Born on 15 August 1892 in Dieppe, France, Louis de Broglie was a Nobel Prize–winning physicist whose proposal of matter waves was crucial to the development of quantum theory. De Broglie studied at the Sorbonne, where he earned degrees in history in 1910 and physics in 1913. After completing his mandatory military service in the French army during World War I, de Broglie returned to the Sorbonne to pursue his doctorate in theoretical physics. Inspired by the work of Albert Einstein on the wave–particle duality of light, de Broglie proposed that matter also has both particle and wave properties. His 1924 thesis on the subject made his career and launched the new field of wave mechanics (see the article by Heinrich Medicus, Physics Today, February 1974, page 38). By 1927 experimentalists had confirmed de Broglie’s theory by demonstrating the wave nature of electrons. Two years later, in 1929, de Broglie was awarded the Nobel Prize in Physics. After completing his PhD, de Broglie joined the faculty at the Sorbonne, where he became chair of theoretical physics in 1932 and would remain for almost four decades. Besides his teaching duties, he continued to work on various aspects of wave mechanics, such as its applications to nuclear physics. He also wrote many scientific articles and more than 25 books, many of which became very popular. De Broglie received the Henri Poincaré Medal in 1929, the Albert I of Monaco Prize in 1932, the Max Planck Medal in 1938, and the French National Scientific Research Center’s gold medal in 1956. He died in 1987 at age 94. (Photo credit: Burndy Library, courtesy AIP Emilio Segrè Visual Archives, Brittle Books Collection)
