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Hello D&D! This thread is a spin off of a discussion that happened in USPOL. Originally, we were discussing the Fermi Paradox and the prospect of distant alien life that may or may not exist, but feel free to discuss and debate other weird space poo poo like Nemesis Theory (probably not real) or whatever here. As long as it's about space or aliens or somehow adjacent to that, it's kosher itt. If you want to go to bat for the idea that aliens have visited Earth and there's government conspiracies to cover it up then more power to you I guess but I will lol at you. Please be respectful, I expect that this topic should be less controversial and high blood pressure inducing than your average D&D affair. Also don't be a weird gross dick about your evopsyche theories on human evolution or other racist poo poo, and try to root your arguments in good science please. Haystack posted:Aliens don't have interstellar civilizations for exactly the same reason humans never will: it costs way, way, waaaay too much energy, and is way too slow. A physicist on another forum I frequent broke it down like this: LtStorm posted:In USPOL there was mention of alien microbes living among us, including the idea that tardigrades are that. Tardigrades are definitely from Earth, but, there's still potential that microbes of an alien source could be hiding all over Earth and we just haven't spotted them yet. More likely, but also yet unproven, is the idea there is life that evolved on Earth alongside the life we know, but that we haven't noticed yet--it'd all be microbial also, most likely. mycomancy posted:Great topic LK! Here's my opinion as a molecular and synthetic biologist: there are three Great Filters of consequence, the Nucleosynthesis filter, the Intelligence filter, and the Synthetic Biology filter. mycomancy posted:Did you put my dumb, sleep deprived spelling error in there too? VitalSigns posted:Space predators being the resolution to the Fermi paradox seems unlikely to me because why would an alien species that doesn't share common descent like all life we've heretofore observed on Earth be able to naturally digest anything it finds here, let alone everything. LtStorm posted:I take issue with your issue. There's no guarantees silicon-based life would be rock anemones or stuck at the bottom of oceans. Well, no more guarantee than it'd be anything because we haven't met it yet. Now I get to talk about what I think about silicon chemistry! Lightning Knight fucked around with this message at 17:18 on Dec 10, 2018 |
# ? Nov 29, 2018 15:28 |
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# ? Jun 8, 2024 09:07 |
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https://www.youtube.com/watch?v=wdJvFMAbPF8 Bill Nye's take on the Fermi Paradox.
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# ? Nov 29, 2018 15:34 |
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Well now that we have our own thread for this, I'm going all in because I actually spent most of my youth devouring stuff on aliens and Area 51 and poo poo so I do have some viewpoints on this. But I think the simple one, adding onto Fermi a bit, is this: the universe is just unendingly, mind bendingly, soul crushingly huge and we're just one tiny, likely unremarkable part of it. If anything, the idea that aliens would come visit us instead of billions of other solar systems is just as self absorbed as thinking our star was the center of the entire universe. Who the gently caress are we? That may be part of it. But old, pre-9/11 X-Files stories of visits and coverups still sort of excite me just like they did back then. I do think it's interesting though, how "pilot saw something" is now a legit story that gets reported in the news, not something that causes the pilot to be laughed out of his job anymore.
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# ? Nov 29, 2018 15:40 |
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Great thread idea. One of my favorite resources is Isaac Arthur's Youtube channel/audio podcast, where he makes long-form videos breaking down the science behind insterstellar travel, building superstructures/massive, interstellar projects, and he also spends a ton of time on the Fermi Paradox. Each video can be 45 minutes long, but you get clearly organized videos that walk you through the theories, the scientific principles under-girding them, and even the calculations needed to make it happen. https://www.youtube.com/watch?v=rDPj5zI66LA The short version of his outlook is that he's an endless, Utopian optimist about the possibilities of mankind in space, but also makes very convincing arguments to the effect that there is no real answer to the Fermi Paradox other than intelligent life being ridiculously rare. edit: link fixed! sorry. Zoph fucked around with this message at 15:53 on Nov 29, 2018 |
# ? Nov 29, 2018 15:41 |
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My (very unscientific) take: It seems to me that life on Earth pops up wherever life is conceivably possible, no matter the odds. This would imply that IF life (as we understand it) behaves the same outside of Earth, all we really need to find it is to find habitable environments; if a place can harbor life, it WILL harbor life.
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# ? Nov 29, 2018 15:42 |
Continuing the arguments about the Great Filter from USPOL (for the uninitiated, Filters are basically hurdles that life has to cross getting from chemicals to star-hopping), I’m going to make a totally unresearched claim that the Filter to Civilization is being able to throw poo poo overhanded. Birds are capable of speech, there’s evidence that elephants have culture, but beaning a sabertooth in the noggin requires a good overhand chuck. And humans happily found that “chucking poo poo” is a field with boundless potential for innovation that something like termite fishing or oyster cracking just doesn’t match.
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# ? Nov 29, 2018 15:42 |
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Zophar posted:Great thread idea. One of my favorite resources is Isaac Arthur's Youtube channel/audio podcast, where he makes long-form videos breaking down the science behind insterstellar travel, building superstructures/massive, interstellar projects, and he also spends a ton of time on the Fermi Paradox. Each video can be 45 minutes long, but you get clearly organized videos that walk you through the theories, the scientific principles under-girding them, and even the calculations needed to make it happen. Your link gives me an error, just FYI.
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# ? Nov 29, 2018 15:49 |
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space aliens ate my balls OP
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# ? Nov 29, 2018 15:50 |
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Lightning Knight posted:Your link gives me an error, just FYI. Thanks, should work now.
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# ? Nov 29, 2018 15:53 |
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Zophar posted:Thanks, should work now. Yup! Demon Of The Fall posted:space aliens ate my balls OP Did they at least share a smoke with you after the fact?
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# ? Nov 29, 2018 15:53 |
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Intelligent aliens exist, but like us, are constrained to their own solar systems because you cannot innovate away the laws of physics no matter what Star Trek may have led you to believe. Relativity and radiation are a bitch, yo. This is also a good thing, because it prevents horrible space empires from ever being a thing.
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# ? Nov 29, 2018 15:58 |
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“Aliens don’t exist because we have millions of camera phones and no photographic evidence” doesn’t make sense. Most UFO sightings last seconds and camera phone sensors are about 1/4 the size of your pinky finger nail. I feel like I can’t even get a good photo of my cat unless the conditions are right, getting something in the sky 30 miles away during a fleeting sighting with likely suboptimal lighting is basically impossible.
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# ? Nov 29, 2018 15:59 |
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I suspect the great filter is probably multicellular life, probably the mitochondria step. It's the only thing in the history of life in this world that took a LONG TIME to happen, as opposed to being basically taking over every niche as fast as possible.
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# ? Nov 29, 2018 16:05 |
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There is intelligent life in the universe beyond us, because they built the simulation we are all living as lines of code within.
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# ? Nov 29, 2018 16:32 |
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Threads like this always devolve into "literally whatever political problem earth has right now, that is the great filter" 100% of the time. My answer to the fermi paradox is that without a clean alien free universe to compare to we have no way of knowing what minor meaningless anomalies we know about mean anything until some alien tells us and we retroactively know we detected tons of aliens all the time. Like an uncontacted tribe right now could see plane contrails every day but why jump to the conclusion "flying men are in that thing" when a sane person would just go "oh, guess that is one of the types of clouds that exist" like no one is out there telling them that rainbows are a regular part of nature, contrails aren't, the longer hotter summers are a thing people did somewhere but the earthquake is just a thing that happens sometime. Without context it's never going to be easy to know what is or isn't fully natural and thats stuff you could figure out eventually but there is literally no mystery in astronomy that has existed so long or so deep that we are even 1% of the way to saying "oh, it must be aliens, we studied this so in depth there is no way it couldn't be" even if ultimately something somewhere was. Like there is less than 1/3rd the amount of lithium in the universe current models say there should be, we should spend like at least a hundred years of trying to figure out how our model is wrong before ANYONE goes "an alien ate it" which is good science, but applies to everything and like, if an alien did eat it we aren't gonna know till we really really really exhaust every other way better possibility.
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# ? Nov 29, 2018 16:42 |
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The podcast The End of the World with Josh Clark talks a whole bunch about the Fermi Paradox and what the next Great Filter might be. It's a great listen, though I think it gets a little less interesting as it goes on. It's only ten parts, and it's just about done.
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# ? Nov 29, 2018 16:44 |
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Oh hey, what’s going on in here?
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# ? Nov 29, 2018 16:49 |
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Like here is a short list of some currently unsolved problems in astrophysics. You could write a sci-fi story about any of these being caused by aliens, but anyone suggesting that seriously should rightfully be kicked out of science, no one anywhere is anywhere near that stumped that anyone should be jumping to that conclusion, but that means humans are not actually far enough along to detect aliens at all. Our knowledge is way too simple to be anywhere near the point that we ruled out everything to the point we could look at something weird and go "yup, must be aliens". Maybe in a thousand more years of trying and failing to answer questions with more realistic answers. We need to know a hell of a lot more about the universe to be anywhere near the point we could see anything but bleep blorp the alien personally to detect something and say "yes, only explanation for this is aliens did it". We detect things we can't currently explain constantly, even knowing if anything meant anything is way beyond where we are. Even if something did. ---------- Astrophysical jet: Why do only certain accretion discs surrounding certain astronomical objects emit relativistic jets along their polar axes? Why are there quasi-periodic oscillations in many accretion discs?[33] Why does the period of these oscillations scale as the inverse of the mass of the central object?[34] Why are there sometimes overtones, and why do these appear at different frequency ratios in different objects?[35] Diffuse interstellar bands: What is responsible for the numerous interstellar absorption lines detected in astronomical spectra? Are they molecular in origin, and if so which molecules are responsible for them? How do they form? Supermassive black holes: What is the origin of the M-sigma relation between supermassive black hole mass and galaxy velocity dispersion?[36] How did the most distant quasars grow their supermassive black holes up to 1010 solar masses so early in the history of the universe? Rotation curve of a typical spiral galaxy: predicted (A) and observed (B). Can the discrepancy between the curves be attributed to dark matter? Kuiper cliff: Why does the number of objects in the Solar System's Kuiper belt fall off rapidly and unexpectedly beyond a radius of 50 astronomical units? Flyby anomaly: Why is the observed energy of satellites flying by Earth sometimes different by a minute amount from the value predicted by theory? Galaxy rotation problem: Is dark matter responsible for differences in observed and theoretical speed of stars revolving around the centre of galaxies, or is it something else? p-nuclei: What astrophysical process is responsible for the nucleogenesis of these rare isotopes? Ultra-high-energy cosmic ray:[17] Why is it that some cosmic rays appear to possess energies that are impossibly high, given that there are no sufficiently energetic cosmic ray sources near the Earth? Why is it that (apparently) some cosmic rays emitted by distant sources have energies above the Greisen–Zatsepin–Kuzmin limit?[4][17] Rotation rate of Saturn: Why does the magnetosphere of Saturn exhibit a (slowly changing) periodicity close to that at which the planet's clouds rotate? What is the true rotation rate of Saturn's deep interior?[37] Origin of magnetar magnetic field: What is the origin of magnetar magnetic field? Large-scale anisotropy: Is the universe at very large scales anisotropic, making the cosmological principle an invalid assumption? The number count and intensity dipole anisotropy in radio, NRAO VLA Sky Survey (NVSS) catalogue[38] is inconsistent with the local motion as derived from cosmic microwave background[39][40] and indicate an intrinsic dipole anisotropy. The same NVSS radio data also shows an intrinsic dipole in polarization density and degree of polarization[41] in the same direction as in number count and intensity. There are several other observation revealing large-scale anisotropy. The optical polarization from quasars shows polarization alignment over a very large scale of Gpc.[42][43][44] The cosmic-microwave-background data shows several features of anisotropy,[45][46][47][48] which are not consistent with the Big Bang model. Space roar: Why is space roar six times louder than expected? What is the source of space roar? Age–metallicity relation in the Galactic disk: Is there a universal age–metallicity relation (AMR) in the Galactic disk (both "thin" and "thick" parts of the disk)? Although in the local (primarily thin) disk of the Milky Way there is no evidence of a strong AMR,[49] a sample of 229 nearby "thick" disk stars has been used to investigate the existence of an age–metallicity relation in the Galactic thick disk, and indicate that there is an age–metallicity relation present in the thick disk.[50][51] Stellar ages from asteroseismology confirm the lack of any strong age-metallicity relation in the Galactic disc.[52] The lithium problem: Why is there a discrepancy between the amount of lithium-7 predicted to be produced in Big Bang nucleosynthesis and the amount observed in very old stars?[53] Ultraluminous pulsar: The ultraluminous X-ray source M82 X-2 was thought to be a black hole, but in October 2014 data from NASA's space-based X-ray telescope NuStar indicated that M82 X-2 is a pulsar many times brighter than the Eddington limit. Fast radio bursts: Transient radio pulses lasting only a few milliseconds, from emission regions thought to be no larger than a few hundred kilometres, and estimated to occur several hundred times a day. While several theories have been proposed, there is no generally accepted explanation for them. The only known repeating FRB emanates from a galaxy roughly 3 billion light years from Earth.[54][55]
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# ? Nov 29, 2018 16:59 |
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This thread is great and the Fermi Paradox is a legit fascinating thing. I read a great book on it last year: If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?: Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life The book covers a whole bunch of potential solutions to the Fermi Paradox from the super trivial (God is real and it only made humans) to the more complex (we live in the equivalent of the boonies of the galaxy) to the meta-physical (reality is simulated). Personally I think it's either that the universe is simulated, that space is really, really big and we just aren't close enough, or that we currently lack the method of communicating with other species and they don't care enough to use our methods to talk to us. The Great Filter is a rather scary prospect though and every time we find indications of life on other planets my heart sinks. At this point the only Great Filter candidate in the past is probably the development of eukaryotic life or the development of general, human-level intelligence. Everything else seems fairly common. And if the Great Filter hypothesis is correct, it's more likely it's in our future than our past which...isn't very reassuring. Anyway, go read that book I linked if you wanna learn about the Fermi Paradox. Also when I get some more time I'll write an effort posts about Our Mathematical Universe which had a very, very good explanation of known science about the Universe's formation and a pretty good hypothesis on how things fundamentally work that's a bit mind-blowing. edit: for those unfamiliar the Great Filter postulates that there is a "filtering" event that prevents most life from colonizing nearby places. Basically there's a process for making a space-faring civilization which is roughly: 1. Have the right star system (including organics and potentially habitable planets) 2. Star system must create reproductive molecules (e.g., RNA) 3. Simple (prokaryotic) single-cell life must be created 4. Simple life must evolve into complex (eukaryotic) single-cell life 5. Complex life must evolve to use sexual reproduction 6. Multi-cell life must evolve from sexually reproducing single-cell eukaryotic life 7. Tool-using animals with big brains must come into existence 8. Tool-using animals must make it to where humans are now 9. Colonization explosion happens If the Great Filter exists in steps 1-7 it means it's very likely that humans are alone. However if it's in steps 8 or 9 that's very, very bad for continued human existence. At this point the only early steps that look unlikely are 4 and maybe 7. edit 2: And for those not familiar with the Fermi Paradox, here it is laid out in the Drake Equation. The Drake equation is: N = R ∗ fp * ne * fl * fi * fc * L where: N = the number of civilizations in our galaxy with which communication might be possible (i.e. which are on our current past light cone); and R∗ = the average rate of star formation in our galaxy fp = the fraction of those stars that have planets ne = the average number of planets that can potentially support life per star that has planets fl = the fraction of planets that could support life that actually develop life at some point fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations) fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space L = the length of time for which such civilizations release detectable signals into space If you do out the math based on what we know, N should be a very, very high number and yet right now our observed N is 1 (us). So if that's the case one of the numbers here must be spectacularly low and it's unlikely its R, fp, or ne just based on what we've discovered in the last 20+ years. Which means you need at least one very low number for the equation to work out and some of them being low (e.g. fc) implies that humans are extremely likely to destroy themselves. The "good" news is that L is most likely the value that's really, really low as we already have seen our civilization move away from releasing detectable signals into space as things like terrestrial radio/TV are being deprecated. axeil fucked around with this message at 17:31 on Nov 29, 2018 |
# ? Nov 29, 2018 17:10 |
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Every single alien civilization has lived and died in its own home system. Even if FTL travel were possible (which it almost certainly is not), the resource costs of operating in space are too high. Gravity wells are a bitch, to say nothing of the radiation.
Haystack fucked around with this message at 17:22 on Nov 29, 2018 |
# ? Nov 29, 2018 17:19 |
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Haystack posted:Every single alien civilization has lived and died in its own home system. Even if FTL travel were possible (which it almost certainly is not), the resource costs of operating in space are too high. Gravity wells are a bitch, to say nothing of the radiation. What about von Neumann probes? https://en.wikipedia.org/wiki/Self-replicating_spacecraft#Von_Neumann_probes Why don't we see them? You'd only need 1 civilization around our tech level in the galaxy to decide to make them for us to likely see evidence of their existence.
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# ? Nov 29, 2018 17:29 |
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As just some idiot on the internet, I've found the idea quite compelling that as the universe expands, the distance between galaxies increases at such a speed that it makes even near-light speed travel between systems prohibitively difficult. I believe I picked up this idea from a Kurzgesagt video on YouTube, but is there anything more to this?
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# ? Nov 29, 2018 17:31 |
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feedmyleg posted:As just some idiot on the internet, I've found the idea quite compelling that as the universe expands, the distance between galaxies increases at such a speed that it makes even near-light speed travel between systems prohibitively difficult. I believe I picked up this idea from a Kurzgesagt video on YouTube, but is there anything more to this? There is more "space" in between everything in the universe in general as time goes on but on a local scale you have our galaxy generally occupying the same space and things are still moving toward us (e.g. the Andromeda galaxy) even as the universe on average moves away from us. The constant expansion of the universe is a good reason why everything will end up very cold and lonely in a trillion years, but I don't think it's a good explanation for why we're so lonely now.
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# ? Nov 29, 2018 17:33 |
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This is an older article but I share it whenever this topic comes up because it's a good summary of the various outcomes of the Great Filter: https://waitbutwhy.com/2014/05/fermi-paradox.html I'm personally a fan of the "we're first" outcome. There's another article (I don't remember enough details to find it and I might be getting some of these details wrong) where someone graphed the "complexity" of life on Earth and worked backwards to find that the origin "should" be before the universe formed, another point in favor of "we're first".
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# ? Nov 29, 2018 17:34 |
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A Wheezy Steampunk posted:This is an older article but I share it whenever this topic comes up because it's a good summary of the various outcomes of the Great Filter: Yeah that Wait But Why article is good and it's before the author completely lost his marbles talking about cryo-freezing his head and how Elon Musk is our savior. I'd be interested in reading that 2nd bit you talk about as it sounds interesting and lines up with the theory that you need a star of at least the 3rd generation to generate life because you need heavier elements.
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# ? Nov 29, 2018 17:36 |
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Haystack posted:Every single alien civilization has lived and died in its own home system. Even if FTL travel were possible (which it almost certainly is not), the resource costs of operating in space are too high. Gravity wells are a bitch, to say nothing of the radiation. Say the opposite, say that aliens are flying around everywhere in ships the size of buildings nonstop every day. Unless one was like, right here right now, why would we detect that? How would we detect that? If someone DID detect it why would "aliens" be a reasonable explanation instead of literally any other explanation. Like if there was a billion spaceships flying between random stars right this second what exactly are we supposed to have detected? radio waves? anonymous mass distribution? high energy particles? unexpected element distributions? we detect that sort of stuff all day every day and simply do not have any sort of information to determine why. We aren't gonna get a picture of an alien holding a sign or something.
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# ? Nov 29, 2018 17:36 |
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axeil posted:I'd be interested in reading that 2nd bit you talk about as it sounds interesting and lines up with the theory that you need a star of at least the 3rd generation to generate life because you need heavier elements. Found it after more searching! Here's the summary: https://www.technologyreview.com/s/513781/moores-law-and-the-origin-of-life/ and the original: https://arxiv.org/abs/1304.3381. I did have some of the details wrong, it wasn't before the universe formed, it was before the Earth formed: quote:Sharov and Gordon say that the evidence by this measure is clear. “Linear regression of genetic complexity (on a log scale) extrapolated back to just one base pair suggests the time of the origin of life = 9.7 ± 2.5 billion years ago,” they say.
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# ? Nov 29, 2018 17:45 |
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feedmyleg posted:As just some idiot on the internet, I've found the idea quite compelling that as the universe expands, the distance between galaxies increases at such a speed that it makes even near-light speed travel between systems prohibitively difficult. I believe I picked up this idea from a Kurzgesagt video on YouTube, but is there anything more to this? They also have a very popular video on the Fermi paradox, which looking at that waitbutwhy article, may be heavily based on it. https://www.youtube.com/watch?v=sNhhvQGsMEc Cool idea for a thread op.
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# ? Nov 29, 2018 17:47 |
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Here's what I wrote about this in the other thread: We're at the point in our technological development where we can reason about harnessing the energy of entire stars and colonizing an entire galaxy. The sort of stuff that is really easy to notice if anyone's done it, or has ever done it. Moreover we don't need a lot more technological advancement to get there: the biggest hurdle in fact is probably modifying our own bodies both to survive the trips between stars and to live long enough to make making the trip worthwhile for a single individual (and the second part is optional, strictly speaking, though we'd probably want to do it and almost certainly could do it provided we've already solved the first bit). Our actual space travel technology is pretty rudimentary but suitable for purpose, or nearly so, if we had more rugged bodies. Point being that even if we do destroy ourselves, we can conceive of another species similar to ourselves but a little less self-destructive and tribal, and consequently a little bit better at global civilization, which doesn't destroy itself. Instead, they build themselves better bodies and use space travel technology not much better than our own, to travel to other stars and within a few million years or so colonize an entire galaxy. And they build up their industry to the point that they can feasibly build Dyson spheres or Dyson swarms or what-have-you over the course of a few hundred thousand years or something, which is peanuts to an immortal species of intelligent life which has adapted itself to living in space. If we were to look at such a galaxy with a telescope, it would be immediately apparent to us that that galaxy was populated with intelligent life. We have found no such galaxy, in spite of a lot of looking. My guess is that if there is intelligent life like us in the universe it must occur only once in every several hundred thousand galaxies or so. Or maybe it's never occurred and we're the first. It doesn't mean that there will never be other intelligent life. There are a lot of red dwarf stars in the universe, and the planets orbiting them in their habitable zones have hundreds of billions or even in some cases a few trillion years to develop intelligent life. There may come an age of the universe where it is teeming with intelligent life all growing up and discovering one another, but it seems like that age is far off. Like "several multiples of the current age of the universe" far off. 1glitch0 posted:I think you might be looking at this from a very human-perspective. It's a very child-like analogy, but sixty years ago a computer took up an entire room and couldn't do a lot, now we all have one in our pockets that is infinitely more powerful. While we're looking for Dyson spheres or whatever, an advanced civilization might have the equivalent of an iPhone that can orbit a sun and give them all the energy they need. Or maybe colonization of entire galaxies with a large population isn't even the best path for an intelligent species to take. We only look for, and can only really look for, what we would consider advanced or can imagine. Maybe another species' environment or biology or technological path led them somewhere that we can't even comprehend. Dark matter is a complete mystery. And there's probably other many other mysteries we haven't even discovered that could go a long way to explain where everyone else is. Honestly I think part of the insistence that there must be other intelligent life out there is borne of a desire not to be human-centric just for the sake of not being human-centric. But unless we have a really, really flawed understanding of physics, we really are at essentially the very beginning of the history of life in the universe. Even if intelligent life formed immediately after the Big Bang, in the grand scheme of things humans arose not too long after that. The other consequence of this desire to not be human-centric is the idea that, well intelligent life exists it's just so advanced that it's really all around us and we can't possibly comprehend it. But it seems unlikely that all intelligent life would evolve technologically in such a way that they would be utterly imperceptible to us. That's a sort of hubris on it's own kinda, IMO I guess the point I'm driving at is this: I can step outside my front door, and see all around me incontrovertible evidence of the existence of life on Earth. If I stepped outside my front door and saw nothing but land devoid of any evidence of life no matter where I looked, I might start to guess that I was alone. Why would the universe be any different in this regard? e: also lmao get a load of this dickhead: i am harry posted:
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# ? Nov 29, 2018 17:50 |
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My personal bullshit theory is that there has to be something else besides us humans out there, because the universe might as well not exist if there's nothing capable of observing it.
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# ? Nov 29, 2018 18:00 |
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MSDOS KAPITAL posted:Here's what I wrote about this in the other thread: I love how your post can literally be boiled down to "Okay, BUT WHAT IF everything physicists have observed about our universe so far is 100% wrong and my favorite pulp fiction comic is right? What then, smartie pants?!?" Some people really don't like the idea that intelligent life in general, and humanity in particular, have far, far shorter shelf lives than they want to believe. We are not special, we will never be special, and we will all die out without having amounted to even the equivalent of a gnat's fart in terms of impact as far as the universe is concerned. Get over it, and yourself. Outer space is where everything goes to die, including and especially your hopes and dreams. Kerning Chameleon fucked around with this message at 18:13 on Nov 29, 2018 |
# ? Nov 29, 2018 18:08 |
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Kerning Chameleon posted:I love how your post can literally be boiled down to "Okay, BUT WHAT IF everything physicists have observed about our universe so far is 100% wrong and my favorite pulp fiction comic is right? What then, smartie pants?!?" This is a more doomsaying way than I would have put it but you have a point here: in the cosmic timeline of planets and stars forming and etc, our overall lifespan is a mere blip on the heart monitor. We'll have been around a few thousand years if we're lucky in a universe where millions of years can pass without anything notable happening nearby. The sheer odds of our short existence overlapping with some other spacefaring species' are long indeed.
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# ? Nov 29, 2018 18:22 |
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When you look at distant galaxies you're not seeing them as they are now, but as they were millions or even billions of years ago. It's impossible to know what the rest of the universe is like "now."
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# ? Nov 29, 2018 18:29 |
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Here's a horror movie type take on it: -Let's assume that life is extremely common and intelligent life is only slightly less common. -Let's further assume that the technological curve of any given civilization is similar to our own, i.e. an Industrial Revolution type event can make a military from the year 2000 completely obliterate every military combined on an 1800-era planet. -Let's also assume technology doesn't ever entirely stall out / there will always be some advancements to be made. -This means no two civilizations will ever be at the same stage of development and the more advanced civilization is extremely likely to technologically and militarily dominate the weaker one. Insert colonialism comparison here. -This also means the weaker civilization can never catch up without immense effort. -Based on the law of large numbers, any given civilization is vanishingly unlikely to be the most senior. Unless you're leading the Galactic Council and have personally checked, you can never be sure. -It is also vanishingly unlikely that all civilizations have the same benevolent mindset. Wholly benevolent civilizations could happen, but they themselves would never be sure there isn't a Big Bad out there. A Big Bad would also never know whether it was the biggest. Game theory suggests a preemptive arms race of some type is a certainty by at least some civilizations; even if they don't run into the Biggest Bad they could always come across an only slightly inferior and hyper militarized force. -If you don't have galactic FTL scanners and cannot check everything, how do you deal with this? What happens when you can build Dyson sphere type monuments but they're a galactic broadcast to anyone who uses the visual spectrum? Aren't you eventually marking yourself for death? If you're a sufficiently unified and late stage civ, I think the answer is that you pick a planet, build a big shell around it, put giant thrusters on it and sail off away from the galaxy into the deepest, darkest corner of space possible, trusting the unlikelihood of anyone checking that exact region for the next few trillion years. The only way to compete in a game like that is to remove yourself from the board and make sure no one ever finds you.
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# ? Nov 29, 2018 18:30 |
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VH4Ever posted:The sheer odds of our short existence overlapping with some other spacefaring species' are long indeed. This is why I think the "we're [among the] first" is the most likely explanation to the Fermi paradox. Prokaryotes were on their own for two billion years before eukaryotes came about, then another two billion to get to us. The universe is only around 14 billion years old and the early universe didn't contain any heavy elements as axiel pointed out. I don't think enough time has passed for intelligent life to bridge the vast distances of the universe, if that's even possible under the current physical laws governing the universe.
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# ? Nov 29, 2018 18:34 |
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Adar posted:Here's a horror movie type take on it: Isn't this similar to the Three Body Problem take? I've only read a summary. There's a lot of sci fi that uses malicious conquering races or all devouring Von Neumann machines as the solution for the Fermi paradox.
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# ? Nov 29, 2018 18:38 |
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MSDOS KAPITAL posted:If we were to look at such a galaxy with a telescope, it would be immediately apparent to us that that galaxy was populated with intelligent life. How? Name a single measurement we could make that any sane scientist in 2018 would look at and say "gotta be aliens". We already have galaxies that are wrong or against our predictions in every way imaginable, but that is because we are still very new to astrophysics and have a very very basic understanding of what the numbers even SHOULD be. Declaring anything aliens at this point would be madness. We literally do not have the tools to see an alien at this point or to know if anything we could see could even be a sign of an alien. Like we need like 500 more years of astrophysics to have any numbers solid enough to know something is wrong. The answer to the fermi paradox is "welp, we've looked no where and found nothing, time to give up" before even knowing enough to even know if we found something.
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# ? Nov 29, 2018 18:44 |
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My guess is that it's more likely that any sort of "filter" is just related to interstellar space travel being impossible (or impractical to the point of uselessness) for complex life, rather than something related to the development of life itself, or aspects of civilizations. I can pretty confidently say that simple life is virtually guaranteed to be extremely common, to the point where I wouldn't be surprised if it even exists elsewhere in our solar system. Complex life is trickier, because it took a very long time to develop on our own planet, and when you're talking about time periods on the order of "billions of years" the universe is actually pretty young. There's also the fact that, IIRC, a lot of the heavier elements necessary for life as we know it to exist didn't exist for the first couple generations of stars, limiting the time frame further. edit: I think it's still likely that other intelligent organisms confined to their own solar systems exist, though. Ytlaya fucked around with this message at 18:52 on Nov 29, 2018 |
# ? Nov 29, 2018 18:48 |
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zoux posted:Isn't this similar to the Three Body Problem take? I've only read a summary. There's a lot of sci fi that uses malicious conquering races or all devouring Von Neumann machines as the solution for the Fermi paradox. A little but not quite. Sci fi tends to focus on one race being conquered by another or an automated threat like von Neumanns. But even in those cases the conquerer or probe is not going to be the Biggest Bad, because across the entire universe the probability of that is effectively 0. In fact no sane race would ever deploy a von Neumann voluntarily because a Bigger Bad, which the probes will eventually always encounter, will trace them back to their source. The law of large numbers is a real bitch when you think in those terms. For the same reason, the simplest and possibly single most probable take on why we've seen nothing unusual is that everyone is hiding from everyone else.
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# ? Nov 29, 2018 18:49 |
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# ? Jun 8, 2024 09:07 |
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axeil posted:This thread is great and the Fermi Paradox is a legit fascinating thing. I read a great book on it last year: One thing which I've never really seen discussed is running the Drake Equation backward, an idea that came to me a couple years ago. Of the constants we see in it, there are a bunch for which we we now have fairly decently known values - R, fp, ne. Setting N=1, we could back out a value for the product of the remaining constants that should give us a ballpark estimate of what the terms must at least work out to be. https://arxiv.org/ftp/arxiv/papers/1705/1705.07816.pdf This paper gives values for R≈7/yr, fp=1, ne =0.2. The other terms are the "unknowns" that are kind of sociological in nature, we can call them "λ". Setting N = 1 gives us: 1/(R*fp*ne) = λ ≈ 0.714 So (fl*fi*fc*L) must work out to be greater than or equal to 0.714, because below that we can't account for our own existence.
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# ? Nov 29, 2018 18:54 |