484 DOCUMENT 409 JUNE 1912 es sich handelt. Was sagen eigentlich die Kollegen zu dem Aufgeben des Prinzips von der Konstanz der Lichtgeschwindigkeit?[11] Wien sucht sich da- durch zu helfen, dass er die Schwere der Energie in Abrede stellt.[12] Das ist aber unhaltbare Vogel-Strauss-Politik. Mit den besten Grüssen an Sie und Ihre Eltern[13] verbleibe ich Ihr A. Einstein. [. . .][14] ALSX. [13 286]. [1]The year is provided by the reference to the Laue photogram. [2]With Alice Goldschmidt (1892-?). [3]The term used by Max Laue is "photogram" (see, e.g., Laue 1912, p. 363). See Doc. 406, note 13 for more information on Laue's experiments on X-rays. [4]Only two days earlier Einstein wrote to Max Laue himself that the experiments belonged to the most beautiful in the history of physics (see the preceding document). [5]See Einstein 1912c and 1912d (Vol. 4, Docs. 3 and 4), which appeared 23 May. See Vol. 4, the editorial note, "Einstein on Gravitation and Relativity: The Static Field," for a dis- cussion. [6]Einstein and Max Abraham were engaged in a polemic on their theories of gravitation. See Doc. 343, note 3, for more on the dispute between Einstein and Max Abraham. [7]Einstein 1912b (Vol. 4, Doc. 2). See Vol. 4, the editorial note, "Einstein on the Law of Photochemical Equivalence," for more on this paper. [8]Einstein was returning to Zurich in the autumn of 1912 to take up a teaching appointment at the ETH (see Doc. 341). [9]H. F. Weber died 24 May 1912 . Einstein's animosity toward him was rooted in the con- viction that Weber had hindered his search for an academic position in 1900-1901 (see Doc. 406, note 14). A suggestion of this animus is also given in Doc. 406. [10]Georg Pick. [11]This was one of the key aspects of Einstein's theory of the static gravitational field. [12]In mid-May Einstein had pointed out to Wilhelm Wien that one has to give up the con- stancy of the speed of light if one wants to maintain the equivalence of energy and gravitational mass (see Doc. 395). [13]Hans and Elise Hopf, whom Einstein probably met while they were visiting their son in summer 1910 in Zurich (see Doc. 218). [14]A postscript by Mileva Einstein-Marid is omitted. 409. To Paul Ehrenfest [Prague, before 20 June 1912][1] Lieber Herr Ehrenfest! Ich gratuliere Ihnen herzlich zu Lorentz' Nachricht.[2] Ausser Ihnen würde sich niemand mehr freuen wie ich, wenn Sie nach Holland berufen würden. Sie sind einer der wenigen Theoretiker, denen die Mathematik-Seuche nicht den natürlichen Verstand geraubt hat!