More pleasant post-prandial coffee-talk from the lecture notes of everyman's Professor of Popular Science. This time Mr. Asimov gallops with his usual verve through remarkably tidy round-ups of discoveries in the fields of cellular biology, physics, astronomy, space travel and entomology—all fairly simple presentations for the layman. Mr. Asimov enjoys posing impossible questions and plunking down the incredible answers while moving through an impressive number of discoveries. ("We must ask ourselves"; "Suppose"; "Consider the question. . . ") The scientist or serious student might quail at Asimov's simplifications through the decades and centuries; nonetheless for the uninitiate or those who like their science neat if not necessarily complete, this is very-easy-readable summary.