Hawking is both a scientific superstar and a man widely admired for overcoming—indeed, all but ignoring—the degenerative muscular disease ALS (Lou Gehrig's disease), which has robbed him of almost all movement but left his mind intact. Hawking is hot on the trail of the ``Theory of Everything,'' the basic understanding of how the universe came into being and what makes it tick. His brilliant theories encompass the big bang (if there was one); black holes (which may not be black); and the astonishing question of why, among the infinite possibilities, the universe chooses to exist in the unlikely way that it does. God, time, and our place in the cosmos all seem as important to him as the complex equations governing the fundamental particles. This splendid, carefully researched study of the man and his ideas—based on interviews with Hawking, a good knowledge of his subject, and many secondary sources—balances the fascination of physics (extremely well described) with the fascination of the man. By his work, Hawking has earned a comfortable home to share with his wife of 26 years and his children. Still, he and Jane Hawking are separated; she says he wants to do "Areabsolutely everything that comes to his notice,'' leaving little time for the family. Ego? Overcompensation? Or the sense of being so close to understanding that there's room for little else? Does the personal drama have anything to do with the universe? With this man and this universe, probably. B&w photos; graphs and diagrams; full source notes; bibliography; glossary; index. (Nonfiction. 13+)