Concept
Urbain Jean Joseph Le Verrier FRS (FOR) HFRSE (yʁbɛ̃ ʒɑ̃ ʒɔzɛf lə vɛʁje; 11 March 1811 – 23 September 1877) was a French astronomer and mathematician who specialized in celestial mechanics and is best known for predicting the existence and position of Neptune using only mathematics. The calculations were made to explain discrepancies with Uranus's orbit and the laws of Kepler and Newton. Le Verrier sent the coordinates to Johann Gottfried Galle in Berlin, asking him to verify. Galle found Neptune in the same night he received Le Verrier's letter, within 1° of the predicted position. The discovery of Neptune is widely regarded as a dramatic validation of celestial mechanics, and is one of the most remarkable moments of 19th-century science. Le Verrier was born at Saint-Lô, Manche, France, in a modest bourgeois family, his parents being, Louis-Baptiste Le Verrier and Marie-Jeanne-Josephine-Pauline de Baudre. He studied at École Polytechnique. He briefly studied chemistry under Gay-Lussac, writing papers on the combinations of phosphorus and hydrogen, and phosphorus and oxygen. He then switched to astronomy, particularly celestial mechanics, and accepted a job at the Paris Observatory. He spent most of his professional life there, and eventually became that institution's Director, from 1854 to 1870 and again from 1873 to 1877. In 1846, Le Verrier became a member of the French Academy of Sciences, and in 1855, he was elected a foreign member of the Royal Swedish Academy of Sciences. Le Verrier's name is one of the 72 names inscribed on the Eiffel Tower. Le Verrier's first work in astronomy was presented to the Académie des Sciences in September 1839, entitled Sur les variations séculaires des orbites des planètes (On the Secular Variations of the Orbits of the Planets). This work addressed the then most-important question in astronomy: the stability of the Solar System, first investigated by Laplace. He was able to derive some important limits on the motions of the system, but due to the inaccurately-known masses of the planets, his results were tentative.
