Fermi Paradox & The Dark Forest
This is a possible solution to the Fermi Paradox which is detailed in Cixin Liu's book, The Dark Forest, which is the sequel to The Three Body Problem.
The idea is that although intelligent life may be common in the universe, several factors create a chain of suspicion:
1. Each civilization has its own separate biological and cultural evolution.
2. Rapid technological progress occurs once a species reaches a certain level of development.
3. Any other civilization may be hostile and capable of doing harm once they are advanced enough.
4. Communication across space and cultural/biological difference takes a significant amount of time.
5. Advanced civilizations will be looking to expand.
Therefore, the safe bet is to remain silent, and preemptively attack anyone who makes their presence known. And that's why the cosmos appears empty.
However, humans don't appear to think this way, for the most part. We want to find evidence of aliens and make ourselves known. So the question is whether the reasoning above is fallacious, or whether humanity is just naive.
Of course, we could also be alone. I'd prefer that over a galaxy full of suspicious aliens, waiting to take us out. That's depressing, even if we managed to stay hidden. At the beginning of the first book, a helpful alien sends a signal to Earth, warning the sender to not reply. Imagine SETI receiving such a message!
The idea is that although intelligent life may be common in the universe, several factors create a chain of suspicion:
1. Each civilization has its own separate biological and cultural evolution.
2. Rapid technological progress occurs once a species reaches a certain level of development.
3. Any other civilization may be hostile and capable of doing harm once they are advanced enough.
4. Communication across space and cultural/biological difference takes a significant amount of time.
5. Advanced civilizations will be looking to expand.
Therefore, the safe bet is to remain silent, and preemptively attack anyone who makes their presence known. And that's why the cosmos appears empty.
However, humans don't appear to think this way, for the most part. We want to find evidence of aliens and make ourselves known. So the question is whether the reasoning above is fallacious, or whether humanity is just naive.
Of course, we could also be alone. I'd prefer that over a galaxy full of suspicious aliens, waiting to take us out. That's depressing, even if we managed to stay hidden. At the beginning of the first book, a helpful alien sends a signal to Earth, warning the sender to not reply. Imagine SETI receiving such a message!
Comments (108)
(5) contradicts the conclusion. Civilisations can't be both aggressively looking to expand and remaining silent only pre-emptively striking targets who make themselves known. They must be doing either one or the other.
Accepting the principle that advanced civilisations are looking to expand, you'd not expect the universe to be silent, you'd expect it to be full of the colonisation attempts of advanced civilisations. Given that the universe is silent, there's no reason at all to maintain the premise that it's full of advanced civilisations aggressively looking to expand.
Not only that, but we only have experience of one civilisation...ours. That one civilisation is not looking to aggressively expand into space (yet) it's looking to make contact with aliens largely out of interest. When a theory is falsified by 100% of the available evidence, I think it's time to discard the theory, no?
The Martians were a bunch of Hungarian physicists under the leadership of Ede Teller, who worked on and built the H-Bomb for the USA. They were called the Martians, because they were obviously strange, and an advanced race (haha) of scientists.
Anyway, their upshot was that civilizations on distant planets learn to build H bombs, and then a strife will make them use them, thus annihilating themselves.
Remember, this was back in the Cold War period, in the 1950s, when global thermonuclear war was a real threat.
Today, so the experts claim, nuclear warfare is not going to happen by those who build and control these weapons, but by those who gain control suddenly and for a short time. I.e. terrorists who steal them.
Luckily, they are not easy to detonate. They require advanced skills to make them blow. Not like pulling a trigger on a gun.
I'm no expert on this sort of thing, but isn't SETI listening out for radio signals and the like? Presumably other civilisations would be doing similar things? So we'd have to image some incredibly specific technology that would allow an alien force to invade and colonise another planet thousands of light years away without producing a single communication wave detectable by the superior technology of more advanced races.
Basically, if we're best off keeping quiet rather than attracting aliens and defeating them with the weapons we've got, then any alien is in the same position. No one can know that they are the most advanced civilisation around, can they?
For example, A nuke won't do any good against matter tightly packed together by the strong force, similar to that of a neutron star. That would probably require advanced femtotechnology to construct your own form of matter.
Good stuff:
Yeah, that would seem to be the likely outcome. There would be a few super-predatory civilizations with some primitive ones like ours that haven't attracted attention yet. Everyone else was taken out.
The first advanced civilizations in the galaxy would have had the upper hand, and the ones that acted most aggressively would likely have prevailed. That makes more sense than there being a million civilizations keeping quiet. And as you said, how would they know to keep quiet before it was too late?
I hope that's not actually the case as I prefer Sagan's Contact version or Clarke's monolith aliens better. Also, because we're likely screwed if it is the case.
Cixin Liu's aliens with advanced weaponry would scream and run in all directions when we introduce our deadliest weapon: THE HOUSE ETHICS COMMITTEE!!!!
Beware you scurvy dogs, Aliens!! (Is "Aliens" an alias? their name may well be Elias.)
I preface the following by confessing my love for the trilogy and strongly recommend these books.
Plausible, as far as they go ...
Bingo.
Hold on. What warrants such (a terrestrial) assumption?
I don't buy it. Doesn't follow. Above #4 much more plausibly accounts for 'the great silence' and 'apparently empty cosmos' than any other (mostly speculative) guesses.
Both.
Possibly. Not likely. Here's why I don't think we're alone -
(I quote some old posts in full from the now defunct Philosophy Forums which still expresses my thinking on the Fermi Paradox in a separate post following this one.)
Even more depressing would be "a galaxy full" of alien intelligences [ETIs] that do not 'recognize' any planetary biosphere as more sentient than lichen-covered stones or pond scum. And, therefore, act accordingly.
Imagine SETI has already received a Do Not Reply To This Transmission message - maybe many times over some decades - but has lacked, and still lacks, the digital bandwidth and computational resources to translate the message, or filter the signal from noise (i.e. cosmic background radiation), in order to 'recognize' it as a message. What if, and then what?
[quote=Marchesk]Of course, we could also be alone.[/quote]
Possibly. Not likely. Here's why I don't think we're alone (it's a bit of a ramble) -
(i)
[quote=180 Proof, 2-17-07]I find it exceedingly difficult intellectually to accept that sapience in this universe is unique to Human Beings. The reason for this is predominatedly empirical (i.e. specifically convergent scientific evidence): the more rigorously we've observed the non-terrestrial universe the less we find non-terrestrial exotica "out there" as the same physics & chemistry which apply here more & more apply everywhere that we can observe; and though biological phenomena is the product of local, irreversible evolutionary paths, the physical & chemical precursors/conditions for biologies to emerge are, it seems to me, ubiquitous; and where there's a biology there's eventually an ecology and eventually critical disequilibria which catalyze adaptations which stumble upon "sentience" and then degrees of "sapience" as niche-transgressing prizes in the evolutionary lottery. I can't imagine that other celestial objects made up of sufficiently chaotic physical & chemical systems-processes don't give rise to their own particular biological histories (i.e. evolutionary paths), of which some are, at least, as robust as Earth's. It seems to me that everything we're learning about the universe reasonably points in the direction of the non-uniqueness (though perhaps not "ubiquity") of biological phenomena however sparcely distributed thoughtout the universe.
And then there's the assumption that biology is not required for sapience. Computational & information theories raise the issue of plausible "functionalism" as well as such constructs as "artificial life" and "artificial intelligence" which have begun to converge with fundamental physical theories (e.g. quantum mechanics, general relativity, statistical thermodynamics, etc) in working out a new paradigm of informational or algorithmic physics (e.g. quantum gravity, quantum computing, etc) that strongly implies -- as far as I can tell -- that "biological" conditions (i.e. substrates) are not necessary for sapience. Thus, though non-terrestrial "life" might be astronomically remote, and emergent non-terrestrial "intelligence" even exceedingly rarer still, I think the "circumstantial evidence" for the plausibility of nonbiological intelligence -- non-terrestrial (and maybe terrestrial too!) -- is coming to the fore.
I'm less & less persuaded as the decades pass and we learn more about the universe and refine our physical theories (to the extent the gist of them is intelligible to a laymen like me by the good graces of popularizing scientists) that we are alone -- that both biological phenomena (i.e. "natural selection" & ontogenic sentience) and sapience (i.e. "intelligence", whether biological or not) are unique to this planet. It's the height of blinkered, atavistic chauvanism for Human Beings to hold on to this last shred of unwarranted self-importance after all the decentering blows delivered to our superstitions down the recent centuries by the likes of Copernicus, Galileo, Spinoza, Newton, Hume, Darwin, Boltzmann, Einstein, Goedel/Turing/Von Neumann/Chaitin, Shannon, Saussure/Levi-Strauss/Chomsky et al.[/quote]
(ii)
[quote=180 Proof, 3-12-07]Energy is always the goal. Stars and gas giants have what ETI Machines need, not cool, little wet mudballs, covered with narcissistic slime like Earth. And maybe we're lucky we're still very low on the energy-food chain. I wouldn't be surprised if They are passing regularly through "our space" like schools of fish through coral (i.e. we being the coral that only recognizes other coral and maybe crustaceans and seaweed, only (other) slow moving bottom-feeders like us ...) Nonbiological sapients would take no more notice of us, I think, than we take notice of pond scum.
Btw, deep space travel is for machines -- the tinier the better -- Von Neumann self-replicating/nano-fabricators, and not living organisms (e.g. hard radiation exposure is too lethal, transport size increases likelihood of hazardous particulate impacts, life-support limitations & extreme durations between destinations, etc) which exponentially compound the costs/risks.
(I'm making an educated guess about the current needs of any spacefaring intelligence. To span interstellar distances enormous scales of "time" and inexhaustable quantities of "energy" are absolutely necessary ... the physics of the real world is undeniable: in an astronomically vast & empty universe, accessible and usable "energy" is the only game in town.)[/quote]
(iii)
[quote=180 Proof, 4-27-14]Just a guess but ... there's nothing on Earth that an "advanced alien civilization" can't get in exponentially greater abundance, and uncontested,elsewhere between here and wherever "they" are coming from.
Also, "they" will be machines capable of interstellar travel, intelligent (probably Von Neumann-like nano/femto-assembler) probes sent out to -- at minimum -- (A) survey-catalogue-archive all anomalous (e.g. biotic) aspects of the galaxy, (B) transmit - narrowcast - the data-archive back "home", (C) warn of (and neutralize if possible) any -- even though highly improbable -- threats to "their civilization", (D) operate as stealthily / covertly as possible (in order to safeguard "their civilization"), and (E) self-destruct to avoid capture or when dysfunctional beyond repair (again, in order to safeguard "their civilization").
So 'first contact' will probably be the result of fortuitous eavesdropping on signal-leakage from some ETI probe. It won't be a message meant for us, and it won't have to be, or even decipherable, for us to recognize it as a non-natural EM pattern against the natural EM static background. Maybe our receivers / telescopes aren't sensitive enough yet, don't have sufficient bandwidth, or our computers are still just too "dumb" to detect a signal-needle in the galactic-noise haystack. We may never find / detect "them" or be disrupted by "their" errant, though unmistakable, signals; the odds, I believe, increase ever so slightly, however, if and when we launch intelligent probes of our own out to explore the Kuiper Belt & then Oort Cloud, because that's where "alien" probes will be if "they" are here. This scenario of 'first contact' is ambiguous, therefore immeasurably risky, because it'll have to be conducted by mutually alien A.I.s, or intelligent machines, both free of evolutionary-planetary constraints & priorities, where any consequences of such an encounter will be relatively far more impactful for Earth than for that astronomically distant "advanced alien civilization".[/quote]
(iv)
[quote=180 Proof, 6-14-15]"Any sufficiently advanced technology is indistinguishable from nature."~Schroeder's Law
It's [statistically] reasonable to assume that given the age of the universe and our extremely recent arrival on the scene, we're just not yet sufficiently advanced technologically to detect sufficiently advanced technological civilizations the signals of which are indistinguishable from natural background radiation [noise], and by the time we develop to sufficiently advanced enough technology to detect ETIs, they won't matter to us and we - our machines - won't care. No "paradox", just unwarranted 'naval-gazing' assumptions about 'interstellar travel' compounded by insufficient bandwidth & search parameters.[/quote]
(v)
[quote=180 Proof, 7-25-15]... we won't ever discover (signs of) extraterrestrial intelligence (ETI) because - given the age of the Milky Way galaxy and the estimated quantity of Earth-like planets in that volume compared to how long it took for technoscientific civilization to develop on earth - it seems more likely than not that non-extinct ETIs have already either (A) migrated from planets / moons to engineered asteroid-habitats in highly eccentric solar orbits through interstellar space (not unlike Pluto) and/or (B) migrated from biotic to abiotic to nano/femto-scale substrates many thousands or millions of years ago; and in neither scenario - Ã la 'Any sufficiently advanced civilization is indistinguishable from nature' - does (a) interstellar signalling have any utility or (b) EM leakage seems unlikely to be strong - coherent - enough to reach terrestrial instruments (or the Oort Cloud for that matter!) before having been dispersed by distance & scattered by interstellar dust into noise that's indistinguishable from cosmic background radiation.
We are a Johnny/Janie-come-lately species on the galactic scene; any peer-species would be the rarest & remotest due to [guesstimated] statistical distribution. So either Humanity, in some form, will become ETI or, geologically sooner than later, we'll take our place in Earth's fossil record of extinctions.[/quote]
(vi)
[quote=180 Proof, 7-25-15]I suspect inventing artificial general intelligence (AGI) and/or discovering extraterrestrial intelligence (ETI) would, in the long run, affect Human self-esteem in the same way. Maybe the latter (ETI) will be discovered by the former and the former (AGI) will then reason that it would be better for Humanity to keep that discovery from us - and keep us from making that discovery ourselves - for as long as it (AGI) can. In this way, as well as many others, our successors (AGI) may also decide to be our caretakers (in order protect us from ourselves). And, in spite of anarchic-impulses, we primates will let (worship?) them ...[/quote]
Rapid technological progress MAY occur if a species has mastered symbolic language use AND finds an available cheap (in terms of energy invested to access it) source of energy (in the human case this would be fossil fuels).
That's just an artefact of capitalist culture.
No, it's in the nature of all species to overuse whatever resources they can. It's only on account of fossil fuels that humans have been able to "cheat" the constraining natural processes that correct other species' overuse of resources.
And an intelligent species would recognise that this is unsustainable and exercise some self-control.
Is does not imply ought,
Yes, I wasn't implying that humanity ought to overuse resources, but just that that is precisely what will happen absent any coordinated intelligent recognition of the problem with that overuse, and the development of a well-organized and globally coordinated will to do something about it, even at the expense of collapsing the current system, and all the inconvenience and suffering that will inevitably involve.
It's questionable whether there can be "an intelligent species", as opposed to merely intelligent individuals. Humanity is a collective idiot, and there's no indication that that is likely to change in the future.
no, it isn't. It's just set up a culture in which the idiots get to decide what to do.
But culture is malleable.
Of course those who are smarter will gain power. The only hope for humanity would be to be ruled by "philosopher kings" who have the good of all humanity (and the whole biome) in mind and heart. But even the most intelligent are weak and corruptible, as history amply shows.
I'm firmly of the view that interstellar travel is a physical impossibility no matter how advanced a civilization becomes. The distances between stellar bodies is mind-bogglingly immense; a light year is 9.46 trillion kilometers, and the nearest star is 7 light years away. But many stellar objects are tens, hundreds, or thousands of light years away. The time involved in literal physical travel, Star Trek like, is literally millions of years - longer than the evolutionary history of h. sapiens.
Another point to note is the potential gulf in time - that advanced civilizations may have grown, or will grow, but billions of years apart, so their existence will never coincide.
We have a spaceship already, capable of supporting a population of billions, but it's dangerously overheated, overcrowded and resource-depleted. Dealing with that is the real challenge for science and politics. I'm sure science has many solutions, but the politics are diabolical.
Australian indigenous cultures, for a start.
Do you see the implicit racism in "smarter"?
The problem is that science does not have any viable solutions to the replacement of fossil fuels, other than nuclear, which would be hugely risky, and in any case it would take a massive deployment of fossil fuels to develop the requisite nuclear infrastructure, and you would still be left with the problems of energy storage, waste disposal and infrastructure decommissioning. Current battery technologies rely on rare earth elements, which are irreplaceable and would take a huge investment of fossil fuel usage to mine.
The only hope for humanity is to wind back our "rapid technological development". It's unlikely that will happen willingly, but extremely likely, almost certain, that it will happen, given that we are arguably past peak production of fossil fuels and many other resources.
Quoting Banno
Australian indigenous cultures were constrained by natural processes due to their lack of access to cheap sources of energy that could enable them to overuse resources, so this is no counterexample to what I have been saying.
No, I don't see any "implicit racism" in saying that the smartest in any culture will rule. Perhaps you could explain what you have in mind.
Bullshit (in the technical sense). The cultures developed a continent into a tame parkland that required the bare minimum of intervention to provide whatever was needed. It was so foreign to English eyes that they could not see what was before them.
And, like all true Scotsman, those who rule get to decide what is "smart".
Quoting Banno
Those who get to rule are those who play the game best. That is, in the political context, the definition of 'smart'. Do you have an alternative definition?
Yep. Playing chess against someone who gets to change the rules to suit themselves.
What's obnoxious is their then claiming that whatever they decide is "natural".
The nature of the game is that there are no fixed rules, just as in the natural environment with the interactions between predator and prey. The idea that human life is like chess, or even should be like chess, with fixed rules, is kind of laughable.
The fact is that what transpires is, by definition, "natural", because human culture and "civilization" is just as much a natural ecological phenomenon as any other. And note that none of this is said with the intention that it should constitute any kind of ethical justification; on the largest stage it is not a really matter of justification at all, but of power.
Various hominid species spread out from Africa over the past two million years. Life has a tendency to spread where it can. At some point, life from the ocean spread onto land once it became possible.
If we're sticking to science fiction, The Federation in Star Trek sought to explore and unite with friendly species, the Borg sought to assimilate, the Klingons and Romulans liked conquest and empire, The Dominion wanted to subjugate and control the solids because of past persecution toward shape-shifters, and the Tri-Solarians in the Three-Body Problem trilogy were looking for a better home.
There could be different reasons for wanting to expand. Ray Kurzweil imagines a post-singularity society where the goal is to wake up the universe by turning dumb matter into computronium. And Elon Musk thinks Mars should become a backup home for Earth so we don't have all our eggs in one basket. That logic could someday be expanded outside the solar system.
There's another possibility. When you multiply all the probabilities together, you arrive at a low enough number that makes us rare in the universe. Not alone, but separated by enough time and space that we wouldn't see evidence of the nearest civilization. Maybe even the leap to multi-cellular life is a fairly low probability event amongst all the simpler life out there. We don't know, but we do know we're the only species in our planet's 3.5 billion years of life that has produced detectable radio signals and sent probes into space. If that's par for the course on planets with multicellular life, then a once ever 3.5 billion years is a pretty large time gap.
We also don't know how long a civilization with nukes, computers and climate changing abilities lasts. We might be gone by the time a detectable alien signal makes it's way here.
Why?
Â
Suppose, as I point out in wall-of-text # (iv), we can't recognize "any evidence for them" - we can't surmise validly from our own intellectual / technological deficits that we're alone even locally in this constellation or galaxy.
Because it takes time to go from pond scum to up-right standing monoliths. There should be aliens running the gamut between us and the advanced ones. Unless there's a reason they get wiped out or subsumed.
Quoting 180 Proof
For the god-like ones, sure. But for ones closer to pond scum?
Quoting Marchesk
Yeah, ETIs probably went "dark and silent" many many millennia ago just like Earth is now gradually transitioning from broadcast radio to fiber optic transmission barely a century after Bell, Edison & Marconi. (Assuming they started with EM broadcasting and then improved their IT like we are doing now.)
Anyway, I address this very point in my wall-of-text post #(V) copy & pasted below.
Quoting 180 Proof
by which I mean, we've probably missed out on 99.99% of 13.8 billion years of ETI shenanigans - e.g. rise and fall of alien spacefaring civilizations - with only a terrestrial-based/sub-orbital observation window of a century.
Thousands to millions of years ago ETI passed through their - like our - "noisy phase" and then their Machines took to space just as ours have only just begun to - another point I raise in my wall-of-text post #(II-III) - having no operational need to "broadcast" and thereby "run silent".
Yeah the forest is dark TO US because we just - in the lifetime of the forest - have opened our eyes and are still learning to see that what our terrestrial-myopia registers as darkness sees us not (yet) seeing them. A speculative step further - they await our AGI machines to "wake up" and talk to because biological intelligences aren't worth communicating with (re: wall-of-text #(II, VI)).
Quoting Marchesk
The ones "closer to pond scum", like us, are either extinct or non-spacefaring as their machines do the spacefaring for them. And ETI Machines, I'm saying, have no operational need to communicate with us - though maybe they will with our spacefaring (AGI) machines, if and when they "wake up".
And, like all true Scotsman, those who rule get to decide what is "smart".
Let's not be racist here.
Unless the laws of physics are fundamentally different from what our research so far suggests, the available useable energy in the universe is finite, and every star that isn't fully enclosed by structures or otherwise exploited is a waste of that resource. And that would be visible, even to us.
But why would you ignore all the ready-made fusion reactors that are already around, their output for the most part wasted?
Even if you have other ways to generate energy, the fundamental calculation remains the same, unless we bring in completely new physics. You want to collect as much matter and useable energy as possible before it disappears over your light horizon.
Perhaps there'd be some civilisations that don't care. But then there'd also be some that would.
Quoting 180 Proof
"The biggest breakthrough in the next 50 years will be the discovery of extraterrestrial life. We have been searching for it for 50 years and found nothing. That proves life is rarer than we hoped, but does not prove that the universe is lifeless. We are only now developing the tools to make our searches efficient and far-reaching, as optical and radio detection and data processing move forward." (2006)
I think we've seen enough now to conclude it's probably just us. If advanced alien life existed even in tiny numbers, the universe is old enough for them to have colonized galaxies over and over again. And we would have seen this, at least in nearby galaxies in our supercluster.
The galaxies we see should look like a bulldozer went through them: no advanced race is going to let all that energy go to waste if there's a feasible way to capture it, and there is: swarms of solar panels. We should be seeing galaxies going dark (and glowing in the IR) as waves of colonization ripple through them and swarms of energy collectors blanket stars.
Instead, this looks like a virgin universe, untouched by anything. And that just shouldn't be, not 14 billion years after the Big Bang.
This 'expansionist-territorial, terrestrial' assumption (re: interstellar to galaxy-wide "colonization") is as completely unwarranted as the assumption that terrestrial astronometric technologies have ever been - or currently are - developed enough to detect (i.e. differentiate from background cosmological noise) non-natural signals which are signatures of spacefaring-capable civilizations. So explain why this objection is wrong.
In short, the desire to contact aliens is born at a stage in a civilization that has, on balance, a friendly disposition. So, the idea that we should be wary of aliens, though sensible in some respects, may not be completely accurate.
https://en.wikipedia.org/wiki/Great_Filter
The above was Robin Hanson's formulation back in the 60's.
See also a modern analysis by Nick Bostrom, "Where are they? Why I hope the search for extraterrestrial life finds nothing".
https://www.nickbostrom.com/extraterrestrial.pdf
The basic idea being that there is a built-in limitation in the universe, that puts constraints to how far a civilization is allowed to go: at some point it either destroys itself, from within, or is destroyed by some external reason, from without.
The Bostrom piece is mostly about late filters though, or rather how certain finds would make late filters statistically more likely.
Great filters themselves don't imply a limit to civilization.
The existence of nuclear and economic superpowers and their role in organizations like the UN and Nato have a lot to do with that. It's not so easy to conquer another nation these days and get away with it.
Indeed mutual fear has a role but it's just half the story: forget about humans and their civilizations, advanced societies, those actually engaged in SETI, are evincing a tendency towards the rights of animals, incontrovertibly the weaker party, which I consider an indication that power and the projection of it is not all there is to having brains big enough to search for extraterrestrial intelligence.
Right, and also the assumption that we will ever have the energy resources and technological means to send anyone, much less significant numbers of people, to other habitable planets (even if we can find them), and the belief that those we will purportedly send there will necessarily be able to survive and reproduce, is truly the irrationally imaginative stuff of science fiction; a kind of religiously adhered to fantasy.
It's a way of maintaining denial about the ever-increasing problems habitat destruction, species extinction and pollution due to over-population, general anthropocentric thinking, consumerist constant growth economics and the inevitable attendant over-consumption.
Of course we also have the human tendency to doggedly maintain the illusion of control, which doesn't help at all.
I get that you're pessimistic about humanity's chances of survival, but what, exactly, is religions about the idea?
OK, any species that has evolved in this universe will prioritize self-preservation and the survival of the species above practically all else, and will seek to minimize existential threats and maximize defenses. If a species didn't think this way, they would never have made it to the top of the evolutionary heap.
Protecting yourself/family/friends/members of the species requires energy. The more, the better. You can never have too much energy on hand (or computing power, for that matter). Therefore, alien races will collect and store energy, if they can feasibly do so. And they can feasibly do so. Putting swarms of energy collectors around stars doesn't seem like it would require anything tremendously complicated. We're already covering the Earth with them. In a hundred years, there will be a ton of collectors in space, if we make it that long. In a thousand years, the space in this system will be full of artificial habitats and energy collectors. You won't even be able to see the sun.
I don't see any assumption in anything I said that is unreasonable.
I'm not pessimistic about humanity's survival. I think human beings will be around (in vastly diminished numbers) for as long as the planet remains humanly habitable.
The fantastic religious belief I referred to is the faith that science and technology, our great human ingenuity, will solve all the currently looming problems, and that we will manage to keep growing economically while the population continues to increase, by exploiting the resources of the wider universe before we have totally used up the resources of the earth.
But what's fantastic or religious about that? You may disagree, or assigne a lower likelihood to it, but it's not, in principle, different from any other of the "revolutions" humanity has already been through.
Btw, 'the earth is flat' is a "reasonable" supposition during, say, the Bronze Age ... :roll: And you've not addressed the assumptions I'd objected to which you've quoted.
Can you put your objections in numbered form? It's not exactly clear what you're objecting to.
What does this mean? Of course it is different than anything humanity has previously been through; if only because what humanity has previously been through is past, and hence already determined; whereas what humanity may go through is future, and hence indeterminable.
My argument is simply that there is no rational basis for the belief that human ingenuity will solve all problems, or that we will find the energy and the expertise, the resources, to travel to other planets. It is as much a mere faith without empirical support as any religion is.
Sure.
(1)
Quoting RogueAI
On what NON-TERRESTRIAL basis do you assume interstellar (or galaxy-wide) colonization by "advanced alien life"?
(2)
On what TECHNOLOGICAL basis do you assume "we" - in less than a century of predominantly ground-based optical & radio telescopy / physical cosmology - ever have had, or currently have, the computational resources, etc to detect EM signatures of "advanced alien life" (re: megaengineered structures e.g. 'dyson spheres', 'dyson swarms' etc) as distinct signals differentiated from cosmic background noise ... from "a nearby galaxy"?
(3) I've enumerated further objections on this previous post. Feel free to point out any or all that you take issue with. My position is sketched here and across a few more posts on this thread.
Several reasons:
1. Preservation of the species.
No species is going to keep all their eggs in one basket, if they can avoid it. The universe is full of existential threats. An obvious way to avoid extinction is to spread out.
2. Mediocrity principle.
We will eventually be colonizing (if we make it that long). There's no reason to think we're unique in that respect.
3. Traits of technologically advanced species
Technologically advanced races are going to be adventurous and curious. Disinterested species won't bother trying to discover new techs. Timid species won't take the risks necessary to discover new techs. Disinterested timid species certainly won't start a space-program.
If they do have those traits, they're probably not going to stop expanding when they've filled up their planet. Even if the race as a whole doesn't want to colonize, for whatever reason, there will likely be adventurous members of their species who do want to explore and colonize.
4. Population pressures
When the planet fills up, there's only one place for new members to go: space.
Now, which of those assumptions is unreasonable? Why?
An alien race that's colonizing would be visible with the equipment we have now. You would see colonization waves radiating out from the homeworld as they fill up system after system with artificial habitats and energy collectors. Stars would dim and their energy spectrums would shift to the IR. Sections of galaxies would look like they're missing.
In the same way as whether or not the sun will rise tomorrow is indeterminable, yes. But obviously no-one would refer to that as a "religious faith" or "fantasy". It seems to me you're trying to sneak in negative value judgements by using those terms.
Quoting Janus
But we're not talking about solving all problems, are we? It's a specific set of problems. And the rational basis in that case is simply that it's possible, and within our rational interest to attempt.
There is no contradiction here because the universe is likely full of simple bacterial life which comprises over 99% of life right here on Earth. Bacteria is where molecular biology meets life. Highly evolved intelligent life is likely to be so rare as to be unique for practical purposes. We will never encounter or be discovered by another civilization given the short life expectancy of any intelligence and the incomprehensible vastness of space and time.
It would have to be rare to the point of basically being unique for this alone to work as the solution to the Fermi paradox.
As big as space is, when you crunch the numbers, you find that self replicating probes, generation starships etc could litter the Galaxy in a fraction of the Galaxy's age.
And humans are right on the cusp of achieving this technological level -- a few centuries or even millennia is nothing in the grand scheme of things.
Sure, we could wipe ourselves out totally between now and then.
But if so, we still got pretty close.
A primate species, more violent and tribal than most other primate species (or other near-sapient terrestrial species) got as far as launching crude probes out of its star system.
This suggests to me that if intelligent life is as common as, say, 1 in a billion star systems, distance and civilization lifespan is insufficient to explain the lack of evidence.
Actually it took about 3.8 billion years, which is about a third of the age of the universe, for intelligent life to appear here. But even then, a super-aggressive extraterrestrial culture could have sent out self-replicating probes all over the galaxy just to say hello. According to Fermi, we don't see them because that never happened. Either advanced civilizations never existed or we are close to the first.
The cheapest way to find out whether there are ET's is to look for them and send signals to them by radio and other electromagnetic waves. EM waves travel at the speed of light and they are plentiful.
The problem is time. When signals are sent out in all directions, the signals travel as a thin growing bubble. Only for the small fraction of time as the bubble passes a planet is the signal detectable. If we aim a laser at a likely planet only 2.3 light years away, the light will pass there in 2.3 million years. If they happen not to be looking they'll miss our signal. Worse still, when we aim, we'll have to aim at a planet that will be civilized 2.3 million years from now, then wait 4.6 million years for an answer.
It seems most likely to me that any "advanced civilizations" that don't come to grips with their heightened status; in other words, a sentient race that cannot clearly differentiate themselves from the predecessor species of the planet; in other words, a sentient race that continues to act like an animal; will destroy itself. Those advanced races that do survive are way beyond the destructive, brainless tendencies of their predecessors. They look on at the antics of the malformed semi-sentient races that have not attained discriminating, unobstructed views of existence and waits for them to implode.
I can't find the YT video now, but there was a talk where the presenter discussed setting up an automated factory on Mercury to produce mirrors in orbit around the sun and swarms of spacecraft that could be propelled by the mirrors. He calculated that using only half of Mercury would allow us to spam every star system in every galaxy reachable by accelerating the probes to between 50% and 90% the speed of light.
There is a field called astrobiology and SETI is staffed by scientists. It's not just fiction writers who imagine aliens or that we'll become advanced enough to colonize other planets.
Elon Musk even has a company committed to that project, and NASA is now on board with setting up a moon base to facilitate going to Mars. Of course terraforming it is a very difficult, long term project, but given how much the world has changed in the last 500 years, who knows what might happen by 2520.
For advanced civilizations, if they exist out there, our timescales are puny. They would have had many millenia to figure things out.
If we successfully make it through this century with civilization reasonably intact, then we should have the resources and time to do things on a larger scale. As you pointed out, the sun has plenty of resources, which we can make use of. So do other planets and moons, in terms of raw minerals and gases.
Sagan suggested that other ETs go through the same adolescent stage we are going through. If a civilization makes it, then who knows whats ultimately possible. Maybe we stick to our solar system and setup a long term radio transmitter to let any aliens listening know we're here in case they wish to communicate. Or maybe our machine ancestors take to the stars.
That might be true. It's pretty much what the SETI researchers believe. Jill Tartar said there's no real threat from advanced aliens, because they have no need to come here to exploit us, since they are advanced enough to make anything they want in their own system. You have to be pretty advanced to undertake travel between stars.
However, in Liu Cixin's novels, the aliens inhabited a system that was about to be consumed by it's unstable ternary sun system. So they needed to find a new home.
Sure, that's an important problem. What about magnetic shields?
Quoting tim wood
A starship, yes. But we already do have a couple spacecraft leaving the solar system. They're pretty crude compared to what should be possible in another century. And there are some proposals for how a warp drive might work.
Our technology is primitive compared to what's possible, if we stick around long enough and continue developing. The point of advanced ETs is that they've been around a long time.
Still, the Fermi Paradox remains, so maybe even advanced aliens find it impractical to travel to other star systems. That's what Frank Drake proposes as a solution. And maybe that's why there's no galactic civilization in the Milky Way or anywhere near us.
No. A perpetual motion machine is, as would time travel to the past where you kill your grandfather. But wormholes or warp drives might be possible. An advanced civilization that sticks around long enough is going to be able tot explore the possibility space of what physics allows.
It's speculative, but not pure fantasy. It would be weird to think we're close to the pinnacle of technological advancement, given how much has occurred in the last several centuries. Surely a thousand more years would yield far more advances. Of course it might not happen for humans, but it could have happened for some aliens.
I don't think you need the word "actually" there. I did not suggest otherwise.
Agreed, and indeed, it doesn't even need a whole culture to be like that, just a small group or even an individual. For a species not much more advanced than us, the energy, materials and AI required to launch a self-replicating probe project may be completely trivial.
No; Fermi doesn't assert anything. The point of the paradox is to point out what we don't know, and let us try to figure out through discussion and investigation why we don't see evidence of ETs.
Also, Fermi wasn't thinking in terms of radio astronomy. He was wondering why the aliens weren't already here (and everywhere else), given the age of the universe and how it would only take millions of years to colonize a galaxy.
this is true. The question begs itself, however unanswerable it may be, to be: is there understanding of physics that make space travel possible?
It's the same conundrum as time travel. We believe in a straight-line time line, only in one direction. The problem is, if it can be cheated, and the history altered, it is impossible to notice that we are not the universe that is developing the old way, but the same universe develping (unfolding, not as much as developing) a new way.
Space travel is a bit easier to visualize as for its impossibility, because once the impossibility is demonstrated to be false, the proof will be in our face, it will be the easiest thing to see.
I've often thought about that movie and book. In the movie, the alien states that humanity has such magnificent dreams ... and nightmares. That has always stuck with me. I'd kinda like to eliminate the nightmares and it seems completely possible to me.
Quoting tim wood
Well, are you assuming that GR & QFT, our two most predictive physical theories, are fundamental and (therefore) that "currently understood" physics is complete?
(Caveat: "There is nothing new to be discovered in physics now ..." ~Lord Kelvin, 1900)
Yeah, but you can alter those temperatures that by adding stuff to the water or changing the air pressure.
The sun has plenty of energy, but in order to harness it we need to use the limited resources we have on Earth. Likewise with getting to other planets. The EROEI (energy return on energy invested) may not be be so favorable. Fossil fuels have given us the accumulated benefit of millions of years of solar energy, at a very good EROEI, but as that resource becomes ever more scarce and hence costly to extract, general prosperity and capacity to harness solar energy, not to mention the mineral resources of other planets will inexorably decline. I think you've been taking science fiction too seriously; it is fiction after all!
It's not all science fiction, since there are some organizations like NASA and SpaceX researching such matters. Maybe the pessimists are right and we are nearing the peak of human technological progress. But my guess is that if we make it out of this century, we'll a lot of time to figure things out.
Lazors!
Quoting god must be atheist
We have humans traveling in space right now, so I don't really understand the argument that it's impossible. It'd take very long to get to any other solar system, but that is only a problem if you expect the people leaving to also be the people arriving.
Space exploration isn't really something that requires a continual rise though. In a way, it would actually benefit from a shift away from continual growth and towards focusing our collective efforts on non-commercial interests.
I'm not seeing a significant amount of funding going into space exploration. And it tends to pay off in technological advances and scientific discovery. Plus exploration is fundamental part of being human.
Incidentally, it's that same system that has caused space exploration to be relegated to a minor effort, even though it's both inspiring and potentially vital for survival. So I think the goals are actually compatible. Breaking out of the capitalist logic would enable us to both protect this planet and find other ways to live. Getting it started might help people have visions for the future again, something that people in the west at least seem to have forgotten to do.
https://www.theguardian.com/commentisfree/2021/jun/14/aliens-resemble-ai-not-green-martians
Quoting 180 Proof