[RadioAstronomer]

Rare Earth: Why Complex Life is Uncommon in the Universe by Peter Douglas Ward and Donald Brownlee gives a fairly convincing argument that Earth is pretty much it when it come to intelligent life.

I heard the same type of arguments when I was in school for other solar systems. I had a prof who once told me we would never discover a solar system outside of our own. We see life in the most unusual places. Places we would die in seconds. This universe may be teeming with life that does not resemble us in the least. If they become tool builders the laws of physics dictates that RF is RF no matter who or what generates it.

[Pres Raygun]

I heard the same type of arguments when I was in school for other solar systems. I had a prof who once told me we would never discover a solar system outside of our own. We see life in the most unusual places. Places we would die in seconds. This universe may be teeming with life that does not resemble us in the least. If they become tool builders the laws of physics dictates that RF is RF no matter who or what generates it.

Actually the authors of Rare Earth argue that simple life forms probably exist throughout the galaxy, but the probability of complex life existing anywhere in the galaxy other than on earth is extremely low. None of the discoveries of extra-solar planets made to date improve the probablitiy of complex extraterrestial life since all extra solar planets found so far are gas giants with either highly elliptical orbits or orbits in the habitable zone. Have you read Rare Earth?