the book was
"the rare earth"
written by brownlee and another u of wash prof
an amazing book.
They go thru all the arguments why complex life is so rare. This is my solution to fermi's paradox.
My solution is there is no paradox what so ever. When you consider just how vast the distances are and the limit of information exchange (to include travel) at "c", I don't wonder at all that we have not "seen" anyone else. Even the EM frequency band is limited due to both atmospherics and the Galactic Halo Noise.