
Silurian hypothesis - apo
https://en.wikipedia.org/wiki/Silurian_hypothesis
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api
Part of this is the realization that backward (or forward) tens of millions of
years or more is a place as awesomely distant as a star hundreds of light
years away. Billions of years may as well be another galaxy. Time as well as
space is vast, and we really can't see details very far. There could have been
two or three "flowerings" of high intelligence on Earth so far and we would
have little direct evidence.

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mooreds
Definitely! I often wonder about the evidence (who knows if the dinosaurs had
computers and mechanical flight for a short time(geologically speaking)?) How
could we?

[Edited to make it clear I was talking about airplanes]

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ardy42
> Definitely! I often wonder about the evidence (who knows if the dinosaurs
> had computers and mechanical flight for a short time(geologically
> speaking)?) How could we?

We've found fossilized dinosaur bones in silted up riverbeds, but no dinosaur-
era subway tunnels that silted up with what would now be mudrock. If dinosaurs
had computers and mechanical flight, they'd almost undoubtedly have had
subways, sewers, and bunkers that we could find at least trace evidence of.

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mooreds
I don't know if subways would have fossilized if they were only around for
1000 years, 60-120 million years ago.

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ardy42
> I don't know if subways would have fossilized if they were only around for
> 1000 years, 60-120 million years ago.

I think you misunderstand. The extent and location of the systems would matter
more than the duration of their use. What we'd be looking for is the
geological result of artificial tunnels filling up with sediment that then
undergoes normal geological processes to solidify into rock.

