Langevin , Paul

Langevin , Paul
(1872–1946) French physicist
Langevin, a native Parisian, studied at the Cavendish Laboratory in Cambridge under J.J. Thomson and at the Sorbonne, where he obtained his PhD under Pierre Curie in 1902. He became physics professor at the Collège de France in 1904 and at the Sorbonne in 1909.
Langevin worked on the application of ultrasonic vibrations, which, following Pierre Curie's discovery of piezoelectricity, could be generated by applying a rapidly changing electric potential to a crystal, making it vibrate and produce sound waves in the ultrasonic region. Because ultrasonic wavelengths are shorter than those in the audible range, they are better reflected and Langevin saw that this might be put to military use in World War I. His development of echo location to detect submarines in fact came too late to be used in the war, but this work was the grounding for the later sonar.
Langevin also studied paramagnetism and gave a modern explanation of it incorporating electron theory. In this way he was able to deduce a formula correlating paramagnetism with absolute temperature, which gave a theoretical explanation of the experimental observation that paramagnetic moment changes inversely with temperature. The formula also enabled Langevin to predict the occurrence of paramagetic saturation – a prediction later confirmed experimentally by Heike Kamerlingh-Onnes.
Langevin also studied the properties of ionized gases, and Brownian movement in gases. He publicized in France Einstein's views on the equivalence of energy and mass.

Scientists. . 2011.

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  • Langevin, Paul — (1872 1946)    physicist    Paul Langevin, who is credited with the first successful development of sonar, as well as the development of a modern theory of magnetism, was born in Paris. He attended the École Lavoisier and École de physique et de… …   France. A reference guide from Renaissance to the Present

  • Langevin, Paul — ► (1872 1946) Físico francés. Autor de numerosos e importantes trabajos sobre magnetismo, ultrasonido, etc …   Enciclopedia Universal

  • Langevin — Langevin, Paul …   Enciclopedia Universal

  • Paul Langevin — Saltar a navegación, búsqueda Albert Einstein, Paul Ehrenfest, Paul Langevin, Heike Kamerlingh Onnes y Pierre Weiss en casa de Kamerlingh Onnes en Leiden en Países Bajos. Paul Langevin ( …   Wikipedia Español

  • LANGEVIN (P.) — LANGEVIN PAUL (1872 1946) Physicien français né et mort à Paris. «J’ai grandi au lendemain de la guerre de 1870 entre un père républicain jusqu’au fond de l’âme et une mère dévouée jusqu’au sacrifice, au milieu de cet admirable peuple de Paris,… …   Encyclopédie Universelle

  • Paul Langevin — (* 23. Januar 1872 in Paris; † 19. Dezember 1946 in Paris) war ein französischer Physiker. Er studierte an der Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris und setzte dort auch seinen Berufsweg fort, zuletzt als… …   Deutsch Wikipedia

  • Langevin Funktion — Die Langevin Funktion lautet: . Sie ist nach dem Physiker Paul Langevin benannt und wird zur Berechnung von Polarisation, Magnetisierung und Widerstand verwendet. Die bekannteste Anwendung ist die halbklassische Beschreibung eines Paramagneten in …   Deutsch Wikipedia

  • Langevin — (Paul) (1872 1946) physicien français: travaux sur la relativité …   Encyclopédie Universelle

  • Paul Langevin — Pour les articles homonymes, voir Langevin. Paul Langevin Naissance 23 janvier 1872 …   Wikipédia en Français

  • Paul Langevin — Infobox Scientist name = Paul Langevin |224px image width = 224px caption = Paul Langevin (1872 1946) birth date = birth date|1872|1|23|mf=y birth place = Paris, France death date = death date and age|df=yes|1946|12|19|1872|1|23 death place =… …   Wikipedia