42 ms·
We are definitely not alone. The great filter, in my opinion, does not exist. It's only the vastness of space and the relatively short time a civilization produ
by callamdelaney 4y ago
We are definitely not alone. The great filter, in my opinion, does not exist. It's only the vastness of space and the relatively short time a civilization produces radio signals that makes it appear this way.
- bpodgursky 4y agoThat's a pretty shallow view of the Great Filter. Your implicit assumption is that not a single other intelligent species decided to harness the universe by, for example, consuming stars for their raw matter, or building Dyson spheres to black out entire sections of the sky. It is imo on you to explain why there's a hard cap on the exponential growth of intelligent life that prevents it from EVER reorganizing the universe in its own image. Not 99% of the time — that's not enough for these purposes.
- Ekaros 4y agoThe truth might be than physics are harsh mistress and there is no way to cheat. Thus actually working extra system space colonization is just not something that we or anyone else can do. Maybe even technology to do stellar engineering is out of reach.
- kevin_thibedeau 4y agoSpace colonization is best done by robotic ships. These could very well be plying the galaxy and just staying away from primitive life.
- jhgb 4y agoYou should still be able to see them, even from distance, if they have any reasonable power output. Stealth doesn't really work in space.
- cpuguy83 4y agoHaven't we lost satellites that are just orbiting our own planet?
- jhgb 4y agoMaybe we have, but those don't emit terawatts of power while trying to propel themselves in interstellar space.
- giantrobot 4y agoYou can only get so much power before something vaporizes. Some sort of ship emitting enough power to be detected at a non-trivial distance from Earth (see inverse square law) would vaporize itself. Just because stealth in space doesn't work doesn't automatically mean you can see everything in space at all times. We need to build giant telescopes to see stars thanks to the inverse square law. The bigger our telescopes with better light collection the narrower their field of view. An antimatter spaceship could fly past Pluto tomorrow and we could easily miss it since we can't monitor all 4πr^2 of the sky at once with powerful telescopes.
- jhgb 4y ago> Some sort of ship emitting enough power to be detected at a non-trivial distance from Earth (see inverse square law) would vaporize itself. Then you can say goodbye to those robotic spaceships. Note that I'm not claiming that they're possible -- I'm just saying that if they do exist, they're very detectable. > An antimatter spaceship could fly past Pluto tomorrow and we could easily miss it We can detect Voyager from way past Pluto, even though it emits only several dozen watts. I'm not sure how you'd miss an antimatter-powered spaceship at a comparable distance.
- dotnet00 4y agoTo be fair, we know exactly where Voyager is and know to look for it. It would be pretty hard to detect otherwise.
- zabzonk 4y ago> Space colonization is best done by robotic ships. But why do it? If you send a robot to (say) Alpha Centauri what have you actually acheived, at probably enormous cost?
- coenhyde 4y agoTo establish supply lines. If Alpha Centauri has something of value you could send out a self replicating robotic AI entity. It establishes its footing then start sending deliveries to Earth. If each one way trip takes 50 years, after say 120 years you could have a steady supply of resources.
- crygin 4y agoWe have no evidence that we will ever be able to build sufficiently adaptable systems to engage with unfamiliar environments without constant direct human intervention, which is not possible at light-year (or even light-second) ranges.
- goatlover 4y agoWould Alpha Centauri have resources we lack in our solar system? Mars, Venus, The asteroid belt, various moons and gas giants should be ample for anything we need.
- asdff 4y agoIt's also a hedge against issues with our sun.
- TheOtherHobbes 4y agoThis has always seemed like a hopeless star-eyed and wildly impractical idea. So your robot ship turns up and what happens then? If it's going to self-replicate it needs to recreate most of the features of an entire industrial civilisation. In our terms that would be metal refinement, chip manufacture, chemical life support and more - all done by bug-free software running on hardware which is perfectly error-free and reliable and lasts indefinitely. If it's going to seed biological (or equivalent) colonists it needs to be clever enough to find candidate planets with an ideal biosphere and no biological threats. Then it needs to teach the colonists how to survive and colonise. A lot of SETI and colonisation seems to be based a naive idea that all you have to do is get from A to B and you've solved your expansion problem. In reality propulsion is just the loading screen. Winning the game is a much harder challenge. So many things that can break, fail, be destroyed by chance, or go wrong because of design flaws that it's an insanely difficult problem without very much more advanced tech.
- bpodgursky 4y agoOk, but to be clear, this is an argument that there IS a "Great Filter". It's just a Great Filter that is in front of us rather than behind us.
- SemanticStrengh 4y agono this is a filter to technological progress/expansion, not a filter to life appearance and sustainability in the universe..
- Jach 4y agoIt seems some people in this thread need a reminder of what the Great Filter is: https://mason.gmu.edu/~rhanson/greatfilter.html https://mason.gmu.edu/~rhanson/greatfilter.html
- koheripbal 4y agoThe concept of the Great Filter is a shallow view on evolution. Humans are likely at the end of our biological evolution. The next steps of human artificial evolution will accelerate which means extra terrestrial intelligence is unrecognizable to us currently. We look for modern human-like civilizations, and those obviously won't exist much.
- asdff 4y agoHumans are not at the end of our biological evolution. Who produces offspring is still a matter of fitness.
- elorant 4y agoThe Great Filter can be a myriad of things. From how improbable life is to the hostility of the Universe. A magnetar has a hiccup and it sterilizes everything in a fifty light year radius. There are a shit ton of things out there that could eradicate life.
- danlugo92 4y agoWikipedia says closest magnetar is 50k light years from earth...
- elorant 4y agoAnd the closest Neutron star is 200 ly away moving our way, thankfully in a safe distance in some 300.000 years. Had this thing flung in a short distance it could disturb planetary trajectories. Supernovas can have the same effect as magnetars, as also black holes. There could even be a tiny one lurking in the outskirts of our solar system (the so-called planet 9). What I wanted to point out is that the Universe is a very hostile place. There could have been myriads of civilization that were eradicated because of a cosmic event every now and then.
- est31 4y agoHow is a black hole of the mass of a planet more dangerous than a planet of the mass of a planet?
- elorant 4y agoA black hole can emit gamma rays.
- jjcon 4y agoBlack holes do not emit gamma rays... black holes emit nothing (aside from potentially hawking radiation). Matter around supermassive black holes can give off gamma rays but planet massed black holes are just as likely to cause gamma as planets themselves are.
- nine_k 4y agoAny civilization that realizes that they are not alone quickly stops bleeding RF signals to outer space, or at least learns to mask them as natural. Chances that two civilizations, if they detect each other, would be on the same level of development are slim. And once a less technologically advanced civilization meets a more technologically advanced one, game is over soon. Ask Aztecs, or Sioux, or pick any other historical example.
- CamperBob2 4y agoThe masking is just a natural result of technological development. We can pick up recognizable signals only from civilizations that have worked out electromagnetic theory but have not yet developed information theory. 50-100 years is probably par for that particular course. A very narrow timespan in the grand scheme of things.
- surge 4y agoEven now we've adopted encryption, which appears sufficiently random. How long til all signals are just encrypted by default. Anyone picking up those signals would have a hard time proving they're not noise.
- CamperBob2 4y agoYep, and that's another layer of noise on top of the noise that results from efficient spectrum utilization. Only n00bs transmit carriers or intelligible sidebands.
- dotnet00 4y agoPlus our receivers have gotten more sensitive allowing us to reduce transmit power and a lot of systems use much higher frequencies, which are attenuated more strongly in atmosphere. With another 100-200 years of progress it would probably be pretty hard to pick up a radio signal (that isn't intentionally broadcast) at all from the nearest stars.
- 4y ago
- babelfish 4y agoSociety is about to Great Filter itself away over the next thousand years with climate change…
- marcosdumay 4y agoThe great filter is something with odds around 10^-30 of surviving. It's hard to find any convincing argument that climate change will destroy our civilization with anything near 1/2 odds. It's a completely different ballpark.
- asdff 4y agoHow can you even put odds on something like this?
- ben_w 4y agoI think it’s a definitional thing: “a great filter” assumes that life is basically everywhere and yet one specific something (or perhaps as many as “a few”) almost always prevents it from taking over a significant fraction of its future light cone. If there are 10^30 stars in ours, the lower bound on the odds of surpassing it have to be close to that. Personally I expect there to be many smaller filters rather than a few great filters — 30 things each with a factor of 10 has the same effect, after all.
- marcosdumay 4y agoPersonally, abiogenesis by itself looks like something on the 10^-60 to 10^-140 range, so it fully explains everything. Anyway, there are indeed a few things in our past that look like a 10^-10 odds filter, like each time our genetic encoding changed to increase our codons and the oxygen catastrophe. There are more that look like merely "almost impossible to survive" (I'd guess some ~10^-4 filter) like large asteroid impacts, but not nearly enough to make a difference.
- colechristensen 4y agoEh it might suck for a while but I really doubt that the situation will go beyond human survivability.
- goatlover 4y agoYou're assuming the probability for life, or at least intelligent life forming, is a lot greater than the amount of habitable places in the observable universe, such that there would be many civilizations. But we don't know what the probability is. It could be rather low, approaching the number of habitable worlds, such that we're alone or very rare, spread apart by vast distances of space and time. Would explain the lack of evidence just as well.
- naikrovek 4y agoI'd bet that the types of life that may exist in the universe far outclass our narrow definition of life. I get why we only look for life like ours, and I'm quite sure we're excluding the vast majority of life by narrowing the scope so much. I'm saying that there are absolutely many more habitable planets around than we believe there to be, even among the planets we've observed. We just don't know what to look for, because we don't know what's possible. "Life, uh, finds a way."
- sph 4y agoThat's just a fallacy because we're life and surrounded by life and want to believe it's everywhere. But the little we've explored of space, it's just dead rocks. There is literally nothing that has suggested a hint of life outside our atmosphere. I'm not completely discounting alien life, I'm saying all we have now is hope, wishful thinking and not a shred of proof.
- neuronic 4y agoIt's not a fallacy because that would imply you know better. You don't. Wishful thinking maybe, but not a fallacy.
- taylorius 4y agoWhy is it a fallacy to believe life is elsewhere in the universe? It seems the most likely possibility to me. Of course we have no proof either way - because we've not really looked anywhere (we're not able to, yet), apart from the moon, and a few tens of square metres of Mars (both of which we knew, a priori were barren rocks - but at least they're not too far away). That doesn't make the idea of other life in the universe "wishful thinking", surely?
- Razengan 4y agoWhenever someone asks about why we haven’t seen aliens yet if there are any out there, ask them about dinosaurs: We wouldn’t even have known about such different life ON THIS VERY PLANET if we hadn’t chanced upon their remains And we will never see them again.
- demygale 4y agoIt may be that the vastness of time is the real filter. We may not be alone but our reach can’t span the time between us and our nearest neighbors
- jonathankoren 4y agoThat’s functionally alone.
- jonathanstrange 4y agoRight now I rather believe in the Great Filter. If you look at e.g. Climate Change and the current war mongering including unprecedented nuclear threats, it's hard to imagine the current technical civilization is long-term survivable. During the next 500 years we will get delayed genetic weapons that can eradicate all of mankind, intelligent killer robots, probably even weapons that can destroy a whole solar system, in combination with exhausting all of Earth's natural resources. I used to be more positive but looking at our own behavior and judging that most intelligent life might evolve from former predators and technology involves heavy resource exploitation, the Great Filter seems quite credible. It's also worth noting that long-term space survivability seems to be extremely hard to achieve, we haven't even managed to create long-term sustainable fully closed biospheres yet.
- closedloop129 4y agoWhy would you need a biosphere? You need processes that turn energy into nutrients. Those processes can be entirely chemical or cell-culture based.
- patentatt 4y agoOne possible solution to the great filter is that we're 'first.' It usually gets dismissed out of hand as both improbable and egotistical (or whatever the whole species level equivalent is). But it's also not impossible, and whatever species was 'first' would always think it improbable that they were first, but there has to be a first (if there are eventually more). Since there are so many unknown unknowns in discussing the great filter or the Drake equation, I'd even argue that being 'first' has as much merit as any other explanation for why we don't see other advanced life out there (even if it's statistically unlikely itself).