Was There a Civilization On Earth Before Humans? (theatlantic.com)

Adam Frank, writing for The Atlantic: We're used to imagining extinct civilizations in terms of the sunken statues and subterranean ruins. These kinds of artifacts of previous societies are fine if you're only interested in timescales of a few thousands of years. But once you roll the clock back to tens of millions or hundreds of millions of years, things get more complicated.

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 farther than the Quaternary and everything has been turned over and crushed to dust.

And, if we're going back this far, we're not talking about human civilizations anymore. Homo sapiens didn't make their appearance on the planet until just 300,000 years or so ago. [...] Given that all direct evidence would be long gone after many millions of years, what kinds of evidence might then still exist? The best way to answer this question is to figure out what evidence we'd leave behind if human civilization collapsed at its current stage of development. Mr. Frank, along with Gavin Schmidt, Director of the NASA Goddard Institute for Space Studies, have published their research on the subject [PDF].

Comments

Re:No (evidence: coal is still there)

[angel'o'sphere]

We already had a steam age around 100 BC.

https://en.wikipedia.org/wiki/...

But people that time had no idea what to do with them, they used them for "spectacular tricks" like "magically" opening huge doors of temples.

If we once had another civilization (there are plenty of plausible reasons, which I will explain in another post) then two thinks are most important to consider:
a) coverage of the ground with dust. The city Troy has about 9 layers of destroyed buildings and rebuild buildings on top of it. And that is a town just 5000 years old. When it was found it was more or less unrecognizable covered under earth.
b) Considering the last "ice age", sea levels where some 120m lower than now. E.g. Australia was nearly connected with Asia via a land bridge. A civilized nation most likely would have many cities at the coast. Today that would be hundreds if not thousands of miles away from the coast line. In water depths of about 120+ meters. And obviously, depending of about what time frame we are talking, last "ice age", or 6 "ice ages" ago, those areas would be covered with perhaps a mile of mud.

No one is searching dozens or hundreds or thousands of kilometers out in the sea in depths around 150m - 60m under a mile or hundred meters of sludge. If you would try to get funding for something like this people would declare you mad. Anyway, if another Schliemann shows up and gets enough funding I could imagine we find something (note: I said imagine, not that I'm convinced or believe there is something)

Here, two nice pictures about coast lines and sea levels: https://www.iceagenow.com/Sea_... Note Japan, Indonesia, North America and Europe, the land bridge closing Spain with north Africa. The second picture has the outline of the coast lines during the last "ice age" as a grey frame around the green land masses.

Re: High Pure ConcentrationsRare Ore

[jwhyche]

Why would an ancient civilization use nuclear power?

Because it's a clean, reliable, and safe means of generating electricity for a technologically advanced society to use. Assuming they don't have a bunch of smelly fucking hippies get in the way of developing into such clean, reliable, and safe source of power.