The contributions made by Poincaré to mathematics, physics, and celestial mechanics are equalled perhaps by only a few others such as Isaac Newton, Albert Einstein, and Carl Friedrich Gauss. Born in Nancy, France, Poincaré was the son of a doctor and the cousin of Raymond Poincaré (1860-1934), who was elected president of France in 1913. As a child, his eyesight and motor coordination were poor, but his photographic memory helped him to succeed in school, and his brilliance soon became obvious. While a student at the lycée, he won first prize in a national mathematics competition. After graduation in 1873, he enrolled in the Paris Ecole Polytechnique, where he gained a reputation as a "monster of mathematics." Poincaré continued his graduate work at the Ecole des Mines. He served briefly as an engineer before receiving his doctorate in mathematics in 1879. Almost immediately, Poincaré...