Poincaré, Henri

(1854-1912)

   mathematician

   The last great universal mathematician and one of the foremost mathematicians of the 19th century, who made fundamental contributions to almost all the branches of mathematics and their application to the science of physics, Henri Poincaré was born in Nancy and educated in Paris. His cousin was the statesman Raymond Poincaré. one of his most important discoveries (1881) was that of automor-phic functions (which he called "fuchsian" in honor of I. Fuchs, the German mathematician). Poincaré made original contributions, too, to differential equations, linear equations, probability, and analytical mechanics. He did important research involving the electromagnetic theory of light and on electricity, heat transfers, thermodynamics, celestial mechanics, and fluid mechanics, and anticipated the chaos theory. He is likewise considered a founder of analytic geometry and topography. Some of his conclusions can be considered as the first draft of the problem of relativity stated by Albert Einstein some years later. Additionally, Poincaré devoted much of his time to reflection on the philosophy of science (he supported the essential role of intuition in all research), and his book La Science et l'Hypothèse (1902) had a great influence on several generations of scientists. He left more than 500 other works. Poincaré was elected to the Academy of Sciences in 1887 and to the Académie Française in 1908.