Paul Davies does a really good job here of illustrating the issues of SETI’s lack of success, and Fermi’s Paradox. He goes into the science and philosophy of it in depth, explaining all the terms and generally making it crystal clear. What amazes me is that he’s still somewhat optimistic about finding intelligent life elsewhere in the universe, given all the things he says in this book — I’m now almost completely sure that even if intelligent life has arisen elsewhere (and that’s still a big if) that we’ll have trouble finding it because of the issue of the sheer amount of time and space involved.
Not that I don’t think the search is worth doing. Even if we’ll never manage to communicate with intelligent life elsewhere in the universe, we might find signs of it, and understand more about how life begins. There’s so much we can learn along the way, and maybe the idea that we may not be unique will keep us a little bit more humble.