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, a Northumberland gentlewoman. The family seat was Glenlair in Kirkcudbrightshire, a fifteen-hundred-acre estate Maxwell's father had taken on by inheritance and slowly improved. James was raised on the estate from two years old, taught by his mother to read the King James Bible from memory, and ran the burns and dykes of the Galloway hills until he was nine. His mother died of stomach cancer the year he turned eight, the same cancer that would kill him at forty-eight. His father took him to Edinburgh in 1841 to begin formal schooling at the Edinburgh Academy.

He was a strange-looking, country-accented boy with a slow speech impediment, and was nicknamed Dafty at the Academy. Two years in he started winning the mathematical and English-verse medals. 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; the secretary read it to the Society because Maxwell was thought too young to take the floor. He matriculated at the University of Edinburgh at sixteen, transferred to Peterhouse, Cambridge in 1850 and to Trinity the following term, and graduated Second Wrangler in 1854. He was elected to 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 four parts in 1861 and 1862, and A Dynamical Theory of the Electromagnetic Field in 1865 in the Philosophical Transactions of the Royal Society. The work consolidated the experimental electrical and magnetic results of Coulomb, Ampère, Gauss and Faraday into a single mathematical structure, and from the structure derived the consequence that an electromagnetic disturbance propagates through space at the speed of light. The unification was the most far-reaching theoretical achievement in physics between Newton and Einstein. Einstein, who kept a portrait of Maxwell over his desk in Princeton, said the work was the deepest and most fruitful that physics had experienced since the time of Newton. The four field equations as we read them today were tidied into vector form by Heaviside and Gibbs in the 1880s, and are the foundation on which the twentieth century built radio, radar, satellite communications and the electrical economy.

He also gave the world the first colour photograph. At a Royal Institution lecture on 17 May 1861, Maxwell showed a projected image of a tartan ribbon, produced by separating three black-and-white photographs taken through red, green and blue filters and recombining them on the screen with three matched lanterns. The principle is the basis of every colour image we make today. In parallel he was building the kinetic theory of gases that with Boltzmann would give us statistical mechanics: the Maxwell distribution of molecular speeds, the demon of his 1867 thought experiment, the proof in 1859 that the rings of Saturn are particulate, the equipartition theorem. Each of these is 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. He was recalled to Cambridge in 1871 as the first Cavendish Professor of Experimental Physics and given the task of designing and equipping a laboratory that became the most productive single physics building of the next century. He worked on it for eight years. He was diagnosed with abdominal cancer in early 1879 and died at Cambridge on 5 November of that year, aged forty-eight, with his wife Katherine, who had nursed him through his illnesses for twenty years, at his side. He is buried in Parton Kirkyard near Glenlair beside his parents. The Maxwell name carries the weight in modern physics of being the surname of the equations on which the field is built.