Jules Henri Poincaré

Jules Henri Poincaré (1854-1912), French physicist and one of the foremost mathematicians of the 19th century.

Poincaré was a cousin of the French statesman and author Raymond Poincaré. He was born in Nancy and educated at the École Polytechnique and the École Supérieur des Mines in Paris. He taught at the University of Caen from 1879 to 1881 and was lecturer at the University of Paris from then until 1885, when he became professor there of physical mechanics, mathematical physics (1886), and celestial mechanics (1896).

Poincaré made important original contributions to differential equations, topology, probability, and the theory of functions. He is particularly noted for his development of the so-called Fuchsian functions and his contribution to analytical mechanics. His studies included research into the electromagnetic theory of light and into electricity, fluid mechanics, heat transfer, and thermodynamics. He also anticipated chaos theory. Among Poincaré's more than 30 books are Science and Hypothesis (1903; trans. 1905), The Value of Science (1905; trans. 1907), Science and Method (1908; trans. 1914), and The Foundations of Science (1902-8; trans. 1913). In 1887 Poincaré became a member of the French Academy of Sciences and served at its president in 1906. He also was elected to membership in the French Academy in 1908.