Biot, Jean Baptiste

Born Apr. 21, 1774, in Paris; died there on Feb. 3, 1862. French physicist, geodesist, and astronomer. Member of the Paris Academy of Sciences (1803).

Biot received his education at the polytechnical school in Paris. He became a professor at the College of France in 1800 and at the University of Paris in 1809. From 1806 he worked on the staff of a geodesic commission which was engaged in measuring the length of a meridian. At the beginning of his scientific activity Biot was concerned with celestial mechanics and the study of the properties of gases. In 1804, together with J. L. Gay-Lussac, he completed a flight in a balloon in order to study the properties of air at various altitudes. Biot’s most important scientific works pertain to research on the polarization of light, the magnetic field of an electric current, and acoustics. Biot established the law of plane rotation in the polarization of light (1815). He studied plane rotation in the polarization of light in crystals and organic substances, thus laying the foundation for sac-charimetry. Jointly with F. Savart, Biot measured the magnetic field of a direct electric current, thereby establishing an important law of thermodynamics (1820). He concerned himself with problems in the history of science, in particular with studying I. Newton’s works. Biot was the author of a widely known treatise on experimental and mathematical physics (1816).