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Was There a Civilization on Earth Before Humans?
- mycall 8y agoIf there was a civilization 50 million years ago, I would think some parallel species or genus would continue that DNA lineage to this day.
- gpm 8y agoWould geostationary satellites from a previous civilization still be orbiting in an approximately geostationary orbit? Or would they have been perturbed enough that they would either exit earth orbit or impact earth? Or pounded into dust by collisions? If a previous civilization had metal-based moon landers, would we likely have found them/found areas with an unlikely amount of metal on the moon? Or would they have probably been obliterated by meteorites by now?
- scottie_m 8y agoIt depends? If the satellites used chemical rockets to produce stationkeeping thrust then they’d be long gone, but if they used some exotic power source who knows? If they had a good AI and power, there is no real limit on how long they could stay in orbit. If they were using technology like ours they’d be gone, but a hypothetical civilization might use exotic materials and power sources that would stand the test of time. For the moon thing, the above applies, but assuming that they were obliterated we’d have to get pretty lucky to detect their remains. They could also be totally intact because there would be essentially no weathering, they would never be buried by shifting regolith, and so on.
- eunoia 8y agoHow much stationkeeping does a geostationary satellite have to do to remain in orbit over a long time scale? I would think not much?
- ianai 8y agoI think none if positioned well enough.
- gpm 8y agoThings like the moon will perturb it - orbits assume a 2-body system when we are strictly speaking in a (chaotic) n-body system. Over millions of years that will add up, honestly I'm hoping someone else will do the math/research and figure out if they add up to enough that they wouldn't still be orbiting earth.
- ianai 8y agoThat’s my point though. The moon hasn’t degraded and crashed into the earth so it’s clearly possible for a satellite to orbit the earth indefinitely - for some suitable definition of indefinite.
- gpm 8y agoThe moon's stability is a good point, but not conclusive. The moon's orbit isn't perturbed by it's own gravity. It's also much larger, so much more mass (radius cubed)/surface area (radius squared), so less affected by solar wind, micro meteor impacts, and the like.
- pxi 8y agoBut still, it's more likely we'd find evidence of a distant past civilisation on the moon than on earth right?
- scottie_m 8y ago
- pndy 8y agoHave you seen Battlestar Galactica, the 2004 series ending to be exact? The Colonials after long and "bumpy" journey arrived on our Earth and in order to start anew they decided to abandon all technological advancements by setting their fleet on a collision course with the Sun. We can't exclude the possibility that previous civilization also decided or was forced to abandon all its technology due to reasons known to them - that is, if they were enough advanced to have space-reaching technology.
- sovande 8y agoA geo-stationary satellite can stay in orbit for billions of years. I’m surprised this was not mentioned in the article at all.
- aaron695 8y agoWiki says no. We can't/see no need to keep them in place short term. https://en.m.wikipedia.org/wiki/Geosynchronous_orbit https://en.m.wikipedia.org/wiki/Geosynchronous_orbit A perfectly stable geostationary orbit is an ideal that can only be approximated. In practice the satellite drifts out of this orbit because of perturbations such as the solar wind, radiation pressure, variations in the Earth's gravitational field, and the gravitational effect of the Moon and Sun, and thrusters are used to maintain the orbit in a process known as station-keeping.
- wool_gather 8y ago> And then there’s all that plastic ... creating a layer that could persist for geological timescales. Won't the plastic eventually turn back into oil, on geologic timescales? Or are the conditions for that too specific to be relied on? Or am I completely mistaken, and oil->plastic is basically one-way?
- hyperman1 8y agoIve heard there is too much oxygen in the air now for the original oil forming processes
- JumpCrisscross 8y ago> there is too much oxygen in the air now for the original oil forming processes This is addressed in the article: “...our work also opened up the speculative possibility that some planets might have fossil-fuel-driven cycles of civilization building and collapse. If a civilization uses fossil fuels, the climate change they trigger can lead to a large decrease in ocean oxygen levels. These low oxygen levels (called ocean anoxia) help trigger the conditions needed for making fossil fuels like oil and coal in the first place.”
- _plastics 8y agoThe plastic that humans create will disintegrate and crumble into dust, but over very long time scales. When we pull crude petroleum from the earth, it's mostly fossilized plants from the carboniferous period. It's a deposit of stabilized mixtures, sealed in a natural chamber, air-tight and pressurized deep underground. Humans take the stable mixture out of its pressurized environment, bleed off volatile compounds, distill and crack with heat, separate groups of solvents from precipitates, and sort out chemicals according to classification. Plastics sourced from tar and oil are only a portion of the volume of crude resources mined from the ground. Also, synthetic plastics are created from chemical processes that result in plastic from reacting feedstock. So, no, it's one way. Fossil fuels are the fossils of plants from a period long before animal life was even a kingdom that emerged from the sea. It's not going back into the ground to become that stuff. And plastics are an incomplete fraction of what the crude mixture was. It's the solid components robbed of all the volatile solvents, and cured into hard or rubbery chunks. Ultraviolet sunlight, heat without pressure, and kinetic impact damage will degrade and reduce objects to dried out, brittle ash over thousands of years. But those thousands of years are nothing, next to the many millions of years of metamorphic, subterranian tectonic action needed to create them within a mixture of sister compounds.
- vertline3 8y agoI think Neanderthals buried their dead and looked after their elderly @ shanidar cave site. Does this imply civilization?
- sgt101 8y agoI think it implies a sophisticated culture, but people say that civilisations are those cultures that create cities. It's a narrow conceptualisation, but it goes hand in hand with the capabilities to create technologies that significantly modify the environment in favour of the members of the culture doing the city building. I don't think that anyone has found any indication of Neanderthals using any sort of pottery, agriculture, domestication or metalwork. This is not to say that they didn't have poetry and mathematics and understandings of the world we would find interesting and unexpected, or that they didn't have any of these technology - it's just that there is no evidence at all that I am aware of.
- brownbat 8y agoI know they are focused on markers of industrial civilizations, but the prevalence of purpose built stone tools millions of years ago still blows my mind a little. https://en.m.wikipedia.org/wiki/Oldowan https://en.m.wikipedia.org/wiki/Oldowan
- all2 8y agoI always chuckle (and wonder at the veracity) when I find stuff like this: http://www.s8int.com/page8.html http://www.s8int.com/page8.html It makes me wonder if the Ancient Aliens guy might be partially right.
- speeq 8y ago> “Wait a second,” he said. “How do you know we’re the only time there’s been a civilization on our own planet?” Imagine for a moment that we're Martians who managed to terraform Earth because of some runaway climate catastrophe on Mars. That now, we're in the early stages of repeating the same mistakes because of some extinction event in the past that wiped out all of our prior history and knowledge.
- skookumchuck 8y agoWe're too similar to other life on earth for that to be credible.
- interestica 8y agoWe says we, the martians, didn't bring the other stuff with us?
- pdonis 8y agoLife has been on Earth for at least 3.8 billion years. All of the life on Earth today is descended from that original life. So if life on Earth originally came from Mars, it would have had to do so at least 3.8 billion years ago. But that's too close to the origin of the solar system as a whole for it to be credible that an industrial civilization could have evolved on Mars, caused a climate catastrophe, and then migrated to Earth.
- landryraccoon 8y agoI don't think it's at all likely that life on Earth originated on Mars, but if it did then there could have been cross pollination of microorganisms over billions of years due to meteor impacts on both worlds throwing bits of crust into space. In fact if we do find life on Mars at some point it wouldn't be shocking if they are quite similar to bacteria found on Earth, since they might just be descendants of earth bacteria carried over from the impact that killed the dinosaurs.
- evanb 8y agoThis reminds me of "The Habitable Epoch of the Early Universe" https://arxiv.org/abs/1312.0613 https://arxiv.org/abs/1312.0613 where it is pointed out that for some time during cosmological evolution, the universe would have been quite comfortable and rocky planets (if any existed) could have had liquid water, with no need to be in a Goldilocks zone---the whole universe was Goldilocks!
- emilfihlman 8y agoWhoa. Now this is super interesting!
- vatys 8y agoBack then everything would have also been so much closer together. The universe could have been like one great bustling city. Perhaps, from that perspective, we are already in some long-tail end-of-days time. Planets and stars and galaxies are so far apart as to make travel difficult or impossible.
- api 8y agoA science fiction story set in this time would be truly epic and beautiful.
- vatys 8y agoTruly. But a story which inevitably must end with expansion, cooling, and a new need to huddle around stars.
- mikeash 8y agoOur story inevitably ends with the Earth roasting and then freezing as the Sun ages. There’s still lots of good stuff to tell in the meantime.
- evanb 8y agoThe Integral Trees (Larry Niven, 1984) is about a society living in a ring of gas around a neutron star. Not quite the same, but a similar interesting astrophysical idea.
- interestica 8y agoAlan Weisman's "The World Without Us" is an interesting book/thought experiment that highlights just how fast the features and evidence of a civilization might be erased through natural processes. https://www.goodreads.com/book/show/248787.The_World_Without_Us https://www.goodreads.com/book/show/248787.The_World_Without...
- skookumchuck 8y ago"Inherit the Stars" by James Hogan is a good scifi story about this. Also "The Hab Theory" by Allan Eckert.
- fdavison 8y agoI really enjoyed the whole Giant series by Hogan. Star Trek Voyager had an episode with the idea of an ancient saurian species that left earth many millions of years ago. https://en.wikipedia.org/wiki/Distant_Origin https://en.wikipedia.org/wiki/Distant_Origin
- devoply 8y agoDid that come first or did Doctor Who do it first?
- pndy 8y agoI think TNG's The Chase is yet more interesting; it's also a shame its plot was never pick up again by series creators. https://en.wikipedia.org/wiki/The_Chase_(Star_Trek:_The_Next_Generation) https://en.wikipedia.org/wiki/The_Chase_(Star_Trek:_The_Next...
- scottlegrand2 8y agoI'm actually more interested in if there was ever some sort of extraterrestrial outpost on this planet in the past 1 billion years or so. At that time scale, exploring the entire galaxy seems reasonably practical. And stopping here to refuel and recuperate, not so unlikely, at least to me.
- human20190310 8y agoWouldn't it make more sense to acquire fuel from bodies with weaker gravity, so that you don't have to burn as much of it to get the rest back into space?
- Zhenya 8y agoYou're assuming they didn't have an anti-gravity engine
- krapp 8y agoThey didn't, because anti-gravity is not a technology that can actually exist.
- human20190310 8y agoWhy not?
- krapp 8y agoLike FTL, nothing in physics as we understand it, or that we've observed in the universe, allows for even the possibility of anti-gravity. Theories always require some magical fudge-factor like "negative mass" that, as far as we know, don't really exist either, and can't apply to our universe. As far as is known, the only way to generate gravity is mass, and the only way to counteract gravity is to push against it in the other direction hard enough, but that's just rocketry.
- vardump 8y ago
- interestica 8y agoOnline version of the original paper: "The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record?" https://www.cambridge.org/core/journals/international-journal-of-astrobiology/article/silurian-hypothesis-would-it-be-possible-to-detect-an-industrial-civilization-in-the-geological-record/77818514AA6907750B8F4339F7C70EC6/core-reader https://www.cambridge.org/core/journals/international-journa...
- ianai 8y agoMy best reasoning for why we may conclude we’re the first civilization here is the brain sizes seen before us in the fossil record other biological features. You need big brains (in absolute volume), tool use, and culture forming. Of course, just a guess.
- raverbashing 8y agoWell, humans are not the ones with the biggest brain volume right now, but the question stands: why other animals have not evolved bigger intelligence before.
- ianai 8y agoHence suggesting it’s more than just brain size that leads to civilization. Edit-this is also why I’ve never considered the threat of a singularity creating a malevolent super-AI to be serious. Larger brains do exist on earth and they only kill humans rarely.
- riffraff 8y agoin "the science of discworld"[0] this is touched upon through the nice example of: T-Rex have been on the planet for a few million years, they were huge, and we found a handful of their fossils. It is plausible (but not probable) that a civilization of smart lizards evolved and disappeared in 100k years without leaving any trace that we could find. [0] https://en.wikipedia.org/wiki/The_Science_of_Discworld https://en.wikipedia.org/wiki/The_Science_of_Discworld
- deburo 8y agoYou have to look at the brain-to-body mass ratio, but even that is not accurate by itself, you have to look at the encephalization quotient for a more accurate measure. As per the wikipedia's page on brain-to-body mass ratio.
- deleted 8y ago[deleted]
- sgt101 8y ago
- RikNieu 8y agoWhat interests me is the possibility of human civilizations between the Eemian and last glacial maximum. Any evidence of civilization from that period would either be hella deep under the sea or obliterated by glacial expansion and retreat. Homo sapiens have been here 300k years. I find it ridiculous to assume we only started living in cities about 5-7000 years ago. Conveniently the period immediately after the last rapid glacial retreat...
- sgt101 8y agoThere is some consistent evidence for the current timelines for human civilisation - although it's all sketchy. - complexity and type of tools & technology dug up - change in pollen due to agriculture - change in genetics of domesticated animals None of these (as far as I know) point to cities or civilisations that didn't have cities (if such a thing is conceivable, which it could be) way further back than the current records show.
- agumonkey 8y agodo you think large cities can exist without a record system ? or maybe we just have no traces of these records ?
- morkfromork 8y agoMaybe a past civilization created a simulation we are living in.
- marci 8y agoWhat do you mean by past? If we look like the Sims to them, the current player may find it funny that we refer to their Game Devs as being part of a past civilization, which could make them wonder if they're part of a sim...
- morkfromork 8y agoThe player downloaded the sim to a Universe Console, watched the big bang, eventually became bored and has moved on.
- totemandtoken 8y agoSomewhat incidentally, I was watching a Wisecrack episode on the philosophy of Tolkien which seemed to imply that his middle-earth universe was meant to be read as preceding our own history [0]. Following in that vein, I wonder what a high fantasy story that used prehistoric motifs would be like. Not a sci-fi story, actual fantasy. Instead of a high fantasy with elves and hobbits, maybe one with neanderthals and cro-magnons, but show them as having advanced, competing civilizations to homo sapiens. Maybe instead of increasing technical progress, we see primitive technologies evolve into living things like plants and animals. "Every sufficiently advanced civilization is indistinguishable from nature" as someone once wrote. Idk, I guess this doesn't add to the discussion, but it's stimulating to say the least. [0] https://www.youtube.com/watch?v=_-sTbaH-aA0 https://www.youtube.com/watch?v=_-sTbaH-aA0
- phs318u 8y agoI always liked this aspect of H.P.Lovecraft’s Chthulu mythos i.e. the allusion to the existence of pre-human civilisations (specifically in ‘Hyperborea’).
- zmkzrk 8y agoThis reminds me of the great short story "The Next Ten Billion Years" by John Michael Greer: http://archdruidmirror.blogspot.com/2017/06/the-next-ten-billion-years.html?m=1 http://archdruidmirror.blogspot.com/2017/06/the-next-ten-bil...
- martinpw 8y agoI liked this part from the "10000 years from now" section believers in most traditional religions declare piously that the climate changes of the last ten millennia are the results of human misbehavior, while rationalists insist that this is all superstition and the climate changes have perfectly natural causes.
- TMWNN 8y agoSCP-1115 [1] is proof! [1] http://www.scp-wiki.net/scp-1115 http://www.scp-wiki.net/scp-1115
- charliebrownau 8y agoWould they want to return to EARTH currently the Global SOCIALIST LEFT refuses to accept Facts Science Biology Common sense over the CULT of the NARRITIVE Most if not ALL Western society has been ruined via Socialism , the LEFT and "Diversity" Almost every part of western society is on the colapsing point due to refusal to look at problems and issues and corruption but hey SOCIALISM will SAVE america Just like it worked in RUSSIA CHINA AU NZ and Canada
- zaro 8y agoWell don't all the megalithic sites which are all over the planet suggest exactly that?
- zw123456 8y agoPerhaps dolphins are descendants of an ancient civilization, they evolved from land animals https://www.whalefacts.org/dolphin-adaptations/ https://www.whalefacts.org/dolphin-adaptations/ about 50 million years ago. Just imagining here, but what if they had an industrialized civilization that caused global warming that led to the PETM temperature rise, their civilization declined and they had to adapt to a water world. Chuckle, just a kooky thought I had after reading that article.
- grawprog 8y agoThis reminds me of a couple of old sci-fi series I read a long time ago. Michael Moorcock's The Dancers at the End of time series about the last of humanity that's become apathetic, decadent and godlike as all the stars die around them and they come up with a plan to travel back in time and start civilization earlier so humanity get get on its feet quicker, but discover time is cyclical. And another series, I wish I could read again but cannot remember the author or titles, but it was about a world where civilization ended because we'd genetically engineered ourselves and animals and everything into fairy tale creatures who overran everything. The whole time it seems like it's set in the future but it ends up the main characters become Adam and Eve and it implies all our current mythology came from the society that genetically engineered themselves out of existence.