Slashdot Mirror
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].
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].
There are those who believe that life here began out there, far across the universe, with tribes of humans who may have been the forefathers of the Egyptians, or the Toltecs, or the Mayans, that they may have been the architects of the Great Pyramids, or the lost civilizations of Lemuria or Atlantis. Some believe that there may yet be brothers of man who even now fight to surviveâ"somewhere beyond the heavens!
But where is the space-junk?
You are assuming they existed long enough to reach a space age. They may have just reached the age of steam then collapsed. The fact they they failed to do something about the incoming asteroid would support this clam.
There is another answer too. If they did reach the space age they might have simply been more tidy about space than we are. Plus a 70+ million years is plenty of time for all orbital space junk to fall back to earth.
I read at +2. If your post doesn't reach that level I will not see or respond to it.
But where is the space-junk?
You are assuming they existed long enough to reach a space age. They may have just reached the age of steam then collapsed. The fact they they failed to do something about the incoming asteroid would support this clam.
There is another answer too. If they did reach the space age they might have simply been more tidy about space than we are. Plus a 70+ million years is plenty of time for all orbital space junk to fall back to earth.
Maybe they made it off this rock and we are the descendants of some pets that got left behind to run wild.
The only thing necessary for evil to triumph is for it to be pitted against a slightly greater evil
There was one expedition to the area decades ago by Miskatonic University, but it was disastrous. There were no survivors of the original expedition; the only two men who returned were from the rescue team dispatched by the University. They came back ranting about shifting eyes in the darkness and kept repeating a nonsense sound: "tekeli-li." There have been no other attempts made to explore that place afterwards. Even if the rumors of a great and terrible city, ancient beyond all measure, are true, we only have the word of two men barely clinging to their sanity after being exposed to one of the most extreme environments on Earth.
No, there is nothing to be gained by exploring the Transantarctic range. There is nothing but madness in those mountains.
The paper addresses this geological impact paradox. For the signal to be obvious in the geological record, it has to be sustained, but for a civilization to persist long enough to be obvious in geological time scales, they have to be in equilibrium with the environment.
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.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
We were the first to mine coal, drill for oil, extract deposits of rare earths, and precious metals.
Citation needed.
Also, some things shouldn't go missing. Tracks on the moon
Why would they have necessarily gone to the moon, and even more importantly, why would one of our very few manned missions, or other landing craft, have landed in the right place to have seen those tracks? If we're talking about the scale of millions of years, wouldn't an impact on the moon be an obvious candidate for removing evidence?
orbital satellites
Satellites in a stable orbit for millions of years? The moon is not in a stable orbit when you're talking about geologic time.
undecomposable manmade polymers and alloys
I don't think we've made anything that would be considered "undecomposable" after millions of years. Moreover, even if we could, wouldn't they be buried after millions of years instead of sitting on the surface?
"Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black
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.
I read at +2. If your post doesn't reach that level I will not see or respond to it.