George Paget Thomson as a young man, c 1909.

UNITED KINGDOM - MAY 13: One of a set of five family photographs in a frame. Sir George Paget Thomson (1892-1975) was an English physicist who discovered the diffraction of electrons by atoms in crystals and received the Nobel Prize for physics with C J Davisson in 1927. The process of electron diffraction which these experiments established has been widely used in the investigation of the surfaces of solids. In 1930 Thomson was appointed Professor at Imperial College, where he became interested in nuclear physics. In 1940 he was made Chairman of the British Committee set up to investigate the possibilities of atomic bombs. He later became Scientific Adviser to the Air Ministry. Sir George was the son of Joseph John Thomson (1856-1940) who was responsible for the discovery of the electron. He is shown here as a young man. (Photo by SSPL/Getty Images)