Superstrings and the Search for the Theory of Everything

How did the universe begin? What is the nature of matter? What is the ultimate meaning of physical laws? To answer these questions, physicists must somehow join the two pillars of theoretical physics, quantum mechanics and relativity, in one all-encompassing theory. Science-writer Peat ( The Nuclear Book , etc.) here takes readers to the edges of ``postmodern physics.'' Leading candidates for the ``Theory of Everything'' are superstring theory and twistor theory. In superstring theory, we're shown, matter and space-time itself are made up of infinitesimal one-dimensional strings vibrating in 10 dimensions. Our familiar four-dimensional world (three spatial dimensions plus time) emerges when the six extra dimensions are curled up (compactified) smaller than the length of the strings. In twistor theory, developed by British physicist Roger Penrose, space-time and elementary particles are properties of a highly complex geometry. Many physicists believe that some deeper principle will eventually unite these two approaches into one true ``Theory of Everything.'' Peat grapples with these amazingly recondite notions, and succeeds brilliantly in making them clear to knowledgeable lay readers. Illustrations not seen by PW. (Nov.)