[bethelgrad]

Isn't this like looking for the one red-painted silver dollar mixed in with billions and billions of silver dollars spread out 10 square miles?

[ghostrider]

I said with billions and billions of planets, that the prospects for extraterrestrial life are fascinating. I said nothing about looking for life on one planet.

[Stultis]

I tend to agree. As I was just saying (typing) and as your analogy suggests, the probability of finding extraterrestrial life depends not on the absolutely number of planets that have life, but on the density of their distribution (and of course the percentage that acheive intelligence, techonology and the propensity to transmit detectable signals).

I'm a skeptic, frankly. I don't think we will detect extraterrestrial life anytime soon (say within the next hundred years). In fact, and of course I'm just guessing, I don't think the probability is particularly good that we will discover it in the next thousand years, even though I also tend to think that extraterrestrial life does exist.

[Old Professer]

Well, considering that you could get about 1.8 billion such silver dollars on a 10 square mile grid, if you had a vantage point that allowed you to scan from high enough I believe you could spot the red one rather quickly; scanning the universe from the inside through and about would be as difficult as Archimedes searching for a "place to stand."