Sir Joseph Larmor, a physicist and mathematician who made innovations in the understanding of electricity, dynamics, thermodynamics, and the electron theory of matter. His most influential work was Aether and Matter, a theoretical physics book published in 1900. He grew up in Belfast, the son of a shopkeeper. He was a student at Royal Belfast Academical Institution, Queen's University Belfast, and St John's College, Cambridge. After teaching natural philosophy for a few years at Queen's College, Galway, Ireland, in 1885 he accepted a lectureship in mathematics at St John's College, Cambridge. In 1903 he was appointed Lucasian Professor of Mathematics at Cambridge, a post he retained until his retirement in 1932. He never married.