Christian Wiener

Ludwig Christian Wiener ( born December 7, 1826 in Darmstadt, † July 31, 1896 in Karlsruhe ) was a German mathematician, physicist and philosopher, known for his explanation of Brownian motion, which marked him as a skilful experimenter. He mainly dealt with geometry.

Life and work

Vienna was the son of a judge and from 1843 studied architecture and engineering subjects in casting. After the state examination, he was a teacher in 1848 ( for physics, hydraulics, mechanics and descriptive geometry ) at the higher vocational school (later Polytechnic ) in Darmstadt. In 1850 he received his doctorate in mathematics at Giessen ( Certain solution of the problem on the distribution of pressure on more than three points), then went to Karlsruhe to further studies in mechanical engineering at Ferdinand Redtenbacher, returned shortly after casting and in 1852 professor of descriptive geometry at the University of Karlsruhe (then Polytechnic ), which he remained until the end of his career. 1884-1887 appeared to be at that time widely used textbook of Descriptive Geometry, which deals with the history of the subject and accuracy estimates of geometric constructions brings. In Karlsruhe, he also established various mathematical models, including the cubic surface with 27 real line ( Clebsche diagonal surface ). His models, some of which were made ​​at the suggestion of Alfred Clebsch, were then exhibited internationally.

Wiener said the 1828 discovered by the English botanist Robert Brown Brownian motion, the trembling motion of small particles suspended in liquids, as a result of molecular motion of the liquid. Wiener was able to show by experiments that the cause was not yet in temperature fluctuations in chemical reactions or even ( as even Brown accepted ) in biological causes. Also, evaporation, mutual attraction and repulsion of the suspended particles or mechanical causes during placement of the drop and other ways he graduated from. Wiener could show, however, that the dither motion to increase, the smaller particles were suspended.

As an applied mathematician, he also dealt with the problem, to escape a maze (1873 ), dealt with cartography, examined the possibility of geometrically to determine the direction of view in portrait paintings, and other subjects of painting. He also wrote philosophical works.

His son Hermann Wiener was also a mathematician who studied under his father and at times, was his assistant. His students also counts his nephew Alexander von Brill.

Writings

• Textbook of descriptive geometry, 2 volumes, Teubner, Leipzig, 1884, 1887, online at archiv.org: Volume 1, Volume 2
• The first sets of knowledge, especially the law of causation and the reality of the outside world, Berlin, Lüderitz 1874
• The freedom of the will, Darmstadt, Brill 1894
• The basic principles of the world order, Leipzig, Winter 1863, on google.books here
• Online at archiv.org: About polygons and polyhedra, Teubner 1864