Jules-Henri Poincaré | Biography

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 obtained a teaching position at the University of Caen and in only two years became professor of mathematics at Paris University. At the age of 33, Poincaré was elected to the Academy of Sciences.

Poincaré's mathematical output was staggering. By the end of his life, he had published nearly 500 papers on such topics as function theory, Abelian functions, probability theory, algebraic geometry, number theory, and algebraic topology. His contributions to differential equations, celestial mechanics, and physics were especially noteworthy.

Poincaré was among those scientists who began, at the end of the nineteenth century, to develop a penetrating insight into the nature of space and time that went far beyond Isaac Newton's mechanics. This line of thought culminated in Albert Einstein's epoch-making paper in 1905 on special relativity. Poincaré arrived at many of the conclusions Einstein was reaching, though from a very different direction. For example, he anticipated Einstein in 1901 when he declared that absolute motion in space is undetectable and that the mathematical equations that form the so-called Lorentz transformations, used by Einstein in forging relativity theory, are the most precise transformations that relate electromagnetic laws from one moving reference frame to another. Poincaré also noted that, from the perspective of the Lorentz transformations, nothing can exceed the speed of light.

Poincaré's excursions into mathematical physics led him to investigate problems in the study of the motion of celestial bodies. His insights into the famous " three-body" problem, which seeks a precise mathematical solution to how three or more massive objects in space are influenced by each other's gravity, stand as towering achievements in physics. No single mathematician since Isaac Newton has made such an impact on the understanding of celestial mechanics. Furthermore, Poincaré's theories on orbital motion led him to create an entirely new field of mathematical inquiry called topological dynamics.

Poincaré's writings were not restricted to complex mathematical topics but also explored the philosophy of science. He believed that in many cases mathematical ideas are born not out of a framework of logic but as a consequence of psychological creativity and that a respect and nurturing of the human capacity for creativity is of supreme importance to the furthering of scientific progress. It was his general writings, which appealed to a wide audience outside the world of mathematical science, that endeared Poincaré to people in all walks of life. In 1908, just four years before his death in 1912, Poincaré was elected to the Académie Française. The vacancy he filled was left not by a scientist, but by the poet René Sully Prudhomme (1839-1907). The respect held for Poincaré's creative abilities was such that his compatriots considered him to be an artist as much as a physicist and mathematician.