Rudolf Kohlrausch

Rudolf Kohlrausch. Pen drawing by Ferdinand Justi based on a photograph .

Rudolf Hermann Arndt Kohlrausch (born November 6, 1809 in Göttingen , † March 8, 1858 in Erlangen ) was a German physicist and university professor.

Life

Kohlrausch, son of the Royal Hanoverian General headmaster Heinrich Friedrich Theodor Kohlrausch , studied mathematics and physics at the universities of Bonn and Göttingen , where he in 1832 to Dr. phil. received his doctorate . From 1833 to 1835 he was a teacher of physics and mathematics, first at the Knight Academy in Lüneburg , then from 1835 to 1849 at the grammar school in Rinteln . In 1849 he was appointed professor at the Polytechnic in Kassel , from where he moved to the grammar school in Marburg in 1851 for political reasons . In 1853 he was an associate professor of physics at the local university , and in 1857 a full professor at the University in Erlangen . In 1856 he was elected a corresponding member of the Göttingen Academy of Sciences . He was the father of the physicists Friedrich Kohlrausch and Wilhelm Kohlrausch as well as the agricultural chemist Otto Kohlrausch.

plant

Together with Wilhelm Eduard Weber , he determined the relationship between electrostatic and electromagnetic units and thus confirmed one of the conclusions from the Maxwell equations .

{\ displaystyle c_ {0} ^ {2} = {\ frac {1} {\ epsilon _ {0} \ cdot \ mu _ {0}}}}

which underlies every newer electromagnetic system of units . He reported for the first time in 1854 (letter to Andreas von Ettingshausen ) on preliminary results; Weber did not publish the measurements until 1864 .

He investigated the “electrical residue” in the Leyden bottle , in today's understanding the relaxation of the polarization of a glass, and used the extended exponential function for this

{\ displaystyle \ mathrm {e} ^ {- ({\ frac {t} {\ tau}}) ^ {\ beta}}}

a, which is now also called the "Kohlrausch function" or "Kohlrausch-Williams-Watts function". It was rediscovered in 1970 by Graham Williams and David Watts.

literature

Eugen Lommel : Kohlrausch, Rudolf . In: Allgemeine Deutsche Biographie (ADB). Volume 16, Duncker & Humblot, Leipzig 1882, p. 452 f.

Web links

Literature by and about Rudolf Kohlrausch in the catalog of the German National Library

Individual evidence

↑ The Rintelner Gymnasium in the mirror of the time 1817–1967 ed. from the Ernestinum high school. Bösendahl, Rinteln 1967, p. 96
↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 136.
^ Austrian Biographical Lexicon 1815–1950 : Otto Kohlrausch
↑ Rudolf Kohlrausch: Theory of the electrical residue in the Leidner bottle . In: Annals of Physics and Chemistry . tape 91 , 1854, pp. 56-82, 179-214 ( online (pp. 56-82) online (pp. 179-214) ).

personal data
SURNAME	Kohlrausch, Rudolf
ALTERNATIVE NAMES	Kohlrausch, Rudolf Hermann Arndt (full name)
BRIEF DESCRIPTION	German physicist
DATE OF BIRTH	November 6, 1809
PLACE OF BIRTH	Goettingen
DATE OF DEATH	March 8, 1858
Place of death	gain

[1] The Rintelner Gymnasium in the mirror of the time 1817–1967 ed. from the Ernestinum high school. Bösendahl, Rinteln 1967, p. 96

[2] Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 136.

[3] Austrian Biographical Lexicon 1815–1950 : Otto Kohlrausch

[4] Rudolf Kohlrausch: Theory of the electrical residue in the Leidner bottle . In: Annals of Physics and Chemistry . tape 91 , 1854, pp. 56-82, 179-214 ( online (pp. 56-82) online (pp. 179-214) ).