I wonder...

[davywavy]

...if the entire human race were to drop dead tomorrow of Bird Flu, how long it would be before there were no visible signs that we'd ever existed?

Comments

[barty.livejournal.com]

Really obvious stuff like big stone buildings should last a while. Most of the erosion to such structures is believed to be caused by humans nicking the stones to build new stuff with. Without all that manpower, you'll have to wait for accidental erosion by rain and whatnot, or for buildings to get covered up with sand or forests. I'd give it about twenty five thousand years.

If someone turned up and did a serious study, they'd be digging up plastic bags for a few thousand years. After that we should be easily detectable in core samples as an increase in atmospheric carbon dioxide a few million years from now.

In the fossil record, we show up as short mass extinction event, accompanied by a thin layer of radioactive deposits (from all that coal-burning), and followed by a small explosion in biodiversity. That should last at least a hundred million years, but it might be mistaken for a cometary impact.

The Earth and Moon are scheduled for demolition by the sun in about five billion years anyway. After that we'd be quite hard to detect.

Somebody might stumble across Pioneer 10. Five billion years from now it should still be in galactic orbit carrying a readable message plaque. It'll probably eventually go too close to a star and collide with something. Then we'll be gone.

[davywavy.livejournal.com]

Sobering, isn't it?