Dominique François Jean Arago

2026-01-21 09:30:43

Dominique François Jean Arago (Estagel, Kingdom of France, February 26, 1786 – October 2, 1853, Paris, Second French Empire) is a French physicist, astronomer and politician. He discovered the chromosphere of the Sun (the lower layers of the atmosphere, mainly consisting of gaseous hydrogen) and made accurate estimates of the diameters of the planets. He discovered that a rotating copper disc deflects a magnetic needle above it, which indicates the occurrence of magnetism when a non-magnetic conductor rotates. He developed an experiment that proved the wave theory of the world, showed that light waves propagate more slowly in a dense medium than in air, and contributed to the discovery of the laws of polarization of the world. Member of the Paris Academy of Sciences (1809), foreign member of the Royal London Society (1818), foreign honorary member of the St. Petersburg Academy of Sciences (1829).