Gribben's heroic efforts to explicate quantum physics abide in a halfway house: good for those exposed to the issues, somewhat dense and dessicated for the uninitiated. He desperately wants us to understand Planck's constant, Avrogado's number, and Schrodinger's cat--the famous feline caught between life and death. (The cat in a box is either alive or dead depending on whether or not a radioactive atom decays. Common sense says the cat has a 50-50 chance of being alive. Quantum mechanics says the situation is indeterminate until an observer speaks into the box: nothing is real until it is observed.) Such notions obviously occasioned much cerebration and consternation among the principals, and Gribben does provide considerable back-and-forthness between Bohr and Einstein, in particular--dwelling on the Einstein-Podoisky-Rosen (EPR) thought experiments and the various ways that Bohr and the so-called Copenhagen interpretation of quantum theory refined them. He does his best to explain the concepts of black body radiation and Balmer lines, uncertainty and asymmetry, with excursions on spin, polarization and matrix mechanics. Such an account also properly pays homage to the genius of a Dirac and others who carry out the implications of their equations to their logical but commonsense-defying conclusions. The book moves on to current speculations of the kind Gribben has dealt with in his astrophysics popularizations (Spacewarps, Future Worlds, etc.), and also sees him stepping out of his reporter's role to support Hugh Everett's many-world superspace theory. The woozy-headed reader, however, may find it more refreshing to dip into some of the more readable memoirs of principals like Heisenberg or even Schrodinger himself, or of contemporary elder statesmen like Freeman Dyson.