On the Thermodynamics of Moving Systems
by
Dr. Fritz Hasenöhrl
(Presented in the session of October 31, 1907.)
A specific electromagnetic momentum is connected to radiation in a moving cavity. Because the heat content of each body partly consists of radiating energy, each body has a specific electromagnetic mass that depends on its energy content, thus e.g. also on its temperature. This assertion was demonstrated by me in earlier papers.[1] Since then, a paper by v. Mosengeil on the radiation in a moving cavity has been published, in which (besides other things) the energy content of the moving cavity has been calculated by the aid of the relation between energy and momentum.[2] Furthermore, Planck[3] has studied the dynamics of an arbitrarily moving system, where he presupposes the existence of the mentioned electromagnetic momentum.
Planck presupposes the validity of the so called relativity principle in the form of Einstein, then he uses the moving cavity as test body, and so he obtains theorems that are valid for each body.
- ↑ F. Hasenöhrl, these proceedings, CXIII, p. 1039, 1904; Ann. d. Phys. (4), 15, p. 344, 1904, and 16, p. 589, 1905.
- ↑ K. v. Mosengeil, Berlin Dissertation 1906; Ann. d. Phys. (4), 22, p. 867, 1906. – Later, I will discuss v. Mosengeil’s criticism of my papers.
- ↑ M. Planck, Berliner Berichte, 1907, p. 542.
