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Sir William Lawrence Bragg, CH, OBE, MC, FRS (31 March 1890 – 1 July 1971) was an English physicist who shared the Nobel Prize in Physics in 1915 with his father Sir William Henry Bragg. He was the director of the Cavendish Laboratory, Cambridge when the epochal discovery of the structure of DNA was made by James D. Watson and Francis Crick in February 1953.

Biography

Early years

Bragg was born in North Adelaide, South Australia. He was an impressionable boy and showed an early interest in science and mathematics. His father, William Henry Bragg, was Elder Professor of Mathematics and Physics at the University of Adelaide. Shortly after starting school aged 5, William Lawrence Bragg fell from his tricycle and broke his arm. His father, who had read about Röntgen's experiments in Europe and was performing his own experiments, used the newly discovered X-rays and his experimental equipment to examine the broken arm. This is the first recorded surgical use of X-rays in Australia.

Bragg was a very able student. After beginning his studies at St Peter's College, in 1904 he went to the University of Adelaide at age 14 to study mathematics, chemistry and physics, graduating in 1908. In the same year his father accepted the Cavendish chair of physics at the University of Leeds, and brought the family back to England. Bragg entered Trinity College, Cambridge in the autumn of 1909 and received a major scholarship in mathematics, despite taking the exam while in bed with pneumonia. After initially excelling in mathematics, he transferred to the physics course in the later years of his studies, and graduated in 1911.

Career

Work on X-ray crystallography

Bragg is most famous for his law on the diffraction of X-rays by crystals. Bragg's law makes it possible to calculate the positions of the atoms within a crystal from the way in which an X-ray beam is diffracted by the crystal lattice. He made this discovery in 1912, during his first year as a research student in Cambridge. He discussed his ideas with his father, who developed the X-ray spectrometer in Leeds. This tool allowed many different types of crystals to be analyzed. The collaboration between father and son led many people to believe that the father had initiated the research, a fact that upset the son.

Work on sound ranging

Bragg's research work was interrupted by both World War I and World War II. During both wars he worked on sound ranging methods for locating enemy guns, in this work he was aided by William Sansome Tucker, Harold Roper Robinson and Henry Harold Hemming. For his work during WWI he was awarded the Military Cross (London Gazette, 1 January 1918) and appointed an Officer of the British Empire (London Gazette, 15 March 1918). He was also mentioned in dispatches on 16 June 1916, 4 January 1917 and 7 July 1919.^[1]

In autumn 1915 his brother was killed at Gallipoli. At about the same time, William Lawrence Bragg received the news that he received the Nobel Prize in Physics, aged 25, making him the youngest ever winner of a Nobel Prize.

Between the wars, from 1919 to 1937, he worked at the Victoria University of Manchester as Langworthy Professor of Physics.

After World War II, he returned to Cambridge, splitting the Cavendish Laboratory into research groups. He believed that "the ideal research unit is one of six to twelve scientists and a few assistants".

Work on proteins

In 1948 he became interested in the structure of proteins and was partly responsible for creating a group that used physics to solve biological problems. He played a major part in the 1953 discovery of the structure of DNA, in that he provided support to Francis Crick and James D. Watson who worked under his aegis at the Cavendish.

Bragg's original announcement of the discovery of the structure of DNA was made at a Solvay conference on proteins in Belgium on 8 April 1953 but went unreported by the press, he then gave a talk at Guys Hospital Medical School in London on Thursday, May 14, 1953 which resulted in an article by Ritchie Calder in The News Chronicle of London, on Friday, May 15, 1953, entitled "Why You Are You. Nearer Secret of Life."

Bragg was gratified to see that the X-ray method that he developed forty years before was at the heart of this profound insight into the nature of life itself. At the same time at the Cavendish Max Perutz was also doing his Nobel Prize winning work on the structure of hemoglobin. Bragg subsequently successfully lobbied for and nominated Crick, Watson and Maurice Wilkins for the 1962 Nobel Prize in Physiology or Medicine; Wilkins' share recognized the contribution made by researchers (using X-ray crystallography) at King's College London to the determination of the structure of DNA. Among those researchers was Rosalind Franklin, whose "Photograph 51" showed that DNA was a double helix, not a triple helix as Linus Pauling had proposed. Franklin died before the prize (which only goes to living people) was awarded.

Personal life

He married Alice Hopkinson in 1921. They had four children, Stephen Lawrence, David William, Margaret Alice and Patience Mary. He died at a hospital near his home at Waldringfield, Ipswich, Suffolk.

William Lawrence Bragg's hobbies included painting, literature and a life-long interest in gardening. When he moved to London, he missed having a garden and so worked as a part-time gardener, unrecognised by his employer, until a guest at the house expressed surprise at seeing him there.

Honours and awards

He was knighted by King George VI in 1941^[2] and received both the Copley Medal and the Royal Medal of the Royal Society. In 1967 was made a Companion of Honour by the Queen Elizabeth II.

Since 1992 the Australian Institute of Physics has awarded the Bragg Gold Medal for Excellence in Physics to commemorate Sir Lawrence Bragg (in front on the medal) and his father Sir William Bragg for the best PhD thesis by a student at an Australian university.

• Nobel Prize (1915)
• Matteucci Medal (1915)
• Hughes Medal (1931)
• Royal Medal (1946)
• Copley Medal (1966)

Quotations

“The gift of expression is important to them as scientists; the best research is wasted when it is extremely difficult to discover what it is all about … It is even more important when scientists are called upon to play their part in the world of affairs, as is happening to an increasing extent.”^[3]

References

Books containing references to Sir Lawrence Bragg

• Biography: Hunter, Graeme. Light Is A Messenger, the Life and Science of William Lawrence Bragg, ISBN 0-19-852921-X; Oxford University Press, 2004.
• John Finch; 'A Nobel Fellow On Every Floor', Medical Research Council 2008, 381 pp, ISBN 978-1840469-40-0; this book is all about the MRC Laboratory of Molecular Biology, Cambridge.
• Ridley, Matt; Francis Cr* ick: Discoverer of the Genetic Code (Eminent Lives), first published in July 2006 in the USA and then in the UK. September 2006, by HarperCollins Publishers; 192 pp, ISBN 0-06-082333-X; [This short book is in the publisher's "Eminent Lives" series.]
• John Jenkin: "William and Lawrence Bragg, Father and Son: The Most Extraordinary Collaboration in Science", Oxford University Press, 2008.

See also

• 'Death' of DNA Helix (crystalline) joke funeral card.
• Tactical Artillery Terms from World War I

External links

• [1] First press stories on DNA
• Nobelprize.org - The Nobel Prize for Physics in 1915
• Nobel Biography
• A collection of digitized materials related to Bragg's and Linus Pauling's structural chemistry research.
• Key Participants: Sir William Lawrence Bragg - Linus Pauling and the Race for DNA: A Documentary History
• NOVA Episode on Photograph 51
• Oral History interview transcript with William Lawrence Bragg 20 June 1969, American Institute of Physics, Niels Bohr Library and Archives