This is a fine follow-up book for the reader whose interest in atomic energy has whetted his appetite for science in general. In the easy manner of his previous popularizations (Birth and Death of the Sun, Mr. Tompkins Explores the Atom and others) the author manages to explore quite deeply into the great ultimates of modern science -- the meaning of space and time, the origins and concepts of life, the creation of the universe. Within this framework is packed an amazing amount of detail and anecdote, all without any effect of crowding or glibness. Professional scientists will object to the air of certainty which pervades the book -- we tried several passages on a biologist, on a physicist, both of whom felt that Professor Gamow was erring on the side of being too definite. Nevertheless it's a stimulating and provocative book for the science-minded layman.