1892-1987

French physicist awarded 1929 Nobel Prize in physics for discovering the wave nature of matter. By the 1920s it was known that electromagnetic waves sometimes behave like particles. In his doctoral dissertation de Broglie proposed that particles sometimes behave like waves (1924). The wave properties of matter (de Broglie waves) only manifest themselves at atomic levels and had never before been observed. The existence of de Broglie waves was confirmed by diffraction experiments in 1927.