So you know the Great Filter, right?

It’s what happens when you look up at the stars and ask “Where the fuck is everyone”.

There are so many planets out there, yet it’s radio silent. The intelligent life to planet ratio is really, bad. So far we’re the only ones.

You gotta ask, why?

Enter, the Great Filter. Something, at some point in the pipeline, prevents planets from developing and maintaining intelligent life capable of electromagnetic communication.

We don’t know what it is. Maybe it’s a quirk of chemistry that makes the chance of multicellular life forming ridiculously low. Maybe it’s a quirk of biology that makes sapience incredibly rare. Maybe it’s a hyper intelligent space worm that eats any civilisation that makes too much noise. Maybe it’s runaway climate change.

The thing is, we really don’t want to be on the wrong side of that filter, because that suggests that an imminent demise is in our civilisation’s future. And with every discovery of non-intelligent life on other planets, it becomes increasingly likely that we’re on the wrong side of that filter.

Enter, the recent discovery of life on Venus. It means that we’re much more likely to be on the wrong side.

But, watching that debate tonight, I began to feel a sense of relief. At least if we’re on the wrong side of the filter, it’s not as though we’re wasting a once-in-a-galaxy chance. We’re just yet another civilisation that failed to get past that filter. I can live with being unexceptionally mediocre.

  • science_pope [any]
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    4 years ago

    Enter, the recent discovery of life a class of chemicals in the atmosphere at higher concentrations than predicted by an atmospheric chemistry model with large uncertainties especially at mid-altitudes on Venus.

    • 90u9y8gb9t86vytv97g [they/them]
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      4 years ago

      The scientists that presented it were almost certain it is indication of life.

      They just can't confirm that without an actual probe, but there is literally no other explanation they could find.

      • science_pope [any]
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        4 years ago

        They considered it to be the most plausible explanation given that the atmosphere is vertically well-mixed on ~1000 year timescale. If that's not true for whatever reason, or if there are chemical pathways not captured by the model, then abiotic processes may account for the high concentrations they observed.

        My money is still on "not life," but only time and more probes will tell for sure.

  • duderium [he/him]
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    4 years ago

    Hard SF writer here, although I’m not a scientist. I read all the comments. I recommend people check out Richard Lewontin and Christopher Caudwell’s thoughts on science and dialectics. There’s a cool novel called “The Killing Star” which deals with this as well. Unfortunately I don’t think it’s online.

    Regarding the great filter, we’re pretty sure that single-celled life is at least common in the solar system, possibly thanks to unusually high concentrations of phosphorous in this region of space during the sun’s formation. (Life as we know it is impossible without phosphorus I believe—it’s part of ATP production (?) in cellular respiration.) If you play space engine, you learn pretty quickly that the galactic core is way too radioactive for multicellular life, meaning that anything complex is probably living elsewhere. As for detecting it, anything more advanced than us is probably using quantum entanglement rather than radio waves to communicate over interstellar distances. Current technology can’t detect that. Radio waves from civilizations similar to our own are probably just too weak to pick up. It’s also possible that the singularity, if it actually even happens, is not the end of so-called “evolution” or development. Some species may ascend to a godlike state that we aren’t able to understand. Or they may conclude that just hanging out on their homeworlds in a primitive communist state is best. Or maybe climate change or nuclear war does them in. We don’t know. What we do know is that you could use rockets to colonize the galaxy in a few million years, which is much less time than the Milky Way’s age. It seems like no one has tried to do that. But maybe they just didn’t come here!

    I think that not all stories about UFOs or alien abductions can be easily explained, and I also think that most scientists are rich liberals who are biased toward finding “realistic” explanations for things like possible Dyson Swarms, Oumuamua, life on Venus, Navy UFOs, etc. They’ll lose their cushy jobs if they start ranting about little green men. Mack’s book about alien abductions is pretty frightening, and the Harvard professor concluded (after talking with dozens of patients) that something was definitely up. He couldn’t say what it was, however. He also nearly lost his tenure at Harvard because of that.

    Anyway I think about this shit all the time and love that you guys are talking about it. Fingers crossed, in a few months I’ll have a trilogy of novels ready which are sort of like Star Trek: Enterprise but not shitty and way more muscular when it comes to communism. They’re going to be published as ebooks by a small publisher and should be pretty cheap, but I may be able to give them away here for free in exchange for reviews if anyone is interested.

  • Leon_Grotsky [comrade/them]
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    4 years ago

    I subscribe to "Reservation" theory, where there is a giant space sign that says 'CAUTION: NATIVE WILDLIFE MAY USE NUCLEAR ARMAMENTS' outside the solar system and aliens stay way the fuck away from us out of self-preservation.

  • Amorphous [any]
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    4 years ago

    I don't really agree with the "great filter" premise. There are two possibilities that seem more likely to me than just the idea that there never was and never will be another alien civilization out there looking to chat. First, faster-than-light anything is simply impossible. This simple fact rules out most sci-fi scenarios of communicating with or meeting alien civilizations. Second, it's entirely possible we are simply the first of many civilizations to become this advanced, which would explain why we're not hearing the radio-echoes of long-dead civilizations that got to the point we're at.

  • Mardoniush [she/her]
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    4 years ago

    Any contact with an alien civ will be disastrous to us or them, for evolutionary goal orientation/economic material conditions related reasons. A parasitic wasp is likely to be far closer to us in habits and desires than anything we'll meet out there. So either we meet and one wipes out the other, or we meet and one forcibly changes what we want as a species. Kind Civs would just lock them in a reasonable size bubble and move on.

    Luckily, unless they're super stealthed or very young, there are no Type1+ Civs in the Milky Way unless we are very, very bad interpreting our astronomical data.

    No Dyson swarms anywhere, No Sentient star clusters, No Black hole energy factories. Not even tight beam laser traffic within 5000 Lightyears. Not a trace of stellar scale mega-engineering to be seen.

    Of course, further out there's the Bootes Void and the Great Voids, Which are just a bit too large for standard cosmology models to explain, have a few very bright galactic clusters in the centre, and look an awful lot like someone turning off all the stars to conserve electricity (Hydrogen). We've got time before they're a problem, though

    • Obrus [she/her]
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      4 years ago

      Of course, there's the other possibility: There's no way to 'cheat' around relativity. Alcubierre drives are already posited to have the problem of creating massive bubbles of energy that would atomize the star system they're being used in. Tachyons are becoming less and less likely.

      Maybe the answer is that interstellar civilization just isn't feasible because the distance between stars is too great, and thus acquiring the resources for these grand space projects is an exercise in futility. A universe that isn't condusive to dyson spheres, or matrioshka brains, or multi-stellar polities. It could very well be that at best, the most advanced civilizations are a singular well-populated homeworld with a few small research colonies on other planets in their own solar system and maybe a few extrastellar colonies fed by generation ships that are just as likely to fail on their way to their destination as they are to make it there.

      • MarxGuns [comrade/them]
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        4 years ago

        My worst nightmare and seemingly the most realistic. It just makes things boring compared to the sci-fi I've consumed my entire life.

      • Mardoniush [she/her]
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        4 years ago

        You are thinking a bit too small. It would take, at the most conservative estimates 40 million years to conquer the Milky Way by small sublight constrction probes. That assumes no ftl, no advanced nanotech, no uploading or superhuman ai and no radical life extension.

        If you dont care about how long its going to take its more than possible. And every single intelligent civ has to decide this is too much effort for its entire lifetime, when it would take trivial energy expenditure for it to begin and the rewards would be extensive ("let's start moving more stars towards us for power", for instance)

        • Obrus [she/her]
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          4 years ago

          I mean, I don't see it as that unlikely. A consistent interest in a vision of expansion is in and of itself a feat, especially over millions of years, and more than that it's entirely within the realm, if not outright very likely, that sapient species in the industrialized, space-faring level of existence just aren't common. As you lower the numbers, the likelihood of them going "yeah, fuck taking a million years to accomplish something" as a whole becomes more and more plausible.

          The science of nanotech is also looking less amazing than initially thought, what with needing to keep them continuously powered, running into barriers of just how small you can make a computer and have it follow complex commands and so there's that, and uploading also comes into certain barriers already well-tread by anyone who's dipped into existential philosophy and Ship of Theseus and yadda yadda you almost certainly know the arguments and are probably bored of them by now. Rapidly self-improving AI is... Well, I just don't expect the Yudkowskian vision of a singularity sparking superintelligence that will kick us all the way up the Kardashev scale.

          Hell, if you want to move away from the problem of no relativity cheating, there's all sorts of other problems. If you want a space-faring species, you have so many hurdles to overcome. Naturally aquatic? Well, water and fluids in general are a lot heavier than gases and also a very disruptive to sensitive equipment. Carnivore or similar tertiary consumer? Good luck forming a sustainable urban society without causing a massive ecological collapse even faster than humans can. Hell, we don't even know if any of our senses are common out there in the cosmos. Sight seems almost mandatory if you're going out to space - optics are basically a necessity to let you know there is shit up there. Then of course when you're outside your ship, sound's not particularly useful since it needs a vector to travel through Maybe some sort of radio wave sensitivity would help. Of course a species would also need to be sturdy enough to stand the force of take-off into space, and also not die from extended time in zero-g (a problem we ourselves face). Could be there are plenty of species we would consider, in some way, intelligent and even sapient that just can't leave their planet for one reason or another and we are an anomaly on that front, being not so much 'suited' to space travel as... more capable of it?

          Or maybe there is a lot of spacefaring life but it's all so alien that even their structures and priorities pertaining to those structures are so vastly different from our own that we wouldn't even recognize what they've made as the product of an intelligent species. I've been mulling this over while very tired so my point has probably been muddled severely. Sorry.

    • diode [none/use name]
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      4 years ago

      Would stellar megastructures even make sense at all to be built? We all imagine the future as large space ships and dyson spheres and crap, but maybe it's fusion electricity and everyone living in a pod plugged in an anime matrix.

      • Mardoniush [she/her]
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        4 years ago

        Yes, it's possible the great filter is "everyone plays computer games". But you can run much better computer games much faster on a Matrioshka brain.

        That's also an answer, the accelerando hypothesis they all uploaded, spent upwards of a trillion subjective years doing stuff we can't imagine, and decayed in a few thousand objective years. Still, we should be able to see the ruins, but I'm not sure we've checked for what a Dyson swarm looks like after a billion years of neglect.

        The issue is it has to explain every civ from every plausible origin. It just takes one species to go expansionist in the real world and suddenly our planet is getting devoured by nanobots.

        • diode [none/use name]
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          edit-2
          4 years ago

          To me at least on paper a super large computer just sounds dumb. The smaller the computer the better. The larger the scale the slower the communication between parts. And if you want a super large network of computers, to me it makes way more sense to distribute that on the surface of the planet instead of hauling it to space. And hell cooling and powering it would be easier on earth probably, too. And of course a space computer will mean that anime matrix ping would be shit.

          Expansionism may be impossible, because of the scales involved and the impossibility of faster than light travel. I'm not sure how feasible those super large generational ships that are common in sci fi are. Maybe there isn't an energy source that could get you into the next galaxy and power your ship for centuries/millenniums. And honestly, it takes one accident, one civil war or mutiny, and the generational ship is over.

          • Mardoniush [she/her]
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            4 years ago

            It's not one computer. It's a very large number of networked computers in a swarm around the sun. The first shell uses the sun's light, the next shell uses the waste heat from the first shell etc. Its true there's a trade off between complexity of the computer and speed, you'd have microscopic fast thinkers mediating more complex machines all the way up to "jupiter brains"

            The problems of interstellar travel are easily solved by Von neumann probe. It's very unlikely that your alien invasion is by anything bigger than a coke can. It hits the outer Kupier belt and begins building. By the time you notice it's too late. Swarm noms solar system, turns it into habitat for host species if that's it's thing, makes a bunch of probe copies and launches them.

            • diode [none/use name]
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              edit-2
              4 years ago

              I still don't get how that computer would not overheat massively, current computers need cooling solutions and so would any complex computation, the computer is also getting blasted by full spectral radiation from the sun. Current electronics and ultra violet-gamma ray spectrum go about as well together as snails and salt. I honestly don't know what kinda computation wouldn't get interrupted by it. Biological and optical solutions would have problems as well.

              And of course, anime matrix ping is still shit.

              • Mardoniush [she/her]
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                4 years ago

                You make it a diamonoid (possibly ferrousoid to prevent melting on the inner shells) molecular rod logic device.

                You also make the architecture reversible to reduce heat, now most waste heat is from the entropy of the mechanical operation.

                stirling engines on the front to reduce the light to usable energy, heat radiators on the back to cool, computation moves down the energy gradient.

                All of these elements are very small.

                • diode [none/use name]
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                  4 years ago

                  The ultra violet-gamma spectrum will run havoc on molecular logic device, as well. And probably more so than on a transistor. Heat will also breakdown the molecules. And just radiating heat away is not feasible for the current computers (that are also around cold air, don't have that in space), but it will be enough to cool of a future computer, that is also being blasted by the sun?

                  And my waifu is teleporting all over the place, because anime matrix ping is so dog crap.

  • Vayeate [they/them]
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    4 years ago

    The intelligent life to planet ratio is really, bad.

    We don't have any evidence of this. It could in fact be really good, at least in terms of planets that have the conditions for sustaining animals of any sort.

    I think the more likely answer is one of two things:

    1. Sending communications between planets is really fucking difficult and takes a really long fucking time. Literally millions of years. It just hasn't happened yet towards Earth or it isn't possible for intelligent life.

    2. World ending events are not unheard of even on our planet and it's possible they're even more common on other planets. Even if intelligent life is common, perhaps it gets reset quite frequently too. Meaning that even though intelligent life is common, the overlap between our intelligent life and that of another planet could be mismatched by a million years or more very easily.

    Also, even though we "listen" for alien life, we have a pretty narrow range of coverage and not the best tools for doing it and may not even be looking for the right things.

  • Koa_lala [he/him]
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    4 years ago

    I like the theory that we are the first. That would be dope af.

    • Vayeate [they/them]
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      4 years ago

      There are 10,000,000,000,000,000,000,000,000 planets in the universe. Ignoring the stats on which planets in which areas of the universe are more likely to host life, you're more likely to win the lottery thousands of times in your own lifetime than Earth is to be the host of the first life in the universe.

      And that's only planets around stars, and only in the observable universe.

      • finale [he/him]
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        4 years ago

        It’s possible. Having a surface with both water and land is exceptionally rare and gives us a huge head start, as water is a better environment for the early stages of evolution while land is a better environment for intelligent life to arise. Also, coasts are an amazing environment for life to begin.

        And having tides makes our coasts even more volatile for combinations of amino acids. Not to mention Earth’s resource and biome diversity, which also encourages the development of intelligent life.

        There’s also all the other prerequisites for life to exist in the first place, which seem to be extraordinarily rare.

        • Vayeate [they/them]
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          edit-2
          4 years ago

          which seem to be extraordinarily rare.

          I think it's hard to make this conclusion. We know very little about planets outside our solar system. We can make guesses and some small measurements about their general composition but that's about it. We can't really tell if there's water or beaches or tides or anything else. We can only make guesses.

  • CEGBDFA [any]
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    4 years ago

    deleted by creator

  • Tychoxii [he/him, they/them]
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    4 years ago

    Hence, the only thing at the other side of the filter is space comrades

    Of course there multiple solutions other than self destruction. If rare Earth is true then we could very well be the most "advanced" civilisation in our galaxy which, good luck to the aliens if that's the case.

  • Zuzak [fae/faer, she/her]
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    4 years ago

    Eh. Assuming that life on Venus is confirmed (last I heard it was promising but still speculative),I think there's a good chance that it developed from the same source as life on Earth. I tend to think that the conditions for life developing from non-life are incredibly rare, which is why we can't recreate it and have no real idea of how it happens.

    Probability gets weird when it comes to existence and consciousness. A lot of pretty incredible things had to happen for human life to develop, if things didn't line up exactly right, we could easily have just not had air. But the thing is if they hadn't happened that way then we wouldn't be there to observe it not happening. It's survivorship bias. If you have to flip tails 20 times in a row in order to exist, then everyone who exists will have done it. This is known as the anthropic principle, from Wikipedia:

    The anthropic principle is a group of principles attempting to determine how statistically probable our observations of the universe are, given that we could only exist in a particular type of universe to start with. In other words, scientific observation of the universe would not even be possible if the laws of the universe had been incompatible with the development of sentient life.

    I think the anthropic principle explains how life can exist yet be so rare, without the need to assume that every possible species would be as fucked up as we are and nuke each other or let their own planet burn. Otoh, that's just my opinion because there's not really a scientific consensus on the matter, and the idea that life does develop often but burns out after civilization develops is certainly a valid possibility.

    • constantly_dabbing [none/use name]
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      4 years ago

      if things didn’t line up exactly right, we could easily have just not had air.

      Some dialectics of nature are actually very likely because common elements like oxygen work consistently

    • Not_irony [he/him]
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      edit-2
      4 years ago

      I somehow didn't figure out Paper Clips and basically got bored of it before the end game

      edit: but yeah, the great filter is likely just how big space is. The rocket fuel equation plus some sort of catabolic collapse could mean that its basically, mathematically impossible for advanced societies to expand in any meaningful way beyond their own planet, let along building structures large enough to be seen from across the void.

    • worker_democracy [they/them]
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      4 years ago

      Oh man, DO NOT read The Three Body Problem series then. It'll fuck you up.

      I'm 100% egalitarian commie for Humans and other Earth animals, but that book practically made me a Space Fascist when it comes to aliens. As in ... we need to hide from any life forms we can't destroy.

  • mazdak
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    1 year ago

    deleted by creator

    • Owl [he/him]
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      4 years ago

      The known factors seem like they should make life very common. A single factor that prevents this would be the simplest solution, so it's natural to assume it is. Being simpler is the only reason to assume it's a single great filter, though.