Sir William Lawrence Bragg CH, OBE, MC, FRS was an Australian-born British
physicist and X-ray crystallographer, discoverer of Bragg's law of X-ray
diffraction, which is basic for the determination of crystal structure. He
was joint winner of the Nobel Prize in Physics in 1915: "For their services in
the analysis of crystal structure by means of X-ray", an important step in
the development of X-ray crystallography.
Bragg was knighted in 1941. As of 2014, Lawrence Bragg is the youngest ever
Nobel Laureate in physics, having received the award at the age of 25
years. Bragg was the director of the Cavendish Laboratory, Cambridge, when
the discovery of the structure of DNA was reported by James D. Watson and
Francis Crick in February 1953. Biography
= Early years = Bragg was born in North Adelaide, South
Australia. He 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.
After beginning his studies at St Peter's College, Adelaide in 1905, Bragg
went to the University of Adelaide at age 16 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 with first class honours in 1911. In 1914 Bragg was elected to a
Fellowship at Trinity College – a Fellowship at a Cambridge college
involves the submission and defence of a thesis.
Among Bragg's other interests was shell collecting; his personal collection
amounted to specimens from some 500 species; all personally collected from
South Australia. He discovered a new species of cuttlefish – Sepia braggi,
named for him by Joseph Verco. = 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 analysed.
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 and appointed Officer of the Order
of the British Empire. He was also Mentioned in Despatches on 16 June 1916,
4 January 1917 and 7 July 1919. On 2 September 1915 his brother was
killed during the Gallipoli Campaign. Shortly afterwards, William Lawrence
Bragg received the news that he had been awarded the Nobel Prize in Physics, aged
25. Between the wars, from 1919 to 1937, he
worked at the Victoria University of Manchester as Langworthy Professor of
Physics. He was director of the National Physical Laboratory in Teddington in
1937. After World War II, Bragg 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 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 14 May 1953, which
resulted in an article by Ritchie Calder in The News Chronicle of London on
Friday 15 May 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 to 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 haemoglobin. Bragg
subsequently successfully lobbied for, and nominated, Crick, Watson and Maurice
Wilkins for the 1962 Nobel Prize in Physiology or Medicine; Wilkins' share
recognised the contribution made by researchers 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
was awarded. The crystal structure of hen egg white
lysozyme, which was solved by D C Phillips et al. in 1965 under the
directorship of Lawrence Bragg at the Royal Institution, London, led to the
discovery of the helix. The lysozyme structure was determined from crystals
of hen egg white lysozyme chloride, which belong to the tetragonal space
group P2 with the unit cell dimensions a = b = 79.1 Å, c = 37.9 Å and have one
lysozyme molecule in the asymmetric unit. The existence of the helix, as
opposed to Pauling's alpha helix, was predicted by W L Bragg, J C Kendrew & M
F Perutz in 1950. Apparently, many workers failed to mention the discovery
of the helix, and failed to acknowledge the part it plays in the lysozyme
structure. Pauling never acknowledged that at least part of the
above-mentioned 1950 paper made sense. Unlike myoglobin, in which nearly 80 per
cent of the amino-acid residues are in the alpha-helix conformation, in the
lysozyme protein the alpha-helix content is only about 40 per cent of the
amino-acid residues in four main stretches. The helix is an earlier
proposal for the structure of polypeptides made by Bragg W L, Kendrew
J C & Perutz M F in 1950. It is based on the crystallographic idea of an integral
number of residues per turn of the helix. In this conformation, every third
peptide is hydrogen-bonded back to the first peptide, thus forming a ring
containing ten atoms. Royal Institution
He had a long association with the Royal Institution including:
Professor of Natural Philosophy, 1938–1953
Fullerian Professor of Chemistry, 1954–1966
Superintendent of the House, 1954–1966 Director of the Davy-Faraday Research
Laboratory, 1954–1966 Director, 1965–1966
Emeritus Professor, 1966–1971 In 1931, 1934 and 1961 Bragg was invited
to deliver the Royal Institution Christmas Lecture on The Universe of
Light, Electricity and Electricity. He also introduced the Schools' Lectures
Program during his time at the Royal Institution.
= Personal life = He married Alice Hopkinson in 1921, with
whom he had four children, Stephen Lawrence, David William, Margaret Alice,
born 1931, and Patience Mary, born 1935. Alice was on the staff at Withington
Girls' School until Bragg was appointed director of the NPL in 1937.
Bragg's hobbies included painting, literature and a lifelong 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. He died at a hospital near his home at
Waldringfield, Ipswich, Suffolk. He was buried in Trinity College, Cambridge;
his son David is buried in the Parish of the Ascension Burial Ground in
Cambridge, where Bragg's friend Rudolph Cecil Hopkinson is also buried.
Honours and awards Bragg was elected a Fellow of the Royal
Society in 1921—"a qualification that makes other ones irrelevant". He was
knighted by King George VI in the 1941 New Year Honours, and received both the
Copley Medal and the Royal Medal of the Royal Society. Although Hunter, in his
book on Bragg Light is a Messenger, argued that he was more a
crystallographer than a physicist, Bragg's lifelong activity showed
otherwise—he was more of a physicist than anything else. Thus, from 1939 to
1943, he served as President of the Institute of Physics, London. In the
1967 New Year Honours he was appointed Companion of Honour by Queen Elizabeth
II. Since 1992, the Australian Institute of
Physics has awarded the Bragg Gold Medal for Excellence in Physics to commemorate
Lawrence Bragg and his father, William Bragg, for the best PhD thesis by a
student at an Australian university. Nobel Prize
Matteucci Medal Hughes Medal
Royal Medal Guthrie Lecture
Copley Medal See also
Tactical Artillery Terms from World War List of Nobel laureates in Physics
References Further reading
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 978-1-84046-940-0;
Ridley, Matt; Francis Crick: Discoverer of the Genetic Code, first published in
July 2006 in the United States, and then in the UK in September 2006, by
HarperCollins Publishers; 192 pp, ISBN 0-06-082333-X.
John Jenkin: "William and Lawrence Bragg, Father and Son: The Most
Extraordinary Collaboration in Science", Oxford University Press, 2008.
External links First press stories on DNA
Nobelprize.org – The Nobel Prize for Physics in 1915
Nobel Biography A collection of digitised 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
Bragg, Lawrence National Library of Australia, Trove, People and
Organisation record for William Lawrence Bragg
The Nature of Things: Oil, Soap and Detergent, Ri Channel video, November
1959 The Nature of Things: Atoms and
Molecules, Ri Channel video, October 1959
The Nature of Things: Solids, Liquids and Gases, Ri Channel video, November
1959