.
-Facing zero-warning obliteration, you use your new FTL tech to pack up your civilization and head up the black hole chain. If within your capability, perhaps you take your entire solar system as a long-term travel vehicle (thus leaving no artifacts).

Only half-joking about that, but still. There's a possibility civ's hit a point where a rational species decides to get out of dodge instead of looking for civilizations that have nothing to teach them. (Since any superior tech civ would have left already also.)

As for the simulation exercise, I don't see a lot of value in that. It could help us work out kinks in what we already decided was our best package, but the devil is in the details, and the details are unknown on another planet. In other words, physical simulations would be extremely useful for honing execution choices, and that's about it. Computer simulations would be almost completely worthless. Since they only parrot back the results you told them to expect, they really wouldn't lead you to any significant aha moments unless you were a moron.

It's like the biosphere test they actually tried. The oxygen levels dropped to a lethal level and they couldn't figure out why. Turned out the concrete was absorbing it out of the air. Your computer model would only produce that result if you had told it to expect it. Any non-predicted problem wouldn't be detectable that way. A lot of the idiocy of global warming advocates originates from exactly this problem.

256:

Now, say you wanted to simulate the earth for whatever reason, if you are only interested in the earth, would you go ahead and simulate the rest of the universe? It would seem that there is no need to simulate all of andromeda, say in detail, an approximation would do. In fact, the further you get away from earth, the less detail you are going to need.

So, imagine your approximation consisted of simply running things at a lower clock rate when you need less detail, for every 10 cycles you devote to earth, you give 7 cycles to something further out, and so forth in a straightforward fashion that depends only on distance. What would the universe then look like to us? Well, the further away things are, the slower time would be going for them, hence, we would observe them being 'redshifted'. in fact, what we would see is a redshift proportional to the distance, perhaps with a proportionality equal to hubbles constant. In fact, this is exactly what we do see when we look up. Perhaps the correct interpretation of hubbles law should not have been that the universe is expanding everywhere, but rather than our solar system actually is at the center of the simulation.

257:

Now, say you wanted to simulate the earth for whatever reason, if you are only interested in the earth, would you go ahead and simulate the rest of the universe? It would seem that there is no need to simulate all of andromeda, say in detail, an approximation would do. In fact, the further you get away from earth, the less detail you are going to need.

So, imagine your approximation consisted of simply running things at a lower clock rate when you need less detail, for every 10 cycles you devote to earth, you give 7 cycles to something further out, and so forth in a straightforward fashion that depends only on distance. What would the universe then look like to us? Well, the further away things are, the slower time would be going for them, hence, we would observe them being 'redshifted'. in fact, what we would see is a redshift proportional to the distance, perhaps with a proportionality equal to hubbles constant. In fact, this is exactly what we do see when we look up. Perhaps the correct interpretation of hubbles law should not have been that the universe is expanding everywhere, but rather than our solar system actually is at the center of the simulation.

258:

The simulation argument is particularly unconvincing for a number of reasons.

Let's start with complexity:

People have been arguing back and forth about the fundamental complexity of a simulation -- essentially, whether a simulation is subject to compression or not. A compressed simulation, the argument goes, would only require enough storage to, for example, run a solipsistic universe for one person.

This is kind of missing the point. Say this were true -- that simulation of one person would still not be more compact than a similar person living in the Host Universe. It can't be -- if that were possible, Host People could simply run their own minds more efficiently. In fact, it must be much less efficient at best, since you need to simulate the rest of the universe, even in a simplified form.

A simulation inside the simulation would end up taking, at best, the same fundamental resources in the Host Universe as it does in the Simulation0 universe. That is, you can imagine a compression scheme in your simulator that turns entire galaxies into mere blips on your computer monitor when you read wikipedia, but for the Simulation1 universe to actually work, it can't be simplified more than that. The same irreducible complexity that Simulation0 boils down to also exists in Simulation1.

Let's look at this another way. Say running a solipsist universe for one person requires 1m3 of compute resources. If that simulated person herself builds a solipsist simulator, then it will require at least 1m3 of computer in her universe (or the equivalent in complexity), and her universe now requires 2m3 in the Host!

You can probably see where this is going:

Simulation cannot eliminate complexity, it can only eliminate redundancy. A simple way to understand this is to consider why you can't reduce a zipped file, or why an mp3 or a JPEG has reduced quality compared to the original.

So, what does this actually mean?

Simple:

The total amount of intelligent life in Simulation0 and all possible sub-simulations is less than or equal to the amount of intelligent life that will fit on Host's computing machines.

In other words, simulation does not increase the number of people at all. It only gives them a weird environment to live in (at some loss of compute efficiency). And given that it's less efficient, why would Host allow its compute resources to be squandered on this anyway?

The argument is totally bogus!

259:

Complexity isn't the only basic problem with the simulation argument though. The fundamental argument is one of statistics: it's most probable that we live in a simulation because of such and such.

This is essentially the same method used in the Doomsday argument to argue our species will probably die out soon. That argument basically goes like this:

1. Since we're average, we probably exist about in the middle of the timeline of all people who will ever live.
2. Population has been growing exponentially.
3. The total number of people who lived in the past will be exceeded by people who'll live in the future in a few generations.
4. But we live in the middle.
5. Therefore history will end in a few generations. Apocalypse.

I hope nobody found this argument very convincing. It's a pretty amusing method of argument, though. Let's apply it to a few other situations to see if it works:

1. This is a perfectly ordinary comment.
2. There are currently 258 comments.
3. But this comment, being ordinary, is probably in the middle.
4. Therefore there will probably be 516 comments in this thread.

1. The Trade of Queens is a perfectly ordinary Merchant Princes book.
2. It's the 6th.
3. Therefore there will probably be 11 Merchant Princes books.

1. Apollo 17 was a perfectly ordinary moon landing.
2. Therefore we'll land on the moon five more times.

The basic problem with these arguments is that we know nothing about the distribution of these events, and in fact we can't know until they happen. Statistics works by making an argument like, "A repeatable event usually works like this, therefore the probability of another event is X."

Is this comment ordinary? I have no idea. What is the probability of the most recent book being in the middle of a series? What is the expected average number of moon landings a species like ours will make in its history? How could we possibly know that without studying thousands of intelligent species?

To find out how likely it is to live in a simulation, we'd have to find a representative set of universes and then sample the population living in them (simulated and otherwise). What percentage of the population live in simulations, and don't know it?

That would be quite a census.

260:

I have spent some time over the years on the Fermi paradox purely for my own amusement (I keep threating to write a simulation that would show the various settlement patterns depending on what your starting assumptions are but some how the code remains unwritten).

I am currently enthralled with the idea (question really) from the comments section in the previous thread that asks if the minimum population size required to maintain a current technology rises as the technology level rises. So that the maximum tech level a system can achieve is limited by the carrying capacity of that system.

If true, this to me would have real impact on the whole equation.

It may be that the tech level required to launch a successful interstellar colony requires an enormous base population that very few systems can achieve.

Yes I know that even 1 such civilization should be able to cover everything in a billion years or so but that requires that a very high level of tech be maintained for a billion years.

As the civ advances across the galaxy, if the population needed at each new base to support the very high tech level needed to launch the next jump is significantly large, it may not be possible to march across the galaxy even given a very long time frame.

Great stuff, well worth a few hours of vacation time for reading.

261:

Ryan North has said it better than I can.

http://www.qwantz.com/index.php?comic=1150

So I'm not going to say anything more.

262:

The kind of argument this paper makes, and more generally an "Old Ones" type answer to the Fermi Paradox seem to best match the evidence.

First of all, looked at from an evolutionary perspective, the universe isn't that old. The age of the universe about 14 billion years. The age of the Milky Way main disk, about 8 billion years, The age of life on Earth, about 3.5 billion years.

So at the most you would have had 4 prior evolutionary cycles to produce intelligent life. If intelligent life is rare (and the fact that it took 4 billion years to arise on earth suggests that it is), this isn't going to be enough time to get a big population of alien civilizations.

And we know that the universe is not static so it is likely that there has been even less time for evolutionary processes to make intelligent life, because the early universe was more violent and lacked the heavier elements needed for life.

Add all this to the fact that we don't see anybody up there and I think it is not unlikely that we are one of the first intelligent beings in the universe.

263:

One class of resolutions of the Fermi paradox is that what matters is density of civilizations, not numbers. There can be lots of advanced civilization out there, but if they aren't close enough together, or don't exist at the same time, they won't encounter each other. If advanced civilizations tend to implode once becoming advanced over periods of hundreds of thousands of years or less, and the universe if many billions of years, and advanced civilizations are many, many light years apart, the odds of advanced civilizations encountering each other may be low.

There may be 10^22 stars in the universe, but there are far fewer Sun-like stars with Earth-like planets within 100 light years of Earth, which is a 1000 years plus trip even if you are going very fast. The places where you would expect advanced civilizations to come into contact with each other are closer to the galactic core where distances aren't as great, not out here in the spiral arms where plausible real estate is much more widely spread out.

We have also made only the most superficial examination ourselves. We have yet to send a probe to a single Earthlike planet in another solar system and have been listening to radio signals from space for less than a century.


264:

As an aside; If we are a simulation. Its curious that as a sentient species we have no knowledge of what lies beyond biological birth / death.

Perhaps we are an advanced space going civilization that (chooses) to exist in a temporal reality as a means of passing the time. The stipulation of (ignorance) beyond this reality a condition of entry into the simulation.

Best of all we are on timer to guarantee the expiry of the experience. Lets put it this way, if a galactic civilization had reached an omnipresent state with eternal existence then these kind of simulations could be the equivalent of recreation activities. :)

Damian

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