Maxwell, James Clerk
Maxwell, James Clerk (1831-1879), a Scottish physicist. Maxwell demonstrated mathematically that electromagnetic radiation travels through space in transverse waves, and that the waves are formed by pulsating electrical and magnetic fields. He postulated that light is a form of electromagnetic radiation and predicted that other forms of this radiation would be found. The discovery of radio waves and X rays soon proved him to be correct.
Maxwell's work was based on data from Michael Faraday's experiments on electricity and magnetism. Maxwell summed up his findings in Treatise on Electricity and Magnetism (2 volumes, 1873), one of the outstanding works of the 19th-century physics. Maxwell's equations express the fundamental mathematical relationships between electric and magnetic fields. The maxwell, a unit of magnetic flux, is named for him.
Maxwell was born in Edinburgh. He attended the University of Edinburgh, 1847-50, and then Cambridge University, from which he graduated in 1854. During his postgraduate years at Cambridge, 1854-56, he showed that combinations of red, blue, and green produce almost every color of the spectrum. While a professor at Marischal College in Aberdeen, 1856-60, he showed by mathematics that Saturn's rings have to be composed of disconnected solid particles. Maxwell taught at the University of London, 1860-65. In 1871 he was appointed to the newly created chair of experimental physics at Cambridge. Cavendish Laboratory was opened there under his direction in 1873.
In the 1870's Maxwell established the kinetic theory of gases, which explains the properties and behavior of gases by the action of molecules. He introduced statistical probability methods to determine the speed of individual molecules in a gas, and the average distance they travel between collisions with other molecules. These calculations enabled Maxwell and Ludwig Boltzmann, an Austrian physicist, to develop formulas for determining various properties of gases.