| There are multiple problems with the claim that a lack of evidence for intelligent life makes it more likely that it doesn't exist. First, the further out we look, the less recent our data. Every event we observe that's more than 200 light-years away happened before slavery was abolished in the U.S., and well before Earth's first radio emission. I'm not saying we shouldn't base conclusions on evidence, but I will say that our ability to gather _current_ data about our surroundings is limited to an infinitesimal fraction of the universe. Worse, it degrades with distance. Bacteria were there, but we couldn't see them for a long time. (They were theorized, though, their existence reasoned out and later proved with evidence) Second, unlike bacteria intelligent life is...well, you know. Suppose we're the last ones to the interstellar party, or at least not the first. We come in, blasting radio waves like a toddler, BEEP BEEP BEEP BEEP. No signal hygiene whatsoever. Our neighbors on the other hand likely learned a long time ago to hide their presence from all but those they trust, and certainly from those on a lower technological playing field. If the intelligence we're trying to prove can consciously avoid us finding out about them, then taking absence of evidence as evidence of anything becomes suspect. Of all the intelligences that could exist - not just those we could detect, mind you - what percentage of those do you think are more advanced than us? |