Coulomb, Charles-Augustin de

born June 14, 1736, Angoulême, France

died Aug. 23, 1806, Paris

French physicist.

After serving as a military engineer in the West Indies, he returned to France in the 1780s to pursue scientific research. To investigate Joseph Priestley's law of electrical repulsions, he invented a sensitive instrument to measure the electrical forces involved. A light rod made of an insulator, with a small conducting sphere at each end, was suspended horizontally by a fine wire so that it was free to twist when another charged sphere was brought close to it. By measuring the angle through which the rod twisted, Coulomb could measure the repulsive forces. He is best known for formulating Coulomb's law. He also did research on friction of machinery, on windmills, and on the elasticity of metal and silk fibres. The coulomb, a unit of electric charge, was named in his honour.

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▪ French physicist

born June 14, 1736, Angoulême, France

died August 23, 1806, Paris

 French physicist best known for the formulation of Coulomb's law, which states that the force between two electrical charges is proportional to the product of the charges and inversely proportional to the square of the distance between them. Coulombic force (Coulomb force) is one of the principal forces involved in atomic reactions.

      Coulomb spent nine years in the West Indies as a military engineer and returned to France with impaired health. Upon the outbreak of the French Revolution, he retired to a small estate at Blois and devoted himself to scientific research. In 1802 he was appointed an inspector of public instruction.

 Coulomb developed his law as an outgrowth of his attempt to investigate the law of electrical repulsions as stated by Joseph Priestley of England. To this end he invented sensitive apparatus to measure the electrical forces involved in Priestley's law and published his findings in 1785–89. He also established the inverse square law of attraction and repulsion of unlike and like magnetic poles, which became the basis for the mathematical theory of magnetic forces developed by Siméon-Denis Poisson. He also did research on friction of machinery, on windmills, and on the elasticity of metal and silk fibres. The coulomb, a unit of electric charge, was named in his honour.

 

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