1713-1765

French Mathematician

Alexis-Claude Clairaut is best remembered for his book Théorie de la figure de la terre, an outgrowth of studies he made during a 1736 journey to Lapland. In it, he discussed the curvature of the Earth, and thus proved Sir Isaac Newton's (1642-1727) theory that the shape of the Earth is that of an oblate ellipsoid. This in turn led to widespread acceptance of Newton's gravitational theory.

Born in Paris on May 7, 1713, Clairaut was the son of Jean-Baptiste, a mathematics teacher, and Catherine Petit Clairaut. The couple had some 20 children, of which few survived. Their son made an early display of his talent, studying calculus at age 10 and writing erudite mathematical treatises when he was barely a teenager. He went on to conduct a lively correspondence with some of the leading mathematical figures of the day, including Leonhard Euler (1707-1783) and Johann Bernoulli...