Either intelligent life is rare in the universe or there's something that happens to it that prevents it from what we envision as the future of our own species, i.e., colonizing and spreading among planets. Maybe 99.99% of species ruin their own climate before getting off-world. Maybe they all decide it's happier living as hunter-gatherers. Unless we're alone, there is some fate that's common to all intelligences and it isn't a Star Trek future. The universe is simply too old. If anything else like us existed and it was possible to exist like us for a long period they'd have filled every planet before we ever evolved.
Personally I think just the fact the universe hasn't been eaten by Von Neumann machines means we're alone.
The third option is that everything is simply too far apart and any detectible transmissions are either too faint or buried behind all those massive fusion furnaces.
For instance, if our best Earth tech was pointed at Earth from a distant star, how far away would we be able to detect our own traces of life? We know that life is "a little rare" at least, but there is a huge range of rarity where life is everywhere across the vast, vast universe but sparse across the dinky number of light years we could see each other. Maybe aliens have tech that is 10,000x better than ours but the scale of distance is just too big of an obstacle.
There is an assumption that alien races must have figured out things well beyond our understanding and be doing things like harnessing stars in some dramatic way, but maybe that just isn't a reasonable thing for life forms to do? Or if they do have that ability, they may operate on a much longer timeline, simply nudging things along in a way that escapes notice.
Another possibility is that energy is really hard to come by. Humans absolutely struggle to amass much energy. Think of the insane amount of energy required to lift things into space, and how many millions more amounts of energy we’ll need just to build something in space. Heck if you go drive off grid on Earth, you can barely bring any energy with you and you won’t really be able to generate an appreciative amount of energy to do anything major. Climate change is ultimately caused by our energy needs.
One day we might be able to harness the output of a whole star but the amount of energy we’d need to get to that point seems out of reach right now.
I wouldn’t be surprised if the lack of energy is a universal issue across the stars.
A huge game changer would be if we discovered some physical phenomenon to allow us to safely extract energy easier from mass. It would do to our progress like what the telephones and the Internet did to communication.
What I don't see being brought up often.. So, the universe could be infinite right? Or at least many orders of magnitude larger than the "visible universe"?
If that's the case, the occurance rate of life could be very very small, and we are still practically gaurenteed to exist, along with many (infinite) more life.
But it's entirely possible that they are all over a "visible universe"'s distance away. Which with an expanding universe, would mean that we could never meet or even observe them.
In some ways, that's maybe more lonely, or at least sad, than being entirely alone.
Maybe we give ourself too much indulgency about how further we are in the technological evolution. Maybe we are just at caveman level +1 and looking for radio signals is like trying to find smoke based communications in NY.
Maybe we are still missing something fundamental about the universe and we don't know, like we ignored electricity or nuclear forces existed just decades or 150 years ago.
That UFO the US navy has in footage, from 2019, making a diving nose maybe at 200 mph into the ocean without making a single wave or splash, is telling you something: you don't know everything about physics, just yet.
This is what I find most plausible as well. If we just look at facts we currently believe to be true, then we know there are enormous distances between planets and no fast way of travelling between them. Then for a lot of probabilities you want to assign to the likelihood of intelligent life emerging on a Goldilocks planet, the universe would look exactly like it does today. I.e. we’re all on isolated islands on a fast ocean, and it doesn’t matter how advanced our tech gets: we’re still all limited by the laws of physics so we all think we’re alone.
Why are we assuming that we would be able to see intelligent alien life by just looking at the right spot in space? If we take it at face value the figure that the universe is 13 billion years old, and that the observable universe is 90 billion light years wide, presumably that means that there's a whole lot of universe that could have evolved intelligent life at a pace similar to our own, but that we just can't see because there hasn't been enough time for light to get from there to here.
The assumption that an advanced life form would be able to take over the universe and be visible to us requires that said life form is able to travel large distances. So to be able to travel far enough to enter our field of vision, they need to basically speedrun evolution and space travel proportional to the distance from us, i.e. the farther they are, the faster they need to evolve and the farther they need to travel for us to be able to see them. But the age of the universe poses a hard limit on how much of a head start a civilization can get over us.
So if we think this way, it seems somewhat plausible that life could exist, but be undetectable due to the sheer size of the universe and time constraints, even if they are capable of interstellar travel.
Our evolution was not a straight line. We could stay in bacterial form for a couple of billion years if not the great oxygenation event, or have a couple of billions of years of advantage if it happened that earlier. The evolution from simple marine life to us happened in an instant compared to pre-O2 era.
Actually, the universe might be too young for life, and we're one of the first. The further you go back in time the more violent events like supernovas you'd find which would make the universe a very hostile environment for life.
A galaxy is really a pretty dangerous place for organic life.
One supermassive black hole merger in the same or nearby galaxy, a biggish black hole merger within 10,000 light years, a magnetar hiccup within 500 ly, or a workaday supernova 5 ly off might be enough to sterilize a whole solar system. There is no guessing how many times life has been wiped clean that way.
The sooner our descendants can get the hell out of the galaxy, the better.
Always remember that intergalactic travel is exponentially harder than interstellar travel and that is already brutally hard. We need only be among the first in our galaxy to explain the Fermi paradox.
> Personally I think just the fact the universe hasn't been eaten by Von Neumann machines means we're alone.
Or maybe it'd make sense to consider how big the Universe is, how fast it expands and combine it with how very local is our perception of it.
If you do that and account for how young our capabilities to hear and see stuff out there actually are, Fermi's paradox doesn't make any sense just like the certainty of statements that start with "that must mean..."
The fermi paradox makes sense within "just" the milky way, so the size of the entire observable universe or the speed it expands doesn't seem relevant.
What if civilizations go dark after a century or two of rapid technological progress. Look at what we're doing. The bulk of our data bandwidth is now confined to fiber optics, that leak virtually nothing to outer space. Remaining wireless comms interfere with one another, using ever decreasing power, and are designed to be hard to distinguish from noise. It's like we've enclosed ourselves in a primitive Dyson sphere.
A faint shift in the molecular spectrum of our atmosphere might be telling.
It is but they get cleared out of the equation by f sub c, the fraction of intelligent life that invents high technology capable of interstellar radio transmission.
How about the possibility that perfect VR is invented, every person can live inside their own perfect universe, and the whole species just doesn't give a fuck about exploring the (real) universe?
That would stop a civilisation from exporting any spacecraft or signals outside its homeworld.
I particularly like the short story in there "Wang Carpets".
It builds on Wang Tiles, discovered by Hao Wang when trying to solve a tiling the plane problem. He discovered that it is possible to simulate a Turing machine with a given tile set which meant that solving that tiling the plane problem was equivalent to solving the halting problem. ... but you can simulate a Turing machine with tiles.
If that piques your curiosity, Andrew Glassner's Notebook: Recreational Computer Graphics has some examples of tile sets that can solve math problems.
I think there is always going to be diversity in how humans choose to live. Just like the Amish, whom have neglected much modern technology in their world, there will always be cultures that choose a different path. Some will want to never leave Earth, avoid the Matrix for the real world and experiences, not want to become a cyborg, etc. Diversity of opinion really is beautiful and is the modern evolution.
Edit: and some will want to dedicate their lives to the expansion of life throughout the universe
This is my main theory. Humans will eventually abandon their own bodies and live in a VR world. I think you'd still have massive energy requirements in the real world to deal with of course.
> If anything else like us existed and it was possible to exist like us for a long period they'd have filled every planet before we ever evolved
Yeah because you know exactly what alien civilization would have done right? Because that's what you would do, as a human. We are talking about aliens and we don't know what they would be like so assuming that they would think like us is just stupid.
I've never understood the Von Neumann probe conjecture. Why would anyone design a probe that uses all of the available resources within a system to produce new probes that are sent to the N nearest systems? Surely it's more efficient to use a smaller number of more capable probes than to use a larger number of less capable ones when you consider the fuel mass necessary to get them to the next star. Ideally, you need one foolproof probe that can bootstrap a manufacturing facility in the next system. More likely you would send a few backup probes but you wouldn't send billions of them.
I think multiple Von Neumann probes could have come and gone from our system using little more than a few asteroids and a sip of the Jovian atmosphere.
It's also worth repeating that Von Neumann probes are only useful for information gathering. It would be highly impractical to pre-build all of the colonization infrastructure ahead of time and then mothball it for millions more years while the biologicals caught up, assuming they ever did. So these devices would be limited to scientific exploration or monitoring.
The only thing that I think Star Trek got right about the future is that many people will live in space full time aboard starships. All the planet hopping they do is just to further the plot and provide a familiar backdrop to the audience. Once a species transitions to living in space they will most likely stay there and have little use for planets. Depending on their mastery of fusion or other energy sources they may not even bother hanging around stars anymore. If we want to talk about anthropocentric perspectives the whole concept of visiting other worlds is probably as progressive as vacationing in natural caves, an entertaining novelty done once but never repeated by people who enjoy a roof over their heads, modern conveniences and climate control.
Stars, anyway, have Kuiper belts full of useful materials, with lots of room to spread out, and far enough out not to be inconveniently warm. Any civilization working with very large energies will have large cooling needs: if there is anything we can say confidently about future technologies, it is that they will remain bound by thermodynamics.
Expansion is a property of k>1 reproduction. We could make a sustainable happy civilization even on this dirty planet, if not our biological drive to multiply and eat all gifted to us resources with time. My bets are not on climate ops or hunting-gathering for mature civilizations, but simply on k~=1, the simplest form of existence that brings more value with time instead of more size.
In my opinion this comment brings the discussion full circle, from reasoning the difficulties of intergalactic travel back to the quandary of our home.
1. I'd presume life is exceedingly rare to start with, but I guess in the future we'll get a lot more tech to verify that -- direct imaging for biomarkers?
2. I'm sure there must be a "long term survival" equation for a given intelligent species that involves parameters such as "individual intelligence", individual lifespan, individual aggression level, individual empathy level, lifetime mating strategies that would predict if a species can go interstellar or not.
There's just so much to unpack about humans -- we did not evolve to live like we do today and because this transition is so abrupt, it could lead to a collapse of modern civilization, in my humble opinion.
We did not evolve to live in mega communities where antisocial behavior is rewarded (all kind of leaders), it is very likely that such an antisocial leader ends the human race in the future.
It could be that a much more intelligent species where individuals have much greater "actuator power" that was able to reach our technological level with much fewer individuals would be able to eliminate such leaders and not have this problem.
It could be that a species with a much higher lifespans but a bit less intelligence than humans would have a lot more individual and collective wisdom and be better equipped to deal with tyrants or climate change. To me it seems that we are not capable of long-term survival goals. I find it sad that as a species we haven't invested in a planetary asteroid defense, or transition to nuclear-solar-electric energy. It's just so sad we developed nuclear technologies only for this technology to enable perpetual tyrants. Or electronics only to enable the same tyrants in perpetuity.
Looking back just a few thousand years we can see events that cam wipe out 90% or more of the population of the Earth (such as the eruption of a supervolcano that would destroy all crops).
A species that can think of transcending historical-biological limitations should immediately strive to do so.
It could be that a species with much higher intelligence and much higher empathy would not destroy its planet and would not let greed destroy the very fabric of their society and actually make it over the "hump".
I don't see humans as having it to make it over "the hump", our "human condition" will prevent us from making it.
Maybe intelligent life isn't so rare, but technologically advanced intelligent life is exceedingly rare? It's possible that there could be planets where life emerged, evolved to an intelligent species that didn't have to compete for resources, maybe there were no large carnivores to worry about, maybe resources are even less scarce than they are here, maybe they developed a very collective culture and thus no concept of war, whatever - some scenario where technology doesn't really develop very far. It would never occur to this species to want to leave their planet to go exploring. They could be quite content to live this way for millions of years. We'd never see any signals from them.
When it comes to questions like the one posed in the fermi paradox we always seem to assume that all intelligent lifeforms would be very much like us with similar drives and culture. But it seems exceedingly unlikely.
Ants live in cities surrounded by humans, but have no idea what a human is or what humans do, and literally cannot experience - never mind imagine - what a human is, what a city is, what transport networks are, what culture is, what technology is.
Every so often an ant nest is destroyed because it's an irritant, but if the ants notice at all they carry on relatively unthinkingly. There are only other ants, pheromone trails, and food sources. [Other] may register very fleetingly but does not align with any ant concepts or ant goals, and therefore leaves no lasting impression.
Wide differences in intelligence make more advanced lifeforms invisible - not physically but conceptually. Which turns out to amount to the same thing in practice. Even between two species who share the same physical space.
We could be surrounded by a universal or galactic civilisation and we wouldn't know.
Exactly. For an optimist, we might one day colonize Mars. Next, getting out of our solar system is incredibly unlikely as the first habitable destination in our own galaxy is just so far away.
Say we stretch our optimism and do make it. Now the colonization of the Milky Way starts. It's a 100,000 light years to the other end. You'd be a completely different species by the time you arrive. Say you achieve that (you won't), now we need some type of coordination and communication. Suck badly though that messages have a delay of 100.000 years. There is no such thing as the human species if we spread out as the delay between even closest habitable zones would be so large that orchestration is impossible.
And we're still within the bounds of a single galaxy, not even intergalactic travel. It simply can't be done. We'll never even escape the solar system.
Long before that would even become a question, it's questionable whether our species continues to exist in its current form. Human level AI is at the horizon within our lifetime. And will then accelerate away. Add a few centuries to that and it's strange to assume we'll still be there, unchanged, as primates controlling a machine a billion times more intelligent. The only path would be to become a machine instead, slowly replacing biological parts with superior silicone. Until nothing biological remains.
Sounds crazy or unlikely? The idea that we remain as-is is far crazier.
Or maybe Von Neumann machines can't be built because they're impractical.
Consider that you need an AI that can deal with a huge range of potential environments, build extraction, processing, and assembly machinery, and do all of this with perfect error correction and oversight. Pretty much eternally.
It's an interesting thought experiment. But as a practical engineering project, it really doesn't sound even remotely credible. Not without appealing to "Yes, but one day..." magic unobtanium technology.
I wouldn't be surprised if there's some kind of hard entropy limit on how long complex systems can remain functional and stable. Sooner or later you're going to run out of memory, and if you restart a build process from scratch at each iteration without accumulating information, what have you actually achieved - beyond a rather pointless machine infestation?
You understand that we, personally, are von Neumann machines? Not very well-tuned ones, because we happened by accident. Bacteria did, too, and are more efficient, just limited in scope.
So, we have proof it is possible; it only needs refinement.
Perhaps the intelligent life is so rare that we're the first species that exist across the universe and we're destined to reach for the stars - unless of course we manage to annihilate ourselves first. But then, if there's nobody else but us then perhaps all what we experience is just an elaborated simulation of more advanced species - perhaps our ancestors, who decided to keep us and our universe as a kind of memoir, or as some sophisticated experiment.
A future of Star Trek, where the protective veil of some kind of "prime directive" is being lifted as we reach certain level of development as civilisation and then we get a galaxy-wide club membership feels like naive funny fairy tale. It would be of course great if that would happen but it's more likely reality is, or will be way too mundane and unattractive.
> A future of Star Trek, where the protective veil of some kind of "prime directive" is being lifted as we reach certain level of development as civilisation and then we get a galaxy-wide club membership feels like naive funny fairy tale. It would be of course great if that would happen but it's more likely reality is, or will be way too mundane and unattractive.
A story on that topic - The Crystal Spheres by David Brin
That fate is the technology acceleration with the scientific method versus the glacial development of species.
Meaning its comparable easy to unlock exponential technologys (energy density/ information density) and its very hard to actually self + "tame" a species fresh out of the woods. Just look at our world of 9 billion, longing for ever more surplus, handing dangerous technology to the individual without providing any self-control beyond basic self-surveillance to society members.
Anyone with a basic understanding of biology and a garage full of hamsters, can create a new covid based bioweapon right now. Ever more centralizing systems allow for one hacker to do incredible damage to a society. And while this plays out, there are still people demanding flying cars, so whoever hacks them, can fly them into buildings in case of civil unrest.
The denial about this species being unfit for the stars, unfit even for nuclear energy and the idea that ever more powerful toys will magically fix this "retardation" is whats at the core of the fermi paradox. Most species just murder one another off with exp-tech once the environment and the surplus machinery runs out.
There's a 2,000 year old document that claims we're in a recreation of a long dead world from within a world to come by a being that self-established in light and everything we see around us is just that creator's light in the images of what existed before.
It says souls that depended on bodies were screwed and it's better to be a recreation - that the whole point of the recreation is to provide an afterlife for the dead.
At the time it was written, it went over everyone's heads and eventually even devolved into Gnosticism.
But it seems very pertinent in an age where we stand on the cusp of having AI self-evolve and are heavily investing into photonics for AI, and are then employing our nacent AI to bring photos of great grandparents "to life" and Microsoft was even granted a patent on resurrecting the dead using social media data and AI.
Even the best software authors tend to put in Easter Eggs. I see no reason why the creator of a simulation wouldn't have put in some obscure lore that breaks the 4th wall on the nature of it.
I agree; any galaxy that produces even one civilization capable of launching self-reproducing interstellar probes will never be the same afterwards; it's like a phase change. We don't observe any activity from Bracewell - von Neumann probes today -- nothing is rampaging through our asteroid belt turning it into new probes.
The thing to remember is that given enough time and space, nearly every event has probability 0 or 1. BvN probes are either impossible or inevitable.
I think you need multiple generations (subsequent) of stars in order to get heavier elements - which are probably needed by life.
So maybe the universe is not _that_ old.
The stars that make the elements we need form and blow up in only a few million years. A billion years is plenty of time, once you get the hydrogen gathered together enough to get things started.
You make hypothetical scenarios sound like presupposed fact. You don't know that life is rare or that something else happens to make it appear as such. There are multiple alternative scenarios that you haven't considered amongst the vast sea of possibilities. That you suppose thusly is indicative of your lack of imagination.
The Moore's law-like analysis of the exponentially increasing comlexity of life over time suggests the time for life of our complexity is... about now. We may he first.
> The universe is a dark forest. Every civilization is an armed hunter stalking through the trees like a ghost, gently pushing aside branches that block the path and trying to tread without sound. Even breathing is done with care. The hunter has to be careful, because everywhere in the forest are stealthy hunters like him. If he finds other life—another hunter, an angel or a demon, a delicate infant or a tottering old man, a fairy or a demigod—there’s only one thing he can do: open fire and eliminate them. In this forest, hell is other people. An eternal threat that any life that exposes its own existence will be swiftly wiped out. This is the picture of cosmic civilization. It’s the explanation for the Fermi Paradox.
I always liked this description because it is so similar to the descriptions of untouched cultures in West New Guinea when they were first discovered in the middle of last century.
These cultures were entirely untouched and it gave anthropologists a look into what life was like before before civilization.
The island was divided into tiny tribes which lead an incredibly brutal way of life. One of the interesting features that anthropologists remarked upon was the fact that when two people met each other out and about, if they didn't know each other, the first thing they would do is immediately start trying to kill each other.
If you take a cultural evolutionary point of view, then it is clear that these practices evolved because it was the best way to guarantee their own survival, and those tribes and people who behaved this way had a better chance of having offspring and passing on their way of life to the next generation.
Anyway, I don't see any reason to believe that the dark forest of our universe would be any different to the dark forests of West New Guinea.
I dunno, the dark forest trilogy definitely sparks interesting conversations.
But a counter example to it is that only via cooperation a tribe can become technologically advanced.
All those tribes are just tribes due to their constant squabbling and fighting, while the other that cooperated, traded and exchanged ideas ended up advancing. Wars were/are part of humans but in Europe it quickly became evident that technology and ideas > traditional warfare. Each tech eventually falling out of favour when better strategy/tech emerged.
I believe that the solution to the Feremi paradox is biology/game theory, the only way for intelligence to emerge is via evolutionary competition where intelligence is justified cost for the enormous energy requirement. And that mechanism is the local maxima where competition is wired in and drags down sufficiently large groups down.
Any successful organism/organisation will fall prey to an exploiting organism/individual due to its size, be it internal or external. Empires. countries dominant species all fall prey to exploits over time.
Getting out into space is really hard and we hardly scratched the 'surface' of space exploration. And even if we somehow managed to colonize mars and/or Europa, i think Expanse have an accurate picture of what would happen, new species of humans will develop (slowly) and will culturally diverge putting whole 'one humanity' going into space into wishful thinking category back again.
I really enjoyed the Dark Forest. The ending felt like the first time I saw The Usual Suspects.
Another alternative hypothesis could be that the universe / even the galaxy is just too big to settle. Any civilization going out would take centuries to cross to other spaces, and completely lose touch with those members which stayed behind. It's hard to have a galactic "empire" when it takes centuries to send resources/soldiers to other worlds. The nearest planet to us, New Horizons, would take nearly 7 hours just to send a message at the speed of light!
The logical thing to do would be to send out machines to mine for resources and send them back and the machines may not be that interested in other lifeforms, other than possibly avoiding them.
We know this much from planet Earth, and therefore this should be our starting point when considering life elsewhere:
The Earth is 4.5 billion years old.
Life existed by roughly 3.5 billion years ago, possibly earlier.
Multicellar life only got going about 0.7 billion years ago.
So, roughly speaking, 1 billion years to get to life, but 4 billion years to get to multicellular life. So we know that multicellular life is 4 times more difficult than life itself.
So for every 4 planets where we find life, we should expect 3 of those planets to only have single-celled life.
Of course, it is possible that life arose on Earth as early as 4 billion years ago. We have no record of that, partly because the Earth was still getting hit by asteroids that left craters 1,000 kilometers in diameter (we know this because we can see that the moon was hit with these asteroids, back at that time). Since such events would sterilize the planet, that would also imply that life re-started many, many times. But it would also mean that the single-cell/multicell ratio is more like 1 in 8.
Fun! But if abiogenesis happened more than once, and we don't see any alternate-root lineages, then we've admitted the possibility that major advances towards complex life can have a resource lock out effect leading to the extinction of alternates; this could apply to any or all of the critical steps towards technological intelligence.
e.g. did the evolution of homo sapiens and its subsequent monopolization of earth resources decrease the chances of another intelligent species evolving? Probably.
maybe eukaryoticity and sexual reproduction are also advantages so great they confer world domination to their lineages, and therefore will exhibit this kind of founder effect.
Once a world-dominating feature evolves, the rest of the tree must produce a competitor before resources are exhausted, otherwise the feature will only appear once in present lineages. It'd be interesting to know what effects modelling this might have on the resolved probabilities. Seems like the time-to-takeover/time-to-evolve ratio would be the critical factor.
The thought experiment would be: if you took away all the life with feature X, how long would it take to re-evolve that feature?
It might seem like Earth's resources are so vast that they couldn't possibly be 'taken over' in a meaningful way, but consider that all life is competing for a very narrow window of mineral availability, pH, and temperature, and that straying from these consensus boundaries requires you to evolve a huge amount of technology to begin using energy. Also recall that life tends to reproduce conditions suitable for its own continuance. So the result would be, that if you evolve something cool like a mitochondria, you might be able to replace your ancestors in every currently exploitable niche with significant energy flow in fairly short order.
> But if abiogenesis happened more than once, and we don't see any alternate-root lineages, then we've admitted the possibility that major advances towards complex life can have a resource lock out effect leading to the extinction of alternates; this could apply to any or all of the critical steps towards technological intelligence
I have often wondered if this is not exactly what occurred on earth, basically immediately after life first appeared. That direct ancestor to modern humans, maybe not even a real unicellular organism yet, won that very first resource race and extinguished any/all other contenders. That distant ancestor would have suffocated any possibility for carbon-based abiogenesis to occur again, leaving us with the tree of life we have today.
> e.g. did the evolution of homo sapiens and its subsequent monopolization of earth resources decrease the chances of another intelligent species evolving? Probably.
Only if you assume that intelligent life fills an ecological niche. As far as I am aware that’s some hot debate in evolutionary biologist circles.
There’s a strong chance this is all a massive fluke, given the configuration of our solar system and happenstance of earths position and chemical makeup.
Then again we wouldn’t be around to observe what we see today if it wasn’t for all those things aligning.
As observations of extra solar systems increase, I’m more inclined to think life is rarer and intelligence is exceedingly more rare.
Nothing wrong with an empty universe. Less to contend with.
If you start looking into definition of life itself you end-up deep into philosophical weeds, and start debating life like crystals, that dont feel alive but act as if they are biological organisms[0].
Heck even closer, is virus alive or its just a random runaway mutation of organic code?
I don't think life is rare, but self aware intelligence probably is exceedingly rare, given how expensive it is in terms of energy cost, and the balance of disadvantageous environment needed for it to emerge and survive but not enough to destroy it.
There are organisms that haven't evolved intelligence for millions of years because they are good enough to survive and not to mention the self awareness.
Dumb physics question: If a dying civilization 99,000 light years away sent its last radio transmission 100,000 years ago, we'd never know it happened, right? Maybe I'm missing something with those radio waves bouncing back and forth around us off of various big objects in the milky way.
You’re right. If we were not listening right when it passed us we would miss it. Any bouncing around would be so weak it probably could never be detected above background even with absurdly huge antennas.
Gravitational lensing could give us a few more chances if they were in just the right place, but the event would have to be really massive (supernova level) for light echoes from interstellar material
Interestingly, an infinite amount of chances, since signals can wrap around a black hole an arbitrary amount of times - they are just incredibly weak and have to be viewed from the right position!
On top of all these probabilities I think you also have to add the probability of high technology. Humans existed for 100k years before we started doing things like harnessing steam and electricity and we have no evidence early humans were insufficiently intelligent. There is a whole chain of mental and cultural developments that may very well not be common.
The official history says humans started diverging from advanced monkeys only 12k years ago. The unofficial history describes a few impressive and socially advanced civilizations before that "flood" event, but all of them valued knowledge only so long as it helped with day to day tasks. So they've built some interesting structures, but weren't technologically advanced by our standards. Our generation, that started 12k years ago, is the first that values knowledge for the sake of knowledge, so we we have things like theoretical math.
nope! 300k years ago, people who were anatomically as smart as us were walking around. Just not very many on account of the glaciers, megafauna, and competing hominids. Can't do agriculture on a glacier
Very good article. The Earth chauvinism in trying to theorize about extraterrestrial life is blinding. There could be magnetohydrodynamic life in star plasmas for all we know. We need to explore WAY more before we try to reach any conclusions.
Readit News
Personally I think just the fact the universe hasn't been eaten by Von Neumann machines means we're alone.
For instance, if our best Earth tech was pointed at Earth from a distant star, how far away would we be able to detect our own traces of life? We know that life is "a little rare" at least, but there is a huge range of rarity where life is everywhere across the vast, vast universe but sparse across the dinky number of light years we could see each other. Maybe aliens have tech that is 10,000x better than ours but the scale of distance is just too big of an obstacle.
There is an assumption that alien races must have figured out things well beyond our understanding and be doing things like harnessing stars in some dramatic way, but maybe that just isn't a reasonable thing for life forms to do? Or if they do have that ability, they may operate on a much longer timeline, simply nudging things along in a way that escapes notice.
One day we might be able to harness the output of a whole star but the amount of energy we’d need to get to that point seems out of reach right now.
I wouldn’t be surprised if the lack of energy is a universal issue across the stars.
A huge game changer would be if we discovered some physical phenomenon to allow us to safely extract energy easier from mass. It would do to our progress like what the telephones and the Internet did to communication.
That's very likely. There are only two known systems with possibly habitable planets within 40 light years.
Those who talk about the feasibility of alien life visiting us very simply haven't thought it through, or are ignorant of the reality of space.
It's just too staggeringly big.
If that's the case, the occurance rate of life could be very very small, and we are still practically gaurenteed to exist, along with many (infinite) more life.
But it's entirely possible that they are all over a "visible universe"'s distance away. Which with an expanding universe, would mean that we could never meet or even observe them.
In some ways, that's maybe more lonely, or at least sad, than being entirely alone.
Maybe we are still missing something fundamental about the universe and we don't know, like we ignored electricity or nuclear forces existed just decades or 150 years ago.
That UFO the US navy has in footage, from 2019, making a diving nose maybe at 200 mph into the ocean without making a single wave or splash, is telling you something: you don't know everything about physics, just yet.
The assumption that an advanced life form would be able to take over the universe and be visible to us requires that said life form is able to travel large distances. So to be able to travel far enough to enter our field of vision, they need to basically speedrun evolution and space travel proportional to the distance from us, i.e. the farther they are, the faster they need to evolve and the farther they need to travel for us to be able to see them. But the age of the universe poses a hard limit on how much of a head start a civilization can get over us.
So if we think this way, it seems somewhat plausible that life could exist, but be undetectable due to the sheer size of the universe and time constraints, even if they are capable of interstellar travel.
https://www.shutterstock.com/ru/image-vector/evolution-life-...
One supermassive black hole merger in the same or nearby galaxy, a biggish black hole merger within 10,000 light years, a magnetar hiccup within 500 ly, or a workaday supernova 5 ly off might be enough to sterilize a whole solar system. There is no guessing how many times life has been wiped clean that way.
The sooner our descendants can get the hell out of the galaxy, the better.
Always remember that intergalactic travel is exponentially harder than interstellar travel and that is already brutally hard. We need only be among the first in our galaxy to explain the Fermi paradox.
Or maybe it'd make sense to consider how big the Universe is, how fast it expands and combine it with how very local is our perception of it.
If you do that and account for how young our capabilities to hear and see stuff out there actually are, Fermi's paradox doesn't make any sense just like the certainty of statements that start with "that must mean..."
A faint shift in the molecular spectrum of our atmosphere might be telling.
Wouldn't this be great! Screw universal dominance. Let's play in the woods and hangout with nature. Heat death is coming no matter what.
Is it not possible for intelligent life to exist but not be interested in more?
That would stop a civilisation from exporting any spacecraft or signals outside its homeworld.
I particularly like the short story in there "Wang Carpets".
It builds on Wang Tiles, discovered by Hao Wang when trying to solve a tiling the plane problem. He discovered that it is possible to simulate a Turing machine with a given tile set which meant that solving that tiling the plane problem was equivalent to solving the halting problem. ... but you can simulate a Turing machine with tiles.
If that piques your curiosity, Andrew Glassner's Notebook: Recreational Computer Graphics has some examples of tile sets that can solve math problems.
https://www.google.com/books/edition/Andrew_Glassner_s_Noteb... (page 216 and page 217)
Edit: and some will want to dedicate their lives to the expansion of life throughout the universe
Yeah because you know exactly what alien civilization would have done right? Because that's what you would do, as a human. We are talking about aliens and we don't know what they would be like so assuming that they would think like us is just stupid.
I think multiple Von Neumann probes could have come and gone from our system using little more than a few asteroids and a sip of the Jovian atmosphere.
It's also worth repeating that Von Neumann probes are only useful for information gathering. It would be highly impractical to pre-build all of the colonization infrastructure ahead of time and then mothball it for millions more years while the biologicals caught up, assuming they ever did. So these devices would be limited to scientific exploration or monitoring.
The only thing that I think Star Trek got right about the future is that many people will live in space full time aboard starships. All the planet hopping they do is just to further the plot and provide a familiar backdrop to the audience. Once a species transitions to living in space they will most likely stay there and have little use for planets. Depending on their mastery of fusion or other energy sources they may not even bother hanging around stars anymore. If we want to talk about anthropocentric perspectives the whole concept of visiting other worlds is probably as progressive as vacationing in natural caves, an entertaining novelty done once but never repeated by people who enjoy a roof over their heads, modern conveniences and climate control.
1. I'd presume life is exceedingly rare to start with, but I guess in the future we'll get a lot more tech to verify that -- direct imaging for biomarkers?
2. I'm sure there must be a "long term survival" equation for a given intelligent species that involves parameters such as "individual intelligence", individual lifespan, individual aggression level, individual empathy level, lifetime mating strategies that would predict if a species can go interstellar or not.
There's just so much to unpack about humans -- we did not evolve to live like we do today and because this transition is so abrupt, it could lead to a collapse of modern civilization, in my humble opinion.
We did not evolve to live in mega communities where antisocial behavior is rewarded (all kind of leaders), it is very likely that such an antisocial leader ends the human race in the future. It could be that a much more intelligent species where individuals have much greater "actuator power" that was able to reach our technological level with much fewer individuals would be able to eliminate such leaders and not have this problem.
It could be that a species with a much higher lifespans but a bit less intelligence than humans would have a lot more individual and collective wisdom and be better equipped to deal with tyrants or climate change. To me it seems that we are not capable of long-term survival goals. I find it sad that as a species we haven't invested in a planetary asteroid defense, or transition to nuclear-solar-electric energy. It's just so sad we developed nuclear technologies only for this technology to enable perpetual tyrants. Or electronics only to enable the same tyrants in perpetuity. Looking back just a few thousand years we can see events that cam wipe out 90% or more of the population of the Earth (such as the eruption of a supervolcano that would destroy all crops).
A species that can think of transcending historical-biological limitations should immediately strive to do so.
It could be that a species with much higher intelligence and much higher empathy would not destroy its planet and would not let greed destroy the very fabric of their society and actually make it over the "hump".
I don't see humans as having it to make it over "the hump", our "human condition" will prevent us from making it.
When it comes to questions like the one posed in the fermi paradox we always seem to assume that all intelligent lifeforms would be very much like us with similar drives and culture. But it seems exceedingly unlikely.
Ants live in cities surrounded by humans, but have no idea what a human is or what humans do, and literally cannot experience - never mind imagine - what a human is, what a city is, what transport networks are, what culture is, what technology is.
Every so often an ant nest is destroyed because it's an irritant, but if the ants notice at all they carry on relatively unthinkingly. There are only other ants, pheromone trails, and food sources. [Other] may register very fleetingly but does not align with any ant concepts or ant goals, and therefore leaves no lasting impression.
Wide differences in intelligence make more advanced lifeforms invisible - not physically but conceptually. Which turns out to amount to the same thing in practice. Even between two species who share the same physical space.
We could be surrounded by a universal or galactic civilisation and we wouldn't know.
Say we stretch our optimism and do make it. Now the colonization of the Milky Way starts. It's a 100,000 light years to the other end. You'd be a completely different species by the time you arrive. Say you achieve that (you won't), now we need some type of coordination and communication. Suck badly though that messages have a delay of 100.000 years. There is no such thing as the human species if we spread out as the delay between even closest habitable zones would be so large that orchestration is impossible.
And we're still within the bounds of a single galaxy, not even intergalactic travel. It simply can't be done. We'll never even escape the solar system.
Long before that would even become a question, it's questionable whether our species continues to exist in its current form. Human level AI is at the horizon within our lifetime. And will then accelerate away. Add a few centuries to that and it's strange to assume we'll still be there, unchanged, as primates controlling a machine a billion times more intelligent. The only path would be to become a machine instead, slowly replacing biological parts with superior silicone. Until nothing biological remains.
Sounds crazy or unlikely? The idea that we remain as-is is far crazier.
Consider that you need an AI that can deal with a huge range of potential environments, build extraction, processing, and assembly machinery, and do all of this with perfect error correction and oversight. Pretty much eternally.
It's an interesting thought experiment. But as a practical engineering project, it really doesn't sound even remotely credible. Not without appealing to "Yes, but one day..." magic unobtanium technology.
I wouldn't be surprised if there's some kind of hard entropy limit on how long complex systems can remain functional and stable. Sooner or later you're going to run out of memory, and if you restart a build process from scratch at each iteration without accumulating information, what have you actually achieved - beyond a rather pointless machine infestation?
So, we have proof it is possible; it only needs refinement.
A future of Star Trek, where the protective veil of some kind of "prime directive" is being lifted as we reach certain level of development as civilisation and then we get a galaxy-wide club membership feels like naive funny fairy tale. It would be of course great if that would happen but it's more likely reality is, or will be way too mundane and unattractive.
A story on that topic - The Crystal Spheres by David Brin
https://www.lightspeedmagazine.com/fiction/the-crystal-spher...
Meaning its comparable easy to unlock exponential technologys (energy density/ information density) and its very hard to actually self + "tame" a species fresh out of the woods. Just look at our world of 9 billion, longing for ever more surplus, handing dangerous technology to the individual without providing any self-control beyond basic self-surveillance to society members.
Anyone with a basic understanding of biology and a garage full of hamsters, can create a new covid based bioweapon right now. Ever more centralizing systems allow for one hacker to do incredible damage to a society. And while this plays out, there are still people demanding flying cars, so whoever hacks them, can fly them into buildings in case of civil unrest.
The denial about this species being unfit for the stars, unfit even for nuclear energy and the idea that ever more powerful toys will magically fix this "retardation" is whats at the core of the fermi paradox. Most species just murder one another off with exp-tech once the environment and the surplus machinery runs out.
Maybe we're a simulation of future earth historians?
Maybe they're already here? A computational foam that surrounds us.
Maybe we're the first? Or life is exceedingly rare?
Maybe it's up there, purposefully undetected, killing anything that emerges? Like a spider in wait.
Maybe we've been seeded by them, and they're watching us grow?
Maybe physics breaking shenanigans and things we can't even model or understand are happening?
It says souls that depended on bodies were screwed and it's better to be a recreation - that the whole point of the recreation is to provide an afterlife for the dead.
At the time it was written, it went over everyone's heads and eventually even devolved into Gnosticism.
But it seems very pertinent in an age where we stand on the cusp of having AI self-evolve and are heavily investing into photonics for AI, and are then employing our nacent AI to bring photos of great grandparents "to life" and Microsoft was even granted a patent on resurrecting the dead using social media data and AI.
Even the best software authors tend to put in Easter Eggs. I see no reason why the creator of a simulation wouldn't have put in some obscure lore that breaks the 4th wall on the nature of it.
The thing to remember is that given enough time and space, nearly every event has probability 0 or 1. BvN probes are either impossible or inevitable.
https://www.quora.com/How-many-generations-of-stars-have-the...
> The universe is a dark forest. Every civilization is an armed hunter stalking through the trees like a ghost, gently pushing aside branches that block the path and trying to tread without sound. Even breathing is done with care. The hunter has to be careful, because everywhere in the forest are stealthy hunters like him. If he finds other life—another hunter, an angel or a demon, a delicate infant or a tottering old man, a fairy or a demigod—there’s only one thing he can do: open fire and eliminate them. In this forest, hell is other people. An eternal threat that any life that exposes its own existence will be swiftly wiped out. This is the picture of cosmic civilization. It’s the explanation for the Fermi Paradox.
* https://www.goodreads.com/quotes/7378369-the-universe-is-a-d...
* https://en.wikipedia.org/wiki/The_Dark_Forest
Kurzgesagt video (12m):
* https://www.youtube.com/watch?v=xAUJYP8tnRE
These cultures were entirely untouched and it gave anthropologists a look into what life was like before before civilization.
The island was divided into tiny tribes which lead an incredibly brutal way of life. One of the interesting features that anthropologists remarked upon was the fact that when two people met each other out and about, if they didn't know each other, the first thing they would do is immediately start trying to kill each other.
If you take a cultural evolutionary point of view, then it is clear that these practices evolved because it was the best way to guarantee their own survival, and those tribes and people who behaved this way had a better chance of having offspring and passing on their way of life to the next generation.
Anyway, I don't see any reason to believe that the dark forest of our universe would be any different to the dark forests of West New Guinea.
But a counter example to it is that only via cooperation a tribe can become technologically advanced.
All those tribes are just tribes due to their constant squabbling and fighting, while the other that cooperated, traded and exchanged ideas ended up advancing. Wars were/are part of humans but in Europe it quickly became evident that technology and ideas > traditional warfare. Each tech eventually falling out of favour when better strategy/tech emerged.
I believe that the solution to the Feremi paradox is biology/game theory, the only way for intelligence to emerge is via evolutionary competition where intelligence is justified cost for the enormous energy requirement. And that mechanism is the local maxima where competition is wired in and drags down sufficiently large groups down.
Any successful organism/organisation will fall prey to an exploiting organism/individual due to its size, be it internal or external. Empires. countries dominant species all fall prey to exploits over time.
Getting out into space is really hard and we hardly scratched the 'surface' of space exploration. And even if we somehow managed to colonize mars and/or Europa, i think Expanse have an accurate picture of what would happen, new species of humans will develop (slowly) and will culturally diverge putting whole 'one humanity' going into space into wishful thinking category back again.
Another alternative hypothesis could be that the universe / even the galaxy is just too big to settle. Any civilization going out would take centuries to cross to other spaces, and completely lose touch with those members which stayed behind. It's hard to have a galactic "empire" when it takes centuries to send resources/soldiers to other worlds. The nearest planet to us, New Horizons, would take nearly 7 hours just to send a message at the speed of light!
The logical thing to do would be to send out machines to mine for resources and send them back and the machines may not be that interested in other lifeforms, other than possibly avoiding them.
The Earth is 4.5 billion years old.
Life existed by roughly 3.5 billion years ago, possibly earlier.
Multicellar life only got going about 0.7 billion years ago.
So, roughly speaking, 1 billion years to get to life, but 4 billion years to get to multicellular life. So we know that multicellular life is 4 times more difficult than life itself.
So for every 4 planets where we find life, we should expect 3 of those planets to only have single-celled life.
Of course, it is possible that life arose on Earth as early as 4 billion years ago. We have no record of that, partly because the Earth was still getting hit by asteroids that left craters 1,000 kilometers in diameter (we know this because we can see that the moon was hit with these asteroids, back at that time). Since such events would sterilize the planet, that would also imply that life re-started many, many times. But it would also mean that the single-cell/multicell ratio is more like 1 in 8.
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e.g. did the evolution of homo sapiens and its subsequent monopolization of earth resources decrease the chances of another intelligent species evolving? Probably.
maybe eukaryoticity and sexual reproduction are also advantages so great they confer world domination to their lineages, and therefore will exhibit this kind of founder effect.
Once a world-dominating feature evolves, the rest of the tree must produce a competitor before resources are exhausted, otherwise the feature will only appear once in present lineages. It'd be interesting to know what effects modelling this might have on the resolved probabilities. Seems like the time-to-takeover/time-to-evolve ratio would be the critical factor.
The thought experiment would be: if you took away all the life with feature X, how long would it take to re-evolve that feature?
It might seem like Earth's resources are so vast that they couldn't possibly be 'taken over' in a meaningful way, but consider that all life is competing for a very narrow window of mineral availability, pH, and temperature, and that straying from these consensus boundaries requires you to evolve a huge amount of technology to begin using energy. Also recall that life tends to reproduce conditions suitable for its own continuance. So the result would be, that if you evolve something cool like a mitochondria, you might be able to replace your ancestors in every currently exploitable niche with significant energy flow in fairly short order.
I have often wondered if this is not exactly what occurred on earth, basically immediately after life first appeared. That direct ancestor to modern humans, maybe not even a real unicellular organism yet, won that very first resource race and extinguished any/all other contenders. That distant ancestor would have suffocated any possibility for carbon-based abiogenesis to occur again, leaving us with the tree of life we have today.
Only if you assume that intelligent life fills an ecological niche. As far as I am aware that’s some hot debate in evolutionary biologist circles.
There’s a strong chance this is all a massive fluke, given the configuration of our solar system and happenstance of earths position and chemical makeup.
Then again we wouldn’t be around to observe what we see today if it wasn’t for all those things aligning.
As observations of extra solar systems increase, I’m more inclined to think life is rarer and intelligence is exceedingly more rare.
Nothing wrong with an empty universe. Less to contend with.
Heck even closer, is virus alive or its just a random runaway mutation of organic code?
I don't think life is rare, but self aware intelligence probably is exceedingly rare, given how expensive it is in terms of energy cost, and the balance of disadvantageous environment needed for it to emerge and survive but not enough to destroy it.
There are organisms that haven't evolved intelligence for millions of years because they are good enough to survive and not to mention the self awareness.
[0] https://www.wired.com/2013/01/living-crystal/
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And even on the edge of it you are talking about enormous receivers to capture those transmissions.
When looking into scales of universe its truly staggering how vast distances we are talking about.
https://mediachomp.com/theyre-made-out-of-meat-sci-fi-short-...