Jastrow has for some time been fascinated by the faith and gut reactions of scientists. Science is accepted as a mode of knowing which reveals the nature of the universe. Now the evidence is such that astronomers must come to grips with the concept that the universe had a beginning--some 20 billion years ago. But what was before? and why?--or who? (which is the answer provided by religion). Most scientists find this an awkward, irksome, disturbing turn of events; it was nicer to think of no beginning (or constant oscillations). Many would rather not think about it at all. This is the essence of this short primer on cosmology. Jastrow traces the major developments that have led to the cosmological dilemma: Slipher's calculations of receding galaxies, solutions to Einstein's equations which predicted an exploding universe, Hubble's and Humason's observations of red shifts and distance/velocity laws, Gamow's and Alpher's theories, and the more recent discovery of what appears to be the residue of the cosmic fireball. Jastrow is at his best in describing--in simple terms and graphic anecdotes--Einstein's distaste, Eddington's annoyance, even contemporary astronomer Alan Sandage's astonished disbelief. Each short chapter is followed by a photoessay which amplifies the text. Included are some charming ""family"" portraits of stellar names, thumbnail sketches of the lives of Einstein and Hubble, and dandy color photos of galaxies in all stages of development. Short and sweet and good.