I think the great filter is definitely ahead of us, but I'm not so terrified by the implications of this (or so interested in being a pompous contrarian) that I'm moved to bury my head in the sand and publicly hope for stupid things.
I hope we find current or ancient life on Mars, Europa, etc. because that would be interesting and exciting.
It would bring no more additional existential dread than looking outside at your fellow idiot humans.
Life is hard, and we're probably all going to die. Get over it. We can still hope to find interesting things while we're around to enjoy them.
No, you ARE going to die.
I think the main extinction risk is the secular trend for technology to become both more destructive and more decentralised. If that continues, it might only be a matter of time before independent actors will be able to extinguish the human race. And given the distribution of human motivations, if individuals can do it, someone will sooner or later.
I have a harder time believing independent actors can extinguish the human race. Biowarfare/terrorism is unlikely to do so for a variety of reasons, and nuclear warfare only has the potential to do in superpower level conflict, and even then I don't think it's certain.
Being satisfied that some "naked apes" still living could mean a survival, as a biological species, of the probable destruction of current civilization is setting the bar really low.
I don't think it's likely, but I also don't think it's something one can dismiss easily.
Existential threat multiplier? Probably yes.
By the time we have the technology to do so, we will necessarily have the technology that makes it unnecessary. The primary thing you need is something that can survive effectively indefinitely in deep space where there are no resources available. But if you have that you can build stellar colonies that have unlimited access to solar power and can survive indefinitely just as easily.
It's not like we are short on mass in the solar system either. It will be a long long time until we've used up Jupiter, Saturn, Uranus, the belt, etc...
For a point of reference, SpaceX currently charges about $2,720/kg for LEO. So to get this project off of the ground (literally) you're talking about $1,360,000,000,000. And that's just launch costs. It doesn't include the invention of spacecraft that can survive in deep space indefinitely without resupply, the materials science advances needed to survive 300,000 nuclear explosions (the paper suggests 1mm of stainless steel coated with a thin layer of oil), or the fact that this is only talking about getting to a place we probably don't even want to go.
And this is kind of the point. Once you've invented all of the necessary pre-reqs there's really no point in hitting it with 300,000 nuclear explosions, you already have a self sustaining space colony. You can continue to build those pretty much forever and never ever come close to running out of room. There's no need to travel to some other star system at that point. The sense of adventure has to be weighed against the risk factor of detonating 300,000 nuclear bombs without incident and all of the yet unknown hazards of interstellar travel. Oh, and thanks to the tyranny of the rocket equation it is a one way trip unless you're packing a nuclear bomb factory and enough mining equipment to get the raw materials you need from whatever you happen to find at your destination.
Whether or not you agree, some people like the idea of humanity surviving as a multi-solar system species.
I'm not sure Alpha Centauri has any inhabitable planets, at least for our biology as it stands today, but what we learn along the way might render that moot.
And this is just the tip of the ice berg. I agree with jandrese that people underestimate just how much of a hurdle this is.
― Douglas Adams, The Hitchhiker's Guide to the Galaxy
When talking about interstellar distances people just aren't equipped to think about the scales involved. They're so far outside of the scale of human experience that our brain really struggles to understand the magnitude of the problem.
We're talking about billions of dollars to set up a short term test camp on Mars, and by interstellar standards that is close to nothing.
And that seems improbable, if only because aggressive, exponential expansion is a fairly valid Darwinian strategy.
I'm not at all sure that, even assuming your estimate, ETI would be 'fairly obvious'. Take some speculative figures. The total area of the milky way is about 30 trillion light years. Let's speculate that intelligent life occurs in one in a million planets. There are something like 100 billion planets in the milky way, so that would be 100,00 planets bearing ETI. If one in a thousand intelligent civilizations are super-expansionary, that comes down to just 100. If we divide the area of the milky way - 30 trillion - by a hundred, we get one super-expansionary civilization per three hundred billion square light years. Would that be obvious? Even if we assume that ETI occurs on average on one in 10,000 planets, that would still be one super-expansionary civilization per three billion square light years.
This is inherently Darwinian as well. In fact, cultural evolution is usually smarter than we are; indigenous pre-industrial cultures typically have an excellent practical understanding of how to thrive in their immediate environment even without having anything close to a theoretical scientific understanding of why their own cultural practices work in the first place.
More to the point, cultures that expand and grow, do so at the expense of cultures that don’t. So through natural selection, we would expect to see more expansionary cultures than non-expansionary cultures.
And, even setting aside the argument, you still have the much tougher task of explaining the notion that no extraterrestrial cultures are expansionary, which is what your side of this argument would require.
> I'm not at all sure that, even assuming your estimate, ETI would be 'fairly obvious'.
It would be eventually if it were growing exponentially. On the timescale of the galaxy and by all probability, eventually has already happened unless humanity is an extreme, extreme, extreme outlier early bloomer.
Natural selection cannot apply to societies because there is no reliable mechanism for successful decision-making to propagate itself in the way genes convey successful characteristics to future generations. Does survival depend on expansion? The last century has seen the fragmentation of the imperial world into a proliferation of independent states, big and small. It is now widely recognised that exchange is more profitable than territorial acquisition, and war has become a highly technologically-intensive project bearing exorbitant costs. Most arguments for expansion as a survival strategy would depend upon some version of the realist theory of anarchy, that the absence of a supra-national sovereign creates conditions of mutual insecurity in which states are forced to maximise their relative power. But I would think that any major inter-stellar expansion would require the unification of the world - in some form - removing the realist premise from the argument for super-expansion.
> And, even setting aside the argument, you still have the much tougher task of explaining the notion that no extraterrestrial cultures are expansionary, which is what your side of this argument would require.
That depends on how common intelligent life is, the maximum possible speed of interstellar travel, the number of ETI that would commit to super-expansion, how good we are (not very) at searching the sky for signs of life, among other things. If you take the upper-bound estimate for most of those categories, then it is not at all paradoxical that we do not see alien life teeming around us.
Behaviors, customs, and beliefs face the exact same selective pressure as genes. If a certain behavior or custom consistently leads to fatal consequences for the people who practice it, that behavior will become less common over time, and societies that normalize that behavior will go extinct. If a certain different behavior or custom consistently leads to success--in terms of maintaining or, better yet, increasing the number of people who engage in that behavior or custom--then that behavior will persist and spread.
> The last century has seen the fragmentation of the imperial world into a proliferation of independent states, big and small.
Individual empires always rise and fall. That's the nature of history. But for humanity, at least, there are only two options: either some of us will eventually colonize space (in which case those of us colonizing space will be more numerous 1000 years from now, and the set of behaviors, customs, and beliefs that led that group to colonize space will be the representative set among humanity), or else we won't colonize space because we ran into the Great Filter.
The same is true for any extraterrestrial intelligence.
Earth exists for around 4.5 billion years, life on Earth for 3.5 billion years, the whole known Universe just less than 14 billion years (and we can send some small probes to the limits of our own Solar system only during the last decades). So the Universe is not "old" and the distances between the areas suitable for the life to "expand" are immense and real barriers.
Knowing the distances involved, I believe that had we discovered that we are in much later age of the Universe, not seeing "others" would mean more than it means now. For now, knowing the distances, whatever could be somewhere far could simply be too far from us, nothing more.
Re: "The galaxy is only 100,000 light years across" note that that are the light years -- the distance that the light has to travel that much. We know that the whole islands on Earth were unreachable for many otherwise common species for millions of years. But these distances are nothing compared with problems of maintaining complex life over the cosmic distances and in the cosmically hostile environment. Also "10-50 million years ahead of us" doesn't have to mean what we think it could mean. For a context, the dinosaurs were, historically, 60 million years "ahead of us". Nobody can "just assume" the we will cross the limits that are ours limits now. Biologically, we did multiply "exponentially" as soon as we were able to use the natural resources to do so (1). But apart from that (the certainty of life using available resources for biological growth), the growth in technical capability for interstellar travel is not guaranteed. Not to mention that the resources are by definition limited.
So nobody should ask "why aren't others here" when we can't even claim that we reached somewhere else. What we surely can ask is "why don't we get some signals" because, for example, we are able to send a radio message, but I personally wouldn't assume that the other civilizations make such kind of intentional signalling that we must necessarily be able to detect, being where we are now. It's not "just connect the headset to the wire and a crystal and listen." It's something that has to concentrate immense amounts of energy to reach exactly us. At the moment it's not "is there anybody anywhere" but "is there anybody in the conveniently close neighborhood who's capable to send exactly what we expect to receive, and, most probably, to target exactly in this direction." It's immensely hard to even "see" the planets by the closest stars, that how far everything is. I think that probability for that "targeted messaging" is too low, not to mention that I don't think that the "intelligence" in our sense is inevitably happening on every planet -- we know that from the 3.5 billion years of life on Earth, not even plants existed for 3 billion years. Life can indeed be relatively common but the development that the Earth up to now had could still simply be uncommon enough.
Unfortunately, my account has some very, very low limits on the number of replies I can make per day, which I can't influence. Not all users have necessarily the same possibilities, and the privileges one may have aren't universal.
My belief is, the limits are there to prevent the discussion progressing too fast and if somebody misses some edit and that even helps the thread remaining slower, maybe the measure still achieved a goal. But I admit it can be confusing.
Of course, I'd personally prefer to have at least a bit higher "quota."
I think the most likely reason there isn't any observable alien life is that we're being intentionally undisturbed. Or at least, seemingly undisturbed.
The very lack of contact with aliens might be interpreted as strong evidence that FTL travel is either outright impossible or so impractical that it is effectively impossible.
The answer to the Fermi paradox might be the tyranny of the rocket equation.
Even forgetting high speed travel. If it takes a billion years (less than 10% of the age of the universe) we would still be able to colonize the Milky Way if we're able to either exist on spacecraft for prolonged periods of time or if replicating probes with AI could do so in our stead.
I'm much more of the opinion that exponential tech is self-terminating or that we're being observed by aliens but not largely interfered with or that we're in some sort of simulation or even that we're the first life forms with advanced intelligence and long life spans. The idea that mere physics is what would stop us from reaching the stars when we've already explored our local neighbourhood is just so unbelievable to me. At the very, very least we should be able to communicate over long distances and we've (as yet) been unable to pick up extraterrestrial signals that show signs of intelligence like enumerating the prime numbers, say.
That's quite a strong assumption.
Also there some fascinating alternatives of biochemistry for life that might work:
How we detect those is another question.
Of course, the Great Filter isn't a new concept, but provided that this is an argument made by somebody other than the person who coined the term (that was Robin Hanson I believe), combined with the fact that I read almost the entire article before then going on to find the video, I find the two too similar to write it off to simple chance.
There have been criticisms of Kurzgesagt in the past, one I can recall being the following, in video form (https://www.youtube.com/watch?v=q2dAGU-VJcE). I've now found out that the original video was retracted and the creator issued a public apology (https://www.youtube.com/watch?v=WcgHGslVdrg), in addition to Kurzgesagt committing to performing more scrutiny over their videos and citing their sources wherever possible.
I do applaud this last step on their part, and I understand that you have to admit that the Great Filter video was published back in 2018 before this commitment was made, but something about the lack of attribution throughout the video doesn't sit right with me, still.
Which is to say, I didn't find the lack of attribution worrisome in this video, because the idea is pretty much "public domain" in the circles interested about the future. It was (as you note) before the time when Kurzgesagt decided to get super-thorough about citing their sources, and I charitably assume that the authors of the video were just aware of the concept of the Great Filter, and not necessarily where they learned about it from. It's a simple idea, easy to explain, and easy to make inferences from - so it may not have occurred to them it's worth tracking down who originally coined the term.
If we stay on our current technological trajectory without destroying ourselves, we will spread out into the galaxy, consuming more and more resources in order to produce more copies of ourselves.
From a totally alien point of view, we might be as intelligent, conscious, or sapient to them as trees are to us. That is, we might as well be bio-robots. Von Neumann probes.
Lower then low, to the point that whenever somebody mentions them, I believe there was just a "wish to be true" and then stop.
When checked, it was just a "rerelase" of the old already published material (one can also think about to whose benefit that distraction was) which was already carefully debunked by Mick West:
Mick West's full playlist with explanations:
An article mentioning Mick West:
Also, one day after NYT published their article "No Longer in Shadows, Pentagon’s U.F.O. Unit Will Make Some Findings Public" they published a correction too:
"Correction: July 24, 2020
An earlier version of this article inaccurately rendered remarks attributed to Harry Reid, the retired Senate majority leader from Nevada. Mr. Reid said he believed that crashes of objects of unknown origin may have occurred and that retrieved materials should be studied; he did not say that crashes had occurred and that retrieved materials had been studied secretly for decades. An earlier version also misstated the frequency with which the director of national intelligence is supposed to report on unidentified aerial phenomena. It is 180 days after enactment of the intelligence authorization act, not every six months."
Emphasis mine, now imagine how many articles in how many media were written before the above correction, and it will explain what most of the consumers got as the message (namely, the first, utterly fake version with fake "crashes").
1) Someone has to be first. Let's say that there is no filter, and every species that doesn't destroy itself or get destroyed will eventually become technologically advanced to travel around meaningfully in space. There is a certain amount of time it will take for this to happen. Supposedly the universe is ~14B years old, and Earth is ~5B years old. It takes a certain amount of time for abiogenesis, a certain amount of time for life to evolve, and a species to emerge "victorious" long enough to start conquering the universe before the next extinction event. So we could be the "first", or the top 20% anyway, and it'll still take us a while for those top 20% to get anywhere where they can start detecting/traveling anywhere.
2) What is the maximum distance any extraterrestrial life could observe our technology/planet currently?
Space is huge, like uncomprehendingly huge... even if we could go anywhere ourselves right now, would we go visit every single planet everywhere without a reason to? And how long would that take? Maybe there hasn't been enough time for a civilization to a) detect us from 100s of light years away and b) travel to us. Maybe detection of life from far away is impossible past a certain point, but traveling there isn't (since it just takes time).
So I guess my thought is, yeah, we might not find life in our solar system, but we might. But even if we do, I don't necessarily think we'll get filtered out either.
There were several stars that blew up before we got the sun which means several systems and planets right in our neighborhood and that's just 1 star in the entire milky way.
Even at 1% the speed of light, it would take 2 million years to travel across the milky way which, relative to the age of the galaxy, is nothing.
That growth would be exponential because acquiring resources provides more energy which allows them to acquire more resources even faster.
If an intelligent species doubled the number of stars they control every 2 million years, they'd have every star in the milky way in around 50 million years.
That's still like 0.2% the lifetime of the galaxy.
> Nothing in the above reasoning precludes the Great Filter from being located both behind us and ahead of us. It might both be extremely improbable that intelligent life should arise on any given planet, and very improbable that intelligent life, once evolved, should succeed in becoming advanced enough to colonize space.
I am trying to sort out what are the moral and ethical implications of humans not being the most intelligent or advanced species it is aware of.