Charles-Augustin de Coulomb

Charles-Augustin de Coulomb (Angoulême June 14, 1736 – Paris August 23, 1806) was a French physicist. He is known for Coulomb's law, which is an inverse-square law for electrostatic charges very similar to Newton's gravitational law for masses. An important difference between the two laws is that masses always attract each other, whereas charges may repel or attract. That is, charges may be positive or negative, while masses have the same sign (are always positive by convention). The SI unit of charge, the coulomb, is named after the C.-A. de Coulomb.

Biography

After Charles-Augustin graduated from the military engineering school of Mézières in 1761, he started his career as an engineer-officer in the French colony Martinique. He stayed there nine years rebuilding forts that were destroyed during the Seven Years' War and returned to France when he was thirty-six years old and in poor health.

After his return Coulomb spent his spare on physics research. He shared a prize offered by the Académie des Sciences for the study of magnetic variations. This brought him into the Académie in 1781 and to the invention of the torsion balance. He used this extremely sensitive instrument in electric and magnetic investigations, culminating in the discovery (1785) of the law called after him.

Napoleon appointed him inspector general of public instruction in 1802 and four years later he died in Paris.

Reference

E. Segré, From Falling Bodies to Radio Waves, W. H. Freeman, New York (1984).