born Feb. 14, 1869, Glencorse, Midlothian, Scot. died Nov. 15, 1959, Carlops, Peeblesshire Scottish physicist. His invention of the Wilson cloud chamber, a device that became widely used in the study of radioactivity, X rays, cosmic rays, and other particle phenomena, also led to the later development of the bubble chamber. He shared the 1927 Nobel Prize for Physics with Arthur Compton