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Would it be possible to detect an industrial civilization in geological record?
- notional 6y agoArticle by the authors of this paper, https://www.theatlantic.com/science/archive/2018/04/are-we-earths-only-civilization/557180/ https://www.theatlantic.com/science/archive/2018/04/are-we-e...
- hn_throwaway_99 6y agoI admit I did not read the entire publication, but, at least at face value, this seems somewhat absurd to me. Within the past couple hundred years humans have built massive structures in cities that should last for many millions (hundreds of millions?) of years. I mean, Manhattan may be under water in 100 million years (or, much sooner), but all those gigantic steel, concrete, plastic and glass structures aren't just going to dissolve.
- digitaltrees 6y agoWouldn’t glaciers grind them to dust?
- ChuckMcM 6y agoI would guess that glaciers would encapsulate the skyscrapers and dislodge them from their foundation, and when they receded leaving a huge pile of steel and concrete. Even if that was later encapsulated by magma, future geologists would have to wonder about metal 'veins' that were so structured and why part of the rock was basalt and another part was an exceptionally hard and dense form of limestone. Note to self. Don't speculate on HN. Got it. :-)
- mcguire 6y agoThe oldest known iron artifacts, ca 3200BCE: https://ars.els-cdn.com/content/image/1-s2.0-S0305440313002057-gr3.jpg https://ars.els-cdn.com/content/image/1-s2.0-S03054403130020... https://www.sciencedirect.com/science/article/pii/S0305440313002057 https://www.sciencedirect.com/science/article/pii/S030544031...
- ChuckMcM 6y agoI wonder how it is that the iron in meteorites doesn't just dissolve away. Any thoughts on that?
- nraynaud 6y agoThe meteorites we find fell “recently”? The iron is in a stable oxide?
- ChuckMcM 6y agoI don't think so, meteoric iron (according to the wonderful blog series[1]) is early Egyptian. Iron (and steel) is stable outside the presence of oxygen and water. It doesn't just dissolve. And certainly if it were part of the steel reinforcement inside concrete in a building where special measures had been taken to insure that neither oxygen nor water would come in contact with it (as modern skyscrapers do) would persist for an exceptionally long time. But I'm just guessing ;-) [1] https://acoup.blog/2020/09/18/collections-iron-how-did-they-make-it-part-i-mining/ https://acoup.blog/2020/09/18/collections-iron-how-did-they-...
- analyte123 6y agoWhat about when the skyscraper’s pieces are submerged under saltwater for a million years? Or are covered up by a mile of river sediment and then plunged another 5 miles under the earth for several million years?
- mcguire 6y agoOr the concrete develops cracks, allowing water into the steel reinforcement, which expands, further cracking the concrete until it collapses. Like modern bridges.
- yxhuvud 6y agoIf there are two things the glaciers you mentioned a few posts back would accomplish it would be creating cracks that would expose things to water and oxygen, and also expose the resulting heaps to loads and loads of water. This is how stones found in glacial deposits look like: https://sv.wikipedia.org/wiki/Rullstens%C3%A5s#/media/Fil:Rullstens%C3%A5s_i_genomsk%C3%A4rning.JPG https://sv.wikipedia.org/wiki/Rullstens%C3%A5s#/media/Fil:Ru... Note how rounded all the stones are. And the stones that are there are generally speaking a LOT more resilient than any variant of limestone will ever be (including concrete).
- lmilcin 6y agoThere is better argument and it is surface natural resources. We know, that before industry took off we had huge amount of natural resources almost lying on the ground. Now many of crucial resources have to be dug from huge depths or recovered from dilute sources. I can't imagine a previous industrial civilization leaving huge amount of resources available on the surface. Almost by definition, industry is about scaling and efficiency and it always look to get to the results as quickly as possible.
- api 6y agoDepends on time frame. Plate tectonics will reset things quite a bit over truly vast time scales. Over shorter time scales this argument mostly holds, though one can imagine an intelligence with technology but with less expansionary drive and conspicuous consumption than humans. This intelligence may use resources more slowly.
- a1369209993 6y agoTo be fair, industrial-level civilization (engines, mass production, etc) doesn't actually require large, reinforced concrete structures[0]. That said, the answer to TFA's question is "almost certainly yes, unless they deliberately tried to conceal geological evidence of their existence, and probably even then". 0: nor vice versa, technically, though the logistics of using pre-industrial steel as building material would be prohibitive. see https://news.ycombinator.com/item?id=24591216 https://news.ycombinator.com/item?id=24591216
- gus_massa 6y agoThe steel doesn't last too much, this link claims only 1200 years. https://www.quora.com/How-long-can-stainless-steel-last-for#:~:text=316%20stainless%20steel%20is%20estimated,to%20a%20mere%20260%20years https://www.quora.com/How-long-can-stainless-steel-last-for#.... I'm not sure about that number, but the ancient the bronze swords are better conserved than the steel ones. Plastic will get washed away, and glass may get crunched and be difficult to find. The rest of the concrete has a longer lifetime.
- matchagaucho 6y agoThe Authors seem to be saying a visit to a barren planet shouldn't be written off as "no life". Evidence of civilization could be just below the surface.
- divbzero 6y agoIt sounds like “gigantic steel, concrete, plastic and glass structures aren’t just going to dissolve” really depends on timescale, and geologic timescales are far beyond our typical experience. From the Atlantic article by one of the authors: [1] [2] When it comes to direct evidence of an industrial civilization—things like cities, factories, and roads—the geologic record doesn’t go back past what’s called the Quaternary period 2.6 million years ago. For example, the oldest large-scale stretch of ancient surface lies in the Negev Desert. It’s “just” 1.8 million years old—older surfaces are mostly visible in cross section via something like a cliff face or rock cuts. Go back much further than the Quaternary, and everything has been turned over and crushed to dust. [1]: https://www.theatlantic.com/science/archive/2018/04/are-we-earths-only-civilization/557180/ https://www.theatlantic.com/science/archive/2018/04/are-we-e... [2]: https://news.ycombinator.com/item?id=24601382 https://news.ycombinator.com/item?id=24601382
- nabla9 6y agoIn periods of 100s of millions of years whole continents disappear or move around, new layers of rocks are formed and old layers are buried. The Rocky Mountains formed just 55 - 80 million years ago. Cities disappear completely. Concrete and glass becomes rock (again), steel is oxidized and is just layer of iron ore. Plastics degradate and breaks into nanoparticles. As the article speculates, most evidence would be likely something like synthetic biomarkers in deep sea sediments. Traces of industrial chemicals not produced naturally. Wrong chirality in some organic chemicals. Transuranic elements.
- friendlybus 6y agoSome zircons have been dated back to the hadean era, when the earth was forming. Any information for building something that sticks around long term would be contained in them.
- analyte123 6y agoThere are plenty of places within a two hour drive or train ride from NYC where you can see gigantic steel concrete and brick structures that are less than 150 years old well into the process of dissolving. If you live in prosperous cities and don’t have to maintain property, it’s understandable how you can be unfamiliar with the relentless processes of rust, melt-freeze weathering, erosion, storm damage, how quickly vegetation grows, and so on.
- ncmncm 6y agoEvery time this pops up on HN, people post insisting that it won't all go away, that the skyscrapers will, somehow, still be there. No, they won't. Look at any place in the world where there are mesas. All of the land around the mesa used to be level with the top of the mesa. It has all eroded away, and in only a few million years. So, the metals will corrode, collapse, and wash away. The stone will erode away. The concrete will erode away. The radioactives will decay. It will all end up as a millimeter-thick layer on the sea bottom, one of thousands of millimeter-thick layers with nothing to call attention to itself. Microplastics will abound, but somebody needs to be looking for them in exactly that layer, the way we found iridium at the K-T boundary layer, after specifically looking. There is a huge overabundance of platinum (parts-per-billion) in layers only 12900 years old, just discovered in the past decade, and only because we are really interested in that layer. (It was the start of the 1300-year Younger Dryas cold spell whose end is the start of the Holocene Epoch.) Will anything last? Big mining and quarry pits will fill in, but recognizably. Big mine tunnels will fill in or collapse, but recognizably. A rectangular mine shaft dug down through a thousand meters of sedimentary rock will have no other explanation. Some structures will be buried, instead of eroding away. Those will be deep underground, and then might be exposed again through subsequent erosion or uplift. Again, a brick chimney found buried will have no other explanation, though people will try. Strictly speaking, one is all you need, but some people ("people"?) need more convincing.
- imglorp 6y agoHas anyone methodically looked for artificial materials like microplastics in the geological strata?
- Retric 6y agoYes, in that people try and identify what’s there. No, in that it’s not expected to find evidence of a prior advanced civilization. The prior existence of oil as an easily recoverable resource is a strong indicator that nothing like our civilization existed in the last several million years.
- 6y ago
- tobinfricke 6y agoAbstract: "If an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today? We summarize the likely geological fingerprint of the Anthropocene, and demonstrate that while clear, it will not differ greatly in many respects from other known events in the geological record. We then propose tests that could plausibly distinguish an industrial cause from an otherwise naturally occurring climate event."
- jakeogh 6y agoExcellent yt chan: vlad9vt, just pictures of artifacts and structures set to music https://youtu.be/EHFe10dp0L4 https://youtu.be/EHFe10dp0L4
- AareyBaba 6y agoEvidence for ancient machining technology : Saw cuts, tube drill holes etc https://youtu.be/6KUDu40BC5o?t=1197 https://youtu.be/6KUDu40BC5o?t=1197
- ffhhj 6y agoA highly responsible civilization that achieves space fairing tech could rebuild its environment, leaving a clean planet as a gift for future species to emerge, and move to the stars. Sort of artifical-creationism, but phycally achievable, it's a matter of civilization goals.
- Zhenya 6y agoWhy would they spend resources doing this?
- ffhhj 6y agoMaybe morality, madness, a form of art, investment, or just-because-we-can...
- TeMPOraL 6y agoTo give the next species a chance to grow? While a stretch as a motivation, the Uplift saga by David Brin has this as a core point: ecology and biodiversity is important for all the species in these books; planets are leased and used for a while, and then lain fallow to let them regrow and potentially spawn more sentient beings that could then (be helped to) join the galactic community.
- foxdev 6y agoOtherwise you get species popping up later to find the device one of your people left that kills you in the plane of existence you transcended to. https://en.wikipedia.org/wiki/Stargate%3A_The_Ark_of_Truth https://en.wikipedia.org/wiki/Stargate%3A_The_Ark_of_Truth
- mjevans 6y agoRelated, I highly recommend the videogame Outer Wilds, which notably includes a 22 min timeloop, and, related to this I'll add a tiny spoiler; an extinct civilization that was responsible enough to not wreck the ecology of a world that could have intelligent life in their future.
- pmiller2 6y agoI’ve always loved this paper, for its particular combination of heterodoxy and emphasis on testable hypotheses. There are so many things we don’t know about past human civilizations that have left non-geological markers (who were the “Sea People,” the full story of Petra, tons of undeciphered ancient scripts, etc.) that it doesn’t seem terribly strange that an industrial civilization could have bloomed, died, left few traces, and what traces they did leave are the kind only a geochemist or paleoclimatologist might notice.
- stephc_int13 6y agoIf we can detect traces of life (fossils) I am pretty sure we can detect traces of many of the artefacts produced by an industrial civilization.
- crispyporkbites 6y agoI don’t know much about detecting traces of ancient civilisations, but I can definitely detect traces of someone who didn’t read the paper in your comment.
- aurizon 6y agoWhat areas on the earth have already endured for 65 million, 100 million,200, 300, 400, 500 million years already without changes? Obviously many areas have been subducted via plate tectonics and after volcanic transformation at depth would leave no artifacts. Would you find gold rings on dinosaur fingers? Gold watches? We know gold can endure, and if these prior saurian techies had adornments, they may end up in sediments that can endure. How to find them? Catscans and MRI imaging could show dense metallic residues in some cases. So far there have been scans done on a few fossils, but if they were not looking for residues of artifacts, such residues may not have attracted attention. Funerary buildings? Pyramids are only a few thousand years old and many millions would turn them to dust on the surface, and subducted ones = melted away. There has been time for a 200 million year old race to be very very hard to find - except on the moon's surface? If there was a moon project 200 million years ago, would gradual meteoric impacts over this time period have buried them beyond finding? Direct impacts would have destroyed them utterly. Indirect impacts gradually bury the surface of the moon with impact scattered rock powder. We know the moon is deeply cratered and has a deep coating of impact dust. Metal landers would endure and gradually get some feet of accumulated dust, but various metal detectors would find them - but a huge area would need to be searched. I assume good dino-engineers would use aluminum and titanium instead of steel/iron, so ferrous metal detectors would not work. Even good detectors of conductors are good for only a few feet. So we may never find evidence of the war between the warlike dinosaurs of earth versus the Insectoids of Ganymede - that was won so decisively by the insectoids 65 million years ago with their impactor...
- sunstone 6y agoSure if they were fond of atmosperic testing of nuclear weapons.
- Animats 6y agoThe oldest hard-rock mountains are 1.5 billion to 3.5 billion years ago. Those include some heavily mined areas, such as the Appalachians, If a previous civilization had been into serious mining, we'd probably have seen evidence of that by now. There may be nothing left of the mine, but an area without the good stuff and the remains of a big rubble dump would be interesting. Conversely, a concentration of rusted metal is not likely to occur naturally.
- phendrenad2 6y agoWouldn't metal dissolve over thousands of years? I'd be on the lookout for plastics.
- Animats 6y agoYou'll get rust, but huge piles of concentrated iron oxide in a low erosion zone are not found much in nature.
- nobody9999 6y ago> Wouldn't metal dissolve over thousands of years? I'd be on the lookout for plastics. That's not a bad idea, but finding synthetic isotopes[0] with extremely long half-lifes[1] (e.g., Tellurium-128) would clinch the deal. [0] https://en.wikipedia.org/wiki/Synthetic_radioisotope https://en.wikipedia.org/wiki/Synthetic_radioisotope [1] https://en.wikipedia.org/wiki/List_of_radioactive_nuclides_by_half-life#1030_seconds https://en.wikipedia.org/wiki/List_of_radioactive_nuclides_b...
- samatman 6y agoThat, and the real smoking gun: landfillite. Some significant fraction of landfills are going to fossilize into a pretty distinctive sedimentary rock. I don't know what it would look like, but it would have, like, fossil Barbie dolls in it. I don't think we'd have missed all of them if they existed. We could postulate an industrial civilization which just didn't make landfills? But we've only got ours to go on, and we really like burying trash. If our hypothetical forbearers were anything like us, we'd know about them.
- rbrbr 6y agoIsn’t a much easier way to look around our planet and search for satellites of past civilizations? Or even on the moon where everything lasts much longer. Long after we and everything of us is gone from this planet moon vehicles and other devices which were left there will likely still be there unless a meteorite hit them.
- yissp 6y agoI don't think satellites stay in orbit for very long - like a few decades at the very most.
- treis 6y agoDepends on their orbit. LEO will see drag from the atmosphere and will fall from orbit relatively quickly. Geostationary satellites will orbit basically forever.
- vlovich123 6y agoWon’t solar winds push it out of orbit in a geologically relatively short amount of time?
- nradov 6y agoSome of the Lagrange points allow for more stable orbits so would presumably be better places to look.
- rtsil 6y agoDepends on the orbit. Elon's roadster on its heliocentric orbit has a predicted half-life of 15 million years (1) The moon has been on orbit around the earth for billions of year and will probably remain on orbit forever (whatever "forever" means). (1) https://www.mdpi.com/2226-4310/5/2/57 https://www.mdpi.com/2226-4310/5/2/57
- Frost1x 6y agoI'd say the moon would be an obvious candidate to look at, though no guarantees.
- viach 6y agoMaybe be the remains of ancient civilizations could be found on orbit? Satellites can stay on geostactacionary orbit for a very long time. Some of them are sent to the "graveyard orbit" the radius of which was the same for Earth even millions years ago. Did anyone actually compared the number of objects there with the number of satellites we made?
- titzer 6y agoFTA: "The likelihood of objects surviving and being discovered is similarly unlikely. Zalasiewicz (2009)speculates about preservation of objects or their forms, but the current area of urbanization isless than 1% of the Earth’s surface (Schneider et al., 2009), and exposed sections and drillingsites for pre-Quaternary surfaces are orders of magnitude less as fractions of the original surface.Note that even for early human technology, complex objects are very rarely found. For instance,the Antikythera Mechanism (ca. 205 BCE) is a unique object until the Renaissance. Despiteimpressive recent gains in the ability to detect the wider impacts of civilization on landscapesand ecosystems (Kidwell, 2015), we conclude that for potential civilizations older than about 4Ma, the chances of finding direct evidence of their existence via objects or fossilized examples oftheir population is small. " These people have clearly never been to the beach--any beach. The oceans are absolutely chock full of our garbage and it is being deposited not only on the ocean floor, but on every shoreline the world over, where much is ground up and still more silted over. Plastic trash wafts the world over. Everything from beer cans to glass bottles to cars to aircraft are strewn through the entire industrialized world, in forests, creeks, and backyards. We have landfills the size of small towns. There are thousands of shipwrecks all over the oceans. Bazillions of items will be fossilized and preserved, and the odds of stumbling over something just digging anywhere will be very high. This article is completely full of shit. Humans have left their mark and our junk is going to be here, fossilized, for eternity. If we've discovered hundreds or thousands of fossilized dinosaurs from over 100 million years ago, when there might be only a few thousand such skeletons even to be found, there's a damn good bet that someone is going to find one of the tens of billions of beer cans or beer bottles that are lying around, even if only a tiny fraction survive the aeons.
- kadoban 6y agoYou've provided a good argument that it's obvious _right now_ from our junk that we live here, but what of that do you expect to last, and how long? Pick a type of object or two and let's look into how they are expected to last and what they'll look like. Fossilization isn't a universal process, there's no such thing as a fossilized beer can.
- kevin_thibedeau 6y ago
- user4682 6y agoThere are changes in the geological record that are still unexplained, these could be signs of an older civilization.ld "The Younger Dryas was a period of rapid cooling in the late Pleistocene 12,800 to 11,500 calendar years ago. It followed closely on the heels of a dramatically abrupt warming that brought the last Ice Age to a close (17,500 calendar years ago), lasted for about 1,300 years, then ended as abruptly as it started. The cause of these remarkably sudden climate changes has puzzled geologists and climatologists for decades and despite much effort to find the answer, can still only be considered enigmatic." https://wattsupwiththat.com/2012/06/19/the-intriguing-problem-of-the-younger-dryaswhat-does-it-mean-and-what-caused-it/ https://wattsupwiththat.com/2012/06/19/the-intriguing-proble...
- monkeydreams 6y agoYou are posting a climate-change denying site as your source for this? Consider me incredulous. Edit: From my quick perusal, the warming for the Younger Dryas period is not mysterious at all. The main theory is that there was a sudden cooling due to the failure of the Atlantic meridional overturning circulation around 12,900 BC. This cooling was then rapidly reversed back to the median warming trend about 11,700BC.
- ncmncm 6y agoYou have just pushed the mystery back a step. What caused the failure of the Atlantic meridional overturning circulation? What reversed the failure 1200-odd years later? Evidence for a bolide strike producing a huge meltwater pulse, to start the process, is accumulating, coinciding with extinction of 30+ genera and the sudden end of the Clovis culture. Another strike at the Holocene boundary is less well supported; but we do need a cause.
- dboreham 6y agoThere would be a thin layer of highly compressed shoes.
- thaumasiotes 6y agoConsidering we can measure Roman metal production by the pollution it left in ice deposits in Greenland, I'd have to say "yes".
- timoth3y 6y agoIt more convincing to look at it the other way. It's not what such civilizations would have left, but what they would have taken. Our early civilizations found easily accessible deposits or tin, copper, gold, etc that would have been depleted if another advanced civilization had existed in the past 10 million years or so.
- ksdale 6y ago"Depleted" in this case would just mean mined, transported, and made into something. It doesn't seem farfetched to imagine that, say, an electronics factory would be reduced to an easily accessible deposit of copper or gold in a few million years.
- nitwit005 6y agoIt depends how long the civilization is around. A lot of metal could end up impractical to mine. You can recycle metals, but little chips are being lost to wear and corrosion over time. We're slowly spreading small amounts everywhere. Some of that would be theoretically be recoverable with a lot of effort and energy, but some of it will basically be gone. No one is going to get back small bits of metal fallen off ships into the deep ocean.
- oh_sigh 6y agoTin was actually very hard to find. Which is a huge problem for civilizations that wanted to be a part of the Bronze age. Most of the tin used in Europe and western Asia was mined from just a few places in England, France, and Spain. if you find an Assyrian weapon from the 12th century BC in northern Iraq, it shouldn't surprise you if you find it was forged with tin mined in Cornwall.
- 74ls00 6y agoIIRC tin was one of main motivating factors for the Roman invasion of Britain
- cozzyd 6y agoOil, especially, would probably be less common if there was an ancient industrial civilization.
- jccooper 6y agoYes, over geologic time, nearly anything has no chance of survival. And, yes, the lifetime of such a civilization may be a window that is, geologically, basically invisible. But an industrial civilization makes a LOT of stuff, and much of that is quite durable and easily recognizable as artificial, and is likely to be scattered all over the planet. Given that there are places that preserve tracks over 300 million years old, and fossils, well, up to 4 billion years old, I have a hard time imagining that a worldwide civilization that's producing and using aluminum and titanium and ceramics and all sorts of other stuff on a wide basis would not leave something recognizable in basically all the available fossilizing environments. We might not ever find fossils of the species, but are we really not going to find anything from the million refuse dumps and cities and industrial facilities and whatnot, or millions of miles of roads, or the multi-billions of accidental losses bound to be all over the world? Not to mention objects in high orbit or on the lunar surface, which is a whole other thing. You have to posit a really limited civilization before I believe it.
- JoeAltmaier 6y agoIt wouldn't take a complex material to recognize a previous civilization. Their civil engineering activities would give them away completely. Archaeologists can read worked surfaces with amazing skill. E.g. a bed of pebbles could be a lake bed, a road surface, a floor inside a building, a foundation, and there's ways to distinguish them. Unless the soil was erased/reformed completely there would be a record of almost any activity, from digging a post hole or trench, to building a wall then removing it again then dumping construction waste into the hole then plowing it under. All are different from 'native' soils deposited by random processes. Geologic time is not enough to erase evidence of worked soils. Not unless it gets scrubbed to the bedrock and redeposited. And even if that happened some places, it wouldn't happen every place. And its fair to say today, that our civilization has been pretty much every place.
- sjy 6y agoGeologic time is certainly enough to erase evidence of worked soils. It spans billions of years, the destruction and formation of continents, and multiple global mass extinctions. Archaeology concerns only the last few million years of hominid activity.
- markwkw 6y agoSome tongue-in-cheek ideas: Stockpile of synthetic diamonds A few cemeteries could make for curious fossils Mines - some caves survived for 200+ million years. Conceivably a part of a mine somewhere could survive, with concrete structural reinforcements and parts of non-corroding tools intact
- teslaberry 6y agothe real question is , what kind of technologies and how much effort do you assume we would have to detect it? if a time traveller came to us, from the past , into the present ( which is possible if they discovered near speed of light travel) ---and they told us that an amazing civilization used to exist 300,000 years ago and they told us to spend billlions of dollars and tons of effort to look for it. i think we could accomplish that, especially if it were an international collaboration. now, if only a few academic anthropoligists in a few limited yet presitigoius universities were sent on missions to find it, we'd have much less of a chance. ---everything is probabilities. so the real question is, how much persuading would it take, to make enough people interested, as a collective, to raise the probability to become very likely.....what if some snake oil salesman told you he was from 300,000 years ago and travelled at .98c and slowed down to reach the present while everyone else died. how much 'proof' of that trip, would he need to covincne you to abandon your life now to become indiana jones, or to spend $5,000 of your savings on his non-profit search committee.
- WalterBright 6y agoImpressions of leaves are common in coal. Fossilized remains of industrial society would have been found by now.
- filoeleven 6y agoOne of my favorite quotes from Iain M. banks’ Culture series, paraphrased here since I don’t recall which book it’s in, is that technological progress is more like scaling a rock face than climbing a ladder. There is so much room for surprise and incomprehension. I sometimes think about how vast the parameter space of our physical universe is, and if that vastness means we wouldn’t be able to recognize ancient advanced technology if it’s far enough outside of our current mode of progress. My favorite example is handing an SD card with all of Wikipedia and the Gutenberg Project and maybe even the Wayback Machine on it to a Roman emperor. He’d look at it and might have a mild interest in the geometrical metal bits on an otherwise insignificant tiny flake of weird material. If the deliverer were to tell him that it contained millions of documents, he wouldn’t believe it. An expert in the field of storage media could, if for some reason permitted, spend years trying to explain it to the scholars of the time. Even if the expert succeeded in convincing them, it would take an unimaginable effort lasting lifetimes to ever make use of the thing. It would not succeed. Not because those people were stupid, but because the specialization that’s needed to understand the artifact is so far away from from their cultural knowledge and capabilities as to be unreachable. Why should we expect our culture be any different? The primary counter-argument to this is math and physics, and it’s a pretty strong one. It holds up quite well when dealing with past civilizations that are beneath or somewhere close to our current level of understanding. If you’ll permit another flight of fancy though, imagine an ancient society that figured out how to encode information in the irregularities of crystalline structures: every lame-ass quartz medallion we’ve unearthed could be the equivalent of a 10TB hard drive, and we’d never be the wiser. I think this is pretty unlikely, but it’s good to be humble and interrogate your assumptions.
- jacobr1 6y agoMy favourite example came from my 9th grade physics class, our textbook told a story that attempted to teach scientific method. Imagine a soda vending machine. Now imagine that I tell you that when you insert money and press the buttons, small goblins are can see what buttons are being pressed, take the money and it put it in a box, and then hand you the selected soda. The textbook even had helpful diagrams that seemed plausible (presuming you had such creatures). Now tell me why this is or isn't so ... and prove it even! How many of you have ever opened up or observed a vending machine (well, on HN I bet that number is surpassingly high, but presume you haven't). It was fantastic exercise in intellectual humility. For your SD Card example though, I'll nitpick. Sure, just a card and explanation won't get you very far ... but I think something like an iPad (with a good power-supply) would produce enough evidence to convince them (depending upon the individual, I grant there might be some who just attributed it to supernatural forces even in the face evidence and explanation). I suspect humans in general are more willing to deal with "blackbox" technology that has practical application than most tinker types on HN would admit. Very little historical technology that was hard earned with trail-and-error has a theoretical basis known to even skilled practitioners. Even today, to most most people I know, the technology they use on a daily might as well be magic. Sure they know there some kind of "science" beyond it, but I'm also not sure they could convince me it wasn't just goblins if I demanded some theory of it worked.
- sjy 6y agoI’m never sure whether to trust arXiv papers outside my field, so I checked and found that the paper was published in the International Journal of Astrobiology, and the PDF is open access: 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 https://www.cambridge.org/core/journals/international-journa...
- 8bitsrule 6y agoThere have been many civilizations on Earth, maybe not many were industrial (ancient Egypt was clearly semi-industrial so far as lithic tooling is concerned.) We haven't looked deep enough very much. Many of the 10-25,000 year sites are buried dozens of feet underground. If there are any previous ruins, they're probably a hundred-or-more feet down. Seaside ruins from 10k+ years ago are now under 400 feet of water and 10k+ years of sediment. We've just started to notice evidence of major changes only 13k years back ... with more on the way. Over 100,000 years, water has scoured (and deeply buried) much of the surface. Consider the number of glaciations in the past 2M years ... each one of which has scoured the surface in northern regions repeatedly. Much farther back than that, and most geo- and bio-records are erased. The planet's dynamics would have scrubbed almost anything before 10 million years ago. There've been 400 of those; 5 major extinctions left some traces. The scale of upheavals has been massive. How long ago did the Andes arise? It was first noticed in the 1700s that Whole sections of the Earth's surface have gone missing. https://en.wikipedia.org/wiki/Hutton%27s_Unconformity https://en.wikipedia.org/wiki/Hutton%27s_Unconformity
- ardit33 6y agook... i get your point, but the major counterpoint: as earth / plate tectonic move around, underneath earth is constantly surfaced... from dinosaur fragments, to Cambrian era mollusks found in top of mountains (due to earth's crust movement). If there was a previous 'intelligent' civilization previous to us, they would have altered their environment to be detectable to us even today.
- candiodari 6y agoExactly. Mullusks. Think of them like ants. Almost exclusively small dinosaurs. Things that would have been everywhere, including many places civilization would never choose to go. They are things that would be much more widespread than gameboys (just giving an example).
- 8bitsrule 6y agoOK then let's find it. We're not really looking. Maybe it is indeed detectable, and maybe it will be hard. Maybe it's already staring us in the face, and our ideas about it are -wrong-. We -believed- the Clovis story. Until some people -looked harder-. Plate tectonics ... laughed at. Until some people -looked harder-. Absence of evidence is not evidence of absence.
- hashtagmarkup 6y agoThey may genetically engineer strange beasts that would live on as seemingly gradual improvements on existing beasts. Likely they would reflect on their actions and devolve to ashamedly destroy each other and any record of what had become of them. #Platypus
- rmtech 6y agoYes, it will definitely be possible via hundreds of different pathways, some of which they thought of in the paper and others that they didn't. > The Anthropocene layer in ocean sediment will be abrupt and multi-variate, consisting of seemingly concurrent specific peaks in multiple geochemical proxies, biomarkers, elemental composition, and mineralogy. It will likely demarcate a clear transition of faunal taxa prior to the event compared to afterwards. Most of the individual markers will not be unique in the context of Earth history, but the combination of tracers may be. However, we speculate that some specific tracers that would be unique, specifically persistent synthetic molecules, plastics, and (potentially) very long-lived radioactive fallout in the event of nuclear catastrophe. One that they didn't mention was our artifacts on the moon which will last 100 million years or so. Geostationary and HEO satellites will stay for a while but I'm not exactly sure how long. However if you wait 50 million years or so, most of the stuff on earth won't be obvious and you would need to check very carefully.
- dvdkhlng 6y ago> One that they didn't mention was our artifacts on the moon which will last 100 million years or so. Geostationary and HEO satellites will stay for a while but I'm not exactly sure how long. Erosion due to micrometeorites erodes the surface of the moon at 1mm per 1e6 years [1]. I wonder whether erosion of human-made moon artifacts will commence at a comparable rate. Note that the hull thickness of the apollo lander is just 0.3 mm [2]. Part of the propulsion system, tanks etc. would be the components to last longest, butt 100 million years may be quite a stretch. [1] https://mauricejscollins.wixsite.com/moonscience https://mauricejscollins.wixsite.com/moonscience [2] https://space.stackexchange.com/questions/924/what-would-have-happened-if-the-skin-of-an-apollo-lunar-module-was-ruptured https://space.stackexchange.com/questions/924/what-would-hav...
- rmtech 6y agoWell, 100mm is not that much, I suspect there is something in all that stuff that is at least that thick. Maybe the bags of excrement? That would be pretty funny.