“Most promising signs yet” of alien life on a planet beyond our Solar System

If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise too, will come before too long.

If, on the other hand, life is relatively rare, or we're the sole example, our future can't be statistically estimated that way.

You seem to be conflating life, multicellular life, and intelligent life. Life appears to have developed on Earth pretty quickly, multicellular life took a long time to appear, and we are only aware of one species that developed civilisation building capabilities.

Life might be very common, but intelligent life still be incrediblY rare.

Most of the sky is left unexplored. I think it’s premature to suggest we don’t see things. There are too many things to see in a single lifetime.

Not to take away from you personally, but civilization as we understand it is our own cliche.

Organisms developed on different planets could absolutely have a different view on life and society in general. Even on earth we have highly intelligent and physically capable organisms that care naught for your conceptions of how groups should function together. There are even organisms that seem to have no intersection with our set of interests that are way more successful in terms of populating earth and invading space. Putting our understanding and interests at some panacea is just hubris.

If life is quite common, that still leaves an option that we are among the oldest of civilisations.

Besides, lack of comical presence doesn’t necessarily mean demise: maybe all face the problematic consequences of uncontrolled industrialisation and go solar punk?

Say another human-like civilisation existed and was more technologically advanced, what sort of tell-tale signs do you expect to see?

Not sure how bad it could be given the hypothetical "millions of years more technologically advanced". They'd need to have a pretty good reason to care about us. Otherwise, we'd be so insignificant that it seems much more likely that whatever natural resources they'd want, would also be likely nearer and easier to obtain.

War-mongering, and otherwise zero-sum mentality shouldn't make all sense if they have the technology to actually reach us. [3-body spoiler warning] Kinda like in the Three Body Problem. It was kinda silly how advanced the Trisolarian were, while still bothering traveling to earth, rather than approach the problem in any number of more obvious ways

Indeed. We might finally start getting some real estimates for those factors in the Drake Equation.

Possibly a more advanced civilization than us has long understood that it should not try to contact and bother other ones, but rather focus on their happiness where they are

Did you read the parent in haste or did they edit their post? They said:

> [1] It means that civilizations should exist that are millions of years more technologically advanced than us;

> [2] and should be leaving telltale signatures across the sky that we'd likely have detected by now.

> [3] And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived.

> [4]Suggesting that our demise too, will come before too long.

So they were talking about the great filter, not alien invasions, which is what you appear to be replying to.

It is quite plausible that life is abundant, but sentience is not. If we take Earth, it formed 4.5 billions years ago, conditions became suitable to support life like 4B years ago and first known signs of life are dated 3.7B years ago.

Now, in just .5B years Earth would likely become uninhabitable due to Sun becoming a red giant. In other words, on Earth life spent 90% of its total available time before sentience emerged. So on one side life is constrained simply by time, and on the other, sentience might not be necessary for organisms to thrive: crocodiles are doing just fine without one for hundreds of millions of years. To think of it, it is only needed for those who can't adapt to the environment without it, so humans really might be very special, indeed.

The sun has about 5B years more to go before it turns into a red giant, not 0.5B years...

Scientists use the term "technosignatures", which you can google for more info. But broadly: radio signals, infrared from megastructures, optical signals like laser pulses. We haven't put a huge amount of effort in searching for such signatures, but there has been some.

> that is probably bad news for us.

Apart from the Sun, the nearest star to us is four light-years away. I'm not loosing my sleep on the thought of being "discovered" by anyone over there.

It depends what you mean by "civilization building". I think we gloss over that a bit too much. We're not the largest population, not the largest total mass, not the only one that builds large structures. We're the only one that sent stuff outside of Earth, yes, and a few other things. But discussing the definition is itself interesting

> And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived.

If dark forest theory is right, alien civilizations may stay undetectable by hiding biological signatures of their worlds.

I mean game theory and equilibria are universal. I don’t see why the basic rules of civilization would not apply to any level of organism sophistication.

We are capable of rapidly changing chemical composition of atmosphere, which may be noticeable even at our technological level.

Maybe there's some truth to Douglas Adams' writing - we are just insignificant enough that nobody cares. In the Star Trek series it's similar, they are interested to see how pre-warp civilisations develop, seeing them as quaint, but that's it.

> Far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy lies a small unregarded yellow sun. Orbiting this at a distance of roughly ninety-two million miles is an utterly insignificant little blue green planet whose ape-descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea.

While it has more time to become a red giant, it'll become more luminous over time and life on Earth will be impossible much earlier. I've seen estimates of 0.5B to 1.5B years.

Earth may become uninhabitable in 1By due to increasing brightness of the sun. In 3-4B years it will be too hot for liquid water on the surface.

In 500 million years, hopefully humans (or whatever humans have become at that point) will be able to modify the Earth's atmosphere to deal with the increased luminosity of the Sun.

>It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now.

Or they've reached their technological plateau millions of years ago. Like we did 50 years ago.

>And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived.

We know for a fact that life have existed on Earth for >2 billion years.

Plenty of lifeforms have changed the composition of the atmosphere. At faster rates than we are changing it now.

Not so! Humans are just early: https://www.youtube.com/watch?v=l3whaviTqqg

We'll put a giant sunshade in the Earth-Sun L1 Lagrange point.

And the evidence of that is what? What is the mechanism behind that? How is it testable?

This is what annoys me about this field. It is just magical thinking and baseless speculation. Random ideas get given names like "dark forest theory" like they are deep and consequential.

What you said is the only consequence of that "theory", because that "theory" is literally just the idle speculation that "alien civilizations may stay undetectable by hiding biological signatures of their worlds."

Maybe technology development is not exponential but s-curve. And anything large scale is impossible. So outside some radio signals there would not be any grand things that could be observed.

> Or they've reached their technological plateau millions of years ago. Like we did 50 years ago.

What a bizarre thing to say, considering this very discovery leans on decades of science and engineering over the past 50 years!

Dark forest theory is wrong. Staying undetectable is always inferior to both staying undetectable and safely deploying varyingly detectable decoy targets at safe distance to probe the situation and gather intelligence.

But if there was a Kardashev type III civilization in the Milky Way, they would have had full control of our entire galaxy in a mere 200 million years or so. And we can be pretty sure that such a civilization doesn't actually exist. Which suggests that either advanced life is rare, or dies off long before it ever reaches such technological breadth.

The dark forest theory makes for a great book premise, but it probably doesn't apply in real life simply because the distances are so far.

The universe is not a forest. It's a gigantic, empty ocean. The next, dangerous tribe is not lurking behind a bush 2 meters away, but is sitting on an island that's so far away it will take centuries to go there, if it is possible at all

If you include our crops and livestock then our civilisation has about half the land biomass. 38% of the earths land is farmland. (We use the richest parts as farmland) https://www.ncesc.com/geographic-faq/what-percentage-of-land...

Another 34% is Forrest, much of which is managed for logging.

We might need to do that by the end of this century.

If we are able to harvest the solar system resources it would take by then.

Trial run for the bigger “solar warming” event.

I see it differently -- if we are all alone, then our disappearance will be an unfathomable catastrophe. If it's abundant, well, so it goes.

Faster? Do you have an example? What species can add 10^12 tons of any chemical in just few hundred years?

There were geological events and asteroid impacts that may result in more dramatic changes, but their signatures will be different.

We don't have to look to the stars to tell that humans have a horrible tendency to make the majority's life a struggle and constantly balancing on the verge of demise.

Dark forest hypothesis explains this in a “dark” way. They exist but are smart enough to hide from hostile hunter/predator life forms. Meanwhile our dumbasses are blasting radio signals into space like a little kid trying to talk to every stranger they see.

We might be lucky enough to do that, but it could have easily taken intelligence another 500M years to evolve on another planet. First animal fossils are something like 700M years old, so it took 2-3G years to just any animals.

lol 0.5B to 1.5B is a pretty big difference. Sounds like we really don’t know what we are talking about.

Intelligent life most like arose from the extinction level events that wiped out less intelligent super predators. This gave those who are far weaker but with higher brain capacity the chance to express their genetic variations.

>we are only aware of one species that developed civilization building capabilities.

well, the first one just doesn't leave any chance for any other one.

>Life might be very common, but intelligent life still be incrediblY rare.

the time period between big ape and nuclear bomb is extremely short - few millions years. In a hundred or a thousand - doesn't really matter - years we'll be an interstellar species or may be we destroy ourselves by Covid-2319. The point is that complexity develops exponentially and tremendous changes are happening in an extremely a short period of time - i.e. if life has 4B years to develop when it most probably has 4.01B years to develop civilization.

Deploying decoy target requires more advanced technology (space travel) than hiding the signature (we may be able to do it long before we reach another star). I don’t think this is a good argument. Let’s say, some civilization decides to invest in decoy. It needs to shine brightly, the energy footprint is huge, a lot of work has to be done to transform the entire system. Then what? If there’s a hostile player, capable of destruction, they research and destroy the target, and start surveying the neighborhood. You cannot just build a decoy on another end of the galaxy, right? The further you have it, the more complicated is the task. And then you can only hope that the time left will be enough to collect enough energy (even if you have the tech) for defense.

Yes, but what we live in is well beyond a decision with four outcomes and all this assumes "we are doing it right".

Maybe it'll help if you think of it as 5-6.5 billion years instead.

Maybe they just don't feel the need to blast their emissions all over the sky like some sort of a caveman.

Our own technological signature is coming to form a very thin shell. Once we switch fully to fiber optics, lasers, and beamformers, there won't be any aliens learning English from listening in on our TV transmissions anymore. Radio broadcasting was cool, but also horribly wasteful.

It's probably incorrect to assume that more technologically advanced civilizations would be louder.

Considering the distances between stars, we might not see civilization spreading as coherent empires but more like humans spreading through the islands of the pacific archipelago. Certainly the same species but also culturally seperated to develop on their own.

Unless faster than light travel or communication becomes avaliable, it might not even make sense to travel through the galaxy.

None of those discoveries help with space travel whatsoever. Our most advanced space propulsion still works on the principle of throwing a lump of matter in the opposite direction. The rocket equation remains undefeated. Special relativity remains undefeated. This is the plateau that I'm talking about. And we have zero idea if anything can be done about it.

5B more years and we're here for max 100 years. Cruel joke. Life's too short.

It's also largely bunk. More a story than a hypothesis, really. Game theory shows cooperation beats aggression on a long enough timescale. Politics shows alliances and MAD deters first strike. Even actual "dark forests" are full of animals that have bright colors and make loud noises.

Bostrom's trilemma and the notion of the Great Filter!

But in the grand scheme of things, even its "bad news" just ONE datapoint of life elsewhere is at least something to start working with.

The lower end estimate depends on the specifics of the increase in brightness accelerating the weathering of silicates, leading to more CO2 absorbed out of the atmosphere until C3 photosynthesis isn't possible. Some plants use a different method which will continue to work (C4), but consequences of plant life as we know it dying off would be catastrophic for life on this planet - barring of course, whatever adaptations are made.

But it's certainly the mark of "the beginning of the end" for life on this planet - it's a major milestone that we (the species) do need to leave eventually if we want to continue.

See, it all comes together! ^.^

  > And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived.

Stars are abundant, long-lived, and go through cycles of life and death.

Now look at the night sky. The chance that you eye will detect a star at any given patch of sky that is roughly the size of a star, is nearly nill. That is not bad news for those who wish to see that stars continue to exist - it is a feature of the size, vastness, and expansion of the universe. Same for life, presumably.

The fact that sharks have existed for 450 million years fairly unchanged fills me with hope. Our existence might be a huge fluke even if eukaryotic life can happen once and again in the Universe.

It’s game theory, mathematics. Let’s say every player has 3 actions: do nothing, expose yourself and destroy the player you aware about. Your goal is survival. If you expose yourself in this game and there’s at least one player choosing „destroy“ action, you loose.

Now, of course there’s a question of applicability of this model: 1. are there other players? (if the game started, we won’t know until we observe destruction event - but that’s falsifiability) 2. do they have means to destroy you? (we may find out) 3. do they have motivation to destroy you? (we may find out) 4. can you protect yourself against unknown level of technology? (we may find out).

This theory meets scientific criteria, it’s just that those criteria require level of technology that we may not reach in thousands of years.

Isn't that the point of the dark forest theory? It's not the fact that there is a dangerous tribe behind a bush it's more that you don't know if they're dangerous or not so you have to err on the side of caution - because you don't know if they're doing the same.

It's the whole chain of suspicion theory that it's safer to shoot first and then ask questions later because the speed you can communicate is the same speed you can mount an attack.

Many trolls hiding in these comments... either that or they just dont understand what the scientific method is.

Thing is, though, it kind of assumes megastructures. AIUI Earth is already getting less radio-noise-y, as fibre-optics take over, and would be difficult for us to detect from the next star (at least to detect the technological civilisation; the biosignatures would be obvious).

Maybe people just don't _actually_ build that many megastructures.

Of course, the risk is, thinking that centuries is a long time may be merely a human, and not a universal, trait.

I really wish natives of places we discovered knew about this. they could've evaded all the bad parts and just explained how it is just a story.

What do we mean by alone?

Life isn't this "magical" force. Life is just an outcome which is just incredibly rare. Or maybe its not? Maybe we are just too primitive in the sense that we haven't analyzed all planets (like this planet is just 120 light years away, still huge but still, who knows how this search continues, and maybe we can even find more/maybe advanced species as well?

But also, as others have pointed out. I think that getting to civilisation level is pretty rare. Its not like the signs on this life that we have found automatically means that they are one day going to be a civilization level life. They may or may not & so many other comments above this comment have beautifully shown the amount of rarity in that which was the major takeaway from this HN atleast for me.

Its still just so fascinating how human societies exist. Maybe I am pessimistic, but like we believe in gold because everyone else does, but for the first time ever, Imagine the people who started trusting in gold and started trading in gold.

They couldn't eat gold, For all its worth, they might have thought that its just shiny rock and its abundant, we just haven't discovered it yet and its going to be worthless so we might as well use grains.

But such trust in gold,maybe even religion/ general trust on society structure beyond the people you know directly is just so bizarre. People believing and dying for nations made those nations have power. And now we trust those nations and their power because our ancestors said so & taught us so. I have read sapiens book 4-5 years ago and I think I had never wondered about such things until now.

Our ancestors could change things way more radically. They had such freedom.

Voltaire used his reason to pursuade people for a revolution.

I am not sure, but in the vastness of the internet, people have just stopped caring about reason but rather all they care about is authority. Change fears so many people.

People would know that some things are bad yet just because they exist, they think it as something so highly and won't even conceive of the possibility of fixing it. And others would be peer pressured into we can't change it. And the people who want change would be ridiculed and made fun of. So much of the time, reason falls off on dead ears in today's world & emotions are hijacked by echo chambers.

Much of our society(I can't say nobody,because I would do grave injustice to people who reason) wants to reason because we want the comfort of emotion.

Or this is merely sci-fi and it's physically impossible to build anything even close to such structures as Dyson spheres. There is no reason whatsoever to believe that just because we can conceive of something like that, it's actually possible to build it using real materials in real quantities with real amounts of available energy in a star system, and even less so to maintain these magical devices even if built.

why isnt a crocodile sentient?

Conversely, it should mean there would also be lots of civilisations millions of years technologically behind us. We're more likely to be an average civilisation than the least-developed

Yes, but the next bush is dozens of light years away. The analogy breaks down because the distances are different in quality.

The only reason why this becomes such a problem in the Three-Body-Problem is the existence of magic in that universe. Thinking protons, instant communication, folded dimensions, easy interstellar travel, it's all interesting speculation inspired by physics, but incompatible with our actual universe.

The probability of advanced civilization is given the probability of life is quite low itself.

For the overwhelming majority of time life has existed on earth only a minuscule part of it involved civilization. And an even more minuscule part of it involved technology that has a small chance to send a coherent signal to another star.

Our future is easily estimated by the hardness of traveling through space and the demise of our sun. Probability points to the end humanity by way of the death of our star. We are statistically most likely to end.

This is now much less plausible. Intelligence, like eyesight, is believed to be a result of convergent evolution[0].

[0] https://www.quantamagazine.org/intelligence-evolved-at-least...

Regarding populating earth and invading space.

I was just watching the original (first) matrix movie yesterday because I was just too bored.

And there was this dialogue by Agent Smith:- ```I’d like to share a revelation during my time here. It came to me when I tried to classify your species. I realized that you’re not actually mammals. Every mammal on this planet instinctively develops a natural equilibrium with the surrounding environment but you humans do not. You move to an area and you multiply and multiply until every natural resource is consumed. The only way you can survive is to spread to another area. There is another organism on this planet that follows the same pattern. Do you know what it is? A virus. Human beings are a disease, a cancer of this planet. You are a plague, and we are the cure.```

So yea, I totally agree with you because just as how Agent Smith compared Humans to a virus and just like we know that not every living thing is a virus, In a similar fashion, I think not every species have intersection with our sets of interests (populating earth,invading space).

I actually had just watched matrix for agent smith actually. I don't know why but the guy looks really cool to me for some reason.

I often wonder if the answer to the Fermi paradox isn't just as extremely banal as "turns out that interstellar exploration just isn't economically viable". I think it's entirely plausible that advanced economies are circular, and that within a circular economy, it's just extremely difficult to justify the massive expenditure of resources that it would take to become interstellar.

I mean, think about how many stars had to align to catalyze our first steps on the moon. Now, 53 years later, we're just starting to put serious effort into going back -- not because there's any market reason to do so, but because (once again) there's political pressure for it. Which would suggest that the best case scenario for the current exploration efforts are something along the lines of what we already see in Antarctica: a well-staffed scientific presence that does really cool/valuable work, but nothing remotely approaching even a single major city in terms of human presense.

It seems to me that one of the unwritten priors to the Fermi paradox (at least in popular discourse) is that technology is the only prerequisite to expanding a civilization; in other words, if you have the technology, then interstellar expansion is only a matter of time, and that all civilizations will inevitably eventually develop the technology. And that... seems like a pretty big assumption, if human history is any indication.

Unlikely we will ever be interstellar. The technology involved is speculative and the physics barriers needed to be surpassed are impossible and not well understood.

To reach another star by the laws of physics involves many human lifetimes and that’s just the nearest star.

That in itself makes it more likely that we will never be interstellar.

Sadly it is still only a stop-gap measure. The sun is for all intents and purposes, dying a slow death.

Earth is on course to become uninhabitable for human civilisation its current form within a century, with an associated mass extinction.

Even if all industrial activity stopped tomorrow there's now enough CO2 in the system to guarantee a succession of uncomfortable and expensive droughts, floods, storms, and wildfires for thousands of years.

If it doesn't they will become more and more extreme very quickly.

If ocean acidification and warming destroy the foodchain in the seas, collapse on land will happen very quickly.

Being intelligent doesn't necessarily lead to runaway technological development. Dolphins are smart but they're never going to invent radios to broadcast their existence to other star systems. They're stuck in the water and don't have thumbs. And even orangutans, who have thumbs and live on land, don't seem tracked for technology even if humans weren't around; their ecological niche is small even if we assumed humans weren't wrecking their environment, and they seem comfortable and steady in it.

> millions of years more technologically advanced than us

> should be leaving telltale signatures across the sky that we'd likely have detected by now

I'm not sure the second follows from the first. What if they're hiding?

Who says they aren't? Of all the reptiles, they seem among the smartest.

The only similar example I can think of is when, roughly 2400 million years ago (during the Paleoproterozoic iirc), the ancestors of cyanobacteria poisoned their atmosphere by overproducing oxygen which resulted in an extinction event. But that whole process still took somewhere in the order of millions of years to complete I believe.

The thinking generally would be that while it might take political pressure to initially begin leaving the home planet, once politics has unlocked that capability, commerce will take over.

If we were to begin mining the solar system, it unlocks vast pools of resources that would really change things.

That said, interstellar travel is still a pipe dream because of the time involved. Without finding a cheat code for physics, it may well be that intelligent life is always trapped in its home system and has to live and die within the limitations of stellar evolution.

Cooperation depends on you and your potential allies surviving long enough to be able to contact each other, and being strong enough to counter the threat. We don't know whether we will develop capabilities fast enough to counter an enemy that e.g. at the first sign of radio started accelerating a bunch of super-dense (hence small, hard to detect and stop) kinetic kill devices our way.

MAD is utter bunk. It depends on rational actors that also believes the other actors are rational. Even Reagan realised the folly of MAD after Able Archer in 1983, and realising the Soviet leadership genuinely seemed to believe the US might be prepared to strike first. If either side thinks the other side is irrational and preparing a first strike, MAD falls apart. If either side is actually irrational, it also falls apart.

But MAD also depends on a sufficient ability for both sides to do serious harm. If one side sees a first strike as an opportunity to prevent the other side from gaining that ability, MAD also falls apart, and the thinking behind it can again then push a rational but callous actor to strike first to prevent being pushed into a MAD scenario.

Cooperation might eventually win out, but that won't help you if your civilization has long since been wiped out.

Every field of study, subject, or problem, or even business cases, -- all have different ranges.

Why does this one in-particular sound like they don't know what they are talking about? It would be just as accurate for me to say in the range of responses, yours kind of sounds like an anti-science bot. Typical of that type of thinking.

Dark Forest depends on the presumption that interstellar travel is worth engaging in (ie it's possible to do faster than light), and that spectacularly devastating weapons are possible. So far we have no reason to believe that either of those assumptions is smart.

Human civilisation means intelligence and memory are collective, externalised, persistent, communicable. There's also a layer of symbolic abstraction (science and math) which makes it possible to predict useful consequences with some precision.

Individuals die but their inventions and insights remain. Individuals can also specialise, which is a kind of civilisational divide and conquer strategy.

Most animals don't have that. Some do train their young to a limited extent, but without writing the knowledge doesn't persist. And without abstraction it only evolves extremely slowly, if at all.

They have to reinvent the wheel over and over, which means they never invent the wheel at all.

We actually have this problem with politics and relationships. We keep making the same mistakes because the humanities provide some limited memory, but there's no symbolic abstraction and prediction - just story telling, which is far less effective.

Bonus points: I often wonder if there's a level of complexity beyond our kind of intelligence, and what it might look like. Abstraction of abstraction would be meta-learning - symbolic systems that manipulate the creation and distribution of civilisational learning.

AI seems to be heading in that direction.

There may be further levels, but we can't imagine them. We could be embedded in them and we wouldn't see them for what they are.

Technically, it is: https://en.wiktionary.org/wiki/sentient (the first two definitions). You mean the science fiction definition though (the third), and it's because it's not self-aware and not very intelligent, because it doesn't need to be to survive and procreate successfully. A slightly smarter crocodile must not have enough of an advantage over its peers to matter for evolutionary purposes.

Time does not matter. Space-faring civilizations can adapt their pace of life to the communication and exploration speeds or even live at multiple speeds. They are likely energy and resource-bound: within the same theory Dyson sphere is a risk, so they can only consume a fraction of locally available energy to remain unnoticed - meaning that it’s not the distance but energy consumption that will limit them.

It's a cool speech, but it's also wrong. Mammals don't "instinctively develop a natural equilibrium", reality forces that equilibrium on them. A species gets too good at breeding and/or resource consumption - that's either happy times for their predators who eat them back into balance, or they starve themselves back into balance.

Those things are just sci-fi glitter absence of which doesn’t invalidate the theory.

> But that whole process still took somewhere in the order of millions of years to complete I believe.

The geological evidence is that that oxygen build-up first had to exhaust things that took the reactive oxygen out of the air and water. Iron oxide was laid down as huge deposits of "banded iron ore" The great rust. (1)

This is hard to get an exact number on, but as far as I know, it is estimated to have taken at least 500 million years.

And then oxygen increased again, a billion years later (2)

It was not fast. It was measured in 100 million year ticks.

1) https://en.wikipedia.org/wiki/Great_Oxidation_Event#Banded_i...

2) https://en.wikipedia.org/wiki/Neoproterozoic_oxygenation_eve...

We don't even need to look at other species.

Humans have been just as smart as you and me, maybe even smarter according to cranial measurements, without inventing anything that significantly changed their way of life.

There could be loads of planets with prehistoric humans, having a fine time hunting with bows and picking fruit.

Nevertheless, if abiogenesis is common & intelligence is easy for evolution conditional on abiogenesis, the number of explanations for the Fermi Paradox just shrunk by a great deal, increasing the probability of the remaining explanations.

Faster than light travel isn't needed (and IIRC doesn't occur in the series the dark forest name comes from). Spectacularly devastating weapons are definitely possible - redirect an asteroid into an inhabited planet and you're likely to kill most of its inhabitants; redirect enough and you can kill almost everything. That's not even getting into things like antimatter, gamma rays, etc. The dark forest hypothesis doesn't need destruction of solar systems to be possible, just severe damage to civilisations.

no matter how advanced the civilization is, proxima centauri will always be 42 trillion kms away. Our civilization in current stage is not even close to 0.1% the speed of light but lets say your advanced civilization goes at 99% the speed of light, still doesnt change the fact they need 4.25 years approx to reach earth. Still doesnt change the fact that unless they have a 1 billion km wide telscope, they cannot reliably tell if earth has life or not. So basically you are asking them to take a shot at coming to the solar system on a 5 yr trip when they have no idea what is found here. Now extrapolate the numbers for the average 100 light year trip between 2 points on our galaxy and you ll quickly realize why we dont have aliens

I thought it might just be the rocket equation. Bigger planet = very little of the rocket is payload.

If most planets are bigger than Earth, then most civilizations will be like "muh we can do it but what's the point?" and they'll be content with just having a few science experiments in orbit, and that's all.

Sure, but it may keep Earth habitable for an extra billion years.

> Still doesnt change the fact that unless they have a 1 billion km wide telscope, they cannot reliably tell if earth has life or not.

How come we’re making progress on this without a 1bn km telescope?

Birds are not remotely as smart as humans.

Long before death it will expand to or almost to Earth's orbit. I doubt humanity could isolate Earth from that.

Yeah, but if humans exist by the time the sun fails us, they wouldn’t really be the same species as us, and they’d hopefully have progressed to the point that they could escape the Earth.

Why does the distance change the dynamic? So what if the species trying to exterminate you are 500 light years away, you think they should ignore it ? Maximum travel speed of an extermination weapon in 100,000 years of of science may very much be impressive or even magical by today’s standards

You may want to update your view that non-human animals lack sentience. [1]

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC4494450/

If you're referring to technology/civilization-building capabilities, that is a different matter.

The difference between .5B years and 1.5B (BILLION) years is pretty staggering in a conversation basically focused around the last couple thousand years. Definitely room for the comment.

Your anti-science bot comment however, is very anti-science.

I’m personally not convinced advanced civilizations would necessarily exhibit such technosignatures at all. I even go as far and ask are you sure if an advanced civilization was living and mining in Saturn’s rings we would even notice? If one considers the scales of things and realizes how big the Saturn system is relative to Earth then I doubt they can be so confident we would even notice our neighbors in the solar system yet.

Yes but the point is that the window in which we have developed this capability is quite short.

Honestly, I do not think high-intelligence is useful for life. The most successful life forms aren’t the most intelligent, and humans seem to be fixed to self-annihilate.

I always thought that how far things are in the universe and the impossibility of faster than light travel were enough to explain why life might be abundant in the universe yet we never observed it.

How do you know it's incompatible with the actual universe instead of our current understanding of the universe?

Take us for example, we're communicating instantly (for practical purposes) using thinking machines - how would that not seem like magic to someone thousands of years ago?

My point is, we don't know what the tribe have behind the bush. It's the equivalent of the Mayans wondering what's over that hill and then finding the Spanish with gunpowder, horses, and steel armour.

If they came here and back at .99c it would be ~70 years "time debt"[0] for them (meaning 70 years would have passed for their relatives back home).

[0] Terminology from Dan Simmons's Hyperion. Would also recommend Joe Haldeman's The Forever War for more time dilation themes.

There is no way civilizations make it past a certain point. It’s so completely obvious, just look at our world. In 2025 we are enabling a genocide while the masses don’t seem to care or even know about it.

You think the people that are having these types of atrocities committed against them would think twice about ending civilization as revenge if given the power? What do you think is going to happen with AI?

If we can’t stop a genocide, why would you think we can stop civilization ending?

Sure, and entropy will end us all one way or another

53 years is instantaneous on cosmological time scales.

Did you notice that you aren't wrong because you're not really saying anything at all? "in its current form" - so maybe with slightly different distribution of land use but basically fine and not necessarily as different as today is from 50 years ago? "mass extinction" already been happening for ages for many species. "uncomfortable floods/etc?" Already been happening for all of history. "very quickly" is how quicky? "more extreme" is how much more extreme?

Someone has to be the first. Granted, us being first is extremely unlikely. But the same is true for whoever it ends up having been.

Indeed.

Maybe once day, aliens will drop by and discover what remains of humanity. And stories will be told of how, when the time came, our species decided to bury its head in the sand and hope the problem would go away. Or maybe that we attempted to create god to come rescue us.

Life imitates art. We refused to listen to the scientists.

> and IIRC doesn't occur in the series the dark forest name comes from

The Trisolarians developed FTL travel while they were on the way to Earth, IIRC.

The problem is that there are just so many planets. Sure, another planet could be 500My slower, but with a billion planets, some of them should be 500My faster instead.

It's possible we are absolutely one-in-a-billion uniquely lucky - after all, someone has to be the first and the luckiest. But every year we find indications that our planet is completely typical.

You're saying we wont maintain tradition and our "humanity"?. I like to be a little more optimistic and believe in us as a species transferring values until the end.

And even that notwithstanding, they could use a solar foci telescope. It's kind of a pain to orient, but it /does/ give you extreme magnification.

Really? With the age of a star, that is too wide a range for you to accept? To pinpoint something like this. What if I were to say, "really it's 1.3435 Billion on a Tuesday".

Of course, calling someone anti-anti-science. The new 'right'. Using science arguments against science. Yes. Your comment is typical, just spam fud. "look at this huge range, see, scientist don't know what they are doing"

Unfortunately it looks like we are more in the track to human inhabitable earth :(

I tried to look it up. I think they didn't ever get FTL, based on https://www.reddit.com/r/threebodyproblem/comments/1blvikg/c... and https://forums.spacebattles.com/threads/trisolaris-in-wh40k.....

Where did you get the 1bn km number? I'm asking it seriously, I'd like to better understand how to calculate these things.

Maybe they have different motivations than humans because they are aliens.

Why do you think aliens will drop by? If aliens were visiting every planet in the universe, don't you think we would have noticed that by now? I mean, why didn't they visit the solar system and colonize it (and everywhere else) aeons ago?

Slow but plausible starships can be designed with 1960s technology. The obstacle is not the technology but the scale of the effort, a problem that could be solved by extension of civilization into the solar system with much larger populations.

https://galileo.phys.virginia.edu/classes/109.jvn.spring00/n...

Also even if it's low, it's not impossible that human technology actually is the one with the more advanced in its observable part of the universe.

That is, if there is supposedly one civilisation with clear advance in technology, it could just as well be humanity.

Dark forest theory is about very advanced civilisations not engaging with anything around them. Limited resources are not an issue in this case. You can easily just do everything in parallel with AI or other automated control system, using stars as energy sources, including spawning whole decoy civilisations at different stages of development. Because we see so many stars we know nobody is running out of energy yet.

You're assuming we make it out of the industrial age while we backpedal on all of our climate commitments.

I owned quite a number of pets in my life, so I don't need explaining that they do have some kind of relatively high-order intelligence that allows them to do quite a lot of things. Yet, this is clear that no kind of animal on Earth but us exhibits potential to have capabilities to spread themeselves beyond home planet once it becomes uninhabitable. Moreover, signs show that once a type of species finds their niche, their intelligence levels off and does not tend to increase. In other words, modern crocodiles are no smarter than crocs from 10 millions of years ago, because they are doing mostly fine as they are.

According to this Timeline of the Far Future [0], we only have 500-600 million years.

(warning, this is one of the most depressive pages on Wikipedia)

[0]: https://en.wikipedia.org/wiki/Timeline_of_the_far_future

> so maybe with slightly different distribution of land use but basically fine and not necessarily as different as today is from 50 years ago?

No, probably very much more different than that, more like rolling back on industrialisation and globalisation. Closer to 500 years than 50, without the same hope of "progress" that we had back then.

> "mass extinction" already been happening for ages for many species.

Yeah, we all learned about dinosaurs when we were little kids, but if humanity collapses there's no guarantee of anything similar developing after us.

Someone has to be the first.

They had the sophons which allowed them to convey information via quantum entanglement, i.e. instantly.

They - and the humans - developed close to light speed traveling which IIRC has the same underlying mechanics as that blackout-galaxy-safe-space thing which is the message that your civilization is not harmful.

So, your theory is aliens are abundant, but by extreme coincidence we're first?

Yes, I think GP phrased it badly. This is just about the meaning of words: "sentience" just means sensory or experiential consciousness. It doesn't necessarily imply high intelligence or capacity for using technology

I doubt there is one single grand answer for the Fermi Paradox. Probably it's lots of smaller blockers which all stack up with each other. The chance of life forming, the chance that it becomes multicellular, the chance that it develops complex nervous systems, intelligence, the physiological hardware for tool use and creation, not stagnating or getting wiped out, having the inclination to look out and broadcast their existence, the chance that they survive long enough while doing this to exist at the same time as another civilization of comparable development, etc. It's easy to come up with these and even if they all have modestly small probabilities each, together they stack up to a plausible answer to the so called paradox.

> Dolphins are smart but they're never going to invent radios to broadcast their existence to other star systems.

How could we possibly know this? The only case of "Dolphins" we know of, is on Earth, with the interference of humanity, and we're looking at Dolphins at a really small timescale.

Given N thousands of years without interference from other species, who can really confidently tell exactly how Dolphins would evolve?

I don't think so, though. I think that unless there are limiting factors (no ores or some other necessary component) life would tend toward technology.

Curiosity as an evolutionary trait is quite an advantage, and I would think is necessary for intelligent omnivores. It's what helped us figure out what we could and couldn't eat, and taught us better techniques for living. Curiosity naturally leads to technological developments, I would argue.

We've had at least two developments of ""dolphins"" that I know of. We also have other intelligent sea life, like squids and octopuses, who've been around for a hell of a long time and are on track to never develop advanced tool creation and use. Living in the water is a massive tech nerf.

It's extremely likely that our demise will come before too long.

The problem is that "before too long" is on a universal timescale, not a human timescale.

Humanity could exist for a million times longer than it already has, expand to other planets in our solar system and even to another solar system or two, be wiped out completely, and on the appropriate timescale we were absolutely "short lived."

Another possibility is we're looking for the wrong techno signatures, or just haven't conceived what the technosignatures for a 10,000-year technologically advanced civilization are.

We've been a techno-civ for what? Maybe only 200-ish years? Our paradigm is gobble up all the energy and grow at all costs. So extrapolate that out, and the logical conclusion is a dyson megasphere that radiates all over the infrared.

But then again, that paradigm is careening us towards an environmental and ecosystem collapse: the hunger for infinite growth is warming our climate, it's unclear whether our nuclear-armed social structures can handle the coming disruptions and migrations, and if we don't kill ourselves, unclear how big a population all the environmental degradation and pollution can support.

So we can project our cute 200-year-old patterns out to a maybe-discoverable 10,000-year civilization driven by the same motivations and flows, but those extrapolations quickly run up against some pretty existential pragmatic threats.

Maybe the answer is we aren't seeing any of the technosignatures because the techonsignatures on the other side of the Great Filter look very different from the ones we conceive of now.

> Living in the water is a massive tech nerf.

Says land-living animal :)

Again, are you saying that you confidently can predict a hypothetical future where Dolphins, even given millions of years, would never invent the radio? I think it's unlikely too, but so are humans, so who knows what could happen.

This is where the discussion, as it always does, silently transitions from science into science fiction.

We know absolutely nothing about extraterrestrial life. We can only project our own singular experience onto the rest of the universe. We only have one data point. There is no scientifically acceptable method of induction from a single data point. The possibilities are endless, and are capacity to narrow them down becomes warped by our love of stories and the kinds of art that we have created about extraterrestial life, all of which are in one way or another metaphors for the human condition.

There is nothing wrong with saying, "Anything is possible and we have 0 evidence allowing us to narrow it down." It isn't fun, but it's true.

Humanity will never put effort into this. We don’t have the technology yet but yes we can develop it but doing this is harder than building a bridge across the ocean between Asia and the US.

That bridge is also within our technological capacity. But it’s not happening period.

We can disperse intelligent machines. Possibly with the ability to regenerate biological life.

> life would tend toward technology

Based on what evidence? We only know if it happening once, after a very long delay.

Ah, yes, you are right. They managed to speed up their travel time to Earth greatly, but they did not reach or surpass the speed of light. I have to read the trilogy again.

All humanoids except our species are extinct, and it's not because we killed them.

The thing is we've only been around a tiny period of time, and given the size of the universe, it would have to be an amazingly tiny Goldilocks zone in time to actually notice us, let alone do anything about it.

On a similar note, humans cannot colonize the galaxy. Sending a single message across would take thousands of years. Instead a human ancestor would split into various individual species.

When you think of it, light speed is really slow. Even on Earth we are capped by it.

We really are pretty lucky that the industrial revolution happened. Thank god for England running out of trees to heat homes with, and abundant surface coal on that island.

yea but we don't have predators thanks to fire.

That depends on the scale of human society, doesn't it? Grow the population in the solar system enough and it becomes a smaller fraction of gross output than many trivial and frivolous things are today.

I'm arguing here that if non-interstellar space colonization is possible, interstellar colonization is a natural and feasible extension. You might argue that even colonization in the solar system will not occur, and I admit that's a defensible position.

If their lifespan is 10,000 years, a five-year trip to exotic backwater Earth would be just a vacation.

Living underwater puts a dampener (didn't intend this atrocious pun, sry about that) on any technology that depends on fire. So smelting ores seems out of the question, and of course radios are made out of lots of pieces of metal.

I can't think of any plausible ways a water-bound species would be able to harness and use electricity either

It's not? Didn't most of them coexist with us until they didn't?

The only reason why we can't out sentient protons folded out of 28 microdimensions into our 3 macrodimensions is the same reason we can't rule out that our universe is actually the works of a giant hand puppet player called Zquaarx.

The problem is just - if any of what happens in 3BP was to actually happen, we would not have to be a little wrong (like Newton was in regard to celestial mechanics) but so wrong that it doesn't even make sense to apply what we know at all.

This is, by the way, the exact point of the first part of the first book: physicists discover that all off the known physics are completely wrong.

Dolphins have only lived in the water for 50m years or so, they still breathe air. They could re-adapt to the land in that kind of time frame easily.

The distance completely changes the dynamic. If I tell you there's a crazy axe murderer in your house, you should be afraid. If I tell you there's a crazy axe murderer on Venus, how afraid are you?

And unless we are completely wrong about physics, the maximum speed of a weapon will be the same as it today - very close to 1c.

Look at all types of mammal that exist, from us to platypuses to bats to whales. Evolved in a few hundred million years. Modern humans have been here for a few hundred thousand.

In 500 million years absolutely anything could happen (if we survive this century).

I think by the time we get to modern humans it would only be a matter of time for technology to develop to something like the current stage. The main evidence I can think of is the independent development of agriculture in about 4-5 regions, and the independent development of large complex civilizations in the Americas and Eurasia.

Humans are cultural learners, so this allowed cumulative cultural evolution from at least as far back as the transition from Olowan to Acheulean stone technologies with Homo erectus ~2-3 million years ago. By the time we get to Homo sapiens and Neanderthal this capacity for cultural learning seems much increased. Some paleoarchaeologists (e.g. Dietrich Stout) argue that technological development has been exponential as far back as H. erectus, just that the early stages of the exponential curve look flat for a long time.

Besides the whole fire thing, which is a serious problem for the metallurgy necessary to make radio, to have any chance of it they'd need to get fingers instead of the optimal swimming flippers they have now. They'll never do that as long as they're aquatic. If millions of years of evolution has them climb out of the water and become land animals again then there might be a glimmer of hope for them, but then they'd no longer be recognizable as dolphins. As it stands now, field mice have a more direct path towards becoming radio makers than dolphins do.

They'd still be dolphins in the same way that you are still a fish.

Also, I don't think you're right that they could do this easily. Their hind limbs have almost completely vanished, their pelvis too, and they have no chance of moving on land. To have a chance they would need to redevelop those things which they've lost, and I don't think there's a particularly plausible path where each step helps their survival at that step. In contrast, their four-limbed land adapted ancestors could swim much better than dolphins can walk.

some calculation about resolution of the telescope to be able to see cities and people of another planet from a 100 light years away at the minimum. I forgot the exact calculation but it ll need a humongous sized telescope mirror

Vast pools of /what/ though?

It seems, at present, that energy is more of a constraint on civilization than matter.

With unlimited cheap energy, there's enough material to do most anything we might reasonably want.

It's likely to cost $thousands/kg to bring materials back from beyond Earth orbit. There are only a handful of elements valuable enough, and that's if they existed in pure form.

Hypothetically, if an asteroid made of pure gold existed, and if a Cargo Dragon atop a Falcon Heavy had enough delta-V to make it there and back with a couple of tonnes, it might break even, but all of this is doubtful.

Most valuable minerals are worth hundreds to low thousands of dollars per kg, so you need a launcher that can bring back a ton of rock for $1M - and not from LEO, you probably need to escape Earth's gravity and get back again.

The physics and engineering are proven, but the economics? Unlikely.

Put another way, you can mine a heck of a lot of Earth rocks with a rocket's worth of kerosene.

We'll have colonized the galaxy in 10 million years. In 200 million years, I'd expect that some future historical society could undertake a project to clean out the heavy elements in the Sun to keep it going.

Direct Multipixel Imaging and Spectroscopy of an Exoplanet with a Solar Gravity Lens Mission (with 1 km resolution)

https://arxiv.org/abs/1802.08421

...and someone made an awesome video about it:

https://www.youtube.com/watch?v=NQFqDKRAROI

Nothing a bit of stellar lifting would not fix[1]. Or worst case, move to a bunch of habitats orbiting stellified Jupiter[2].

[1] https://en.m.wikipedia.org/wiki/Star_lifting [2] https://www.orionsarm.com/eg-article/4a48d58c84350

"Roundtrip Interstellar Travel Using Laser-Pushed Lightsails"

https://ia800108.us.archive.org/view_archive.php?archive=/24...

That's not the point: if you have capabilities to do stellar lifting, interstellar travel is likely on the table too. Fermi paradox is about the question, why we can't detect any sign of extraterrestrial civilizations out there. One explanation is that while life in general might be relatively abundant, true sentience as in us humans that allows life to spread besides its cradle might be quite unique.

>The technology involved is speculative and the physics barriers needed to be surpassed are impossible and not well understood.

we can build with today's tech - classic nuclear reactor plus ion drive - a 3 stage ship reaching 1000km/s, 1200 years to the closest star. Once we get to fusion, we'll be able to improve that speed a small order of magnitude.

>To reach another star by the laws of physics involves many human lifetimes and that’s just the nearest star. >That in itself makes it more likely that we will never be interstellar.

That is exactly what makes it _inter_stellar:) We'll have generations - 10-15 to the nearest star with the current tech mentioned above - of people living their lives on those ships. Living on a planet will become a strange thing for them.

I think in 10-20 years, once launching into LEO becomes cheap with Starship, companies, universities and wealthy individuals will be launching solar + ion drive and nuclear + ion to all the places in the Solar System and some automated probes - beyond.

The Indigenous peoples of the Americas knew well enough about the value of cooperation and alliance. That's why they had stuff like the Iroquois Confederacy, and switched between working with the British, the French, and the colonies depending on which was best for each individual group of natives at any one time. To present them as pure victims powerless before the might of white settlers undermines the political and cultural agency that Native peoples in fact had, and exercised.

The predominant form of relationship between European and Native American peoples for hundreds of years was trade, not war. The tragedies and the atrocities that resulted were a slow burn of conflicting interests and epidemiological naïveté, both between Europeans and Natives and also within each group. That's quite different from the hiding and decapitation strikes usually presented as "dark forest hypothesis", because there's no reason that those specific interests and ignorance would carry over to interstellar society (and every reason that they would need to be overcome in order to become interstellar in the first place).

But why do people always use the fate of resource-constrained preindustrial societies (both Europe and America) to try to predict relationships between hyper-advanced Kardashev-level civilizations anyway? It really seems to me like some kind of projected shame. You can see this too with Liu Cixin. He came from a country that was recently dominated, and has more recently been preparing to dominate its neighbors, so his story pretends nothing better is possible. I suppose that's comforting for some, and questioning it brings out people who show what it's really about.

Google Trends shows the top 10 countries for "Dark forest hypothesis" include the US, Taiwan, China, Peurto Rico, HK, Canada, and Aus [1]— Places with a prominent recent or ongoing imperial history, whether as victims or victimizers. I actually find the "dark forest" narratives quite disturbing, not as a prediction of our future, but as a window into the psyche of people who seem to want it to be one.

You might as well say the Romans had a slave-based economy, so therefore spacefaring empires must also be looking for human slaves! That's got exactly the same amount of validity as the Native comparison. But economic and military incentives obviously change as technology and culture develops. If anything, the fact we used to kill a lot of natives, and we don't so much anymore, is a strong sign that advanced societies can trend towards being less genocidal.

1: https://trends.google.com/trends/explore?q=%2Fg%2F11jyk5h9nj...

We haven't visited any other planets so we're not the first either.

Cooperation only depends on anyone, in the history of ever, having at any point survived long enough to contact each other and form an alliance. Once a critical mass of parties that prefer cooperation has been reached, all future cooperative parties are at an automatic advantage over aggressive parties.

You can see shades this of this, e.g., in the difference between single-round versus iterated Prisoner's Dilemmas.

> MAD is utter bunk. It depends on rational actors that also believes the other actors are rational. Even Reagan realised the folly of MAD after Able Archer in 1983, and realising the Soviet leadership genuinely seemed to believe the US might be prepared to strike first.

What do you think the long-term prospects are of a species that goes around flinging RKVs at people? No more North America and no more Eurasia, if that happened. Maybe South America and Africa can pick up the pieces. Just because irrational hyperaggressive actors can briefly exist doesn't mean you're likely to encounter them. They won't survive for long.

MAD exists whether or not any particular participant believes in it, because it's just the cause and effect of competing powers each with their own agency. Or else we wouldn't be here. Even the Soviets knew that a possible US first strike was better than a guaranteed US retaliatory strike, which would happen if they struck first.

> Cooperation might eventually win out, but that won't help you if your civilization has long since been wiped out.

The whole "Fermi Paradox" arguments are based on an extreme form of "eventually, we should expect to see aliens, so why haven't we already?" This doesn't mean aggressive civilizations don't exist, but the reasons to think they're prevalent are overblown.

I think it only takes a small tweak for everything to stall.

Suppose say, that people only trust a small group. Extended family and lifelong friends, for instance. People get very violent as soon as they disagree on something, immediately wanting to settle disputes by force.

Nobody can strike a deal to do anything with anyone outside their group, and you certainly can't make agreements with a guy in Seattle to deliver things to London. You can't mine coal hoping to sell it to an as yet unknown person. There's no point in fishing more fish than you and your friends can eat.

What happens in this world? Well, I think people will still be intelligent. They'll still think about social situations, especially when it comes to mating. There will still be stories, and humor.

But we're not advancing tech, and we're not changing economically.

Why do I say it's a small tweak? Well, we've all met people who seem to not be able to work with anyone. It's not unlikely that out in the stars, there's some planet with people who have everything we have, but they can't get things to work.

The paradox would remain valid in my view. Even with all those stacked difficulties and plausibility levels, the galaxy alone is immense and if life of any kind were to be found, i'd argue that we should be able to see signs of sophisticated life somewhere at least, so where is it? It's still a cause for some speculation and maybe even existential worry.

Humans only started planting grain about 12k years ago. Anatomically modern humans were gathering wild grain, but not planting grain, for about 100k years. Given this very long period of stagnation, I don't think humanities ascension was an inevitability.

what do you consider the most successful life forms to be? humans currently inhabit every continent and are unquestionably at the top of the food chain.

The galaxy isn't really that huge. 10e11 stars. If you stack only a dozen obstacles at 10% odds of overcoming them each, you come up with advanced radio-broadcasting life being an unusual outcome for a galaxy our size. Add a few more and you can bet against another advanced civilization coinciding with us in the entire observable universe.

> in just .5B years Earth would likely become uninhabitable due to Sun becoming a red giant

The Sun will not become a red giant in 500 million years.

I think it's a natural product of curiosity. And I think that intelligent life would only be so because of curiosity.

You want to figure things out or you're interested in seeing what happens when you fuck around with things.

So I think a technological progression is a natural progression for intelligent life.

Does that make sense? I feel like I'm not explaining myself well.

You confused two things. There is the Sun turning into red giant in 5 billion years consuming the Earth, and the Sun getting too bright for Earth to be habitable in 500 million years.

Are we though? Bacteria do better than us. Cockroaches. Rats. Ants. Grasses. Plankton. We aren’t the most numerous. We aren’t the most widespread. We are serious risk of killing off our own species.

If the Earth was about to be hit by a huge asteroid, some people might survive (by fleeing in spaceships) but none of the species you list have a chance unless people choose to save them.

I highly doubt much of the bacteria would care. The amoeba probably wouldn’t either. Also, rodents have already survived such impacts. All mammals alive today are alive because our ancestors didn’t die with dinosaurs.

Suppose the asteroid is much bigger than the one that ended the dinosaurs.

Lots of animals have been curious for hundreds of millions of years, but technology more advanced than breaking bits off rocks and sticks has only been around a couple thousand years. If you say it's a "natural progression", you also have to say there are serious barriers that most species will never pass.

Mutation is random but selection is non-random. Multilevel selection could select against those scenarios you're talking about. Collaboration could be yet another thing that comes from convergent evolution.

Valid arguments tbh. In the struggles between European and Native American, there is the aspect of being able to escape and continue to pose as a threat and such. There is no total extinction. But in dark forest theory there is the total extinction of home planet aspect, without giving in your own location (no vengeance or kill switch can be carried towards you). And also attack factor being so much more advanced that there is little to no defense against it.

In our world, we never had this level of capability amassed in one hand. We were never tested in this scale. But lets think there was a button in cold war that completely erased soviets with no harm to planet, no harm to the western world and without anyone noticing the origin of this action. How many in U.S. would press that button? I think we would've pressed many times. And later, to know that another planet might be having a button exactly like this that they can press and erase us? we would press first so they never get the chance to do it. Paranoia and self preservation prevails, sadly.

I believe our cooperation in society also relies on our capability of projecting power be it physical or economical. The weaker individuals power becomes, the louder powerful peoples actions become. Saying this as Non-U.S citizen, right now the richest guy can easily interfere in state dealings, act like the president in a way, maybe this is evolution of lobbying tradition there but could you imagine such a thing happening in ancient Greece or even in Rome? What prevented this was citizens' ability to exert power. Right now there is little of that, power disparity is huge and so there isn't as much of a cooperation. Sorry if this part deviated from topic or smth. It is just I believe it 100% depends on real, physical factors rather than how advanced we get mentally.

> all future cooperative parties are at an automatic advantage over aggressive parties.

No, that does not follow, because it assumes any cooperation gives sufficient leverage to be able to resist. But an enemy lobbing kinetic kill devices at high speed from locations that does not give them away would require far more advanced tech to stop.

> What do you think the long-term prospects are of a species that goes around flinging RKVs at people? No more North America and no more Eurasia, if that happened. Maybe South America and Africa can pick up the pieces. Just because irrational hyperaggressive actors can briefly exist doesn't mean you're likely to encounter them. They won't survive for long.

On Earth. In space, throwing kinetic kill devices at people won't affect your own territory, and can at least in theory be done without any possibility of tracing it back to you - you "just" need to accelerate a bunch of them outward to starting positions far from your home system. Any civilization smart enough to be able to build devices like that would be smart enough to build autonomous ones that would become operatonal first when in a position that wouldn't give them away.

> MAD exists whether or not any particular participant believes in it, because it's just the cause and effect of competing powers each with their own agency. Or else we wouldn't be here. Even the Soviets knew that a possible US first strike was better than a guaranteed US retaliatory strike, which would happen if they struck first.

The point of the lessons Able Archer is that there were strong indications the Soviets thought there was a line at which point a first strike to preempt a US first strike would be preferable, and that they thought they were getting close to that line.

> The whole "Fermi Paradox" arguments are based on an extreme form of "eventually, we should expect to see aliens, so why haven't we already?" This doesn't mean aggressive civilizations don't exist, but the reasons to think they're prevalent are overblown.

I've seen nobody suggest we have strong reasons to think they are prevalent. That is missing the point. It's one of many possibilities, but one where the temporary existence of even one in any given "neighbourhood" close enough to strike before we've gotten advanced enough to defend against compact kinetic kill devices hammering us at a decent percentage of c (or worse options we don't know about) would mean we'd already be doomed without knowing about it.

It doesn't even need to be a long-lived one. There just need to have been one alive when our first radio signals hit them.

It doesn't even need to successfully kill most civilization. For it to resolve the Fermi Paradox, attacks just need to happen often enough that those who survive quickly decides hiding is the best option just in case.

I know about the Natufan culture gathering and processing grain with grindstones from about 20k years ago, but don't remember anything from 100k years ago. Were they using grindstones to process grain? I'd have thought grass grains wouldn't be a good food source otherwise.

In any case, the seeming stagnation is part of what I meant by the early part of an exponential curve looking flat: broadly it might look like not much is happening, but there are small changes all the time.

Lack of evidence is also a problem when looking that far back: we have little concrete evidence of what these people were doing with wood, fibres, and other perishable materials.

Having said that, archaeologists used to talk about a "cultural revolution" that happened 20-30k years ago. (Maybe they still talk about it, I just haven't looked at the research recently). This was the period of the famous Lascaux cave paintings and what looks like an explosion of greater complexity in tool assemblages. So it's possible there was some rare cognitive leap at that time, or again it could be that we lack the evidence that would show the more gradual progression.

Even if civilizations are relatively common (which, as others have pointed out, doesn't necessarily follow from life being common), the distances involved are really huge.

We have some ideas for crossing huge distances, but none of them are really practical. There are ideas for accelerating tiny probes with light sails, but when we manage to send them somewhere with 90% of the speed of light, we have no way to decelerate them again in a controlled fashion.

What I want to say is: there's good reason to think that doing anything over 200 light years or so is just infeasible.

> relatively strong evidence that life, while common, isn't long-lived.

https://en.wikipedia.org/wiki/Great_Filter

If the Earth is completely destroyed, the humans on space ships wouldn’t survive either. There is no self-sustaining off world colony currently, and there most likely will not be in the lifetime of anyone alive today. At such time that there is, bacteria, rodents, and other life will likely come with humans as humans build the biospheres that we need elsewhere.

Okay?

With a few years to prepare, the humans would have a chance IMHO.

So the notion that "life would tend toward technology", charitably speaking, does not make any useful predictions. Based on all evidence available, including the dearth of extraterrestrial technosignatures, you can't rely on it happening in any particular situation or timeframe. At best it's speculation, more likely it's just false.

Random walks only progress if they don't get trapped in a local minima. GP example is but one entirely contrived scenario. The point is that technological development depends on many factors and it's entirely plausible that some of them aren't strongly selected for.

This seems to be supported if you consider how long it took for humans to emerge and the fact that other fairly intelligent species exist alongside us but didn't follow the same path. If you suppose that technological development has a clear selection path then why isn't there any evidence of space fairing dinosaurs?

Notably the latter example has ideal appendages for tool manipulation - likely far superior to primates with thumbs. Yet somehow they're indefinitely stuck without tool use.

I wonder if things would progress if they had the same level of communication that dolphins do.

Correct, we disagree in what we think.

you don't need to build a physical shell, a dyson swarm would get the job done.

in the book they couldn't stay in their system since it was unstable and our star was the closest to them and they knew we were less advanced than them.

What gives you an impression that I am confusing these two things? Becoming a red giant is a long process and increased luminosity and radius are parts of this process.

You are exactly right. I think I was tired and simply misread. Thanks for clarifying.

Between [3] and [4] I added an assumption, without basis, of implied agency by [1].