James Clerk Maxwell(1831–1879)

James Clerk Maxwell was born at 14 India Street in Edinburgh on 13 June 1831, the only child of John Clerk Maxwell, an advocate, and Frances Cay. The family seat was Glenlair in Kirkcudbrightshire, and Maxwell was raised on the estate, running its burns and Galloway hills as a boy before his father took him to Edinburgh in 1841 to begin formal schooling at the Edinburgh Academy.

A country boy with a soft Galloway accent, he was winning the Academy's mathematical and English-verse medals within two years. By fourteen he had submitted his first paper to the Royal Society of Edinburgh, on a method of drawing ovals with pins and a length of string. He matriculated at the University of Edinburgh at sixteen, went on to Peterhouse and then Trinity College, Cambridge, graduated Second Wrangler in 1854, won a Trinity fellowship, and began the work on electricity and magnetism, on colour theory and on the kinetic theory of gases that would occupy the next twenty-five years.

Maxwell published On Physical Lines of Force in 1861 and 1862, and A Dynamical Theory of the Electromagnetic Field in 1865. The work consolidated the experimental results of Coulomb, Ampère, Gauss and Faraday into a single mathematical structure, and from that structure derived the consequence that an electromagnetic disturbance travels through space at the speed of light. It was the most far-reaching theoretical achievement in physics between Newton and Einstein. Einstein, who kept a portrait of Maxwell over his desk at Princeton, called it the deepest and most fruitful work physics had known since Newton; the four field equations are the foundation on which the twentieth century built radio, radar, satellite communication and the electrical economy.

He also gave the world its first colour photograph. At a Royal Institution lecture on 17 May 1861 he showed a projected image of a tartan ribbon, made by combining three photographs taken through red, green and blue filters, the principle behind every colour image made since. In parallel he built the kinetic theory of gases that with Boltzmann founded statistical mechanics: the Maxwell distribution of molecular speeds, his 1859 proof that the rings of Saturn must be made of particles, and the equipartition theorem, each a foundation stone of a different modern field.

He returned to Glenlair in 1865 to write the Treatise on Electricity and Magnetism (1873), the textbook from which Heinrich Hertz produced the first artificial radio waves in 1887. In 1871 he was appointed the first Cavendish Professor of Experimental Physics at Cambridge and designed and equipped the Cavendish Laboratory, which became the most productive single physics building of the next century. He died at Cambridge in 1879 and is buried at Parton Kirkyard near Glenlair. The Maxwell name carries, in modern physics, the unique weight of being the surname of the equations on which the field is built.