Langevin, Paul 1872-1946
French physicist

Born in Paris, he was educated at the �cole Normale Sup�rieure, spent a year in Cambridge, and came to the notice of J J Thomson. He returned to Paris to take his doctorate and study with Pierre Curie. In 1909 he was appointed Professor of Physics at the Sorbonne. Studying magnetic phenomena, he related the paramagnetic movement of molecules to their absolute temperature (1905), and predicted the paramagnetic saturation discovered by Heike Kamerlingh Onnes in 1914. He worked on the molecular structure of gases, and during World War I applied sonar techniques to the detection of submarines. He was elected a Foreign Member of the Royal Society in 1928, and was awarded its Hughes Medal. Imprisoned by the Nazis, he managed to escape to Switzerland, and after the liberation returned to Paris.

Bibliography: Bernadette Bensaude-Vincent, Langevin: 1872-1946: Science et vigilance (1987)