Rudolf Kohlrausch

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Rudolf Kohlrausch (1809-1858)

Rudolf Hermann Arndt Kohlrausch (November 6, 1809 in Göttingen – March 8, 1858 in Erlangen) was a German physicist.

Biography[edit]

He was a native of Göttingen, the son of the Royal Hanovarian director general of schools Friedrich Kohlrausch. He was a high-school teacher of mathematics and physics successively at Lüneburg, Rinteln, Kassel and Marburg. In 1853 he became an associate professor at the University of Marburg, and four years later, a full professor of physics at the University of Erlangen.[1]

Research[edit]

In 1854 Kohlrausch introduced the relaxation phenomena, and used the stretched exponential function to explain relaxation effects of a discharging Leyden jar (capacitor).[2][3] In an 1855 experiment (published 1857) with Wilhelm Weber (1804–1891), he demonstrated that the ratio of electrostatic to electromagnetic units produced a number similar to the value of the speed of light,[4] a constant which they named . Kirchhoff recognized that the ratio is equal to the speed of light.[5] This finding was instrumental towards Maxwell's conjecture that light is an electromagnetic wave.

Family[edit]

He was the father of physicist Friedrich Kohlrausch.

Published works[edit]

  • Elektrodynamische Maaßbestimmungen : insbesondere Zurückführung der Stromintensitäts-Messungen auf mechanisches Maass (with Wilhelm Weber) 1857. "Electrodynamic Measurements, Especially Attributing Mechanical Units to Measures of Current Intensity". German text. English translation

See also[edit]

References[edit]

  1. ^ ADB:Kohlrausch, Rudolf @ Allgemeine Deutsche Biographie
  2. ^ Wüstner, D; Solanko, LM; Lund, FW; Sage, D; Schroll, HJ; Lomholt, MA (2012). "Quantitative fluorescence loss in photobleaching for analysis of protein transport and aggregation". BMC Bioinformatics. 13: 296. doi:10.1186/1471-2105-13-296. PMC 3557157. PMID 23148417.
  3. ^ "Blasts from the past". physicsworld.com. 28 November 2007. Archived from the original on 28 November 2007.
  4. ^ Assis, Andre Koch Torres. "On the First Electromagnetic Measurement of the Velocity of Light by Wilhelm Weber and Rudolf Kohlrausch". In Bevilacqua, F; Giannetto, EA (eds.). Volta and the History of Electricity (PDF). Universita degli Studi di Pavia and Editore Ulrico Hoepli. p. 280. Retrieved 11 March 2023. Weber and Kohlrausch found √2 c = 4.39 x 10^8 m/s, such that c = 3.1 x 10^8 m/s
  5. ^ Mendelson, Kenneth S. (2006). "The story of c". American Journal of Physics. 74 (11): 995–997. Bibcode:2006AmJPh..74..995M. doi:10.1119/1.2238887. ISSN 0002-9505.

External links[edit]