D O C U M E N T S 3 9 5 , 3 9 6 O C T O B E R 1 9 2 6 3 8 1 communicate it to them. I myself personally am insufficiently cognizant of descrip- tive astronomy. Can you understand that I’m tired of appearing everywhere as a symbolic bellwether with a halo? So, leave me out of it! I would be grateful for a copy of the Meyer letter.[4] If you have found it and saved it for the general public, that is truly laudable. Kind regards, your A. Einstein 395. To Emil Rupp Berlin, 23 [October 1926] Dear Mr. Rupp, I think that the atoms radiate the interference field during the retention time in the excited state.[1] But our experiment only tells us that the generation of the in- terference field corresponding to an atom needs a time that is comparable to that of the classical damping time. With regard to Joos, you are right.[2] It is only questionable whether he means the splitting in that way (in the sense of “doubling”). Incidentally, in the grating case a direction change is involved, not a color change for the quanta. Kind regards, your A. Einstein P.S. Regarding a recent conversation with Mr. Frank,[3] I would like to observe that, in my opinion, your mirror experiment is safe from any criticism. Any repeti- tion in a modified form seems unnecessary. 396. From Emil Rupp Göttingen, 28 October 1926 Dear Professor, Thank you very much for preparing the abstract.[1] I sent out the correction proof right away. It became clear to me that the experiments can only prove a minimum period for the generation of the interference field. Likewise, the necessity for a clear distinction between energy processes in the atom & in wave emission.[2] I had chosen my original representation only because I had been baffled by the near sameness of this time with the retention time & the damping time. Respectfully and sincerely yours, E. Rupp