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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].
If there was a global industrialized civilization like ours 1,000,000 years ago, we would know. Even if all their foundations had long been covered by eons and crushed to dust, we would still see the impact of the civilization in our geology. Humans in the last 100 years have permanently changed millions of square miles of millions of centuries of geologic record. If a species before us had that kind of impact, we would know.
Now, if there was some species of dinosaur at some time that lived in small mud-hut villiages, I can't see that we would ever be lucky enough to find evidence of that.
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
Looks like they had a triumvirate headed by Brahma, Vishnu and Shiva. They had some ministers for water (Varunan) or fire (Agni) etc. The head of the cabinet was Indran. Lots of detail of their biographies are available.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
You are quite wrong.
We basically have no evidence for anything we did not explicitly look for.
Consider the last "Ice Age", North America under an ice shield of about 3 miles thickness. Glaciers flowing outward to the oceans. If there was a "modern building" made from concrete and steel it would have been grinded to dust, it would been smeared over hundreds if not thousands of km of landscape. There is not real a chance in hell to find anything from it.
If there was a civilization on the level of ancient Egypt or even steam age UK before the previous ice age, in the area of the ice shield, then absolutely nothing, except lost tools in a cave, would have survived the ice age. I doubt a WWII battle ship, like Prince Eugene, which survived several nuke strikes, swimming, would have survived getting dragged by a glacier 3000 miles far to the sea under giga tonnes of ice.
A modern city like Las Vegas would have been smeared to dust. Nothing left. A city like New York would be somewhere 1000 miles out in the sea in minimum (originally) 150 yards deep water, probably covered by 50 yards of sludge or more (and grinded to pieces as well).
On the other hand, we found Oezi ... a stone age man inside of a glacier when he got spit out he probably was about 10k years inside (but was not on the ground and got grinded)
So were could we find something? Somewhere where there was no ice shield. But then again, about 1000km out in the sea, modern water depth about 50 or 70 meters, 50 to 100 meters under the sludge that has deposited there.
Good luck in searching there, I doubt we even know how to look below such deep levels of sludge, you probably need detonations and acoustic methods like in oil exploration.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Abuse, yes. Neglect, no. We have glass artifacts in perfect condition from the Mesopotamians (1500BC/3500yr). Glass is just a form of stone you know. And, if by "rarely survives intact" you mean down to unrecognizable as manufactured, then you're much, much more incorrect.