Cite?
A civilization emerges briefly at the end of Jurassic. What geological evidence would we find today?
Not *so *rare as all that. All you need is an anoxic environment. Lakes, bogs, parts of the sea, these all qualify.
Cast fossils aren’t *that *rare. Many brachiopod fossils are steinkern, for example. Ammonite and gastropod *steinkern *are also not that rare. And, of course, Calamites stem casts are a fairly common Carboniferous plant fossil.
i think even styrofoam and plastic soda rings would biodegrade if given 100,000,000 years.
i think our only lasting contributions that could even make it that long would be the aforementioned cut gemstones, a thin layer of soot in the geological rock records, and an unexplained bald spot in the ozone.
Would we maybe find something like this?
That’s interesting. And a very good demonstration of the tendency to prefer a natural explanation. (Which is quite proper of course, but it means it would take an awful lot of unambiguous evidence to convince us of the existence of a Jurassic civilization.)
Agreed on all counts.
Firstly this was already mentioned earlier in the thread or in one of the older threads linked. Secondly I dont agree at all.
This isnt a bunch of radioactive matter by itself in an unusual mineral setting or anything like that, but a very large quantity of uranium ore with unusual isotope signatures. There is no credible manmade explanation for that, even if one considers it as a possibility.
As in we generally arent putting our reactors in the middle of uranium ore deposits. Its a very interesting phenomenon but the relevance seems awfully sketchy to me.
Otara
Exactly. Whereas finding large concentrations of uranium in the middle of a thick sedimentary rock package with no clear source (like the remains of an ancient nuclear power station) would be exceedingly difficult to explain naturally. Since nuke plants have to be sited near water, a lot of them are in estuaries or within the meander plains of rivers, so there’s probably a pretty good chance of them (or at least their fuel) making it into the rock record.
In summary…
At this point, in the spirit of the OP, I think it would be enlightening to divide the question into two distinct camps (1. those who believe the odds favor people today finding evidence of a civilization similar to ours, at this point in our technological development, 150-million years in the past, and 2. those who don’t), and then summarize our position. I’ll start.
I believe the odds favor discovery, simply because of the sheer number of *potential *fossils our species produces.
The argument against discovery: Correct me if I’m wrong, or incomplete, but from what I’ve gleaned from the “discovery is unlikely” side’s replies, the odds disfavor discovery because the number of *potential *fossils our species outputs, attributable to a technological society, falls too short of the mark. Primary reasons include:
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time span: our specie’s age is only in the 10’s of thousands yrs., civilizations’ age only thousands yrs., duration of significant production perhaps only 100’s yrs. Compare this with many species hypothesized to have existed, each of millions years duration, who have not left a fossil record, and humans fall woefully shy of the mark.
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Attribution: chances are great, so the argument goes, that even if a few human-type fossils are discovered, they would be attributed to natural causes, not of artificial provenance.
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Man-made objects, no matter what material they are composed of, will not persist for 100’s of millions of years.
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The primary mode of fossilization that we are familiar with (permineralization) will not engage most of the objects we discard because they are non-porous and inorganic.
I believe there are enough exceptions to the rule with regard to the above listed points to tip the scale in favor of discovery: -
Time-span: what we lose as a species with regard to duration is partially made up for with our high population density compared to at least some species that are represented via fossil record multiple times. We have multiple fossil finds of some Jurassic era top predators, and we can use one of those for comparison purposes. The biomass of top predators on Earth in any given generation is necessarily limited. I don’t know how reliable population estimates of dinosaur species are, but I can accept Stranger On A Train’s figure of 100-billion for the Tyrannosaurids as a total for that family’s entire duration. I don’t think I’m far off in estimating the total number of humans who have/are discarding man-made objects, as 10-billion. Therefore, we have 10% of the total population of a family of creatures for which we have between one and two hundred fossils finds. Using this estimate alone, we should find between 10 and 20 human fossils. Enough perhaps, but I believe that number deserves to be bumped up significantly…
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Attribution: I’ve not much to counter with regard to this, I’m sure it would be a factor for some types of man-made object fossils, but for many more types, I don’t think it would be a problem, particularly if more than one of the same type object fossil were discovered.
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Man-made objects don’t persist: I’m sure this is true for the overwhelming percentage of inorganic materials that we use in production, but we do make a significant number of objects out of materials that are as durable as mineralized fossils, don’t we? The same percentage of those objects should persist as do mineralized fossils—not many percentage-wise, perhaps, but enough in quantity to be discoverable.
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Most man-made objects won’t fossilize by mineralizing: most can’t, but many could, I believe. Look at all the objects scattered around your house. How many are made, or partially made, out of porous material (wood, leather, non-glazed porcelain…etc.)? Many. But, mineralization does not have to be the only type of fossilization method used for man-made objects…
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Impression mold type fossils: again, I’m no expert, but I believe my reasoning is sound concerning the longer an object remains in an environment favoring impression type fossilization, the greater its chance of fossilizing. This method should significantly favor durable inorganic materials as opposed to rapidly decomposing organic material. I welcome arguments to the contrary. If we have some top predator (i.e. low population) species that are represented by multiple impression type fossils (e.g. foot prints), then it’s not a stretch to believe even more durable man-man objects would fossilize via this method…and be discoverable.
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Unknown fossilization methods: I think it’s reasonable to assume that at least some of the artificial materials that we use in production may very well fossilize via methods heretofore unknown to us, simply because none were around hundreds of millions of years ago. We’re limited to fossils or an organic nature. Who really knows what will happen to, say, titanium, or various types of plastics…or even a porcelain thimble, dropped in very specific environments (silt, limestone…the New York City sewer system) for as many years that it resists decomposition?
What about things like mine shafts in geologically stable areas? Sure they’d fill in over the ages, but would not some bright spark find it odd there was a geometric core of non-metamorphic rock A surrounded by layers of rocks B,C, D, E, and F?
Well, what exactly are you saying, then? Your post makes no sense if you don’t agree that it’s proper to prefer a natural explanation.
sheer number of fossils: between cremations and traditional burials, not a lot of us are falling into tar pits, mudflows, or quicksand. fossilization seems unlikely.
manmade objects: quick googling shows: Situs Daftar Judi Slot Deposit Via Dana 10 Ribu Terpercaya - Slot Dana
* Tinned Steel Can: 50 years
* Aluminum Can: 200-500 years (But if recycled, it can be reused within 6 weeks!)
* Disposable Diapers: 550 years
* Plastic Bags : 20-1000 years
* Plastic Jug: 1 million years
* Glass : 1-2 million years
* Styrofoam: 1+ million years
so no. only rocks survive 100+million years, and even then it’s iffy.
in reading the entire post, Blake has shot down a lot of cursory hypotheses. go back and read some of his posts.
That’s not exactly the most convincing of evidence - on what basis exactly does this person conclude that glass will last more or less as long as styrofoam?
Most fossils are rare because most animals get eaten and scattered when they die. Only animals that are left undisturbed and rapidly buried have even a chance of getting into the fossil record. After that, they need to be in the right conditions to be fossilized.
Humans, however, bury a large percentage of our dead, so by and large getting chomped and scattered isn’t really in the cards. So, even though there were more dinosaurs, we would balance out in the fact that we deliberately bury a large percentage of our dead, thus giving us a better chance of becoming part of the fossil record. Then there is the fact that humans are all over the world, in ever type of environment…and that we’ve therefore buried people in all those places and environments.
Couple that with the fact that some non-zero percentage of humans were buried with grave goods and that alone is going to improve the odds that something will be found. Even if it were just a ring on the finger of a fossilized skeleton it’s going to be an indication of metal working at least. Assuming this proposed civilization at the end of the Jurassic was comparable to ours, then we’d find something that would indicate some level of technical civilization just with the human remains…a ring, surgical pins or indications of surgery, other durable grave goods.
And that leaves aside all of the artifacts we create. I’m sure that most wouldn’t last for 10’s or 100’s of millions of years…but if even a 10th of a percent did last, that’s going to be a hell of a lot of artifacts. Thousands, possibly 10’s of thousands. And many times more would have the potential of leaving some data behind (impressions or maybe odd chemical or mineral trace where it shouldn’t be).
The key, to me, is the fact that humans are all over the globe, in every environment out there from arctic to tropical, we travel and leave artifacts everywhere…mountains to the seas. No other species has ever done that, been in so many environments. No other species has ever created artifacts on the scales we create them. No other species buries their dead the way we do. To me the probability of something being found after a hundred and fifty million years or so is pretty much 1. If nothing else, how long will the remains of the lunar lander and all the other junk we put on the moon last? Forever as far as I know, baring every site there being wiped out by some sort of impact.
-XT
I don’t believe this has been the case (or was the case in the other thread like this that I participated in). You’d have to explain why it’s more likely that a leaf would leave an impression from the Jurassic while a computer monitor wouldn’t, or why a bug trapped in amber could last for hundreds of millions of years while a plastic snowman in crystal wouldn’t. I’ve yet to see anyone explain this in such a way that it shoots down all opposition and clearly slam dunks the debate.
The numbers of dinosaurs falling into tar pits, mudflows or quicksand were small, while the numbers of humans deliberately buried are vast. Even if it’s only a small percentage of humans who are buried in places where the conditions are right for fossilization there are a hell of a lot of them that have been and are being buried. Then you have humans tossed into things like peat bogs with ropes around their necks, clothes on their backs and metal artifacts on their persons, who are still perfectly preserved after thousands of years, and who have at least the potential to be completely fossilized in the future…clothing, skin and all. Or, at least their bones and those metal artifacts. You’ve had humans buried in mud slides, floods and lava flows, again wearing metal artifacts…and along with their buildings.
Fossilization seems to me to be extremely likely…hell, I’d say that it’s about as probable as things could get.
Metals can survive those durations too. Gold doesn’t disintegrate, right? There are other materials besides ‘rocks’ that can survive 100s of millions of years. We have examples of soft tissues surviving those time frames. Insects in amber have survived even longer. Foot prints in mud or even the impression of skin have lasted those time periods.
As for your list, it would depend on the environment the item was in. For instance, one of the items in the list is this:
Banana Peel: 3-4 weeks
That’s true enough, out in the open. However, I’ve heard of organic materials in land fills where things like this could last for years, even decades (I remember reading about news paper and meat found in one that had been there for over a decade and looked completely fresh and uncorrupted). So:
Out in the open? Exposed? Or buried in a mudslide? I’d say exposed.
Again, exposed or buried in a landfill?
Even taking these numbers at face value, I’d say a lot will depend on how they are deposited in the environment. If they are in a cave somewhere, or an underground vault, or if they are buried in a mudslide or a landfill it’s going to be different than if they are just sitting out exposed in the environment.
-XT
Well, I would be satisfied with 50 million personally. But given that the number of stainless steel forks is probably in the hundreds of millions, if not the billions, seems a FEW might last, here and there, for 150 millions years, in environments favorable for their preservation. Say, a million.
Its proper to prefer a natural explanation for things that have a credible natural explanation.
This tells us nothing about how we would treat something that doesnt have a natural explanation because the example given clearly did have one and there is no remotely plausible reason to think otherwise.
Otara
I literally cannot figure out what on Earth your point is.
IOW, ‘we’ prefer a natural explanation if there is one. In the case of the cite in question, there is one…it was a natural reactor. However, an artificial nuclear reactor would have nuclear materials and probably unusual concentrations of other trace elements (and quite possible other remnants, depending on the circumstances by which it got buried) that wouldn’t fit a natural explanation. If you found remnants of the container vessels, for instance, or if you found concentrations of nuclear reactor fuel still intact (or the control rods themselves), or if you found recycled fuel, those would all point to something highly unusual and wouldn’t lend itself easily to a natural explanation. Hell, if you found nuclear fuel in a place where it’s highly unlikely it would naturally occur, that would tell you something right there, no?
If the above also doesn’t make any sense to you (IOW, if we are all talking past each other) then I suggest that you take a step back and explain what you are wanting to discuss or what point you are trying to make, because it’s going past me and I think others as well. Might help.
-XT
With regard to materials we use in manufacturing that may actually rival mineralized fossils or amber in longevity, I’m faced with the sobering realization that the lone representatives of our entire species’ existence will be these.
