William Henry Bragg, 1862-1942

Biographical note

British physicist, chemist, mathematician and active sportsman who uniquely shared a Nobel Prize with his son William Lawrence Bragg – the 1915 Nobel Prize in Physics: "For their services in the analysis of crystal structure by means of X-ray".

In 1885, (at the age of 23), Bragg was appointed (Sir Thomas) Elder Professor of Mathematics and Experimental Physics at the University of Adelaide, and started work there early in 1886. Bragg was an able and popular lecturer; he encouraged the formation of the student union, and the attendance, free of charge, of science teachers at his lectures.

Bragg's interest in physics developed, particularly in the field of electromagnetism. In 1895 he was visited by Ernest Rutherford, en-route from New Zealand to Cambridge; this was the commencement of a lifelong friendship. "The turning-point in Bragg's career came in 1904 when he gave the presidential address to section A of the Australasian Association for the Advancement of Science at Dunedin, New Zealand", on "Some Recent Advances in the Theory of the Ionization of Gases". This idea was followed up "in a brilliant series of researches" which, within three years, earned him a fellowship of the Royal Society of London. This paper was also the origin of his first book Studies in Radioactivity (1912). Soon after the delivery of his 1904 address, some radium bromide was made available to Bragg for experimentation. In December 1904 his paper "On the Absorption of a Rays and on the Classification of the a Rays from Radium" appeared in the Philosophical Magazine, and in the same issue a paper "On the Ionization Curves of Radium", written in collaboration with his student Richard Kleeman, also appeared.