William Lawrence Bragg was born
in Adelaide, Australia, on 31st March 1890. He was an
impressionable boy and showed an early interest in science.
His father, William Henry Bragg,
was Professor of Mathematics and Physics at the University
of Adelaide. Shortly after starting school at age 5,
Bragg fell from his tricycle and broke his arm. His
father, having recently read about Röntgen's experiments
in Europe, used the newly discovered X-rays to examine
Bragg's arm. This is the first recorded surgical use
of X-rays in Australia.
Bragg was a very able student,
and from the age of 11 studied at St Peter's College.
He was in a class of older boys who saw him as 'an amusing
freak', but did not tease or bully him. In 1904, aged
15, Bragg entered Adelaide University to read mathematics,
chemistry and physics. He graduated in 1908, aged 18.
In 1908 Bragg's father accepted
the Chair of Physics at Leeds University, and took the
family back to England on the Waratah, a ship
that sank on her next voyage!
Bragg entered Trinity College,
Cambridge in the autumn of 1909. He received a major
scholarship in mathematics, despite taking the exam
while in bed with pneumonia. After gaining first class
honours in Part I mathematics, Bragg transferred to
the Part II Physics course, and graduated with first
class honours in 1911.
Bragg is most famous for his law
on the diffraction of X-rays by crystals, a 'theory
which makes it possible to calculate the positions of
[the X-ray beams] for all dispositions of crystal and
photographic plates'. He made this discovery in 1912,
during his first year as a research student in Cambridge.
To make the discovery Bragg drew together results published
by Laue in Germany and concepts from lectures by J.J.
Thomson and C.T.R. Wilson. He presented his theory to
the Cambridge Philosophical Society on 11th November
Bragg 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 which Bragg could not perform in
the over-crowded Cavendish Laboratory. The collaboration
between father and son led many people to believe that
Bragg's father had initiated the research, a fact that
1914 Bragg was elected to a Fellowship at Trinity College,
but the First World War interrupted his work. Bragg
was commissioned as a 2nd Lieutenant in the Leicester
Royal Horse Artillery, and in August 1915 began working
on sound ranging methods for locating enemy guns. He
supervised this work between 1917 and 1919, rising to
the rank of Major.
autumn 1915, Bragg's brother Robert was killed in the
War. At about the same time Bragg received the news
that he had won the Nobel Prize in Physics.
returned to Cambridge early in 1919, but later that
year became Langworthy Professor
of Physics at Manchester, in succession to Ernest Rutherford.
Bragg was elected as a Fellow of the Royal Society on
12th May 1921, and in December married Alice Hopkinson,
a historian from Cambridge with whom he had four children.
In 1930 Bragg suffered a breakdown,
but recovered quickly after the birth of his third child
in June 1931. In November 1937 Bragg became Director
of the National Physical Laboratory, but found the work
disappointing. On 17th October 1937 Rutherford died.
The following year Bragg was appointed as his successor
at the Cavendish.
Bragg moved to Cambridge with
his family in October 1938, but the Laboratory was rapidly
emptying as research staff left for service in the Second
World War. Bragg again worked on sound ranging, and
on improving a form of sonar. In 1941 he was knighted
a 'Sir Lawrence', and spent six months as Scientific
Liaison Officer in Canada. Between 1939 and 1943 he
was President of the Institute of Physics.
the War, Bragg returned to Cambridge, splitting the
Cavendish into research groups. 'The ideal research
unit is one of six to twelve scientists and a few assistants'.
Bragg was keen that no single research group should
dominate, as nuclear physics had dominated in the past.
The groups were nuclear, radio and low-temperature physics,
crystallography, metal physics and mathematical physics.
In 1948 Bragg became interested
in the structure of proteins. Although he played no
direct part in the 1953 discovery of DNA's structure,
James Watson admits that 'the X-ray method [Bragg] developed
forty years before was at the heart of this profound
insight into the nature of life itself.'
In April 1953 Bragg accepted the
post of Resident Professor at the Royal Institution
in London. Bragg proposed that the Royal Institution
should perform some form of public service, and suggested
series of lectures to show experiments to schoolchildren.
This idea was met with an enthusiastic response, and
by 1965 20,000 schoolchildren were attending these lectures
Some of Bragg's lectures were
televised by the BBC. Bragg became a popular communicator
of science, admired and recognised by the public. He
worked at the Royal Institution until his retirement
in September 1966.
Bragg's hobbies included painting,
literature and a life-long intereset in gardening. He
received both the Copley Medal and the Royal Medal of
the Royal Society, and in 1967 was made a Companion
of Honour by the Queen.
William Lawrence Bragg died at
a hospital near his home at Waldringfield, Suffolk on
1st July 1971.