6 1 2 D O C U M E N T 4 1 9 M A R C H 1 9 2 9 Wir freuen uns sehr, dass Ihre Gesundheit Ihnen jetzt erlaubt, Ihre wissenschaft- liche Tätigkeit wieder aufzunehmen. Hochachtungsvoll Ihre Ergebener, Norbert Wiener M. S. Vallarta TLS. [23 454]. On letterhead “Massachusetts Institute of Technology Cambridge, Massachusetts.” Addressed “Herrn Professor Dr. Albert Einstein Haberlandstrasse 5, Berlin-Wilmersdorf.” At the bottom of the page Einstein wrote: “in Antwort zugegeben. Auch Ungeeignetheit der Januar- Gleichungen mitgeteilt. Auf die Mitteilung vom April verwiesen.” [1] Norbert Wiener (1894–1964) was Assistant Professor of Mathematics at the Massachusetts Institute of Technology (MIT). Manuel Sandoval Vallarta (1899–1977), was assistant professor of physics at MIT. [2] In a brief note in Nature, dated 7 February 1929 and published 2 March, Wiener and Vallarta drew attention to Einstein’s recent papers of distant parallelism but expressed the opinion that a “much more pressing need of general relativity theory is a harmonisation with quantum theory, par- ticularly with Dirac’s theory of the spinning electron” (Wiener and Vallarta 1929c). [3] Wiener and Vallarta 1929a was communicated to the Proceedings on 1 March, 1929. In the paper, it is argued that in the teleparallel framework of Einstein 1928n and 1928o (Docs. 216 and 219), “an electromagnetic field is incompatible in the Einstein theory with the assumptions of static spherical symmetry and of symmetry of past and future” (p. 356). Looking specifically at the case of the invariant of Doc. 219, they furthermore claim that in this case even a gravitational field is impossible. Similar problems with the theory had been pointed out earlier by Jakob Grommer in Doc. 232. In a footnote added at the end of the paper, the authors wrote: “Since writing this paper the authors have learned from Dr. H. Müntz that the new Einstein field equations of the 1929 paper do not yield the vanishing of the gravitational field in the case of spherical symmetry and time sym- metry. In this case he has been able to obtain results checking the observed perihelion of mercury” (p. 356). In a follow-up note submitted on May 23 (Wiener and Vallarta 1929b), the authors give a correction to their argument with a more careful treatment of the tetrads in spherical coordinates, without, however, revoking their basic claim (see Doc. 535). [4] Vallarta spent a year as Guggenheim fellow in Berlin and Leipzig in 1927–28 it was Wiener who traveled with Einstein from Basel to Geneva (see Doc. 540, note 4) their encounter might have taken place when Einstein traveled from Bern to Geneva on 20 July 1926 (see Einstein to Jost Winteler, 20 July 1926 [Vol. 15, Doc. 327]). g   