William Henry Bragg

William Henry Bragg
William Henry Bragg
Born	2 July 1862 Wigton, Cumberland, England
Died	12 March 1942 London, England
Residence	Australia, UK
Nationality	English
Institutions	University of Adelaide University of Leeds University College London Royal Institution
Alma mater	Cambridge University
Academic advisor	J.J. Thompson
Notable students	W. L. Bragg Kathleen Lonsdale William Thomas Astbury
Known for	X-ray diffraction
Notable prizes	Nobel Prize in Physics (1915)
Note that he is the father of William Lawrence Bragg. There was no PhD in Cambridge until 1919, and J.J. Thompson was in fact his Master's advisor.

Sir William Henry Bragg KBE, OM, MA (Cantab), PhD, (2 July 1862 – 10 March 1942) was an English physicist and chemist who shared the 1915 Nobel Prize in Physics with his son Sir William Lawrence Bragg.

Early life

Bragg was the eldest child of Robert John Bragg, a sea captain who had become a farmer after receiving an inheritance, and his wife Mary Wood, daughter of a clergyman. Bragg was born at Westward near Wigton, Cumberland. Bragg's mother died in 1869, and Bragg was taken in and educated by his father's brothers. He was educated at King William's College, Isle of Man, where he took an interest in sports and a variety of extracurricular activities on campus besides his formal studies. and, winning a scholarship, Trinity College, Cambridge. He entered Trinity in 1881, and graduated in 1884 as third wrangler in the mathematical tripos.

University of Adelaide

Upon the implicit recommendation of J.J. Thompson, who was one of his instructors, Bragg won an appointment as the "Elder Professor of Pure and Applied Mathematics, who shall also give instruction in Physics" at the University of Adelaide in Australia and began his duties there early in 1886. He then had what he considered a limited knowledge of physics, but there were only about a hundred students doing full courses at Adelaide of whom scarcely more than a handful belonged to the science school. Bragg was thus enabled to develop his knowledge of the subject in his early years. Bragg married and in 1890, a son, william Lawrence Bragg, was born. but it was not until he was past 40 that he began to do research work of importance. At the meeting of the Australasian Association for the Advancement of Science, held at Dunedin in 1904, Bragg, as president of his section, delivered an address on "Some Recent Advances in the Theory of the Ionization of Gases." This paper was the origin of his first book Studies in Radioactivity, published in 1912. Shortly after the delivery of his 1904 address some radium bromide was placed at the disposal of Bragg with which he was able to experiment. In December 1904 a paper by him "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 number a paper "On the Ionization Curves of Radium," written in collaboration with R. Kleeman, also appeared. At the end of 1908 Bragg resigned his professorship at Adelaide to become Cavendish professor at Leeds university. During his 23 years in Australia he had seen the number of students at Adelaide university nearly quadrupled, and had had a full share in the development of its excellent science school

University of Leeds

From 1909 at Leeds, Bragg continued his work on X-rays with much success. He invented the X-ray spectrometer and with his son, William Lawrence Bragg, founded the new science of X-ray analysis of crystal structure. In 1915 father and son were jointly awarded the Nobel Prize in Physics for their studies, using the X-ray spectrometer, of X-ray spectra, X-ray diffraction, and of crystal structure.. Their volume, X-Rays and Crystal Structure, published in this year, had reached a fifth edition 10 years later.

University College London

Bragg was appointed Quain professor of physics at University College London in 1915 but did not take up his duties there until after World War I. He did much work for the government at this time, largely connected with submarine detection, at Aberdour on Forth and at Harwich, and returned to London in 1918 as consultant to the admiralty. While Quain professor at London he continued his work on crystal analysis.

Royal Institution

From 1923 he was Fullerian professor of chemistry at the Royal Institution and director of the Davy Faraday Research Laboratory. This institution was practically rebuilt in 1929-30 and under Bragg's directorship many valuable papers were issued from the laboratory.

Legacy

He became a Fellow of the Royal Society in 1907, was elected a vice-president in 1920, and served as president of the society from 1935 to 1940.

Ernest Rutherford discussed his theories on the proton and nucleus with Bragg, who disagreed with him.^{[citation needed]}

The lecture theatre of King William's College is named in his memory.

Since 1992 the Australian Institute of Physics has awarded the Bragg Gold Medal for Excellence in Physics for the best PhD thesis by a student at an Australian university.

In 1889, he married Gwendoline Todd, daughter of Sir Charles Todd, who died in 1929. He was survived by a daughter and his son, Sir William Lawrence Bragg, another son died at Gallipoli. Bragg was created C.B.E. in 1917, K.B.E. in 1920, and in 1931 was given the Order of Merit.

Timeline

• University of Adelaide (1886-1908)
• University of Leeds (1909-15)
• University College London (1915-23)
• Royal Institution

Prizes

• Nobel Prize (1915)
• Matteucci Medal (1915)
• Rumford Medal (1916)
• Copley Medal (1930)
• Hughes Medal (1931)

Selected publications

• William Henry Bragg, The World of Sound (1920)
• William Henry Bragg, The Crystalline State - The Romanes Lecture for 1925. Oxford, 1925.
• William Henry Bragg, Concerning the Nature of Things (1925)
• William Henry Bragg, Old Trades and New Knowledge (1926)
• William Henry Bragg, An Introduction to Crystal Analysis (1928)
• William Henry Bragg, The Universe of Light (1933)

References

ISBN links support NWE through referral fees

• Serle, Percival. 1949. "Bragg, Sir William Henry (1862-1942)," in Dictionary of Australian Biography. Sydney: Angus and Robertson. Retrieved May 1, 2007.

• This article incorporates text from the 1949 edition of Dictionary of Australian Biography from Project Gutenberg of Australia, which is in the public domain in Australia and the United States of America.

Honorary Titles
Preceded by: Sir Frederick Hopkins	President of the Royal Society 1935–1940	Succeeded by: Sir Henry Dale

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