3 7 4 D O C U M E N T S 3 8 4 , 3 8 5 O C T O B E R 1 9 2 6 Thank goodness, it is ensured that this spirit will not become extinct, and your father also labored successfully in this direction. His own life was a fulfillment, death at the end nothing other than the period at the conclusion of a well- constructed sentence. On this occasion, I warmly reach out to you, hoping that our lives might have the same relevance. Kind regards to you and yours, your A. Einstein 384. To Emil Rupp [Berlin,] 19 October 1926 Dear Mr. Rupp, Your work, in particular your turned-mirror experiment, is very convincing.[1] Since I am here now, Planck gave me the paper[2] so that I can submit it to the Aka- demie on Thursday. It will be printed directly after mine. In regard to your theoretical conclusion, I would like to comment that the exper- iments do not show evidence concerning the decay time.[3] One has to differentiate between the creation of the interference field (A) and the energy emission (B). The event character of (B) is secured. Your experiments, on the other hand, prove that (A) is a continuous process. Whether (A) happens while the atom is in an excited state, that is, while it contains the full hv, is not certain. But in any case, one is not allowed to conclude that the transition from the excited state to the ground state is a gradual one. I would very much like to ask you to make changes to your manu- script accordingly during proofreading the corrections are only minor. Best regards, your A. Einstein 385. From Kurt Blumenfeld Wilmersdorf, Berlin, Rüdesheimer Platz 7, 19 October 1925 Dear Professor Einstein, Enclosed, I am forwarding you a letter from Dr. Eder[1] dated 13 October, with an enclosure. Please look through the letters and discuss Dr. Grommer with me. I shall be glad to defend the claims of Dr. Grommer however, I would be grateful to you if you would tell me what should happen now.[2] I would be happy to be at your disposal at any time for a verbal discussion.