This is one of my all-time favorite “what if” questions. Some years ago a friend of mine coily posed this same question to me: What does humankind make that would survive 60 million years into the future, and if some other advanced industrial civilization had existed 60 million years ago, how would we know?<p>It turns out my friend had put a LOT of thought into this exact question. Enough to do a masters in geology, his work ultimately making it into a high profile journal with writeups in places like the NY Times.<p>He started talking to various geologists about what might survive as telltale markers of our civilization. Buildings or structures of any sort? Ha! Statues and monuments? Maybe we’d notice the odd deposit or two of minerals.<p>After going through a long list of candidates, he settled on carbon cenospheres. These are little balls of carbon almost exclusively made in internal combustion engines as the result of aerosolizing fossil fuels. Sixty million years ago, our love of the ICE will show up in the fossil record as a light dusting of cenospheres covering the earth—contemporaneous with massive numbers of species going extinct due to mankind’s other influence.<p>And as my friend was telling me his story, this is where my hair stood on end. Sixty million years ago we see a massive species extinction... and a light dusting of carbon cenospheres covering the globe.<p>But we also see unnatural levels of iridium at the same point. And, while it’s hypothetically possible some industrial civilization was mining iridium and blanketing the globe with it, it’s more probable that the iridium was delivered by an asteroid.<p>But how would you know? So my friend, as part of his research, went taking samples of his cenospheres from around the globe. What he found was interesting: namely, the further one gets from the Yucatan (where scientists had already validated there was an asteroid strike), the cenospheres get smaller. The big heavy ones precipitated out of the air closest to the Yucatan asteroid strike. Hardly likely to be coincidence.<p>So much for ancient civilization this time around.<p>However, his work rewrote a critical understanding of the KT asteroid extinction event. Namely, we previously thought most of the carbon at the KT boundary was the result of giant forest fires ignited by the strike. However we now know that the strike must have aerosolized massive oil fields under the Yucatan at that time and set them ablaze.<p>Not a bad contribution to science starting from a sci-fi premise!
Ants are a good candidate for a second civilization. They live on every continent except Antarctica, they build complex structures, they invented argriculture millions of years before humans did (!), and they live in socially stratified societies. But I guess it ultimately comes down to your definition of what is a civilization.<p>If we were to find evidence of an industrial civilization before humans we might not even recognize it as evidence, given how different it might be from ours.
One strong argument against a civilization in the last 100 million years or so is that our separate continents have clearly been completely isolated, and gone separate evolutionary paths.<p>If there was a planetary civilization 20 million years ago, there are tons of "invasive species" that would have spread across all continents then rather than in the 1800s. Think rats, sparrows, cockroaches, etc x 1000.<p>I don't think I have an argument against one back in Pangean times though.
Arthur C. Clarke and Stephen Baxter briefly touched on this idea in The Light of Other Days.<p>(Spoiler) The book is primarily concerned with the development of a miniaturized wormhole technology which allows remote viewing anywhere on Earth, and the effects this has on privacy, etc. They discover it can also be used to view backwards in time, and at the end of the book they trace the tree of life backwards towards the universal common ancestor, and discover that it was a microbe seeded deep in a geothermal vent by a civilization of intelligent trilobyte/arthropod like creatures, which knew its own extinction was imminent at the hand of a massive asteroid.
"It’s not often that you write a paper proposing a hypothesis that you don’t support."<p>We should all do this at least once. What a great practice.
The fact that we found pressurized oil reservoirs ("gusher" oil wells) means that nothing had tapped these cheap and easy sources of energy before.
An older period: Carboniferous [0]<p>Lots of plastic non biodegradable (at the moment): lignin. That's why we have coal, which fueled our Industrial Revolution :)<p>Ended with the Carboniferous rainforest collapse, caused by climate change.<p>[0] <a href="https://en.wikipedia.org/wiki/Carboniferous" rel="nofollow">https://en.wikipedia.org/wiki/Carboniferous</a>
Me: "It would be amazing to go out to the asteroid belt and return a rare-earth metal rich asteroid to solve that problem once and for all."<p>Other: "That's what the dinosaurs thought."
As the article points out, an ancient industrial civilization would need to mine resources. I think it is fair to say that they would mine a lot of gold and silver for use in electronics. If such a civilization existed then one would think that most of the earth's natural veins of gold and silver would have been mined making large easy to find naturally occurring veins rare. It seems though that our civilization has found plenty of easy to find large scale veins of gold and silver.<p>Does that not make it unlikely that any ancient industrial civilization lasting centuries could have existed before us? Or over tens of millions of years would more naturally occurring easy to find veins of gold and silver rise to the surface of the Earth's crust?
The nuclear war between the Dinosaurs and the Martian Kangaroos laid waste to both their planets 65 million years ago. The final phase occurred when the Martian forward base on the moon, from where they bombarded the earth, was wiped out by asteroidal bombardment by the dinosaurs. Then the Venusians moved in and finished the job, eliminated all the remaining dinosaurs and the Martian kangaroo people and retreated behind their cloud cover. A few 'roos survived, but retroevolved to a pastoral state. We had better tread with care - lest we anger Venus...
I wish this article had also gone into how long indicators might survive outside of Earth. Could satellites survive? Things on moon or Mars? Might we go to Mars and find some old Mars Rover or underground base or that we left Mars for Earth after we made it uninhabitable?<p>Edit: typo has -> had
We don't even know about previous human civilizations.<p>Recently discovered Göbekli Tepe<a href="https://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe" rel="nofollow">https://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe</a>, the oldest megalith structure, confirmed by radiocarbon tests to be more than 12.000 years old with massive stone pillars and 3d relief stone sculptures mostly still buried is still a mystery to science and some "scientists" still think hunter-gatherers built it with stone chisels.<p>The interesting thing is that a study based on the drawings on the structure correlated with Younger Dryas period might explain why nothing was found about the ancient civilization that built it.<p><a href="https://phys.org/news/2017-04-ancient-stone-pillars-clues-comet.html" rel="nofollow">https://phys.org/news/2017-04-ancient-stone-pillars-clues-co...</a><p><a href="https://www.newscientist.com/article/2128512-ancient-carvings-show-comet-hit-earth-and-triggered-mini-ice-age/" rel="nofollow">https://www.newscientist.com/article/2128512-ancient-carving...</a><p>So after all the Atlantis and the flood myth found in most cultures from around the world might be real.
This reminds me of Lovecraft. His mythos was based on the premise that Earth has been inhabited by a series of alien and native civilizations, mostly malign, over the past billion years. Occasionally an artifact or part of a city is thrust to the surface by geologic forces. According to Lovecraft, after humanity falls a race of intelligent beetles will arise.
My all time favorite theory: <a href="http://pbfcomics.com/comics/dinosaur-meteors/" rel="nofollow">http://pbfcomics.com/comics/dinosaur-meteors/</a>
On a side, Hindus believe in 4 Yuga's or phases that go around and round in circles, we are in the fourth one at the moment. Humans exist in all Yuga's and there is then a mahayuga after which there is destruction
What if past civilizations exhausted their naturally reachable energy deposits, like we now do with oil, so we can't even guess what did they use as we won't find it on Earth anymore?
There’s a book series by julian may that deals with a time travel device being invented to 6 million years ago where to everyone’s surprise an alien civilization is ruling the planet.<p><a href="https://en.m.wikipedia.org/wiki/Saga_of_Pliocene_Exile" rel="nofollow">https://en.m.wikipedia.org/wiki/Saga_of_Pliocene_Exile</a>
Could something like Fort Knox survive as an unusually concentrated deposit of gold?<p>On a larger scale, would a city like New York leave an area with an anomalous distribution of elements of a similar nature to what we see where there has been an ancient meteorite impact?
There are so many open questions out there. For instance, how do we know that the bacteria don't form an intelligent species, too? What if there's something else out there, that just is not intelligence but just like intelligence enables a life form to advance as far as we have and beyond?<p>Even our understanding of the beginning of the universe is just a model, an idea. It's not like we have proof.<p>From time to time it's quite important to remember how vast the knowledge is that we don't possess in contrast to the one we do.
A very interesting and difficult part of these kinds of questions is that what we look for has to be very carefully considered. If we look for just what we know now, we might not find the evidence, even if it's there. One of my favorite examples of this is radio waves. Try telling someone in the 1600s about them; it seems unlikely they'd believe you--but yet they've existed forever (?) and e.g. lightning and other natural forces can generate them.
Theres a cool ST Voyager episode about this, the species gets labeled the Saurians. They are extremely powerful and dogmatic, due to living in space for millions of years.
The Mediocrity Principle applied to civilisations would suggest we're not the 'special' first one here. We thought we were special in lots of ways that we've since had to abandon<p><a href="https://en.wikipedia.org/wiki/Mediocrity_principle" rel="nofollow">https://en.wikipedia.org/wiki/Mediocrity_principle</a>
Surely, we'll leave a few satellites in high orbit, and presumably the raptors would have done as well.<p>Also, their sitcoms would by now have penetrated a decent bit of intergalactic space, and attracted some attention. Because if it happened twice on this planet, the universe at large would be teeming hi-tech societies.
I imagine we’d find a LOT of stone tools before the civilization developed higher tools and then collapsed. Africa is littered with them deep in some areas (due to a million years of humans), and they’re on all continents but Antarctica.
There's no real evidence for this in archeology. We would find little statues of these non humans. we have highly intelligent non humans like dolphins and octopi but they don't have the ability to make fire despite being extremely intelligent, flippers and tentacles are quite limiting.
The article asks about detecting an industrial level civilization.<p>But what about a former civilization which only rose to the level of the Roman Empire lets say? Could we detect that?
Would our roads would survive? Never before has humanity so dramatically changed the planet in such a fundamental way. Roads from older civilizations like the Romans and the Sumerians would probably erode, but our modern asphalt is pretty insane when you think about it.<p>If left on the surface for millions of years, yes they would fade to nothing. But in many locations, they'd get buried in layers of swamp and sediment. Even if they shifted around via plate tectonics, many of our modern highway junctions are quite massive. With 7 billion people and the insane amount of infrastructure on our planet, surely some of that would survive if a future civilization started digging a few hundred meters through bedrock.<p>How long before roads churned under the pressure of the earth into indistinguishable small pieces of rock? Would they be gone in less than a million years?<p>As a side note, this makes me think about all the world that goes into nuclear waste burial sites, and how we're currently trying to create warnings that may need to outlast our civilization by millions of years.
The lizards...and some say they still are with us! /s
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