Eduard Grüneisen

Eduard Grüneisen at the Solvay Conference 1913 (standing, fourth from right)

Eduard August Grüneisen (born May 26, 1877 in Giebichenstein , † April 5, 1949 in Marburg ) was a German physicist. He wrote papers on the measurement of the speed of sound and solid-state physics and was the managing editor of the Annalen der Physik for 20 years (1929–1949) .

Scientific career

Grüneisen studied in Halle and Berlin, especially with Max Planck and Emil Warburg , who received his doctorate in 1900 with a thesis on electricity and heat conduction in metals. In 1905, Grüneisen completed his habilitation in Berlin. As an assistant he went to the Physikalisch-Technische Reichsanstalt in Berlin-Charlottenburg, became a permanent employee in 1904, head of the low-voltage laboratory in 1911 and director of the department for electricity and magnetism in 1919. In 1927 he became a full professor of experimental physics and director of the Physics Institute in Marburg. In 1940, Grüneisen was elected a member of the Leopoldina .

Grüneisen used the experience he gained with electron tubes as an intelligence officer during the First World War to measure the speed of sound in gases over very wide frequency ranges. The measurement methodology led by his Marburg assistant Hans Otto Kneser to the discovery of the dispersion of the sound of different gases and their interpretation.

Grüneisen has shown that the quotient of the thermal expansion coefficient  α and the specific heat capacity  c _{p is} temperature-independent (Grüneisen rule):

${\displaystyle {\frac {\alpha }{c_{p}}}\neq f(T)}$

Personal

Although in November 1933 Grüneisen had signed the professors' declaration of Adolf Hitler at the German universities and colleges , he ensured a liberal atmosphere at his institute. The “non-Aryan” student Heinrich Hermann Barschall from Berlin was accepted into the institute by Grüneisen in 1936 after mediation by Max Planck , after he was no longer able to complete his degree in Berlin. In his memoirs, Barschall describes the atmosphere at the Marburg Physics Institute as follows:

"The physics institute at Marburg was an oasis where Hitler's existence was barely noticeable."

- Heinrich Hermann Barshall

He attributes this to Grüneisen. In Grüneisen's obituary, the authors write that Grüneisen was “the epitome of refined objectivity and kind humanity, a center of trust before and after 1933, before and after 1945”. In a further obituary, E. Huster writes about Grüneisen's work that "political influences stayed away from the work of the institute in the past epoch and there, until shortly before the war," racially disliked people "worked in harmony with members of Nazi organizations."

See also

• Grüneisen parameters
• Mie-Grüneisen equation of state

Web links

• Obituary in the annals of physics. Volume 440, No. 1-2, 1949, pp. I-xii, doi : 10.1002 / andp.19494400102
• Eckhart Vogt :  Grüneisen, Eduard. In: New German Biography (NDB). Volume 7, Duncker & Humblot, Berlin 1966, ISBN 3-428-00188-5 , pp. 190 f. ( Digitized version ).

Individual evidence

1. ↑ see Hessisches Staatsarchiv Marburg (HStAMR), Best. 915 No. 5778, p. 356 ( digitized version ).
2. ↑ ^{a b} E. Goens, HO Kneser, W. Meissner, E. Vogt: Eduard Grüneisen † 26. 5. 1877 to 5. 4. 1949 . In: Annals of Physics . tape 440 , no. 1-2 , January 1, 1949, ISSN  1521-3889 , pp. i-xii , doi : 10.1002 / andp.19494400102 .
3. ↑ ^{a b} Barschall, HH, Reminiscences , Physics in Perspective, Vol. 1, 1999, pp. 390-444, doi : 10.1007 / s000160050030 .
4. ^ E. Huster, A. Sommerfeld: EDUARD GRÜNEISEN / WALTHER GERLACH 60 years . In: Physics Journal . tape 5 , no. 8 , August 1, 1949, ISSN  1521-3722 , p. 378-379 , doi : 10.1002 / phbl . 19490050806 .