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 = Paris, France
residence = France
nationality = French
field = Physicist
work_institution = 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
prizes = Hughes Medal (1915)
Copley Medal (1940)
religion =
footnotes =

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 6 February 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 was 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.

Langevin is noted for his work on paramagnetism and diamagnetism, and devised the modern interpretation of this phenomenon in terms of electric charges 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.

In 1910 he supposedly had an affair with Marie Curie Fact|date=August 2007 — today, their respective granddaughter and grandson 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.

References

Sources

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

See also

*Born coordinates, for the "Langevin observers" who ride a rigidly rotating disk in an infamous thought experiment in relativistic physics.
* Langevin thermostat [http://www.mse.ufl.edu/~ssinn/Backgrounds/back05_thermo.html]

External links

* [http://scienceworld.wolfram.com/biography/Langevin.html Wolfram research biographical entry] by Michel Barran.
* [http://alsos.wlu.edu/qsearch.aspx?browse=people/Langevin,+Paul Annotated bibliography for Niels Bohr from the Alsos Digital Library for Nuclear Issues]

Persondata
NAME= Langevin, Paul
ALTERNATIVE NAMES=
SHORT DESCRIPTION= French Physicist
DATE OF BIRTH= 23 January 1872
PLACE OF BIRTH= Paris, France
DATE OF DEATH= 19 December 1946
PLACE OF DEATH= Paris, France