C. T. R. Wilson

Charles Thomson Rees Wilson (14 February 1869 – 15 November 1959) was a British meteorologist and physicist who shared the 1927 Nobel Prize in Physics with Arthur Compton for his invention of the cloud chamber.

Early life and education

Charles Thomson Rees Wilson was born on 14 February 1869 in Glencorse, Scotland, the son of John Wilson, a sheep farmer, and Annie Clark Harper. After his father died in 1873, he moved with his family to Manchester, England.

With financial support from his step-brother, Wilson studied biology at Owens College (now the University of Manchester) with the intent of becoming a doctor. He graduated with a B.Sc. in 1887. He then won a scholarship to attend Sidney Sussex College, Cambridge, where he became interested in physics and chemistry. In 1892, he received First Class Honours in both parts of the Natural Sciences Tripos.

Career and research

Wilson became particularly interested in meteorology, and in 1893 he began to study clouds and their properties. Beginning in 1894, he worked for some time at the observatory on Ben Nevis, where he made observations of cloud formation. He was particularly fascinated by the appearance of glories. He then tried to reproduce this effect on a smaller scale in the Cavendish Laboratory at Cambridge, expanding humid air within a sealed container.

In 1895, Wilson discovered that at a large enough expansion, ratio supersaturated water vapour condensates even without dust which he removed by previous condensations, contrary to the previous research by John Aitken. Under J. J. Thomson's mentorship by 1896, he found out that X-rays stimulate the condensation just as well as dust.

In 1900, Wilson became a Fellow of Sidney Sussex College, Cambridge, and was appointed University Lecturer and Demonstrator. He was known by some as a poor lecturer, due to a pronounced stutter. He taught a course on atmospheric electricity as a visiting lecturer at Imperial College London. He was appointed Reader in Electrical Meteorology in 1918 and Jacksonian Professor of Natural Philosophy in 1925.

In 1906, Wilson hypothesised that cosmic radiation generates the ions causing condensation without apparent reasons.

Wilson published numerous papers on meteorology and physics, on topics including X-rays, ionisation, thundercloud formation, and other meteorological events. Wilson may also have observed a sprite in 1924, 65 years before their official discovery. Weather was a focus of his work throughout his career, from his early observations at Ben Nevis to his final paper, on thunderclouds.

Cloud chamber

File:CTRwilsonCloudChamberCavendishLab2013-08-29-17-09-40.jpg

Wilson's original cloud chamber

The invention of the cloud chamber was by far Wilson's signature accomplishment, earning him the Nobel Prize in Physics in 1927. The Cavendish Laboratory praised him for the creation of "a novel and striking method of investigating the properties of ionised gases." The cloud chamber allowed huge experimental leaps forward in the study of subatomic particles and the field of particle physics, generally. Some have credited Wilson with making the study of particles possible at all.

File:Observatory Ben Nevis memorial.jpg

Commemorative plaque at Ben Nevis about the observatory there, and Wilson's cloud chamber

Wilson later experimented with the creation of cloud trails in his chamber by condensation onto ions generated by radioactivity. Several of his cloud chambers survive.

Retrospectively, Wilson's experimental method has received some attention from scholars.

In a period of scientific inquiry characterised by a divide between "analytical" and "morphological" scientists, Wilson's method of inquiry represented a hybrid. While some scientists believed phenomena should be observed in pure nature, others proposed laboratory-controlled experiments as the premier method for inquiry. Wilson used a combination of methods in his experiments and investigations. Wilson's work "made things visible whose properties had only previously been deduced indirectly."

Wilson has been called "almost the last of the great individual experimenters in physics." He used his cloud chamber in various ways to demonstrate the operating principles of things like subatomic particles and X-rays. But his primary interest, and the subject of the bulk of his papers, was meteorology.

Personal life and death

In 1908, Wilson married Jessie Fraser, the daughter of a minister from Glasgow. They had four children. His family knew him as patient and curious, and fond of taking walks in the hills near his home.

Wilson died on 15 November 1959 at his home in Carlops at the age of 90, surrounded by his family.

Recognition

Memberships

Country	Year	Institute	Type	Template:Reference column heading
Template:Flagdeco United Kingdom	1900	Royal Society	Fellow
Template:Flagdeco United Kingdom	1902	Royal Society of Edinburgh	Fellow

Awards

Country	Year	Institute	Award	Citation	Template:Reference column heading
Template:Flagdeco United Kingdom	1911	Royal Society	Hughes Medal	"For his work on nuclei in dust-free air, and his work on ions in gases and atmospheric electricity"
United Kingdom	1922	Royal Society	Royal Medal	"For his researches on condensation nuclei and atmospheric electricity"
United States	1925	Franklin Institute	Howard N. Potts Medal	"Method of making the tracks of ionising rays visible and permanently recording them by photography"
Sweden	1927	Royal Swedish Academy of Sciences	Nobel Prize in PhysicsTemplate:Efn	"For his method of making the paths of electrically charged particles visible by condensation of vapour"
United States	1929	Franklin Institute	Franklin Medal	"Pioneer contributions to atomic physics and to our knowledge of atomic structure"
United Kingdom	1931	Institute of Physics	Duddell Medal and Prize
United Kingdom	1935	Royal Society	Copley Medal	"For his work on the use of clouds in advancing our knowledge of atoms and their properties"

Chivalric orders

United Kingdom

Year	Monarch	Order	Citation	Template:Reference column heading
1937	George VI	Order of the Companions of Honour	"For services to experimental physics"

Commemorations

Wilson crater on the Moon is named after him, Alexander Wilson, and Ralph Elmer Wilson. The Wilson Condensation Cloud formations that occur after large explosions, such as nuclear detonations, are named after him. The Wilson Society—the scientific society of Sidney Sussex College, Cambridge—is named in his honour, as is the CTR Wilson Institute for Atmospheric Electricity—the Atmospheric Electricity Special Interest Group of the Royal Meteorological Society.

The archives of C.T.R. Wilson are maintained by the Archives of the University of Glasgow.

in 1996, a blue plaque in Wilson's honour was installed in a specially built cairn at Flotterstone, close to his birthplace at Crosshouse Farm.

In 2012, the Royal Society of Edinburgh held a meeting in honour of Wilson, the "Great Scottish Physicist."

External links

• Template:Sister-inline
• Template:Nobelprize
• The Papers of C. T. R. Wilson held at Churchill Archives Centre