The third in the author's trilogy about the universe, this propounds the author's theories as an expansionist -- in language that is simple, yet mindful of the complexities of science and relatively unmincing in its terminology. Briefly, Dr. Gamow theorizes that the universe was a compressed superatom some three billion years ago. But in an hour a ""cooking"" process took place and expansion began. Then for thirty million years nothing much happened until the gases formed by atoms broke into clouds and through successive condensations formed protogalaxies -- a continuing process of expansion to infinity. There is an historical survey of the science of cosmology -- the early theories of Hubble, age problems are discussed as well as the expansionist theory itself, and so on.