Siméon Poisson

Siméon Poisson
Siméon Denis Poisson (1781–1840)
Born	(1781-06-21)21 June 1781 Pithiviers, Orléanais, Kingdom of France (present-day Loiret, France)
Died	25 April 1840(1840-04-25) (aged 58) Sceaux, Hauts-de-Seine, July Monarchy
Nationality	French
Fields	Mathematics
Institutions	École Polytechnique Bureau des Longitudes Faculté des sciences de Paris () École de Saint-Cyr
Alma mater	École Polytechnique
Academic advisors	Joseph-Louis Lagrange Pierre-Simon Laplace
Doctoral students	Michel Chasles Joseph Liouville
Other notable students	Nicolas Léonard Sadi Carnot Peter Gustav Lejeune Dirichlet
Known for	Poisson process Poisson equation Poisson kernel Poisson distribution Poisson bracket Poisson algebra Poisson regression Poisson summation formula Poisson's spot Poisson's ratio Poisson zeros Conway–Maxwell–Poisson distribution Euler–Poisson–Darboux equation

Siméon Denis Poisson (French: [si.me.ɔ̃ də.ni pwa.sɔ̃]; 21 June 1781 – 25 April 1840), was a French mathematician, geometer, and physicist. He obtained many important results, but within the elite Académie des Sciences he also was the final leading opponent of the wave theory of light and was proven wrong on that matter by Augustin-Jean Fresnel.

Poisson was born in Pithiviers, Loiret, the son of soldier Siméon Poisson.

In 1798, he entered the École Polytechnique in Paris as first in his year, and immediately began to attract the notice of the professors of the school, who left him free to make his own decisions as to what he would study. In 1800, less than two years after his entry, he published two memoirs, one on Étienne Bézout's method of elimination, the other on the number of integrals of a finite difference equation. The latter was examined by Sylvestre-François Lacroix and Adrien-Marie Legendre, who recommended that it should be published in the Recueil des savants étrangers, an unprecedented honour for a youth of eighteen. This success at once procured entry for Poisson into scientific circles. Joseph Louis Lagrange, whose lectures on the theory of functions he attended at the École Polytechnique, recognized his talent early on, and became his friend (the Mathematics Genealogy Project lists Lagrange as his advisor, but this may be an approximation); while Pierre-Simon Laplace, in whose footsteps Poisson followed, regarded him almost as his son. The rest of his career, till his death in Sceaux near Paris, was nearly occupied by the composition and publication of his many works and in fulfilling the duties of the numerous educational positions to which he was successively appointed.