Thomson, Sir George Paget (1892-1975), a British physicist, won the 1937 Nobel Prize in physics, along with the American physicist Clinton J. Davisson. The two physicists shared the prize for their discovery of diffraction (spreading out) of electrons by crystals. In Thomson’s experiments, he passed beams of electrons through thin films of metal. He found that the electrons emerged in a number of beams in various directions. This spreading suggested that the electrons were behaving as waves do even though they are particles. This wave-particle duality is true of all atomic particles and lies at the heart of quantum theory and hence of all modern physics. See Physics (Quantum theory) .
Thomson was born in Cambridge, England, on May 3, 1892. His father, Sir Joseph John Thomson, won the Nobel Prize in physics in 1906 for his work demonstrating the existence of the electron, a negatively charged particle that makes up part of all atoms. George Thomson studied mathematics and physics at Trinity College, Cambridge University, and was a postgraduate student doing research with his father when World War I broke out in 1914. After service as an infantry officer in France, he returned to England to spend the rest of the war working on aeronautical engineering.
After the end of the war in 1918, Thomson spent three years teaching physics at Cambridge and then became professor at the University of Aberdeen, Scotland. There he carried out experiments passing beams of electrons through thin films of metal.
In 1905, the German-born scientist Albert Einstein had suggested that radiation could sometimes behave like particles instead of waves. In 1924, the French physicist Louis de Broglie had made the opposite suggestion, that particles could behave like waves. Thomson’s experiments, and others conducted independently by Clinton Davisson and Lester H. Germer in the United States, confirmed de Broglie’s ideas. Within a few years, a German physicist, Ernst Ruska, had taken the idea further and built a microscope that used electrons instead of light waves, capable of “seeing” individual atoms. See Electron microscope ; Quantum mechanics .
In 1930, Thomson became a professor at Imperial College, in the University of London, where he remained until 1952. When the fission (nuclear splitting) of uranium was discovered in 1939, he realized that it could provide a source of enormous quantities of energy. During World War II (1939-1945), he worked on military scientific problems. He became chairman of a committee set up to study the possibility of building a nuclear bomb. The committee reported that it was possible, and its analysis was made available to the United States. The United Kingdom subsequently cooperated with the U.S. atomic bomb program, the Manhattan Project (see Manhattan Project ).
During World War II, Thomson was also responsible for scientific liaison between the United Kingdom and Canada, and he served as scientific adviser to the British Air Ministry. He was knighted in 1943. After the war he returned to Imperial College and continued research in nuclear physics. In 1946 and 1947, he was scientific adviser to the United Nations Security Council. In 1952 he returned to Cambridge as a professor of physics until he retired in 1962. Thomson died on Sept. 10, 1975.
