How long would it take for all signs of the human race to disappear if we all were gone?

Question

I asked this question once before and got the old "how would we know because we sould not be here" or " if a tree falles yadda yadda Well you know what i mean. Just someone give me some idea!

Answer 1

Well im no scientist but... Just look at the pyramids, great wall of china ect. ect. ect.

Answer 2

Maybe millions of years.  Metals like gold and platinum are almost inert, and artifacts made from them would likely have to either be melted in volcanoes or eroded by wind/sand.

Plastics are also going to last a very long time, because many of them are also almost inert.

Answer 3

I've pondered this very question myself so you are in great company.

Buildings and strip mines would last several thousand years at best. There would be fossilized items that may or may not be found by the next care takers of the planet. But radioactive waste is the longest lasting item. Have you ever considered if the lead we mine today.....different question.

How to get rid of all evidence we were here, hmmmm.

Look at continental drifting and subduction zones. Everything on the continental plate goes into the planet's core. This may take several billion years, but this is what you'd be looking at.

It's stuff just like this makes me wonder, how do we really know no one has done this before. Life could have been here and evolved in an ammonia based atmosphere with oxygen being a killing gas. A couple of billion years later and after the dinosaurs failed, here we are.