“Well, whatever you say. In the absence of any evidence for Earth being unique, as far as I can see intelligent life on Earth clearly indicates it is possible elsewhere. To assume otherwise requires facts not in evidence.”

In probability there’s a world of difference between possible and probable. Even though it’s possible for me to win the Powerball jackpot, I’d be foolish to part with a dollar in exchange for a ticket, since my chances of winning are approximately zero with or without a ticket. The fact that someone did win says only that it’s possible to win. It absolutely doesn’t make winning very likely for any one ticket holder. If you sample a very large number of planets with conditions similar to those on Earth billions of years ago, abiogenesis is possible on each planet. It still may be extremely improbable. The probability could be so small that one would be foolish to spend time looking (assuming that one actually knows the likelihood; if one has not the slightest clue as to the likelihood, it then becomes an issue of how interested one is to study the problem and what surplus resources one has available for such a project).

Probabilities can be very interesting. In college physics classes students are sometimes given the problem of computing the probability of, for example, one’s head tunneling whole through a concrete wall. Even though such a thing is possible (i.e., it’s allowed by quantum mechanics), it turns out to be so improbable that one should not expect it at any time in the history of the Universe. We don’t know the probability of abiogeneis. It’s not unthinkable that it’s so unlikely that life anywhere in the known universe may be a statistical anomaly. Or it could be so inevitable as to make life cheap and disposable.

Well, whatever you say. In the absence of any evidence for Earth being unique, as far as I can see intelligent life on Earth clearly indicates it is possible elsewhere. To assume otherwise requires facts not in evidence.

If such evidence turns up, I will, of course, revise my thinking. But I am not holding my breath.

Re shuttle hubble vid
So mundane and yet so extraordinary. One of my all time favourite “space” videos now.

“Fair enough. I’ll re-phrase: Why do you think intelligent life arising on Earth does not indicate chances for the same thing happening elsewhere?”

I’ve already addressed that question. My take on it has been my whole theme in this conversation.

It’s all about the sense of wonder – have you seen the video of the Shuttle unlocking from hubble?

Fair enough. I’ll re-phrase: Why do you think intelligent life arising on Earth does not indicate chances for the same thing happening elsewhere?