One quick exchange about life out there–out there–from a Reddit Ask Me Anything with theoretical physicist Sean Carroll:

“Question:

Does the fact that we exist now, in a 7 billion person community, mean that it is very unlikely that “intelligent life” will someday exist in an interconnected civilization of say a billion earths (with 1019 people)?

Sean Carroll:

I don’t think so. Maybe technologically advanced life is fairly rare, appearing on average once per galaxy per ten billion years. Then we would be at the beginning, but the future could have many more civilizations.

But honestly, we have no idea. Some epistemic humility is in order here.”