Originally Posted by
Ggallagher
My thinking on this is, "Yes, they're out there, and no, we're not going to see them".
Life has restarted on earth about half a dozen times after some of the planet's extreme events. Since it has bounced back here under various different conditions, it just doesn't seem reasonable that it wouldn't happen elsewhere given the innumerable other locations where it could happen.
Then assuming they are out there in great numbers, it would seem likely that some of them are hundreds of thousands if not millions of years further along in their evolution than us. And many others might be equally far behind us. But if intragalactic - or intergalactic travel were feasible, because of some technology we haven't discovered yet, then some and possibly many of those further advanced civilizations should have stopped by to say hello by now. I can't buy that they would make the enormous investment required to take a voyage like that, and then just drive by and go home.
So I think that unless the luck of the draw puts multiple life sustaining planets in close enough proximity - there's no way we get to see each other.