Clairaut, Alexis Claude (1713–1765)

French mathematician who studied celestial mechanics. His Théorie de la lune/Theory of the Moon (1752) explains the lunar apogee (at which the Moon is furthest from the Earth in its elliptical orbit), which had been omitted by Isaac Newton. He also calculated the path of Halley's Comet, and wrote several papers on the orbit of the Moon. He evolved a theorem connecting the gravity on the surface of a rotating ellipsoid with the compression, and the centrifugal force at the equator.

At the age of 12 Clairaut produced a treatise on four curves of the second order; this, together with his Recherches sur les courbes à double courbure, written in 1729 and published in 1731, caused him to be elected a member of the Académie des Sciences at the age of 18.