Something that has occured to me in the past whilst thinking about this is that given the miniscule evidence our species and civilisation will leave in the geological record, can we really be sure that no other short-lived civilizations have existed previous to homo sapiens?
I think that even our current civilization, if it stopped today, would be pretty easy to miss in the geological record 200 million years from now.
But imagine if civilization had ended 500 years ago, or even a thousand. There would be absolutely nothing to show for it in a couple hundred million years time.
> But imagine if civilization had ended 500 years ago, or even a thousand. There would be absolutely nothing to show for it in a couple hundred million years time.
I think some stone artifacts (cities, pyramids, roads) would still be identifiable in some cases. Excavation would be needed, of course.
Similarly, some of our concrete, glass and non-ferrous metal construction should survive a long, long time.
