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Étienne Louis Malus

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Nationality
  
French

Fields
  
Physics

Name
  
Etienne-Louis Malus

Notable awards
  
Rumford Medal

Role
  
Physicist

Awards
  
Rumford Medal

Education
  
Ecole Polytechnique


Etienne-Louis Malus httpsuploadwikimediaorgwikipediacommons77

Known for
  
polarization of light Malus\' law

Died
  
February 24, 1812, Paris, France

Etienne louis malus 1775 1812 biography


Étienne-Louis Malus /ˈɛtiˌɛn ˈl ˌməˈls/ ([malys]; 23 July 1775 – 24 February 1812) was a French officer, engineer, physicist, and mathematician.

Contents

Malus was born in Paris, France. He participated in Napoleon's expedition into Egypt (1798 to 1801) and was a member of the mathematics section of the Institut d'Égypte. Malus became a member of the Académie des Sciences in 1810. In 1810 the Royal Society of London awarded him the Rumford Medal.

His mathematical work was almost entirely concerned with the study of light. He studied geometric systems called ray systems, closely connected to Julius Plücker's line geometry. He conducted experiments to verify Christiaan Huygens' theories of light and rewrote the theory in analytical form. His discovery of the polarization of light by reflection was published in 1809 and his theory of double refraction of light in crystals, in 1810.

Malus attempted to identify the relationship between the polarising angle of reflection that he had discovered, and the refractive index of the reflecting material. While he deduced the correct relation for water, he was unable to do so for glasses due to the low quality of materials available to him (most glasses at that time showing a variation in refractive index between the surface and the interior of the glass). It was not until 1815 that Sir David Brewster was able to experiment with higher quality glasses and correctly formulate what is known as Brewster's law.

Malus is probably best remembered for Malus' law, giving the resultant intensity, when a polariser is placed in the path of an incident beam. His name is one of the 72 names inscribed on the Eiffel tower.

Selected works

  • Mémoire sur la mesure du pouvoir réfringent des corps opaques. in Nouveau bulletin des sciences de la Société philomathique de Paris, 1 (1807), 77–81
  • Mémoire sur de nouveaux phénomènes d’optique. ibid., 2 (1811), 291–295
  • Traité d’optique. in Mémoires présentés à l’Institut des sciences par divers savants, 2 (1811), 214–302
  • Théorie de la double réfraction de la lumière dans les substances cristallines. ibid., 303–508
  • References

    Étienne-Louis Malus Wikipedia