Countercounterevidence for 3: what are the assumptions made by those models of interstellar colonization?
Do they assume fusion power? We don’t know if industrial fusion power works economically enough to power starships. Likewise for nanotech-type von Neumann machines and other tools of space colonization.
The adjustable parameters in any model for interstellar colonization are defined by the limits of capability for a technological civilization. And we don’t actually know the limits, because we haven’t gotten close enough to those limits to probe them yet. If the future looks like the more optimistic hard science fiction authors suggest, then the galaxy should be full of intelligence and we should be able to spot the drive flares of Orion-powered ships flitting around, or the construction of Dyson spheres by the more ambitious species. We should be able to see something, at any rate.
But if the future doesn’t look like that, if there’s no way to build cost-effective fusion reactors and the only really worthwhile sustainable power source is solar, if there are hard limits on what nanotech is capable of that limit its industrial applications, and so on… the barrier to entry for a planetary civilization hoping to go galactic may be so high that even with thousands of intelligent species to make the attempt, none of them make it.
This ties back into the hypotheses I left out of my post for the sake of brevity; I’m now considering throwing them in to explain my reasoning a little better. But I’m still not sure I should do it without invitation, because they are on the long side.
Alternate explanations for rarity of intelligence:
3a) Interstellar travel is prohibitively difficult. The fact that the galaxy isn’t obviously awash in intelligence is a sign that FTL travel is impossible or extremely unfeasible.
Barring technology indistinguishable from magic, building any kind of STL colonizer would involve a great investment of resources for a questionable return; intelligent beings might just look at the numbers and decide not to bother. At most, the typical modern civilization might send probes out to the nearest stellar neighbors. If the cost of sending a ton of cargo to Alpha Centauri is say, 0.0001% of your civilization’s annual GDP, you’re not likely to see anyone sending million-ton colony ships to Alpha Centauri. In which case intelligent life might be relatively common in the galaxy without any of it coming here; even the more ambitious cultures that actually did bother to make the trip to the nearest stars would tend to peter out over time rather than going through exponential expansion.
3b) Interstellar colonization is prohibitively difficult. If sending an STL colony expedition to another star is hard, sending one with a large enough logistics base to terraform a planet will be exponentially harder.
There are something on the order of 1000 stars within 50 to 60 light years of us. Assuming more or less uniform stellar densities, if the probability of a habitable planet appearing around any given star is much less than 0.1%, it’s likely that such planets will remain permanently out of reach for a sublight colony ship. In that case, spreading one’s civilization throughout the galaxy depends on being able to terraform planets across interstellar distances before setting up a large population on those worlds. Even if travel across short (~10 ly) interstellar distances is not prohibitively difficult, there might still be little or no incentive to colonize the available worlds beyond one’s own star system. After all, if you’re going to live in a climate-controlled bunker on an uninhabitable rock where you can’t step outside without being freeze-dried or boiled alive, you might as well do it somewhere closer to home.
NOTE: This amounts to “super-difficult life,” but it does not require that there are few intelligent species in the galaxy. If the emergence of life is (for lack of a better term) super-duper-difficult, or if most planets are inhospitable enough to make it impossible, then we could have many thousands of intelligent species in the galaxy without any of them being likely to reach each other.
3c) Interstellar colonization might be “psychologically” difficult. For instance, what if the next logical step in the evolution of modern civilization is an AI singularity, possibly coupled with some kind of uploading of consciousness into machines? Either way, our descendants of 200 years from now might well be, to our eyes, a civilization of robots. To a society of strong AIs, interstellar colonization is liable to look a little different. Traveling to even the nearest stars, you will be cut off from the rest of your civilization by a transmission gap on the order of 10^20 cycles just because of the lightspeed limit.*
That might sound like an even worse idea to them than spending a long lifetime in cryogenic storage and having a twenty year round trip communication cycle with Earth does to us. In which case they’re likely to stay at home and come up with elaborate social activities or simulations to spend their time, because interstellar colonization is just too unpleasant to bear considering.
*Assuming roughly 1 THz computing, for relatively near stellar neighbors. This estimate is probably too low, but I need some numbers and I am nowhere near an expert on artificial intelligence or the probable limits of computer technology.
For a machine-phase civilization, the only one of these that seems plausible is 3c, but I can’t think of any reason why no one in a given civilization would want to leave, and assuming growth of any kind, resource pressure alone will eventually drive expansion. If the need for civilization is so psychologically strong, copies can be shipped and revived only after specialized systems have built enough infrastructure to support them.
It seems far more likely to me, given the emergence of multiple civilizations in a galaxy, that some technical advance inevitably destroys them. Nanomedicine malfunction or singleton seem like the best bets to me just now, which would suggest that the best defenses are spreading out and technical systems’ heterogeneity.
A machine-phase civilization might still find (3a) or (3b) an issue depending on whether nanotech pans out. We think it will, but we don’t really know, and a lot of technologies turn out to be profoundly less capable than the optimists expect them to be in their infancy. Science fiction authors in the ’40s and ’50s were predicting that atomic power sources would be strongly miniaturized (amusingly, more so than computing devices); that never happened and it looks like the minimum size for a reasonably safe nuclear reactor really is a large piece of industrial machinery.
If nanotech does what its greatest enthusiasts expect, then the minimum size of industrial base you need to create a new technological civilization in a completely undeveloped solar system is low (I don’t know, probably in the 10-1000 ton range), in which case the payload for your starship is low enough that you might be able to convince people to help you build and launch it. Extremely capable nanotech also helps on the launch end by making the task of organizing the industrial resources to build the ship easier.
But if nanotech doesn’t operate at that level, if you actually need to carry machine tools and stockpiles of exotic materials unlikely to be found in asteroid belts and so on… things could be expensive enough that at any point in a civilization’s history it can think of something more interesting to do with the resources required to build an interstellar colony ship. Again, if the construction cost of the ship is an order of magnitude greater than the gross planetary product, it won’t get built, especially if very few people actually want to ride it.
Also, could you define “singleton” for me, please?
Sorry for taking so long on this; I forgot to check back using a browser that can see red envelopes (I usually read lesswrong with elinks).
I think if nanotech does what its greatest enthusiasts expect, the minimum size of the industrial base will be in the 1-10 ton range. However, if we’re assuming that level of nanotech, anyone who wants will be able to launch their own expedition, personally, without any particular help other than downloading GNU/Spaceship. If nanotech works as advertised, it turns construction into a programming project.
Also, if we limit ourselves to predictions made in the 50s with no assumptions of new science, I think we’ll find that the predictions are reasonable, technically, and the main reason we don’t have nuclear cars and basement reactors now involve politics. Molecular manufacturing probably cannot be contained this way, since it doesn’t require a limited resource that’s easy to detect from a distance.
Others have defined singleton, so I assume you’re happy with that. :)
Re: Nanotech
That’s exactly my point: if nanotech performs as advertised by its starriest-eyed advocates, then interstellar colonization can be done with small payloads and energy is cheap enough that they can be launched easily. That is a very big “if,” and not one we can shrug off or assume in advance as the underlying principle of all our models.
What if nanotech turns out to have many of the same limits as its closest natural analogue, biological cells? Biotech is great for doing chemistry, but not so great for assembling industrial machinery (like large solar arrays) in a hostile environment.
As for the “nuclear cars and basement reactors” being out of the picture because of politics and not engineering, that’s… really quite impressively not true, I think. Fission reactors create neutrons that slip through most materials like a ghost and can riddle you with radiation unless you stand far away or have excellent shielding. Radioactive thermal generators require synthetic or refined isotopes that are expensive by nature because they have to be [i]made[/i], atom by atom… and they’re still quite radioactive if they’re hot enough to be a useful power source.
The real problem isn’t the atomic power source itself, it’s the shielding you need to keep it from giving you cancer. There’s no easy way to miniaturize that, because neutron capture cross-sections play no favorites and can’t be tinkered with.
This stuff is not a toy, and there are very good reasons of engineering why it never made the leap from industrial equipment to household use, except in the smallest and most trivial scales (such as americium in smoke detectors). It’s not just about politics.
‘singleton’ as I’ve seen it used seems to be one possible Singularity in which a single AI absorbs everyone and everything into itself in a single colossal entity. We’d probably consider it a Bad Ending.
A singleton is a more general concept than intelligence explosion. The specific case of a benevolent AGI singleton aka FAI is not a bad ending. Think of it as Nature 2.0, supervised universe, not as a dictator.
Countercounterevidence for 3: what are the assumptions made by those models of interstellar colonization?
Do they assume fusion power? We don’t know if industrial fusion power works economically enough to power starships. Likewise for nanotech-type von Neumann machines and other tools of space colonization.
The adjustable parameters in any model for interstellar colonization are defined by the limits of capability for a technological civilization. And we don’t actually know the limits, because we haven’t gotten close enough to those limits to probe them yet. If the future looks like the more optimistic hard science fiction authors suggest, then the galaxy should be full of intelligence and we should be able to spot the drive flares of Orion-powered ships flitting around, or the construction of Dyson spheres by the more ambitious species. We should be able to see something, at any rate.
But if the future doesn’t look like that, if there’s no way to build cost-effective fusion reactors and the only really worthwhile sustainable power source is solar, if there are hard limits on what nanotech is capable of that limit its industrial applications, and so on… the barrier to entry for a planetary civilization hoping to go galactic may be so high that even with thousands of intelligent species to make the attempt, none of them make it.
This ties back into the hypotheses I left out of my post for the sake of brevity; I’m now considering throwing them in to explain my reasoning a little better. But I’m still not sure I should do it without invitation, because they are on the long side.
It’s sticky sweet candy for the mind. Why not share it?
Here goes:
Alternate explanations for rarity of intelligence:
3a) Interstellar travel is prohibitively difficult. The fact that the galaxy isn’t obviously awash in intelligence is a sign that FTL travel is impossible or extremely unfeasible.
Barring technology indistinguishable from magic, building any kind of STL colonizer would involve a great investment of resources for a questionable return; intelligent beings might just look at the numbers and decide not to bother. At most, the typical modern civilization might send probes out to the nearest stellar neighbors. If the cost of sending a ton of cargo to Alpha Centauri is say, 0.0001% of your civilization’s annual GDP, you’re not likely to see anyone sending million-ton colony ships to Alpha Centauri. In which case intelligent life might be relatively common in the galaxy without any of it coming here; even the more ambitious cultures that actually did bother to make the trip to the nearest stars would tend to peter out over time rather than going through exponential expansion.
3b) Interstellar colonization is prohibitively difficult. If sending an STL colony expedition to another star is hard, sending one with a large enough logistics base to terraform a planet will be exponentially harder.
There are something on the order of 1000 stars within 50 to 60 light years of us. Assuming more or less uniform stellar densities, if the probability of a habitable planet appearing around any given star is much less than 0.1%, it’s likely that such planets will remain permanently out of reach for a sublight colony ship. In that case, spreading one’s civilization throughout the galaxy depends on being able to terraform planets across interstellar distances before setting up a large population on those worlds. Even if travel across short (~10 ly) interstellar distances is not prohibitively difficult, there might still be little or no incentive to colonize the available worlds beyond one’s own star system. After all, if you’re going to live in a climate-controlled bunker on an uninhabitable rock where you can’t step outside without being freeze-dried or boiled alive, you might as well do it somewhere closer to home.
NOTE: This amounts to “super-difficult life,” but it does not require that there are few intelligent species in the galaxy. If the emergence of life is (for lack of a better term) super-duper-difficult, or if most planets are inhospitable enough to make it impossible, then we could have many thousands of intelligent species in the galaxy without any of them being likely to reach each other.
3c) Interstellar colonization might be “psychologically” difficult. For instance, what if the next logical step in the evolution of modern civilization is an AI singularity, possibly coupled with some kind of uploading of consciousness into machines? Either way, our descendants of 200 years from now might well be, to our eyes, a civilization of robots. To a society of strong AIs, interstellar colonization is liable to look a little different. Traveling to even the nearest stars, you will be cut off from the rest of your civilization by a transmission gap on the order of 10^20 cycles just because of the lightspeed limit.*
That might sound like an even worse idea to them than spending a long lifetime in cryogenic storage and having a twenty year round trip communication cycle with Earth does to us. In which case they’re likely to stay at home and come up with elaborate social activities or simulations to spend their time, because interstellar colonization is just too unpleasant to bear considering.
*Assuming roughly 1 THz computing, for relatively near stellar neighbors. This estimate is probably too low, but I need some numbers and I am nowhere near an expert on artificial intelligence or the probable limits of computer technology.
For a machine-phase civilization, the only one of these that seems plausible is 3c, but I can’t think of any reason why no one in a given civilization would want to leave, and assuming growth of any kind, resource pressure alone will eventually drive expansion. If the need for civilization is so psychologically strong, copies can be shipped and revived only after specialized systems have built enough infrastructure to support them.
It seems far more likely to me, given the emergence of multiple civilizations in a galaxy, that some technical advance inevitably destroys them. Nanomedicine malfunction or singleton seem like the best bets to me just now, which would suggest that the best defenses are spreading out and technical systems’ heterogeneity.
A machine-phase civilization might still find (3a) or (3b) an issue depending on whether nanotech pans out. We think it will, but we don’t really know, and a lot of technologies turn out to be profoundly less capable than the optimists expect them to be in their infancy. Science fiction authors in the ’40s and ’50s were predicting that atomic power sources would be strongly miniaturized (amusingly, more so than computing devices); that never happened and it looks like the minimum size for a reasonably safe nuclear reactor really is a large piece of industrial machinery.
If nanotech does what its greatest enthusiasts expect, then the minimum size of industrial base you need to create a new technological civilization in a completely undeveloped solar system is low (I don’t know, probably in the 10-1000 ton range), in which case the payload for your starship is low enough that you might be able to convince people to help you build and launch it. Extremely capable nanotech also helps on the launch end by making the task of organizing the industrial resources to build the ship easier.
But if nanotech doesn’t operate at that level, if you actually need to carry machine tools and stockpiles of exotic materials unlikely to be found in asteroid belts and so on… things could be expensive enough that at any point in a civilization’s history it can think of something more interesting to do with the resources required to build an interstellar colony ship. Again, if the construction cost of the ship is an order of magnitude greater than the gross planetary product, it won’t get built, especially if very few people actually want to ride it.
Also, could you define “singleton” for me, please?
Sorry for taking so long on this; I forgot to check back using a browser that can see red envelopes (I usually read lesswrong with elinks).
I think if nanotech does what its greatest enthusiasts expect, the minimum size of the industrial base will be in the 1-10 ton range. However, if we’re assuming that level of nanotech, anyone who wants will be able to launch their own expedition, personally, without any particular help other than downloading GNU/Spaceship. If nanotech works as advertised, it turns construction into a programming project.
Also, if we limit ourselves to predictions made in the 50s with no assumptions of new science, I think we’ll find that the predictions are reasonable, technically, and the main reason we don’t have nuclear cars and basement reactors now involve politics. Molecular manufacturing probably cannot be contained this way, since it doesn’t require a limited resource that’s easy to detect from a distance.
Others have defined singleton, so I assume you’re happy with that. :)
Re: Nanotech That’s exactly my point: if nanotech performs as advertised by its starriest-eyed advocates, then interstellar colonization can be done with small payloads and energy is cheap enough that they can be launched easily. That is a very big “if,” and not one we can shrug off or assume in advance as the underlying principle of all our models.
What if nanotech turns out to have many of the same limits as its closest natural analogue, biological cells? Biotech is great for doing chemistry, but not so great for assembling industrial machinery (like large solar arrays) in a hostile environment.
As for the “nuclear cars and basement reactors” being out of the picture because of politics and not engineering, that’s… really quite impressively not true, I think. Fission reactors create neutrons that slip through most materials like a ghost and can riddle you with radiation unless you stand far away or have excellent shielding. Radioactive thermal generators require synthetic or refined isotopes that are expensive by nature because they have to be [i]made[/i], atom by atom… and they’re still quite radioactive if they’re hot enough to be a useful power source.
The real problem isn’t the atomic power source itself, it’s the shielding you need to keep it from giving you cancer. There’s no easy way to miniaturize that, because neutron capture cross-sections play no favorites and can’t be tinkered with.
This stuff is not a toy, and there are very good reasons of engineering why it never made the leap from industrial equipment to household use, except in the smallest and most trivial scales (such as americium in smoke detectors). It’s not just about politics.
‘singleton’ as I’ve seen it used seems to be one possible Singularity in which a single AI absorbs everyone and everything into itself in a single colossal entity. We’d probably consider it a Bad Ending.
See Nick Bostrom (2005). What is a Singleton?
A singleton is a more general concept than intelligence explosion. The specific case of a benevolent AGI singleton aka FAI is not a bad ending. Think of it as Nature 2.0, supervised universe, not as a dictator.
I stand corrected! Maybe this should be a wiki article—it’s not that common, but it’s awfully hard to google.
Done.