I'm listening to NPR right now. On the radio is the author of "Five billion years of solitude: The search for life among the stars." One of the call ins, of course, was "Are we alone?" There was the discussion of the Drake equation. And different scientists use different values to increase/decrease the amount of civilizations out there. Lee Billings contends that we are "practically" alone. Even if intelligent life is present at least once per galaxy and in every galaxy, there is no way to communicate on human time scales because of the sheer distance.
Is this a defeat for science?