The counter argument: dinosaurs were around for a staggering amount of time, no pun intended. 165 million years is reasonably long enough to ensure they left behind some nests, bones, and a feather or two. Modern humans have been around for more like 0.02 million years.
The counter-counter argument is that while we’ve been here for a comparative blink of an eye, we’ve left behind 4 orders of magnitude more stuff than just nests, bones, and a feather or two.
Yea, but if humans went extinct tomorrow, very little human artifacts would remain after millions of years. Indeed, most would be gone well before that. How much stuff from the 18th century still remains, in percentage terms?
Unless it was burned, melted, decomposed or crushed to dust, it's all out there or in a landfill somewhere.
I do find it difficult to believe that we would not leave enough fossil and mineral evidence for future paleontologists to find. I get that the surface will churn, but layers of rock routinely become exposed, revealing the geological history of the area. No tea cup shards, no impressions of rusted cars in the mud, no concentration of metal in strangely rectilinear formations that suggests skyscrapers?
There would still be many signs. Dug up mines, metal alloys that don't exist in nature along with refined metals in quantities they don't exist, animal and plant species we bred along with all the ones we made extinct.
Very few things would in fact remain, you’re correct. But we’ve also created radioactive elements with half lives of many millions of years.
While there would probably very little direct evidence of humans after millions of years, there would probably be at least some anomalous evidence someone could find.
Indeed. Did a rapid check on T-rex, just as an example. Was around for max 3.6 million years. Max population at any one time must have been around 20k individuals. We have about 150 skeletons.
So current human population is 400 thousand times the maximum T-rex population at any one time. A few decades are enough to produce more human individuals than the entire T-rexes history. We also have the ability to go (and die) pretty much anywhere, so there will be human skeletons in every crevice, depth and environment on Earth. We also produce an absolutely staggering amount of artifacts of all kinds, from plastic straws to giant tunnels and artificial caves. There are zero chances an advanced civilisation on Earth won't be aware of us in 400 million years.
>We also produce an absolutely staggering amount of artifacts of all kinds, from plastic straws to giant tunnels and artificial caves.
Plastic will be gone in ~1000 years,
https://www.activesustainability.com/environment/waste-plane...
tunnels and artificial caves in a few million years at most as they are compressed by the weight of the rocks above them ("tunnel squeezing").
How long to dissolve carved stone sculptures (in sizes ranging from 1cm to 100m?)
And how long does it take to dissolve skin? Footprints? Because we have those from hundreds of millions of years ago.
> How long to dissolve carved stone sculptures (in sizes ranging from 1cm to 100m?)
A quick search on "rock weathering depth per century" suggests a "typical range" of 0.05 mm to 6 mm, depending on rock type and environmental factors. At 0.05 mm, a stone object with radius 0.5 cm would crumble in 10000 years. With radius 50 m, it would take 100 million years.
I would expect them to be unrecognizable long before that though.
> And how long does it take to dissolve skin? Footprints? Because we have those from hundreds of millions of years ago.
What do those findings tell you about the cognitive abilities and social organization of the creatures who left them behind?