The m�canique physique of Sim�on Denis Poisson: The evolution and isolation in France of his approach to physical theory (1800?1840)

Abstract

In 1818, the Acad6mie des Sciences announced that diffraction would be made the subject of the prize competition for 1819. Wave theories of light had been gaining some exposure in England and on the Continent I and quite possibly the subject of diffraction was chosen in the hope that a deep investigation of this phenomenon might lend decisive support to the corpuscular theory of light advocated by LAPLACE and BIOT. On 29 July 1818, AOGUSTIN FRESNEL, a man somewhat removed from the inner circle of Laplacian physics, deposited his entry for this prize competition at the Institut. Entitled "M6moire sur la diffraction de la lumi6re," it gave a detailed description of his mathematization of a wave theory of light. POlSSON was one of the judges chosen to review the entries in this competition. Others selected were ARAGO, GAY-LUSSAC, BIOT, and LAPLACE. ARAGO and GAYLUSSAC were sympathetic to an undulatory theory of light, but BlOT and LAPLACE were deeply committed to an emission theory that seemed to preserve their basic perceptions of physics developed within the Laplacian program. Though PoIssoN was inclined toward an emission theory, he did have substantial reservations. In a letter that FRESNEL wrote to his brother L~ONOR in 1818, he observed that "Dans une conversation que j 'ai cue derni6rement avec Poisson, il m 'a avou6 que la multiplicit6 des hypoth6ses que n6cessite la th6orie newtonienne diminuait beaucoup sa confiance en elle. ' 'z Such reservations concerning the