rabble wrote:And yet we see absolutely no evidence of anyone else.
Considering we don't know where to look, the universe is enormous, and our technology is not up to the task, I don't share your surprise that we've thus far failed to find extraterrestrial life. I mean, cut science some slack, man -- we've only been looking for a few decades and our preferred search method (SETI) was based on what I would consider a faulty premise (that advanced civilizations would use radio waves to communicate with themselves or others.)
rabble wrote:We can postulate that, based on our observance of light, the physical laws apply, but we don't know. We can't know.
If you want to play the "we can't know anything really" game, that's fine... we're all brains in jars. But that won't get us anywhere. On the other hand, you could accept that the centuries of scientific observations which led us to our current theories about light sure do a heckuva job explaining what we see and making accurate predictions about what we should see.
rabble wrote:To put it another way, we have as much evidence that extraterrestrials exist as we do that any of the deities exist.
I disagree. I think there is compelling indirect evidence for the existence of ETs and as much or more indirect evidence that deities do not exist. There are lots of things for which we have only indirect evidence that it seems goofy to doubt. Nobody's ever seen a black hole, but even before we found (indirect) evidence, there were still compelling reasons to assume they existed. It's unlikely we'll ever be able to directly observe a quark, but it's a pretty safe bet they exist. I admit that the case for ETs is not as strong as that for black holes or quarks, but it's certainly better than that for a deity.
rabble wrote:To say that because the Universe is infinite there must be other civilizations, is no different than saying that in an infinite universe there must be a god out there somewhere. Both of them require some reasoning combined with leaps of faith.
I disagree.* It is reasonable to assume that life exists elsewhere because life exists here... big universe... laws of physics... yadda yadda yadda. Given similar starting conditions and the same building blocks, expecting comparable outcomes is more of a baby step than a leap. But for a god to be out there somewhere we are required to imagine something wholly unlike anything we've ever seen anywhere and which violates the laws of physics. That's a far, far bigger leap, and one with no basis in probability.
*I also don't recall saying the universe is infinite. But it's irrelevant, anyway. Infinite space doesn't guarantee that anything which can occur will -- you need infinite time as well, and we know the universe had a starting time. And while it may be true that anything which can happen will happen given infinite space and time, since there's no reason to believe that a deity can exist in the first place, you're still making an enormous leap.