British physicist who pioneered the technique of X-ray crystallography, for which he was awarded (with his son Lawrence Bragg) the 1915 Nobel Prize for Physics. He was knighted in 1920, was president of the Royal Society from 1935 to 1940, and was appointed to the OM in 1931.
The son of an ex-seaman turned farmer, Bragg was educated at Cambridge University, graduating in 1884. In 1886 he moved to Australia, where he became professor of mathematics and physics at Adelaide University. He returned to Britain in 1909 and held chairs of physics at Leeds University (1909–15) and University College, London (1915–23).
Bragg's research began in his forties. He first worked on the nature of alpha particles, but on moving to Leeds in 1909 his attention was directed to the related problem of the nature of X-rays. Working with his son, Lawrence Bragg, he devised a means of exploring the structure of matter with X-rays. In 1915 he completed the first X-ray spectrometer and with his son published in the same year the results of their early investigations in X-Rays and Crystal Structure. After retiring from University College, London, in 1923 Bragg was appointed director of the Royal Institution, where he formed an important research centre that attracted several young X-ray crystallographers. It was in Bragg's laboratory, for example, that plans were first made to explore the structure of biological molecules with X-rays.
Subjects: Science and Mathematics — History.