I’m not k9bfriender, but it seems obvious to me that they are making exactly the opposite argument. The apparent fact that intelligent aliens are not spreading self-replicating habitats through the universe is a significant data point, one made by Tipler and Hart in the late 1970s.
The fact that we don’t see any self-replicating habitats or other infrastructure in the galaxy (or their remains) suggests that this strategy has never been followed in the history of the galaxy; a data point that needs explanation. And yes, there are many explanations possible for this data point, but we don’t yet know which one(s) are correct.
The most puzzling thing about the Fermi conundrum is that we do not see these aliens everywhere; if aliens are commonplace and expansive, they should have been here for millions or billions of years. They should be us - we should be part of their galaxy-wide civilisation, and we should be studying their history in our schools.
Imagine for a moment a future where only a minority of Humanity lives on Earth, or on the surface of any planet. Most live in artificial habitats - a spinning metal tube inside a tunnel dug into an asteroid at the low end, massive space stations with the interior surface area of a small country on the high end.
Imagine that there are millions of these habitats all over the solar system. Most are in orbit of Earth and the moon; others might be orbiting Venus or Mars, Jupiter and its moons, or in the asteroid belt. Some few might orbit the other planets, or the sun directly. Some may even have highly eccentric orbits like a comet. And some will even be all the way out in the Kuiper Belt.
Even in the inner system, light lag is a serious concern that would make live conversation impossible. By the time you get to Pluto and the Kuiper Belt, light lag from the sun is around 5.5 hours, and the Kuiper Belt goes out twice that distance. There’s tons of resources there (they’re spread out, and you won’t be populating the Kuiper Belt as densely as you would the inner system; but it’s also orders of magnitude bigger).
What kind of central authority is going to be monitoring milliond of habitats and trillions of people? How, when loght lag is such a serious concern?
And once you’re living in the Kuiper Belt, the resources don’t just stop. The Oort Cloud is even more spread out than the Kuiper Belt, but there are trillions of objects out there. Some could even be quite large. How do you stop a habitat in orbit of a body twice as far as Pluto - one of thousands or more in the region - from deciding to start building a new habitat around another dwarf planet another few AU away?
The Oort Cloud spreads out about 3 light years from the sun. Proxima Centauri is about 4.4 light years away. That means that pur Oort cloud and theirs overlap.
Someone living out at the Kuiper belt will never have seen the sun as anything more than a large star. Someone living in the Oort cloud would probably need our sun pointed out to them to know that it is special to them in any way. Why would someone living that far out, whose ancestors for many generations all loved out in the void in this way, hesitate to keep hopping from icy body to icy body towards Proxima Centauri? To them, they’re doing exactly what they’ve always done - finding a mineral-rich body, digging into it and sticking a rotating tube in the tunnel to live in, then harvesting nearby bodies. And in fact, the region between us and nearby stars is undoubtedly richer in such bodies than other regions, because these are places where leftover junk from both solar systems overlap.
Gradually, with little fanfare, these colonists realize they are closer to Proxima Centauri than Sol, and eventually some future generation may decide to go further, and find whatever mineral-dense region of space the Centauri system has created.
A million years is a LONG time. Plenty for this process, taking millenia each time, to repeat itself - solar system by solar system - across a huge chunk of the galaxy.
I am not sure if this question belongs here - it is closely related though. If deemed to be off-topic my apologies in advance.
Time is an intimately personal “possession” of massive particles - no two particles can have the same “experience” of time because of the history of their motion from the moment of creation.
A proton was ejected by a supermassive black hole at 99% the speed of light. Another proton lives in a cell in my body and has a far more sedate lifestyle. Due to relativistic time dilation, these two protons would not agree on the amount of time that has passed since the Big Bang (or following any arbitrary event since then). Similarly for particles climbing out of a gravitational well. Heck, even a particle in the earth’s ionosphere mark time faster than us on the ground.
Because we humans are co-located on planet Earth, the history of motion of the particles constituting us must have been largely similar since the BB (after all we find ourselves in the same part of the Universe, on the same planet). So maybe we could meaningfully say “13 billion years have passed since the BB.”
However this does not apply to the distant Universe, which could be constituted of particles with a very different measure of elapsed time.
There is no fixed observer that measures time in the Universe. So how is it meaningful to claim a certain amount of time has elapsed since the BB?
“Young” or “old” implies a fixed measure of time relative to something - my point is there is no such fixed measure at a cosmological level.
Well, I think you are absolutely correct. There’s no common frame of reference in the universe, especially when you consider distant galaxies with high redshift.
Here’s a diagram of the different measures of time and distance in the universe; sometimes I look at this diagram and think I understand it, and then it slips away, like one of Dali’s melting clocks.
I think I see the divergence in thought here. So I say it is not easy to seed the galaxy with replicating robots at relatively little cost. I don’t think anyone actually knows a way to do it at very high cost either. It’s a sci-fi dream. I don’t see much of a future ahead for humans past getting control of population growth and monumentally bad ideas so our ancestors can survive here on earth and very minor use of space off planet because that is all we will be able to do. Only uncontrolled population growth would cause intelligent beings to try to colonize or exploit the universe, and uncontrolled population would prevent them from ever dedicating the resources to trying to seed the universe with self-replicating machines. I don’t see a reason to assume that just because intelligent beings exist they will attempt to harvest the universe for a purpose still not explained, and that they will ignore the danger that broadcasting their presence to the universe causes them. The hypothetical ability to create self-replicating space probes doesn’t so easily translate into their existence.
I think the mediocrity principle indicates there are other intelligence beings in the universe, not that they are nearby in our neighborhood or that they have done something that would allow us to detect them in the very brief period of time we were capable of such detection so far. There may not even be any other intelligent beings that have evolved in our own galaxy, it’s not as huge and populated with stars as always imagined, remember that there are more trees on earth than stars in the Milky Way. The most likely, and non-paradoxical reason we haven’t detected any aliens yet is because they are not as common and nearby as we think. Eliminating our mistaken assumptions is the way many paradoxes are resolved.
Well I would take that bet, if there was any way to collect.
Humans are very new to the space game; there are people alive today that were born before Sputnik 1. Yet now we can land probes on asteroids. And, in the meantime, we’ve developed many other enabler technologies like electronic computers (going from nothing to a supercomputer in everyone’s pocket) and crude digital fabricators.
Essentially, what you need to assert, in the context of the Fermi paradox, is that even a species the equivalent of millions of years ahead of us would shrug and tell us that the last required piece: mining an asteroid is impossible.
Because if someone gave 21st century humans some kind of device that mines and sorts material from an asteroid, we would be ready to try making a self-replicating robot ourselves. It’s pretty much the only remaining piece.
I guess Armageddon was right, and the only way to mine an asteroid is to hire Bruce Willis and a ragtag team of oilfield engineers.
I have not made such a claim. I have simply said we do not see aliens doing anything for any purpose.
This alludes to the Dark Forest argument. I think that argument is flawed, but it’s a long explanation, so I’ve leave that for a separate post.
Side question: Apparently it would take millions of years for self-replicating probes/robots to cross the galaxy. I know nothing about computer programming, but I assume the probes would need rather complicated coding to perform the tasks that are needed (replicating, communicating, mining resources, etc.). I understand that each generation of probes would be freshly minted from element harvesting, but what about the code? Would there not be a significant accumulation of copy errors over millions of years, rendering the probes inoperable long before populating the entire Milky Way? Can any code last millions of years and countless replications?
I think you’re trying hard to think of an insurmountable engineering challenge to making replicating probes because you don’t like the implications.
Let me be clear: I don’t like the implications either. I would hate to think we’re the only sentient species. And I would hate to think this immense, beautiful galaxy could be polluted with billions of probes in mere millions of years.
But the universe doesn’t give a shit about my likes, that much has been clear from my infinitesimal time on this planet.
We have to just follow the data, and right now making self-replicating probes definitely looks like one of the easier problems for an advanced race to solve. You wouldn’t bet against humans being able to do this within centuries, let alone millions of years.
Well you can have shielding, both passive and active, and you can have redundancy (e.g. 50 copies of the code, and a repair that kicks in any time one copy gets out of sync). Active shielding and code correction both require power, but the machine is not going from one side of the galaxy to the other in one shot; it only needs to get from one star to the next.
So in fact, this probably belongs to the set of problems humans could solve already. We could probably make a computing device that could survive a few thousand years of interstellar space, given essentially no weight constraint (because, in this context, it’s fair to assume the probes will be launched from space, by a species with access to large amounts of energy).
Organic has advantages over inorganic. Would you rather have a skeleton made of bone or a material somewhat stronger than bone? I’d rather have bone because bone self-repairs the continuous micro-fractures that would otherwise cripple people after a few years. (Materials like titanium are an exception because it can last a human lifetime without fracturing).
Who says our self replicating AI probes will be inorganic? Biological engineering, computer engineering, and materials engineering are all coming together in amazing ways. Give us a few thousand or million years, who knows what we will accomplish?
True, but that can be said about anything. Maybe FTL travel is a minor hurdle we will leap in a thousand years. Maybe magical unicorns will be bred and kept as house pets.
Slow to respond because my internet connection went down. But that just bolsters my point. If the internet was organic it would have repaired itself before failing.
I think there is a universe of difference between our small scale, often flawed technology and seeding a galaxy with self replicating probes. I think that self-replicating thing is much more difficult when we are talking about real machines which have to traverse the stars and a computer virus released into environments we still haven’t figured out how to secure safely. Maybe those aliens don’t show the human trait of making mistakes and they’ll do much better than us though, I leave open that possibility.
On that we agree, we disagree on the logical reason for that. I say it’s something simple like they haven’t got here yet or they are hiding from our very poor eyesight. You seem to think it must be some much more complex or mysterious reason.
Which is why I think organic computers is a speculation that Babale didn’t need to make here.
The only revolutionary (as opposed to evolutionary) technology needed for self-replicating robots is mining and sorting material from an asteroid sufficient to make two more probes.
I guess someone could argue that that is the fundamental block that even millions of years of technological progress would ever solve. No-one has bitten that particular bullet yet.
My point isn’t that biological engineering is the best way to make self replicating machines; my point is that we know that self replicating machines are physically possible, and in fact they’ve spontaneously assembled themselves at least once that we know of. So it’s not like self replication requires some huge physics-defying leap - it’s already commonplace. FTL on the other hand is something there is 0 evidence for in the universe and plenty of evidence against.
I don’t think anyone has managed to show this yet though. As I say, if we could mine and sort material from an asteroid then we’re already there in terms of being able to knock together a prototype of this. Then imagine millions of years of progress – thousand of times more technological progress than all of human history.
Sure, maybe some don’t make probes. Maybe almost every alien ever thinks it would be a bad idea.
But again, in terms of the Fermi paradox, your argument is the one that requires that every faction, of every civilization, of every species, always, for millions of years, to behave that way.
The counter argument doesn’t need to posit such an absolute consensus.
And I gave arguments why we should doubt such explanations.
For “not got here yet”, they a) don’t necessarily need to come here; the Fermi paradox is about any observation of life anywhere and b) the scenario of advanced life being common but none having had time yet to spread around the universe is extremely specific (that advanced life can easily develop but only after 13,700 million years exactly. If life could have developed after 13,699 million years, we have a problem).
For “hiding” you run into the “everys” again: you need 100% consensus among every intelligence for all time.
Yeah, there’s nothing mysterious about “life and/or intelligence is so rare that no advanced alien civilizations exist anywhere in the observable universe”.
