5 1 6 D O C U M E N T 5 1 7 M A Y 1 9 2 7 517. To Paul Ehrenfest [Berlin,] 5 May 1927 Dear Ehrenfest, I have a very bad conscience with regard to you you’re always so good, and I stay so lazily mute. But, on the other hand, one doesn’t write if one has nothing to say, and I had nothing of any consequence to say. First, the Meitner matter. I spoke with Hahn and with Meitner.[1] But they don’t want me to meddle at all, and they have good prospects of getting more radioactive substances. It’s a pity that your gas considerations didn’t lead to the goal, because now it remains open, for the time being, whether Fermi is right.[2] I do gladly admit, however, that his opinion counts for much. Fermi is a splendid fellow overall. His paper about the action of free at- oms upon rotators[3] is one of the most instructive pieces of work that, to my knowledge, quantum mechanics has produced. I have now also done a small inves- tigation on Schrödingerism, in which I show that the solutions can be assigned completely unambiguously to particular motions, which makes any statistical in- terpretation expendable.[4] The latest paper by O. Klein appealed to me very much he really does seem to have a harmonious mind.[5] I’m sorry that I didn’t come to visit you then.[6] I’ve long since published the paper on the relativistic dynamics of a singular point.[7] Yet the dynamic case still isn’t properly dealt with. I have now come far enough along that I believe results are in the making that differ from the classical laws of motion. The method has also become clear and secure. If only I could calculate better! Grommer is an ailing person and helps me little in this respect.[8] It would be wonderful if the familiar differential equations led to quan- tum mechanics and I don’t consider it out of the question at all.[9] I’m glad that you liked the Newton article so much [10] that wonderful man did delight me while I was writing it. Berlin is full of anticipation about Planck’s successor.[11] Sommer- feld-Schrödinger-Born one doesn’t know who among them it will be.[12] Thank God I’m on the sidelines and do not need to participate more than I want in the foot race among intellects. Participation in such races always seemed like a grim bond- age to me, no less so than the addiction to money or power. Warm regards from your Einstein