There are occasional threads about the possibility of ancient civilisations that left no trace. Those interested in such things might find the following paper interesting:

The Silurian hypothesis: would it be possible todetect an industrial civilization in thegeological record?

Quote

If an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today? We summarize the likely geological fingerprint of the Anthropocene, and demonstrate that while clear, it will not differ greatly in many respects from other known events in the geological record. We then propose tests that could plausibly distinguish an industrial cause from an otherwise naturally occurring climate event.

https://fermatslibrary.com/s/the-silurian-hypothesis-would-it-be-possible-to-detect-an-industrial-civilization-in-the-geological-record

I have only skimmed the beginning of the article, but the footnote on the first page is brilliant:

Quote

1. We name the hypothesis after a 1970 episode of the British science fiction TV series Doctor Who where a long-buried raceof intelligent reptiles ‘Silurians’ are awakened by an experimental nuclear reactor. We are not however suggesting that intelligent reptiles actually existed in the Silurian age, nor that experimental nuclear physics is liable to wake them from hibernation. Other authors have dealt with this possibility in various incarnations (for instance, Hogan, 1977), but it is a rarer theme than we initially assumed.

 

This is gold. Also pessimism line.

Edited April 25, 20196 yr by peterwlocke