29 Apr, 2021

Jules Henri Poincaré – mathematician, physicist, astronomer

Jules Henri Poincaré was born on April 29, 1854 in Nancy (France). After graduating with honors from college, he received his higher education at the Ecole Polytechnique in Paris, and then at the School of Mines, from which he graduated in 1879. In the same year, Poincaré defended his thesis for a doctorate in mathematics, which gave him the right to teach. At the Universities of Cannes and Paris, Poincaré lectured on mathematical analysis (1878-1885).

In 1881, Poincaré’s first note on Fuchsian functions appeared in the authoritative scientific journal Compres Rendus. This has become a real event in the scientific community. For two years Poincaré published a series of works on this topic, and four memoirs published under the general title “On curves determined by differential equations” made up the content of a new branch of mathematics – qualitative methods of the theory of differential equations. Before him, this radically new approach was not even touched upon.

Since 1886, Poincaré headed the Department of Mathematical Physics and Probability Theory of the University of Paris, which he headed for 10 years. At the same time, the scientist’s interest turned to the laws of motion of celestial bodies. He built a theory of asymptotic expansions, studied the stability of orbits and the shape of celestial bodies.

He owns important for celestial mechanics works on the stability of motion and on the equilibrium figures of a gravitating rotating fluid. The method of “integral invariants” used by Poincaré has become a classical means of theoretical research not only in mechanics and astronomy, but also in static physics and quantum mechanics.

Poincaré had a tremendous influence on the development of theoretical thought in classical physics. In his articles in 1897-1905, even before the works of A. Einstein, the main provisions of the special theory of relativity were formulated.

Poincaré’s works include Maxwell’s Theory and Hertz Oscillations (1907), The Value of Science (1905), Science and Method (1908), an extensive course of lectures on mathematical physics in 12 volumes, works on topology, the theory of automorphic functions, non-euclidean geometry, number theory …

Poincaré used the methods of mathematical physics to solve problems of heat conduction, electromagnetism, hydrodynamics, theory of elasticity … He proposed the first version of the relativistic theory of gravity, and Poincaré’s philosophical doctrine was later called conventionalism.

Henri Poincaré is a genius French scientist of a wide profile who made a great contribution to many branches of mathematics, physics and mechanics. During his life, he managed to receive many scientific titles and awards, was a member of many academies of sciences. The Mathematical Institute in Paris is named after Poincaré, as well as a crater on the far side of the moon.

Jules Henri Poincaré died on July 17, 1912 in Paris.