A plague wipes out all humans, how long does it take for all evidence of our existence to disappear?

Answer 1

Depends on how carefully some alien species might look if they visited our planet.

Geological changes would eliminate most obvious traces of humanity in under one million years. But there could be random fossils and artifacts that could survive for billions of years, especially if they were in geologically inactive areas of the earth and avoided the impact of some asteroid or meteorite.

For example human structions in Turkey, a very active earthquake area, would probably be eliminated within a few tens of thousands of years. But something in the central deserts of Australia might survive millions of years.

Answer 2

We have made significant changes in the history of the earth, from number of species to chemical distributions to radioactive elements. There will be readable traces of this so long as the earth has a solid surface. When the sun goes red giant and consumes the earth, about 5 billion years from now, there will still be at least two spacecraft in interstellar space .

Answer 3

Perhaps Billion years or more ?
Perhaps until the sun becomes a Red Giant and toasts the earth.
We still have evidence of Dinosaurs & early life from
hundreds & hundreds of millions of years ago and as petrified
stone, it isn't going to disappear anytime soon...

Answer 4

If the human race is wiped out, hundreds - or perhaps thousands of years from then - archaeologists will discover a huge yellow "M" buried under mountains of debris, and they will announce that people from the 21st century worshiped the "golden arches" - the big "M" being a symbol of their god just as the crucifix was the symbol of the gods two thousands years before that. -RKO-

Answer 5

Since there is buried atomic waste a very long time.
Some plutonium isotopes have a half life on the order of 8x10^7 years.

Answer 6

Never. Like at least one other person said, the half life of U-238 (the kind of uranium we use in nuclear power plants) is about 4.5 BILLION years. Our planet will be toast by then.

Answer 7

Forever, someone left McDonalds french fries for a couple of months or years I don't remember and they never got bad, so I heard the lady say your food should disinegrate if your body cannot break it down then maybe you shouldn't eat it.

Answer 8

Why would it matter? If all humans ceased to exist, who would be left to find evidence of our existence?

Answer 9

There is still evidence of civilizations thousands of years old.

Answer 10

Probably never. We're still finding artifacts and remains from civilizations and creatures that were around millions of years ago.