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 (the refractive index of most glasses available at that time varied 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. This law was later explained theoretically by Augustin Fresnel, as a special case of his Fresnel equations.
Malus is probably best remembered for Malus's law, giving the resultant intensity, when a polariser is placed in the path of an incident beam. A follower of Laplace, both his statement of the Malus's law and his earlier works on polarisation and birefringence were formulated using the corpuscular theory of light.[1]
In 1810, Malus, while engaged on the theory of double refraction, casually examined through a doubly refracting prism of quartz the sunlight reflected from the windows of the Luxembourg palace. He was surprised to find that the two rays alternately disappeared as the prism was rotated through successive right angles, in other words, that the reflected light had acquired properties exactly corresponding to those of the rays transmitted through Iceland spar.
He named this phenomenon polarization, and thought it could not be explained by wave theory of light. Instead, he explained it by stating that light-corpuscules have polarity (like magnetic poles).[2]
Selected worksEdit
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
Malus mathematically analyzed the properties of a system of continuous light rays in three dimensions. He found the equation of caustic surfaces and the Malus theorem: Rays of light that are emitted from a point source, after which they have been reflected on a surface, are all normal to a common surface, but after the second refraction they no longer have this property. If the perpendicular surface is identified with a wave front, it is obvious that this result is false, which Malus did not realize because he adhered to Newton's theory of light emission, and Malus's theorem was not proved until 1824 by W. R. Hamilton.
ReferencesEdit
Kahr, Bart; Claborn, Kacey (2008), "The lives of Malus and his bicentennial law.", ChemPhysChem (published Jan 11, 2008), vol. 9, no. 1, pp. 43–58, doi:10.1002/cphc.200700173, PMID 17680582
^Iwan Rhys Morus (2005). When Physics Became King. The University of Chicago Press. p. 29. ISBN0-226-54202-5.
Étienne, louis, malus, french, tjɛn, july, 1775, february, 1812, french, officer, engineer, physicist, mathematician, born23, july, 1775paris, francedied24, february, 1812, 1812, aged, paris, francenationalityfrenchknown, formalus, lawplane, polarizationpolari. Etienne Louis Malus ˈ ɛ t i ɛ n ˈ l uː i m e ˈ l uː s French e tjɛn lwi ma lys 23 July 1775 23 February 1812 was a French officer engineer physicist and mathematician Etienne Louis MalusEtienne Louis MalusBorn23 July 1775Paris FranceDied24 February 1812 1812 02 25 aged 36 Paris FranceNationalityFrenchKnown forMalus s lawPlane of polarizationPolarization of lightMalus Dupin theoremAwardsRumford Medal 1810 Scientific careerFieldsPhysicsMalus 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 Egypte Malus became a member of the Academie 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 Plucker s line geometry He conducted experiments to verify Christiaan Huygens s 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 the refractive index of most glasses available at that time varied 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 This law was later explained theoretically by Augustin Fresnel as a special case of his Fresnel equations Malus is probably best remembered for Malus s law giving the resultant intensity when a polariser is placed in the path of an incident beam A follower of Laplace both his statement of the Malus s law and his earlier works on polarisation and birefringence were formulated using the corpuscular theory of light 1 His name is one of the 72 names inscribed on the Eiffel tower Contents 1 Discovery of polarization 2 Selected works 3 See also 4 Work 5 References 6 External linksDiscovery of polarization EditIn 1810 Malus while engaged on the theory of double refraction casually examined through a doubly refracting prism of quartz the sunlight reflected from the windows of the Luxembourg palace He was surprised to find that the two rays alternately disappeared as the prism was rotated through successive right angles in other words that the reflected light had acquired properties exactly corresponding to those of the rays transmitted through Iceland spar He named this phenomenon polarization and thought it could not be explained by wave theory of light Instead he explained it by stating that light corpuscules have polarity like magnetic poles 2 Selected works EditMemoire sur la mesure du pouvoir refringent des corps opaques in Nouveau bulletin des sciences de la Societe philomathique de Paris 1 1807 77 81 Memoire sur de nouveaux phenomenes d optique ibid 2 1811 291 295 Traite d optique in Memoires presentes a l Institut des sciences par divers savants 2 1811 214 302 Theorie de la double refraction de la lumiere dans les substances cristallines ibid 303 508See also EditPolarimeter Total internal reflectionWork EditMalus mathematically analyzed the properties of a system of continuous light rays in three dimensions He found the equation of caustic surfaces and the Malus theorem Rays of light that are emitted from a point source after which they have been reflected on a surface are all normal to a common surface but after the second refraction they no longer have this property If the perpendicular surface is identified with a wave front it is obvious that this result is false which Malus did not realize because he adhered to Newton s theory of light emission and Malus s theorem was not proved until 1824 by W R Hamilton References EditKahr Bart Claborn Kacey 2008 The lives of Malus and his bicentennial law ChemPhysChem published Jan 11 2008 vol 9 no 1 pp 43 58 doi 10 1002 cphc 200700173 PMID 17680582 Iwan Rhys Morus 2005 When Physics Became King The University of Chicago Press p 29 ISBN 0 226 54202 5 9th edition of Encyclopaedia Britannica Volume 14 page 611 entry Light External links Edit nbsp Wikisource has the text of the 1911 Encyclopaedia Britannica article Malus Etienne Louis O Connor John J Robertson Edmund F Etienne Louis Malus MacTutor History of Mathematics Archive University of St Andrews English translation of his paper Optique Retrieved from https en wikipedia org w index php title Etienne Louis Malus amp oldid 1177394631, wikipedia, wiki, book, books, library,
