Jean-Baptiste Biot

Jean-Baptiste Biot (1774-1862) was a French physicist, mathematician, astronomer, and chemist. Biot was born in Paris 21 April 1774 and died in the same city on 3 February 1862.

Jean-Baptiste got a degree from the École Polytechnique and in 1800 became professor of physics and mathematics at the Collège de France and at the Faculté des Sciences. In 1803 he became a member of the First Class of the Institut de France (in the revolutionary years this was the name for the French Académie des Sciences). Biot became a member (an "immortal") of the Académie française in 1856.

Some of Biot's major works are:

• In 1804 he accompanied Joseph Louis Gay Lussac on the first hot-air balloon ascent undertaken for scientific purposes.

• In 1805 he published the important book: Traité élémentaire d'astronomie physique [Elementary Treatise on Physical Astronomy].

• In 1820 he made his historic discovery, together with Félix Savart, that the strength of the magnetic field caused by a current flowing through a wire varies inversely with the distance from the wire. This is now known as Biot-Savart's law.

• In 1835 he laid the basis for saccharimetry. He found that sugar solutions rotate the plane of polarization when a beam of polarized light passes through and that the angle of rotation is a direct measure of the concentration of the solution. This provides a nondestructive way of determining sugar concentration. For this work Biot was awarded the Rumford Medal of the Royal Society in 1840.