D O C U M E N T 3 1 4 N O V E M B E R 1 9 2 8 3 0 5 314. To Chaim Herman Müntz [Gatow, ca. 15 November 1929][1] Dear Mr. Müntz, I am at present in Gatow (directly across from the Kaiser Wilh. Tower and on the Havel, Lemke Estate, chauffeur’s apartment), and have been calculating very busily. I have found the following: 1) The solution indeed satisfies the field equations. 2) Taking the electric field into account, I have thus far not been able to solve the centrally symmetric case, owing to its complexity. Even solving the variation prob- lem with coordinates fixed before the variation is too complicated for me. But I will keep trying. 3) For the case no real centrally symmetric static gravitational solution exists for the case it is indeterminate. It therefore appears to be fairly certain that the invariant is correctly chosen, if there is anything at all true in the whole theory. Everything now depends on the ex- act solution of the electric problem. With kind regards, your A. Einstein I will stay here for about another week. H hg                 –   =  h   1  r +   2 = =  0 h 4 4 1  r --- – 1  r --- + ------------- = = H hg        = H hg        =