If, in the final 7,000 years of their reign, dinosaurs became hyperintelligent, built a civilization, started asteroid mining, and did so for centuries before forgetting to carry the one on an orbital calculation, thereby sending that famous valedictory six-mile space rock hurtling senselessly toward the Earth themselves—it would be virtually impossible to tell. All we do know is that an asteroid did hit, and that the fossils in the millions of years afterward look very different than in the millions of years prior.

Peter Brannen on deep time.

Brannen is, of course, using this comparison to point out our own ridiculously brief period on this planet… and the difficulty we collectively have in remembering just how “brief” brief really is.