Étienne-Louis Malus

Étienne Louis Malus ( born June 23, 1775 in Paris, † February 23, 1812 ) was a French engineer and physicist.

Life

Louis Malus was the son of Anne -Louis Malus you Mitry and Louise -Charlotte Desboves. His father was in the position of Treasurer. Malus' mathematical talent excelled in school from which he left for political reasons in 1793 had (the French Revolution from 1789 to 1799 ). Extracurricular Malus was almost exclusively privately educated in the sequence, mainly in Greek, Latin and mathematics. He revealed his math skills in 1793 in the qualifying examination at the military school at Mézières. Malus served as an ordinary soldier until 1794 and was then sent to the École Polytechnique. There he was taught by Joseph Fourier ( 1768-1830 ). He was born on February 20, 1796 a sub-lieutenant of engineers and on June 19, 1796 Captain of Engineers, and took part in Napoleon Bonaparte Egyptian expedition and to Syria from 1798 to 1801.

Previously, Malus was stationed in Giessen in 1797 and was the eldest daughter of the chancellor of the University of Wilhelmine Louise Koch married shortly before his departure for Egypt. But he could only be realized after his return in 1801 this marriage. She died on 18 August 1813.

Malus survived in Egypt infection and landed in Marseille on 14 October 1801. From 1802 to 1803 he worked in Lille and as Subdirector the fortifications of Antwerp ( 1804-1806 ) and Strasbourg ( 1806-1808 ). In 1808 Malus went to Paris, where he was appointed on December 5, 1810 Mayor of the engineers. As of July 1807, he was a member of the Société d' Arcueil

In 1810 he was inducted into the French Academy of Sciences. 1811 belonged Malus together with Joseph -Louis Lagrange, Adrien -Marie Legendre, Pierre -Simon Laplace and René -Just Haiiy the Awards Committee of the prize for the best description of the propagation of heat in solids, received the Fourier.

He is immortalized in particular on the Eiffel Tower, see: The 72 names on the Eiffel Tower.

Scientific performance

His research began with experiments on the Huygens refraction and systematic study of the properties of surfaces with respect to reflection and refraction.

Malus found out in 1809 that in the reflection light is partially linearly polarized, ie the light waves vibrate in one plane. This subsequently led to a better understanding of light propagation. The dependence of the intensity of polarized light from the alignment of a pre -preserved polarizing filter ( analyzer = ) is called the law of Malus.

In a further publication in 1810 Malus wrote about the double refraction of light in crystals.

Writings (selection )

• Mémoire sur la mesure du puovoir refringent the corps opaques. in Nouveau bulletin des sciences de la Société philomatique de Paris, 1 ( 1807), 77-81
• Mémoire sur de nouveaux phénomènes d' optique. ibid., 2 ( 1811), 291-295
• Traité d' optique. in Memoires presentes à l'Institut des Sciences par divers savants, 2 ( 1811), 214-302
• Théorie de la double refraction de la lumière dans les substances cristal lines. ibid., 303-508