Leon Brillouin (born the August 7th 1889 with Sevres - died in 1969 with New York) was a Physicien free - American, primarily known for its work in quantum Mécanique and Physics the solid state. It is one of the great names of the science of the 20th century. He in particular worked on the Théorie of the waves and the Information theory.

Biography

Heir to a great line of scientists (his father and its grandfather occupied before him a pulpit of professor to the Collège de France), Leon Brillouin was the son of Marcel Brillouin, the small son of Éleuthère Mascart and the back small son of Charles Briot.

Leon Brillouin between with the National university in 1908. At the end of its schooling, it decides to continue its studies with the Institut of Theoretical physics of Munich whose direction was then assumed by Arnold Sommerfeld. It will work there at the laboratory of max von Laue (1879 - 1960) on the Physics solid state , which was with its first stammerings.

It returns in France in 1913 and begins a thesis on “ the theory of the solids and the quanta ”, which it will be able to support only in 1920, because of its mobilization, during the First World War in the services of radio telegraphy. During his scientific career, Leon Brillouin will contribute to science important shares, as the effect which bears its name, the concept of Diffusion Brillouin, or even the zones of Brillouin, to quote only one of the fields, the physics solid state , where it knew to exert his talent, and that it even contributed to found.

In April 1926, Leon Brillouin synthesized in famous the Journal of Physics nearly ten articles published by foreign physicists like Werner Heisenberg, max Born or Pascual Jordan. He thus played a big role in the introduction in France of the quantum Mécanique.

In 1927, it formed part - with Marie Curie, Paul Langevin and Louis de Broglie - of four French invited to the fifth Congrès Solvay, which marked the official birth of the quantum Mécanique.

It was titular pulpit of physical theories to the Faculty of Science of the university of Paris of 1928 with 1932 before being elected with the Collège de France, succeeding his father Marcel Brillouin. Louis de Broglie succeeded to him the Sorbonne.

In August 1939, one month before the declaration of war to the Germany, Leon Brillouin is named, as a specialist in the propagation in the waves, director of the French Radiodiffusion.

He is also the author of the book Science and information theory where the relations between these two disciplines are examined. Curiously, the title of its english language version, Science and information theory , is definitely more present on the Internet than that of its French original version. It is true that the typography of the latter left much to be desired. A certain number of plays on the contents of information of the texts, due to Claude Shannon, are indexed there. Originators as Walter Lewino will use the concept for the realization of very close interactive games on Minitel.

To ECA of Saclay, to Gif-sur-Yvette, a national laboratory financed jointly by the ECA and CNRS bear the name of Leon Brillouin. One works there in particular on “the use of the diffraction and the neutron Spectroscopie in all the possible fields of the Basic research and applied”.

Its Work

• “ the quantum theory and the Paris, Bohr atom ”, P.U.F., 1923.
• “ quantum statistics and their applications”, Paris, P.U.F., 1930.
• “ elementary Concepts of mathematics for the applied sciences ” (1935), Paris, Masson
• “ Course of Theoretical physics: tensors in mechanics and elasticity ”, Paris, Masson, 1938. (2nd edition published 1949).
• “ Wave Propagation in Periodic Structures ”, New York, McGraw-Hill, 1946.
• “ Science and Information Theory ”, New York, Academic Near, 1956.
• “ Wave Propagation and Group Velocity ”, New York, Academic Near, 1960 (with Arnold Sommerfeld).
• “ Scientific uncertainty and information ”, New York, Academic Near, 1964
• “ Relativity reexamined ”, New York, Academic Near, 1970