If nothing else, this thread suggests some interesting possibilities for science fiction.
A civilization emerges briefly at the end of Jurassic. What geological evidence would we find today?
Stephen Baxter actually presented his take on some of these exact scenarios in his novel Evolution, including a brief dinosaurian culture in the Jurassic and the relics of human civilization after (IIRC) 5,000, 30 million, and 400 million years after the fall of humanity.
Such as a short story on the astroarcheological exploration of ancient LaGrange graffitti. Besides Evil Captor’s pyramid installation piece, what’s likely to be there. Be bold.
Glass is an amorphous solid, but at room temperature, it is not a slow moving liquid, not even over a time scale of millions of years. This is a persistent scientific urban legend that usually pops up in terms of cathedral glass.
As noted in this article about a May 1998 study published in the American Journal of Physics:
Arthur C. Clarke wrote that one a while ago (though he put his signal device on the moon). Stanley Kubrick liked the idea so much, he made a movie out of it.
But those rocks have been buried very, very deep and are hugely altered metamorphic rocks. The conclusions made from them about ancient mountain building and arc collision are mostly based on chemical and mineralogical analysis-- there’s definitely nothing like sedimentary structures that give us direct insight into smaller-scale processes at work at the time. Plus the only reason why you can see them is that the overlying rocks were scoured away by glaciers. Since the cycle of ice ages will continue after we’re gone, we would expect most man-made landforms up there to be destroyed by glaciers mere thousands of years from now.
Plus tectonically stable areas are bad for taphonomy because there’s the oft-overlooked fact that discovery is just as important as preservation. In other words, if something gets buried somewhere where it’s not going to be disturbed, even if it’s perfectly preserved nobody’s ever going to know about it because it’ll never get up to the surface. If you’re looking for fossils (or lost civilzations), you need to head for the mountains.
But all that said, there are some pretty old sedimentary rocks in the world. For example most of the rocks you find in Glacier National Park are from a stupendously thick sequence of 800 million to 1.4 billion year old sedimentary rocks (the Belt supergroup). Little things like ripple marks, mudcracks and bacterial mats are preserved in exquisite detail-- they look like they dried yesterday. If there had been a civilization living in that ancient sedimentary basin there definitely would have been evidence of it.
I know they are metamorphic rocks. The point is not that the rocks there now are sedimentary, but that they are geologically stable now. People today blasting stuff, like highways, through those rocks will leave scars that are (a) visible to observers (we aren’t talking deep mines here) and (b) will last a very, very long time. I doubt that they will all be destroyed by glaciers. Glaciers are great for scraping the loose soil and sand away, and can in some cases leave scars in the rock by grinding other rocks over them, but I dunno if they routinely carve away great masses of bedrock; and even if they do, they will not do so everywhere.
If you happened to break open a rock from the 20,000 year window when they were around. Again, long odds.
Well, consider ignorance fought then. I thought I read somewhere that glass deformed substantially over million year time periods, but if it would take time scales such as that quoted in your article then I’d say that this would pretty conclusively answer the question in the OP…there have to be literally billions of glass artifacts on earth today, and if they would remain essentially intact (assuming they didn’t get broken) even on time scales of hundreds of millions of years then odds are that something would turn up from our theoretical Jurassic civilization at some point.
I seem to recall that there was an article on this by The Master at some point, but I couldn’t find it and don’t remember what he had to say (about glass that is). A search using ‘glass’ doesn’t turn up anything, so perhaps I’m misremembering. At any rate, thanks for the correction.
-XT
As robby points out, a glass bottle (or a pane of glass) won’t just slump on its own. However, glass is both brittle and not very wear resistant, as anyone who has found glass pebbles lying on a beach can attest to. (These rounded glass “pebbles” are the remains of bottles broken in a large lake or ocean which are worn smooth by wave action, which only takes months or a few years.) Over a span of millions of years with successive glacial action, floods, thermal cycles, et cetera, no glass bottle would be identifiable.
Aside from the debate over fossilization of osseous tissue, it is worthwhile to note that while Neolithic-age human technology is based upon the use of hard minerals, and “modern” age technology (3000 BCE to the middle of the 20th century) uses malleable metals (mainly copper, tin, iron, nickel, and aluminum), modern technology is increasingly focused on the use of materials that are easily reclaimed and, incidentally, won’t hold up against wind and weather over the long haul. While we decry non-biodegradable plastics, the fact is that even Styrofoam and disposable diapers will be dissolved into their constituent molecules well inside of a hundred millennia , and over geologic timescales even our most robust structures will be worn or corroded into their basic forms. If an ancient civilization formed that was based upon biochemical technology rather than mechanical tools (such as cephalopod-based intelligence), its detritus may not even be as durable as our modern plastics and silicates, and would leave virtually no fossil records.
Stranger
Re: Moon/meteors
Would micrometeorites act as an erosion force on metal structures?
One could say the same thing for the body of a small animal with delicate bone structures…after millions of years with successive glacial action, floods, thermal cycles, etc etc, nothing would remain intact…certainly, not all together. And yet, we have such fossils that are nearly intact, even down to small delicate bones. Or foot prints. Or the bodies of small insects.
Making a bold statement that ‘no glass bottle would be identifiable’ is a pretty bold claim. Even if the odds of such a bottle or glass object remaining intact are one in a billion (which is may times the odds of a fossil happening, IIRC), then there would still be a good chance that something would remain, since there are billions of such artifacts.
That’s true, though you never know what might be buried in such a way that, if nothing else, the imprint of the artifact at least could survive, long after the materials that make it up are long gone. For that matter, couldn’t the same processes that cause bone to fossilize happen to just about anything, given the right conditions? I seem to recall someone trying to fossilize a shoe or something like that as part of an experiment and at least partially succeeding at it. Then, of course, we have a lot of things that are built on a more permanent basis, or built in more sheltered areas. There are the gold vaults at Fort Knox, for instance, or some of the underground shelters or depositories scattered throughout the world. An abandoned city (a la Life Without Humans) in, say, New Orleans could be rapidly covered in water and mud and at least some of the artifacts there preserved…or one in one of the deserts covered in sand. Or, possibly an already buried city that hasn’t been found (say, something like Pompeii) could eventually be uncovered far in the future.
Good point. It would depend on what technology they were using and how wide spread they were. If they were using all biological or organic based technology then, even if they were as developed as we are (though it’s hard to imagine that happening), there might not be any sign of it at all. I wrote a short story along these lines a couple of years ago, though it was not the main theme.
-XT
The original question was about civilisations similar to ours.
Im trying to imagine a completely biochemical based civilisation with no significant use of materials available to hand like stone or glass before that. Doesnt seem very likely to me.
Otara
Soda-lime glass is a particularly fungible material that is not only readily disintegrated by grinding action and thermal cycling but is also dissolved by even the trace amounts of naturally occurring hydrofluoric acid. Over the span of millions of years, standard bottle and float glass simply would not remain identifiable. Borosilicate glass may survive longer, but even over geologic timescales would not retain a visible form except by the very rare occurrence of being completely submerged in an inert, mechanically stable matrix.
No, and this misapprehension seems to be at the crux of why there is a limit of resolution int he fossil record. The only structures that can themselves fossilize are structures that contain or absorb and are replaced by minerals before they decompose. Because of this, virtually no soft tissues or metal components can fossilize, as they’ll just decompose or dissolve without replacement. As a rule, only skeletal structures and other osseous tissues can fossilize. There are also “trace fossils” like imprints that can be captured in fossil strata under just the right conditions (i.e. being buried in fresh volcanic ash and then covered by a layer of lava) but this is very rare.
As an example, the entire fossil record of Homo heidelbergensis, the precursor to H. sapiens that existed in Eurasia and Africa for roughly 300,000 years going extinct only about 350,000 years ago, consists of about a dozen sites, most of which provide only a handful of fossil fragments and a single biface quartzite axe. This is a species that existed in the last half million years, was an advanced tool-maker, had the most widely distributed population pre-H. sapiens save for H. erectus. If you go back to species if genus Homo that are over two million years old, the number of undisputed skeletal remains is only a handful, and there are hundred thousand year or longer gaps in the record. Discovering a mostly intact skeletal fossil of a species that existed more than ten million years ago, even species that existed for millions of years that were geographically widely distributed is a remarkable find. For instance, the Tyrannosaurids, a family of large dinosaurs that existed for a span of 10-12Mya in the Cretaceous period, has a fossil record of less than two hundred fossils that are >50% intact, and this is one of the most complete fossil records of any family in paleontology. It is also one of the rare instances in which soft tissue has been fossilized in more than trace amounts.
The number of anywhere-near-complete skeletons of land-based macrofauna from the Jurassic period can be counted in the dozens; most of the record are littoral species that lived and were buried in shallow sea beds. It is entirely plausible that an entire civilization could disappear without leaving an identifiable trace, even if they used hard tools and were geographically distributed over a wide area.
Stranger
One important difference being scavengers. Bone and organic residue for large creatures is usually consumed and only a very small proportion end up in situations where fossilisation has a reasonable chance for larger creatures.
There are any number of sedimentary options where far less vulnerable objects fall now, deep sea ooze and bottles being one obvious example. Hydrofluoric acid does occur naturally but is by no means universal, and of course is one way ‘fossils’ might also result - even if it leaches away, theres also the chance for an identifiable pattern to be left as a result.
I think you guys are being a bit too definite about this.
Otara
It would all depend on the conditions. There have been modern as well as ancient towns buried under lava and ash, drown in lake beds, etc…heck, we bury stuff deliberately in landfills, and I’m sure that if humans suddenly just disappeared for some reason (like a big ass rock hitting us and wiping us out), then some non-zero percentage of our current civilization and structures would equally be buried or covered over. Hell, without humans right now a large percentage of Pakistan and the structures there will be buried, same in India. There are also active volcano regions that could bury whatever remains before it decays away.
Also, the OP is not just talking about the civilization that existed at the collapse, but about the civilization going back 40k or so years into it’s past…presumably that would entail this theoretical civilizations stone age and new stone age time periods, which means we are talking about stone buildings
Hm…well, I didn’t know that the glass would break down like that. I’ve seen examples of glass dug up at archeological sites (and even seen natural glass from the Sahara), so assumed it would remain more or less intact unless it was shattered or fragmented by crushing or impact…even then, I assumed that the fragments could still be identifiable as made by some intelligence, as opposed to naturally occurring. At any rate, even if the glass deteriorated away, it’s going to take time, and the impression of a glass bottle might be just as definitive as the bottle itself…certainly, if while digging at a site someone came across just the form of such a bottle they would recognize it as something not likely to be formed naturally, and glass would last a long time before deteriorating…several thousands of years at least, based on the fact that we find glass at least that old that was manufactured by humans.
What about things like gold ingots or titanium artifacts (maybe the head of a golf club :p)? Gold doesn’t deteriorate afaik, and would remain essentially intact over just about any time span in just about any environment. Finding a vault that was formally used as a gold repository would certainly be a good indication of civilization, right?
We’re talking about a civilization (to use that term loosely) that is distributed world wide in just about every environment on earth (and including artifacts in great numbers in the sea itself)…mountains, deserts, arctic and sub-arctic, even the moon. I just don’t see how it’s possible that nothing from such a civilization would be preserved, even over time scales that would shift around continents and drown whole areas in the sea. Considering both the scale of land use AND environmental change, as well as artifacts, I’d say that it’s a near certainty that something would be left, even if it’s just the impression of a landfill preserved in sandstone or one of the tombs in the Valley of the Kings, buried under stand and uncovered when it’s pushed to the top of a future mountain range somewhere.
Over millions of years I assume that billions of dinosaurs roamed about, but most of them were eaten and scattered. Over 10’s of thousands of years humans have created many billions of artifacts, and some non-zero percentage of them are going to be in the sweet spot, luck wise, to be preserved…or, at least, to have some data about their composition and structure preserved. Like I said, even if the odds of any given artifact being preserved are billions to one, there are many billions of artifacts, and even finding just one would be evidence of something. If we found only as many such artifacts as we’ve found animals or other information from the Jurassic we’d have pretty conclusive proof that something was going on…and I don’t think that, given the numbers, it’s all that unlikely that we wouldn’t have found similar numbers of items from a civilization on the scale of human beings over the last 40k years. If nothing else, the lunar debris we left behind alone could potentially still be there hundreds of millions of years from now.
-XT
Of course, our civilization creates artifacts … MUCH hardier artifacts than hominids make … on a scale that is several orders of magnitude greater than our hominid ancestors … hell, greater than our pre-mass production ancestors … could possibly manage. Hell, I wonder how many million rifles there are? Gun barrels are made to contain explosions, they do not disintegrate easily. And there’s all those jewels. Each one not needing fossilization to last a very long time? I’m not sure analogies about pre-hominid tool users apply here.
That said, there are whole civilizations in South America that are only known from their potsherds, I understand. So maybe pre-industrial civilizations and industrial civilizations are very different in terms of their effect on the fossil record.
I believe that if a civilization similar to our own emerged at the end of the Jurassic and lasted as long as ours has thus far (certainly a geologically brief period), then the chances of it being discovered and identified as being technologically advanced are very good, despite reasonable arguments to the contrary. I think it’s simply a case of numbers (i.e. of fossils identifiable as being created by a technologically advanced civilization) and distribution (i.e. having those fossils distributed in areas likely to be found millions of years into the future).
Let me refer to this briefly-lived civilization as BLC. Where the BLC seems to fall most short on the short list of species discovered and identified via fossil record, is in the very brief period of its time-span on Earth (perhaps only hundreds of years outputting objects, that once fossilized, may be identified as being created by a technologically advanced civilization), compared to the millions of years most other discovered fossilized species have been on Earth. Indeed, it would be folly to expect a typical non-technological species to leave a fount of discoverable fossils, if its stay on Earth where a mere few hundred years. You have X number of individuals (most likely millions, on average), spread over Y number of years (hundreds) leaving a quite small Z number of potential fossils/individual (bones, teeth, feces, eggs, footprints…).
Compare that to our current species status: we have a larger X number of individuals (billions), spread over the same Y number of years (hundreds), but leaving a much larger number of potential fossils identifiable as being created by a technological civilization (a significant percentage of stuff the average human discards over a lifetime that has at least as much potential to fossilize as bones, teeth, feces, eggs and footprints…). Whereas each non-technological species individual may leave a few hundred potential fossils behind, I’m guessing the average human leaves behind tens or hundreds of thousands of *potential *fossils over a lifetime. This levels the playing field quite a bit, I believe.
In addition, I’m guessing that, under proper conditions for fossilization, a significant number of the things we leave behind, have a much greater chance of becoming fossilized, simply by virtue of their resistance to degradation. The longer an object remains in an environment conducive to fossilization, the greater its chance of doing so.If something as fleeting and fragile as a footprint may, under proper, though rare conditions, be fossilized and discovered millions of years later, what about the fossil potential of an object much more durable, dropped in the same environment? What if the same dinosaurs that walked the muddy river banks millions of years ago, also dropped coins out of their pockets? Would we not expect to find many more fossilized dino-coins than dino-footprints today? Surely, yes. I’ll leave it to the materials experts to determine the fossilization potential of other man-made objects (made of metals, ceramics, cut stones/gems, etc.) compared to bone, teeth, eggs and feces, but I’m guessing much of the man-made stuff has greater potential on average.
On top of that, many of our fossil-izable man-made objects are more likely to be discovered simply because of their great size, compared to the fossilized remains of non-technological species. T-Rex is no match for a fossilized skyscraper or locomotive when it comes to the "stumbling upon" it potential on an archeological dig, I’m sure.
I don’t completely buy the attribution problem with regard to identifying remains of a technological civilization, either—maybe for some items, but certainly not all, or even most. How difficult, for example, would it be for a future archeologist to identify something as simple as fossilized coin, as being artificially created? No telling what the future discovers may look like, of course—admittedly not likely to look like Washington’s profile on a US quarter—but, I’m guessing they will have heads and will be able to identify the coin’s obverse as being a graphical representation of some type of being. And, if one coin doesn’t convince them, certainly two identical fossilized coins would do the trick (you might find one potato chip what looks like Jesus, but two identical Jesus chips? No way). :dubious:
On average, how does our species compare to other species with fossilized records with regard to distribution? Well, we certainly live and discard things all over the world (including all the venues with conditions favorable to fossilization…heck, I’ve dropped enough objects in mud and silt over the years to be a one-man fossil machine all by myself), so here again, I think we gain additional fossil potential points.
I’m quite confident that a species much like our own would leave a significant fossil record and be highly discoverable millions of years later by advanced and motivated archeologists.
I think the key to the whole question lies in this paragraph.
What are the chances that a coin would, after tens of millions of years of weathering, pressure, continental drift, etc., still be recognizably coin-shaped and retain any visible relief image?
If it’s only billion-to-one odds, then we’ve produced so many coins that a future civilization would be sure to find some. But if it’s quintillion-to-one odds, then a future civilization would be lucky to find one vaguely-disk-shaped lump of metal, which wouldn’t be anything near reasonable evidence of our existence.
Of course it doesn’t have to be coins. If any of our artifacts have those kinds of odds, it only takes one. But what are the odds of cut diamonds, glass Coke bottles, or any of the other things people have mentioned surviving in a recognizable way for that long? I don’t think anyone’s answered that conclusively.
It may help to start from the opposite angle: What would we have to do to intentionally leave a permanent record of our existence? That might make it easier to compare what we’ve unintentionally done to what would be required. (And, even if t doesn’t help, it’s an interesting question in its own right.)
Too definite. Certainly, glass bottles exposed to the action of the sea and rocks will not survive - then, neither would an animal carcass under those conditions. But what about the practically numberless landfill sites, garbage dumps, casual bottle-tossings, etc? We have scattered bottles over most of the globe - I do not buy that none of them will survive.
To speak nothing of pottery, particularly those varieties of pottery such as porcelain - and modern ceramics used in industrial applications. Very tough. I simply do not believe, without evidence, that none of them - produced by the millions and by the billions, and intentionally buried in landfills and the like - would survive; and all it would take is one to be found.