Life on earth

[thebigchill]

For how long has planet earth had suitable conditions for human habitation? While i'm at it, how long ago was earth created compared to the big bang, and if we could time travel how close to the creation of earth could we go and have conditions we would be able to survive in?

[Clanad]

It's generally agreed that the creation event took place around 14.0 billion years (Bya) ago and the formation of Earth occurred around 4.5 bya and fossilized microbes have been found that formed nearly 3.5 bya. However, fossilized multi-cellular creatures don't occur until about 1 bya. Life, resembling anything near what we know today didn't come on the scene until the Cambrian Explosion, around 550 mya (millions of years ago)...That's probably when the atmosphere and other conditions could have supported you, however mammal didn't appear until around 200 mya, so that could be a key as well...

[stevie21]

According to one writer, once the first mammals appeared, there was an "explosive" growth of similar life on earth so it might be that the earth wouldn't have supported us any earlier than we appeared.
I wouldn't expect to be able a lot further back and survive as there was no atmosphere initially. No oxygen to breathe and no atmosphere to deflect/absorb harmful rays from the sun that we're currectly protected from.

[mycats]

ooh serious question there!
dont you worry your pretty little head m'dear lol x x

[thebigchill]

Great answers guys, thanks very much. And a pleasure as always cat ;-)