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Michael Faraday

Michael Faraday, 1791-1867, English chemist and physicist known for his research into electricity and magnetism.

Faraday's interests were various: he studied the condensation of gases, metallurgy, optical illusions (including diamagnetism), acoustics, and the conservation of energy. His discoveries, many of groundbreaking importance, include induced electricity (1831), electrostatic induction (1838), the relationship between electricity and magnetism (1838) and between electricity and gravity (1851), hydroelectricity (1843), and atmospheric magnetism (1851).

Faraday was fascinated by science even as a child. He mentioned the article on electricity in the third edition of the Encyclopædia Britannica (1797) as an early influence: after reading it, he developed a simple electrostatic generator from lumber and old bottles and build a weak voltaic pile. He later attended one of Sir Humphry Davy's popular lectures at the Royal Institution, which convinced him to pursue a scientific career.

Faraday began his professional work in science as an assistant to Davy at the Institution in 1812, and by 1827 had assumed Davy's chair of Chemistry at the Institution. His early career was notable for its chemical research; Chemical Manipulation appeared in 1827.

But his most important work was related to electricity. He was the first to interpret the results of Oersted and Ampère, who had observed that passing electricity through a wire produced a magnetic field. Faraday believed that a magnetic pole could be made to move in a circular pattern around a wire carrying electric current, and by developing a device to prove his theory, he constructed the first electric motor. He announced his many electrical discoveries in the series of Experimental Researches on Electricity published over forty years in the Royal Society's journal Philosophical Transactions.

In 1831 he turned to acoustics, studying sound's ability to produce regular patterns in a thin layer of fine powder. This observation led him to discover induced current in his most famous experiment, where a galvanometer showed the existence of current in a coil wrapped around a current-carrying metal ring, the principle underlying the transformer. Later in the same year he approached his electric motor from the other direction, hypothesizing that a moving magnet could produce an electric current; in proving his hypothesis he created the first dynamo (or generator).

Faraday developed a popular reputation: early in his career he served as an expert witness for his chemical expertise, and he later delivered a popular series of Christmas lectures at the Royal Institution.