Paul Langevin

Paul Langevin
Paul Langevin (1872-1946)
Born	January 23, 1872(1872-01-23) Paris, France
Died	December 19, 1946 (aged 74) Paris, France
Residence	France
Nationality	French
Fields	Physicist
Institutions	Cambridge University Collège de France Sorbonne ESPCI
Alma mater	ESPCI École Normale Supérieure
Doctoral advisor	Pierre Curie
Doctoral students	Irène Joliot-Curie
Known for	Langevin equation
Notable awards	Hughes Medal (1915) Copley Medal (1940)

Paul Langevin (23 January 1872 – 19 December 1946) was a prominent French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the Comité de vigilance des intellectuels antifascistes, an antifascist organization created in the wake of the February 6, 1934 far right riots. Langevin was also president of the Human Rights League (LDH) from 1944 to 1946 — he had just recently joined the French Communist Party. He is buried at the Panthéon.

Life

Langevin was born in Paris, and studied at the École de Physique et Chimie and the École Normale Supérieure. He then went to Cambridge University and studied in the Cavendish Laboratory under Sir J. J. Thomson. Langevin returned to the Sorbonne and obtained his Ph.D. from Pierre Curie in 1902. In 1904 he became professor of physics at the Collège de France. In 1926 he became director of the École de Physique et Chimie, where he had been educated. He was elected, in 1934, to the Académie des sciences.

Albert Einstein, Paul Ehrenfest, Paul Langevin, Heike Kamerlingh Onnes, and Pierre Weiss at Ehrenfest's home in Leiden

Langevin is noted for his work on paramagnetism and diamagnetism, and devised the modern interpretation of this phenomenon in terms of spins of electrons within atoms. His most famous work was in the use of ultrasound using Pierre Curie's piezoelectric effect. During World War I, he began working on the use of these sounds to detect submarines through echo location. However the war was over by the time he had it operational. During his career, Paul Langevin also did much to spread the theory of relativity in France and created what is now called the twin paradox.

In 1910 he supposedly had an affair with the then widowed Marie Curie^{[citation needed]} — today, their respective grandson and granddaughter are married to one another: Hélène Langevin-Joliot and Michel Langevin. He was also noted for being an outspoken opponent of Nazism, and was removed from his post by the Vichy government following the occupation of the country by Nazi Germany. He was later restored to his position in 1944. He died in Paris in 1946, two years after living to see the Liberation of Paris. He is buried near several other prominent French scientists in the Pantheon in Paris.

See also

• Born coordinates, for the Langevin observers who ride a rigidly rotating disk in an infamous thought experiment in relativistic physics.

References

This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please improve this article by introducing more precise citations where appropriate. (February 2008)

Sources

• Asimov's Biographical Encyclopedia of Science and Technology, Isaac Asimov, Doubleday & Co., Inc., 1972, ISBN 0-385-17771-2.

References to the affair with marie Curie is found in Giroud Francoise (Davis, Lydia trans), Marie Curie A life, Holmes and Meier, 1986, ISBN 0-8419-0977-6. and in Quinn Susan , Marie Curie A Life , Heinemann, 1995, ISBN 0 - 434 - 60503 - 4.

External links

Wikimedia Commons has media related to: Paul Langevin

• Wolfram research biographical entry by Michel Barran.
• Annotated bibliography for Niels Bohr from the Alsos Digital Library for Nuclear Issues