Robert Emden

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Robert Emden (born March 4, 1862 in St. Gallen , † October 8, 1940 in Zurich ) was a Swiss physicist , astrophysicist and meteorologist .

Life

Robert Emden studied in Heidelberg, Berlin and Strasbourg and received his doctorate there in 1887 with the thesis "On the steam tensions of salt solutions".

In 1907 Emden became professor for physics and meteorology and airship travel at the Technical University of Munich . Later a professorship for theoretical physics and an honorary professorship for astrophysics were added. In 1934 he moved to Zurich in Switzerland due to political pressure. From 1920 he was a member of the Bavarian Academy of Sciences. He was married to Karl Schwarzschild's sister Klara (1887–1946).

Emden applied his research results on the expansion and compression of gas spheres to the star structure. His work Gas Balls, Applications of Mechanical Heat Theory on Cosmological and Meteorological Problems (1907) was groundbreaking, in which he was the first to consistently apply the results of thermodynamics to the investigation of the internal structure of stars. He used a polytropic equation of state for the matter inside the star, which led to an ordinary differential equation for the density distribution in the spherically symmetrical case, the Lane-Emden equation .

Another important piece of work is the contributions to the theory of the sun , 1901.

He applied Schwarzschild's theory of radiation equilibrium to the earth's atmosphere and explained the transition from the convective ( heat-transporting ) troposphere at a height of 10 km to the stratosphere in radiation equilibrium. As a balloonist he dealt with thermodynamic and aerodynamic considerations up to the calculation for use of the "basics of balloon guidance" and has started experiments on photogrammetric measurements from the air. He took on problems related to glacier ice, the air resistance of projectiles, the theory of relativity and the propagation of sound.

A moon crater ( see also: List of craters of the earth's moon / E ) is named after Robert Emden.

Works (selection)

  • Gas spheres: applications of mechanical heat theory to cosmological and meteorological problems . Teubner, Leipzig / Berlin 1907.
  • Basics of balloon control . Teubner, Leipzig / Berlin 1910.

literature

Individual evidence

  1. ↑ Albrecht Unsöld :  Emden, Robert. In: New German Biography (NDB). Volume 4, Duncker & Humblot, Berlin 1959, ISBN 3-428-00185-0 , p. 476 f. ( Digitized version ).

Web links

personal data
SURNAME Emden, Robert
ALTERNATIVE NAMES Emden, Jacob Robert
BRIEF DESCRIPTION Swiss physicist and astrophysicist
DATE OF BIRTH March 4, 1862
PLACE OF BIRTH St. Gallen
DATE OF DEATH October 8, 1940
Place of death Zurich