Larmor, Joseph (1857–1942)

Northern Irish physicist and mathematician, Lucasian professor of mathematics at Cambridge University 1903–32. His most important work was on the interaction of atomically charged matter and the electromagnetic field, though he also wrote extensively on hydrodynamics. He represented Cambridge University in Parliament as a Unionist 1911–22.

Larmor was born in Magheragall, County Antrim, and educated at Queen's College, Belfast, and St John's College, Cambridge. He was professor of natural philosophy, Queen's College, Galway, 1880–85, before returning to Cambridge. His main work, Aether and Matter, 1900, analysed the motion of matter through the ‘ether’ that many physicists of the time believed was the wave-bearing medium present in all space. In this book, Larmor gave the complete formulae for the Lorentz contraction that was to play a key part in Einstein's theory of relativity. Some of his other important contributions were a formula for radiation of energy by an accelerated electron, and a theory of the precession of electron orbits in a magnetic field. He was knighted in 1909.