The Nobel Prize in Physics 1927
Arthur H. Compton, C.T.R. Wilson
Charles Thomson Rees Wilson was
born on the 14th of February, 1869, in the parish of Glencorse,
near Edinburgh. His father, John Wilson, was a farmer, and his
ancestors had been farmers in the South of Scotland for
generations. His mother was Annie Clerk Harper.
At the age of four he lost his father, and his mother moved with
the family to Manchester, where he was at first educated at a
private school, and later at Owen's College - now the University of
Manchester. Here, intending to become a physician, Wilson
took up mainly biology. Having been granted an entrance
scholarship in 1888 he went on to Cambridge (Sidney Sussex
College), where he took his degree in 1892. It was here that
he became interested in the physical sciences, especially physics
and chemistry. (It was also possible that Wilson's decision to
abandon medicine was influenced by Balfour Stewart, who was
professor of physics at Owen's College at that time - about a
dozen years earlier, J. J.
Thomson, who also went to Cambridge, had passed through the
same College.)
When standing on the summit of Ben Nevis, the highest of the
Scottish mountains, in the late summer of 1894, Wilson was struck
by the beauty of coronas and "glories" (coloured rings
surrounding shadows cast on mist and cloud), and he decided to
imitate these natural phenomena in the laboratory (early 1895).
His sharp observation and keen intellect, however, led him to
suspect (after a few months' work at the Cavendish
Laboratory) that the few drops reappearing again and again
each time he expanded a volume of moist, dust-free air, might be
the result of condensation on nuclei - possibly the ions causing
the "residual" conductivity of the atmosphere-produced
continuously. Wilson's hypothesis was supported after exposure
(early 1896) of his primitive cloud chamber to the newly
discovered (end of 1895) X-rays. The immense increase of the
"rain-like" condensation fitted excellently with the observation
made by Thomson and McClelland immediately after Röntgen's
discovery, that air was made conductive by the passage of X-rays.
When, during the summer of that year, it was firmly established
by Thomson and Rutherford that the
conductivity was indeed due to ionization of the gas, there was
no longer any doubt that ions in gases could be detected and,
photographically, recorded and thus studied at leisure. Wilson's
appointment as Clerk Maxwell Student, at the end of that year,
enabled him to devote all his time for the next three years to
research, and for a year subsequent to this he was employed by
the Meteorological Council in research on atmospheric
electricity. The greater part of his work on the behaviour of
ions as condensation nuclei was thus carried out in the years
1895-1900, whilst after this his other occupations - mainly
tutorial - prevented him from dealing sufficiently with the
development of the cloud chamber. Early in 1911, however, he was
the first person to see and photograph the tracks of individual
alpha- and beta-particles and electrons. (The latter were
described by him as "little wisps and threads of clouds".) The
event aroused great interest as the paths of the alpha-particles
were just as W. H. Bragg had
drawn them in a publication some years earlier. But it was not
until 1923 that the cloud chamber was brought to perfection and
led to his two, beautifully illustrated, classic papers on the
tracks of electrons. Wilson's technique was promptly followed
with startling success in all parts of the world - in Cambridge,
by Blackett (who in 1948
received the Nobel Prize on account of his further development of
the cloud chamber and his discoveries made therewith) and
Kapitsa; in Paris, by Irène
Curie and Auger; in Berlin, by Bothe, Meitner, and Philipp; in
Leningrad, by Skobelzyn; in Tokio, by Kikuchi.
Some of the most important achievements using the Wilson chamber
were: the demonstration of the existence of Compton recoil
electrons, thus establishing beyond any doubt the reality of the
Compton effect (Compton shared the Nobel Prize with Wilson in
1927); the discovery of the positron by Anderson (who was awarded
the Nobel Prize for 1936 for this feat); the visual demonstration
of the processes of "pair creation" and "annihilation" of
electrons and positrons by Blackett and Occhialini; and that of
the transmutation of atomic nuclei carried out by Cockcroft and
Walton. Thus, Rutherford's remark that the cloud chamber was "the
most original and wonderful instrument in scientific history" has
been fully justified.
In 1900, Wilson was made Fellow of Sidney Sussex College, and
University Lecturer and Demonstrator. From then until 1918 he was
in charge of the advanced teaching of practical physics at the
Cavendish Laboratory, and also gave lectures on light. As well as
his experimental work at the Cavendish Laboratory, he also made
observations (1900-1901) on atmospheric electricity (mainly in
the surroundings of Peebles in Scotland). In 1913, he was
appointed Observer in Meteorological Physics at the Solar Physics
Observatory, and most of his research both on the tracks of
ionizing particles and on thunderstorm electricity was carried
out there. In 1918, he was appointed Reader in Electrical
Meteorology, and in 1925, Jacksonian Professor of Natural
Philosophy. He was elected a Fellow of the Royal Society in 1900,
and this Society also honoured him with the Hughes Medal (1911),
a Royal Medal (1922), and the Copley Medal (1935). The Cambridge
Philosophical Society awarded him the Hopkins Prize (1920), and
the Royal Society of Edinburgh the Gunning Prize (1921), while
the Franklin
Institute presented him the Howard Potts Medal (1925).
After his retirement Wilson moved to Edinburgh, and later, at the
age of 80, to the village of Carlops, close to his birthplace at
the farmhouse of Crosshouse, at Glencorse. Life after this,
however, was not an empty one: C.T.R. as his friends and
colleagues called him, maintained social contacts, making a
weekly journey by bus to the city to lunch with them.
Scientifically, too, he was active to the end, finishing his
long-promised manuscript on the theory of thundercloud
electricity (Proc. Roy. Soc. London, August (1956)).
Among the few who enjoyed his personal guidance may be
mentioned:
Wormell (in the general field of atmospheric electricity), C. F.
Powell (Nobel Prize winner 1950,
for his development of the photographic method of studying
nuclear processes and the discoveries made therewith on mesons),
P. I. Dee and J. G. Wilson.
In 1908, Professor Wilson married Jessie Fraser, daughter of Rev.
G. H. Dick of Glasgow; there were two sons and two
daughters.
He died on the 15th of November, 1959, in the midst of his
family.
From Nobel Lectures, Physics 1922-1941, Elsevier Publishing Company, Amsterdam, 1965
This autobiography/biography was written at the time of the award and first published in the book series Les Prix Nobel. It was later edited and republished in Nobel Lectures. To cite this document, always state the source as shown above.
Copyright © The Nobel Foundation 1927