Paul Gerber

Carl Ludwig Paul Gerber (* 1854 in Berlin, † August 13, 1909 in Freiburg im Breisgau ) was a German physicist. Gerber studied from 1872 to 1875 in Berlin. In 1877 he became a teacher at the secondary school in Stargard in Pomerania. He was known primarily for his controversial work on the speed of gravity and of the perihelion of Mercury (1898 ).

Gravity

Basics

Based on the electrodynamic fundamental laws of Wilhelm Eduard Weber, Carl Friedrich Gauss, Bernhard Riemann, some attempts have been between 1890 and 1900 made ​​to combine gravity with a finite speed of propagation and to determine the observed perihelion shift of Mercury. [B 1] [B 2] [ B 3 ] it succeeded Maurice Lévy (1890), derived by combining the weber ' and Riemannian basic Law, the correct perihelion. [A 1] However, since these underlying laws proven over time to be unusable (eg, the Weber replaced by the Maxwellian electrodynamics), were not pursued further these hypotheses.

A variation of this outdated from today's perspective, efforts ( without, however, are based directly on the Weber 's electrodynamics ) introduced Gerber in 1898 and 1902 established theory dar. [A 2] Under the assumption that the gravitational potential propagates at a finite speed, he arrived at the following expression for the velocity-dependent potential:

Using the binomial theorem to the second power of the following:

From this velocity-dependent potential follows the generalized force as a functional derivative

Where the speed indicated. This force is a Gerber in the Newtonian equations of motion and, after some elementary transformations to the conclusion that for the ratio between the speed of gravity ( c) and the Perihelverschiebung ( Ψ ) applies:

Where

This Gerber calculated a propagation velocity of the potential of about 305,000 km / s, which is practically the speed of light. [B 4] [ B 5 ]

Controversy

Gerbers above formula now yields for the Perihelverschiebung:

1916 saw the Einstein and relativity opponent Ernst Gehrcke, [A 3] that this expression formally identical to Albert Einstein approximated formula for the general theory of relativity (published 1915) is. [A 4]

Gehrcke was therefore tanner work from 1902 in the Annals of Physics ( 1917) reprint, with the intention of undermining the priority of Einstein and draw attention to a possible plagiarism. [A 5] After Roseveare [B 3], Klaus Hentschel [ B 6 ] and Albrecht Fölsing [B 7] were immediately rejected these claims, as already published shortly after the Neuabdruck of Gerber's work counter-statements, according to which the theory Gerber was useless despite the correct formula. For example, by Hugo von Seeliger [A 6] and Max von Laue [A 7] Gerber's results inconsistent with the conditions of his own theory in line or even just a "mathematical error ". While Seeliger mocks in a two -page letter in the annals of physics, the functional derivative of Gerber 's potential as a recipe for deriving the velocity-dependent force Laue criticized as well in a two -page letter in the same journal and later in the natural sciences which it believed unphysical Gerbersche potential which no has similarity with retarding potentials. And Einstein wrote ( in this partly polemical debate ) 1920: [A 8]

" Mr. Gehrcke would have us believe that the perihelion of Mercury can be explained without the theory of relativity. There's two ways. Either you invent special interplanetary masses. [ ... ] Or one refers to a work by Gerber, who has given the right formula for the perihelion motion of mercury already in front of me. But the experts are not only in agreement that Gerber's derivation is thoroughly inaccurate, but the formula is not to win as a consequence of the assumptions made ​​by Gerber to the top. Mr. Gerber's work is therefore completely worthless, an unsuccessful and irreparable theoretical attempt. I have noted that the general theory of relativity has supplied the first real explanation of the perihelion of Mercury. I have the Gerbersche work originally very reason not mentioned because I did not know when I wrote my thesis on the perihelion of Mercury; I would have had no occasion to mention it, if I had had knowledge of it. "

In the recent past also Roseveare dealt with this theory, and called Gerber's derivation as " unclear," but he believed himself to have given a consistent derivation of Gerber 's potential [ B 3 ], where the accuracy is however disputed. [Web 1 ] But Roseveare rejects Gerber's theory, and points out that follows after a tanner by a factor of 3/2 to a high value for the deflection of light in a gravitational field. The perihelion shift results in an incorrect value if the relativistic mass is taken into account.

Swell

Primary sources

• Einstein, A.: Explanation of the perihelion of Mercury from the general theory of relativity. In: Proceedings of the Prussian Academy of Sciences. No. 2, 1915, pp. 831-839.
• Einstein, A.: The Foundation of the General Theory of Relativity. In: Annals of Physics. 49, 1916, pp. 769-822.
• Einstein, A.: My answer - About the anti- relativity theory Gm bH In: Berliner Tageblatt. 402, 1920.
• Gehrcke, E.: A Critique and history of modern theories of gravity. In: Annals of Physics. 51, 1916, pp. 119-124.
• Gerber, P.: The spatial and temporal propagation of gravitation. In: Journal of Mathematics and Physics. 43, 1898, pp. 93-104.
• Gerber, P.: The speed of propagation of gravity. In: Annals of Physics. 52, 1902/1917, pp. 415-444 .. (Originally published in " program treatise of the urban secondary school to Stargard i Pomm. ", 1902)
• Laue, M.: The speed of propagation of gravity. Comments on the same paper by P. Gerber. In: Annals of Physics. 53, 1917, pp. 214-216.
• Laue, M.: Historical and Critical of the perihelion of Mercury. In: Natural Sciences. 8, No. 37, 1920, pp. 735-736. doi: 10.1007/BF02449026.
• Lévy, M.: Sur l' application des lois électrodynamiques au mouvement of planètes. In: Comptes Rendus. 110, 1890, pp. 545-551.
• Oppenheim, S.: On the question of the speed of propagation of gravity. In: Annals of Physics. 53, 1917, pp. 163-168.
• Seeliger, H.: Observations on P. Gerber's essay: " The speed of propagation of gravity ". In: Annals of Physics. 53, 1917, pp. 31-32.

Secondary sources

• Fölsing, A.: Albert Einstein. A Biography. Suhrkamp, Frankfurt am Main 1993.

• Hentschel, Klaus: interpretations and misinterpretations of the special and the general theory of relativity by Albert Einstein's contemporaries, Basel: Birkhäuser, 1990 ( = Science Networks, 6 ), pp. 150-162.

• Oppenheim, S.: Criticism of the Newtonian law of gravitation. In: Encyclopedia of mathematical sciences with the inclusion of their applications. 6.2.2, 1920, pp. 80-158.
• Roseveare, N. T: Mercury's perihelion from Leverrier to Einstein. University Press, Oxford 1982.
• Zenneck, J.: gravity. In: Encyclopedia of mathematical sciences with the inclusion of their applications. 5.1, 1901, pp. 25-67.