It's good to see more recognition that the likely extraterrestrial intelligences will be post-biological, but SMETI will have a hard time detecting such life because it will likely not need to move entire planets.
As has been show in other research, a post-biological species can more easily send small replicating probes at high fractions of C in order to populate other star systems (and even other galaxies) within a small fraction of cosmic time (meaning it would have already likely happened in the Milky Way).
Large populations need not be sent. So the question becomes the meaning of life. What does a cosmic-spanning-AI want to do with its life - and how do we detect that?
You say 'likely' but you're talking about an a priori belief. Post-biological civilization is purely speculative science-fiction at this point, there is not a single real example that we can point to yet. This might one day change if we become a post-biological civilization, but so far not a single example of such has ever been seen.
Based on what we've already empirically observed, any life out there is likely to be biological because that's the only sort of life we know can exist. Furthermore, we're unlikely to ever encounter life outside our solar system anyway. We've been looking for decades and can't find anything. The techno-signatures we speculate advanced civilizations might produce remain elusive after years of searching with increasingly capable instruments. Primitive life is unlikely to ever produce conclusive signals we can detect; the best we'll get is suggestive but inconclusive atmospheric analysis which we'll be incapable of investigating properly because going there for a closer look is technologically and socially impossible.
My guess is we're not alone, but we might as well be.
When it comes to extra terrestrial life, past Earth experience cannot be reliably used as a good predictor for the future. We need to map possible future scenarios and apply logic and reasoning.
This is like ants arguing that life outside their ant hill will likely have 6 or 8 legs because all the life they've seen so far have had 6 or 8 legs.
Maybe we cannot be certain that AI can exist, but it's certainly reasonable to predict that AI will surpass us, given the fundamental principles involved. Much like people who predicted that the Earth was round before it was circumvented. We've only seen a fraction of what AI can do, but there is no fundamental barrier to AI cognition.
Also, the only conclusion you can draw from SETI is that no one nearby is actively sending a signal too Earth. We aren't able to pickup "background" EM activity beyond a ~20 light years - which is only a handful of stars. Moreover, the notion of ET omnidirectional broadcasting so inefficient, it would be difficult to explain (thus unlikely).
My guess is that we are surrounded by quiet AI observation nodes, either in elongated orbits, or extra-solar transients. Probably near impossible to detect. There doesn't seem to be any great harnessing or storage of stellar solar outputs in the galaxy, so either their efforts do not involve large amounts of energy - or they've found some other means to capture it (maybe that's what dark matter is).
There is no fundamental barrier to AI cognition that we know of. But we don't have any proof that superhuman intelligence is even possible at this point. It could be algorithmically limited in ways we haven't discovered yet.
Full brain emulation is probably possible, but we don't know if it will be cost efficient compared to baseline humans.
Likewise AIs smarter than humans might be possible, but we don't know what the tradeoffs would be. Maybe they will lose coherence at larger scales. Maybe they will have high levels of goal drift making them functionally useless.
The other thing to consider is that the universe is still very very young vs our best estimates of its lifespan. We are roughly 14 Billion years into something that may very well be going for 100 Trillion years or more.
You're really just making an even more extreme assumption - that human cognition is the peak possible intelligence - biological or technological - based on zero evidence.
It's much more reasonable to assume we are not perfect and maximally intelligent.
> This is like ants arguing that life outside their ant hill will likely have 6 or 8 legs because all the life they've seen so far have had 6 or 8 legs.
I wouldn't scoff at those ants. Ants who conclude life outside their anthill will have 6 legs would be mostly correct. 90% of lifeforms on earth are insects.
Anyway, my guess is that life at least as intelligent as us exists out there somewhere, and that more technologically advanced than us is possible too. But interstellar civilization, from what we are today? I don't think so. I think we're already in the "great filter", which I suspect to be the speed of light and our developing addiction to low latency communication. Turning ourselves into AIs or something won't solve that problem; if anything it would only make it worse. The more intimate our relationship with computers becomes, the more insular our civilization becomes.
> This is like ants arguing that life outside their ant hill will likely have 6 or 8 legs because all the life they've seen so far have had 6 or 8 legs.
I've never liked this kind of argument because ants don't argue. So you're saying that the thing that we're doing is like something else that doesn't exist, and using that impossible connection to draw a larger conclusion.
Ants don't argue because they don't have brains to do so. We argue because we have the brains to do so, and those brains allow us to do so much more like actually measure and interpret the world around us to draw the kinds of conclusions that you're seeing here.
Even if ants could argue with each other the question would become are they arguing about anything relevant? Can they measure and reason about the world around them? Can they do science?
Moreover, SETI really only detects signals intentionally sent straight at us (beyond a small bubble of a few light years where only a handful of stars exist). It's not powerful enough to detect ambient EM radiation around other stars.
The only conclusion we can derive from SETI results is that no one is beaming a signal at us intentionally and continuously.
Is your reasoning similar to this being said earlier in our history?
A post-biological flying machine is purely speculative science-fiction at this point, there is not a single real example that we can point to yet. This might one day change if we become a post-biological flying civilization, but so far not a single example of such has ever been seen.
Suppose the year is 1770 and I am a sailor on one of Captain Cook's expeditions. A fellow sailor breathlessly tells me about the advanced civilizations with flying machines we might encounter, reasoning that such constructions are theoretically possible according to science and extrapolating from extant technology. I'd tell him that I expect nothing of the sort.
I'd also concede that such technology might one day be created: " This might one day change if we become a post-biological civilization, but so far not a single example of such has ever been seen."
So far? No evidence for it. So far, it's only science fiction.
In that case your conclusion shouldn't be that civilizations are only biological. Your conclusion should be: because we have not observed life outside Earth, the more likely thing is that there is not life outside Earth, not that it's biologic.
But I think that you are using correctly your likelihoods but forgetting your priors. The prior in this case is: there is no reason that we know for this not to happen, so, it has to be happening somewhere.
> Furthermore, we're unlikely to ever encounter life outside our solar system anyway.
Eh idk man. If what's been spoken about for decades by seemingly credible government, IC, military, and private officials across the world, and if what Chris Mellon and Luis Elizondo have continuously been hinting at/breadcrumbing/speaking to over the last few years comes out, we already have.
"What does a cosmic-spanning-AI want to do with its life"
Reproduce, evidently, or it wouldn't be cosmic-spanning.
But: of what use is intelligence if you just want to span the cosmos? Would evolution favor less intelligence over more if the goal is just to spread at maximum rate?
There are many things intelligence might be good for. Adapting to an environment that is uncertain and changing would be one. The better you are biologically adapted to your niche, and the more stable your niche is, the less intelligent you need to be. Cooperation would be another. The more social your species is, the more you need to be able to coordinate with one another, which means being able to communicate. Competition with other intelligent forms might be another. Intelligence could be seen as an arms race where in order to beat out the tribe next door, you need to out-think them.
Humans tick all 3 boxes. We are social animals who survive by cooperation, but in a rapidly changing world full of other intelligent animals who are always competing with us for resources. That's a recipe for intelligence. You will find extraterrestrial intelligence in situations where similar forces are at work.
I take it you're referring to artificial intelligence by human standards? Homo sapiens have only been around for ~300,000 years. Should there be an intelligent species/civilization that's been around much much longer, then it's likely they've advanced to develop true artificial intelligence.
When considering the spread of post-biological intelligence we should also spend some time thinking about what the substrate on which it exists would look like. Even just working out a likely size for such a substrate would be informative. It might turn out that we are looking for relatively small objects in orbit around stars. Would we even stand a chance of finding a single such object? Could there be one orbiting the Sun? If so, there could be an alien civilization with trillions of individuals existing in our solar system. We'd have little chance of contacting them unless they decided to speak to us or we managed to accidentally identify them through a telescope.
There was a research paper that described AI robots the size of a toaster traveling from star system to star system (and galaxy to galaxy).
It is difficult to imagine how we would detect those - even if many orbited our sun. ...but if they exist, they likely already detected us and have relayed the fact of our existance.
Agreed. It makes sense to me that biological life would be a transitory phase and that eventually one might be capable of moving beyond those limitations.
At that point, all your civilization needs is lots of energy, some raw meterials, and probably a purpose, be it scientific discovery, novelty, exploration...etc. That's assuming the intelligence is anything like humanity.
Self replicating AI maps closer to a virus than what we consider life I think (maybe our definition is wrong). But I can't substantially articulate why. No matter how i think about it there are exceptions and examples of things we do call life that are similar to an AI. So maybe it's just my inherit bias because I am biological.
You are correct. AI needs biological life to produce energy and means of replications for it. That's how virus depends on cells of living organisms. It is concerning how some persons all around the internet keep pushing someone's narrative about humankind not having right on independent existence and having to be only a supplier of resources for the emergence of AI.
I know you said post-biological, but I sometimes ponder if the bacterium could be that self-replicating machine, extracting into intelligence through natural selection.
Small replicating probes at high fraction of C sound good on paper. In reality, there is interstellar matter that can destroy your high-fraction-C small probes when colliding. Space radiation will deteriorate their condition as well. Do yourself a favor and educate yourself about space radiation. It's really bad in the interstellar space. Even your favorite AI creatures need protection from it.
> What does a cosmic-spanning-AI want to do with its life
For those that have a tendency to exist: Survive and propagate.
If something other than perpetuation of the essential forms and patterns that constitute the entity motivates it, then it will be more likely to cease to exist. Or be replaced by any variation that is more strongly motivated and capable of surviving and propagating.
If Earth were directly in the path of high powered radio signals sent by EI long ago, would it all be undetectable to us if it were encrypted?
It didn’t take long in our tech evolution for SSL to become ubiquitous. Surely the entire SETI program and decades of effort is not premised on aliens not having HTTPS?
>> would it all be undetectable to us if it were encrypted?
Encryption as far as i know does not deal with hiding information in background noise of communication channel. So most types of encrypted communication still can be detected (but not understood).
You would need aliens that are actively hidding their communication inside of natural phenomena, which is a little bit of a stretch to me.
>> Encrypted data should appear no different than random noise right
As far as I know its not true - usually there are statistical anomalies that gives away encrypted data.
The other part is the the randomness of background noise of the universe. Can anybody give some input here ? I do not really know this but if I had to guess the universe does not generator true randomness but some signals that can be recognized as natural background signal?
abiological intelligence has a much larger set of possible habitats. Given the vast possibilities of virtual spaces it's somewhat unclear to me why a post-biological intelligence would even be interested in spreading across the galaxy beyond a few observation outposts.
"A" post-biological intelligence? Why would there only be one?
A post-biological intelligence would want to migrate to another system so it can build its own hosting substrate and increase its own resources without fighting with someone else. (Well... at least initially.)
Explanations based on "oh, they'd never want to do that" need to explain not why "a" post-biological intelligence might conceivably under some particular circumstance not want to spread out, but why all the post-biological intelligences never do. That's a much harder argument to make.
> ...why a post-biological intelligence would even be interested in spreading across the galaxy beyond a few observation outposts.
Continuity of species against some catastrophe with a solar system scale blast radius. You can keep that train of thought out to multiple solar systems, galactic arm, galaxy, supercluster, and so on.
Hopefully curiosity will always be around. I personally would love to have a few billion years to explore the universe (at least, if I could find a way to skip the boring transitions between planetary systems).
This is something I've thought about on and off for awhile.
For completeness, I believe that the speed of light is a hard limit (and no I don't believe in any end-runs around this like warp drives, folding space or wormholes). Secondly, I accept the laws of thermodynamic.
Given this traveling between stars takes an incredibly long time. At a high percentage of c you get time dilation but that's not actually a practical travel speed for a few reasons:
1. The energy cost of accelerating to 0.99c and decelerating at the other end is extraordinarily high;
2. If you even can get to that speed, small objects in the interstellar medium become life threatening; and
3. Beyond about 0.86c gas in the interstellar medium actually creates drag making acceleration even harder.
Given the reaction mass problem, it creates a big question of how you'd actually travel between stars. The more you carry the more energy you need to accelerate and decelerate it. It's likely you'd need fusion at a minimum and possibly some far-future tech (eg antimatter, black holes).
So what do you do? Well, there are rogue objects not bound to any solar systems. We've seen some of these. We can't easily detect them so can only speculate on how many there are but it's likely to be a fairly large number.
So what if you opportunistically wait for one of these objects to travel through the Solar System and then hitch a ride? Imagine a planetoid 100 miles in diameter. That's likely all the resources you'd need. It then becomes less of an issue that it might not reach another star for 100,000+ years because your attitude is that this is a new home.
Obviously you still have to match velocities with this object but that's vastly easier to do with a bunch of people and equipment than it is with those same things plus all the same materials that are already traveling at intersellar speeds.
If you've solved the energy problem of accelerating most of a human colony and its gear to interstellar object speeds, do you really get much from trying to hitch a ride on such an object? You've also presumably solved energy storage so the time spent waiting for a suitable object you might as well spend on storing energy to accelerate an object at hand.
Good point. The only advantage that occurs to me is that you could spend the journey (waves hands) converting the interstellar object into reaction mass to enable deceleration at the other end. And maybe also for course correction, because the object is very pretty unlikely to be going anywhere interesting just by chance
I typed slapdash things into Wolfram Alfa just to get a sense of the kinetic energy of something like a 100km metal sphere buzzing as at 40 km/s (it's a screaming chonker of an overestimate but hey) and got something like a millionth of total yearly solar output or 1/5th of lunar kinetic energy (orbiting earth). As D. Wooderson famously said, we're talkin' some fuckin' muscle, to ride such a thing. If you have it, you might even be better off just taking the moon instead.
So for a colony to last centuries in interstellar space with little to no prospect of resupply of any kind, you have to build in an awful lot of redundancy. You also need to cater for growth. You need a lot of infrastructure for long term care (eg hospitals). What you're building is living quarters for a thousand years over multiple generations.
But for a rogue planet you need far less. Consider the Moon. It has lava tubes. You can seal these, fill them with air and live in them. You don't need to accelerate that living space. Sure you still need to bring some things but it's far, far less.
What's more, if you have several such settlements in different lava tubes you have automatic redundancy. A single catastrophe won't snuff out the entire colony.
So for a true interstellar colony you really have to build a fleet because a single colony is too big of a failure mode.
A colony of fleshy biological creatures in an unsuspended form?
This seems silly. Even if intelligence remains biological (which I find exceedingly unlikely), then why wouldn't you just freeze them? That's a lot easier than moving a PLANET.
FYI - rodents can be frozen and revived. There's no fundamental reason you cannot freeze and thaw a human.
You still need to accelerate and decelerate and you need to alter the course of this object to match your course. But you get all the resources for almost free.
How would this compare to a raft of asteroids you select in your home system to have the exact stuff you need and the accelerate it? I realize there's differences in mass here but I am asking is it material given the scope? Because you are kind of guessing what is going on with that rogue planetoid but the asteroids you could select at your leisure and also hollow out easily while you are in your home system with access to orbital factories, etc.
Anyway, fun thought experiment! I totally agree that you would have to approach this as if this is your new home and you MIGHT get to a planetary system you could also colonize at some point. Generations in that idea might seem as foreign as living on a colony flotilla.
Even on the issue of accelerating and decelerating to a system you fly through or near, in the case of a colony ship you would need to carry that fuel and pay the energy costs for housing it, accelerating it and decelerating it.
With a rogue planet you should be able to refuel from that rogue body so your fuel payload required is really only to get to the rogue planet.
It seems like there is an implicit assumption in both article and comments that interstellar travel necessarily involve living things. If a civilization is willing to put possibly millions of years into waiting and preparing for a wandering planetoid, why not launch robotic ships with the equivalent of frozen embrios onboard? The timescales involved are pesumably much longer than the life of an individual anyway, so the end result should be no different.
I propose that extraterrestrial civilizations may use free-floating planets as interstellar transportation to reach, explore and colonize planetary systems.
Is it just me or is that completely idiotic? It's like building a spaceship whose mass is 99.99% inert. Migration is incredibly unlikely to be a thing on interstellar scales unless some kind of magical transport is discovered. That is because, under almost any conceivable schema, it takes less energy and resources to sustain an individual for its entire life than it takes to transport that individual to another solar system. Advanced civilizations may very likely spread to other solar systems, but there's no practical reason to migrate.
> That is because, under almost any conceivable schema, it takes less energy and resources to sustain an individual for its entire life than it takes to transport that individual to another solar system.
I've thought about this in relation to colonizing other planets in our solar system let alone ones in another one. I'm of the opinion that we'd be better off building orbital habitats similar to the ISS and then iterating on those until they can house more people safely, become more and more self-sufficient, and we have the ability to put them into solar orbits and/or making them self-propelled. I always assumed we would populate earth orbit and bases on the moon first, then expand our infrastructure to be able to mine metals from asteroids and start building larger space stations outside of earth's orbit.
If Mars were more Earth-like I could see pushing for that first but I think we're getting ahead of ourselves. There is solid ground we can build on, but the atmosphere is almost non-existent, the radiation is incredibly high, water is scarce, it's a long way away, and there are two gravity wells to deal with. Unless we're talking about terraforming Mars, which is an even larger project than colonizing it, we're still talking basically people living in the equivalent of tin cans.
In terms of people living off of our home planet it seems to me that we could increase the population much faster in space stations and lunar bases than we would be able to do so on Mars.
If I were a billionaire space tech guy, I'd be working toward O'neil cylinders instead of Mars colonization.
I'm not a space scientist or an engineer, though. Or a billionaire, sadly enough.
> If I were a billionaire space tech guy, I'd be working toward O'neil cylinders instead of Mars colonization.
While I agree with you in the longer term, I don’t think we’re even close to ready to build O'Neill cylinders. First thing I’d go for would be a lunar colony. Lots of useful resources, relatively short trip home in emergencies, a way to get experience working in real vacuum, and non-rocket launch systems could already be built there with current tech.
It's just you. There may be various reasons for a civilization to leave its planetary system. Its host star may be dying and turning into red giant. A nearby star may be close to going supernova or hypernova. The civilization may send its own space explorers on a passing by free-floating planet. For example, if the civilization's scientists determine that there is a hypervelocity free-floating planet passing through their Oort cloud and heading to a nearby star, they may send their machines to ride the free-floating planet to that star to study it. Why would not they catch a ride when an opportunity presents itself?
> I propose that extraterrestrial civilizations may use free-floating planets as interstellar transportation to reach, explore and colonize planetary systems
If you can muster enough energy to accelerate a planet, you probably don't need a planet for migration in the first place.
Also, the planets would get cold during the journey. Very cold. You'd better pack a load of welding kits for the brass monkeys.
The Puppeteers took 5 planets with them when they found out about the galactic core explosion. It honestly sounds like the guy who wrote this just finished Niven's known space series.
Not unless you’re orbiting the supernova-ing star. It’s easier to put a big thin metal sheet between your planet and the exploding star to block the radiation, than to evacuate a billion people.
As has been show in other research, a post-biological species can more easily send small replicating probes at high fractions of C in order to populate other star systems (and even other galaxies) within a small fraction of cosmic time (meaning it would have already likely happened in the Milky Way).
Large populations need not be sent. So the question becomes the meaning of life. What does a cosmic-spanning-AI want to do with its life - and how do we detect that?