born July 17, 1894, Charleroi, Belg.
died June 20, 1966, Louvain
Belgian astronomer and cosmologist.
He served in the Belgian army during World War I, then entered a seminary and became a priest. In 1927 he became a professor of astrophysics at the University of London and proposed the big-bang model of the formation of the universe. Lemaître's theory, as modified by George Gamow , has become the leading theory of the universe's origin. Lemaître also studied cosmic ray s and the three-body problem, which concerns the mathematical description of the motion of three mutually attracting bodies in space.