Ludwig Edelstein

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Interviewed by
Thomas S. Kuhn
Interview date
Rockefeller Institute, New York City
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Preferred citation

In footnotes or endnotes please cite AIP interviews like this:

Interview of Ludwig Edelstein by Thomas S. Kuhn on 1962 May 07,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,

For multiple citations, "AIP" is the preferred abbreviation for the location.



Part of the Archives for the History of Quantum Physics oral history collection, which includes tapes and transcripts of oral history interviews conducted with circa 100 atomic and quantum physicists. Subjects discuss their family backgrounds, how they became interested in physics, their educations, people who influenced them, their careers including social influences on the conditions of research, and the state of atomic, nuclear, and quantum physics during the period in which they worked. Discussions of scientific matters relate to work that was done between approximately 1900 and 1930, with an emphasis on the discovery and interpretations of quantum mechanics in the 1920s. Also prominently mentioned are: Albert Einstein, Philipp Lenard; Deutsche Naturforscher-Gesellschaft meeting (Bad Nauheim, 1920), and Universität Heidelberg.



It probably was in 1920. As I told you I had started school, but I happened to be in Bad (Nauheim) then. The meeting of the Deutsche Naturforscher-Gesellschaft was taking place. Einstein’s theory of relativity was discussed — it seems to me for the first time at a public meeting. I am really not sure. By some device I was able to get into the morning session. It started rather early in the morning. Practically everybody I had ever heard of in physics was there; Planck, Debye, Nernst, a number of other people. The discussion went on and on, and I did not understand anything at all, naturally. But I remember very much that after two hours or so Mr. Lenard got up and attacked Einstein quite violently.

One felt that there was great tension and great emotion on both sides…You had the feeling that people somehow feared Lenard might say things which it would not be agreeable to hear. I do not remember anything except the remark he finally made. He turned to Einstein and said, “Well surely if I tell the guard of the railroad company, who is watching the train, that he is moving and the train is standing, this is against common sense.” And there was silence for a moment, and finally Einstein said in a very low voice, “May I point out to my colleague Lenard that common sense is something very relative.” As far as I can recall the words, he said in German “Darf ich dem Herrn Kollegen Lenard sagen, dass der gesunde Menschenverstand etwas sehr relativitischist.” Laughter is not the adequate word to describe the reaction. Nobody could say anything, and people went home. It was also near lunchtime, I think. But it was more, I feel, that was said at the argument between Lenard and Einstein. You see I at that time didn’t know anything about the debate that had gone on behind the scenes, so my impression as I have remembered it through all these years was really, I think, the impression I had at that moment. I did not even know about the controversy, and the tension between Jewish physics and German physics…Later on it was quite clear, you see. I came as a student to Heidelberg in 1925, and by that time I knew. As a matter of fact I went to one of the lectures of Lenard, a general lecture in physics. But you see, I did (???)


And in his general lectures this was already an explicit issue in 1925?


I could be very much mistaken. You see the Jewish question was in Heidelberg at that time already quite an issue…


When you were at Heidelberg later, was it entirely clear to people like yourself not in the sciences that Lenard’s influence was just keeping people away?


Keeping away from what?


Well Heidelberg is never a contributor in this period any more, to scientific development.


This I didn’t know…I should think that the general feeling at Heidelberg was that Lenard was a very outstanding, respectable physicist. I cannot remember that I ever heard people wouldn’t come to study with him.


Well undoubtedly people did come, or at least I assume they did, but they do not show up then as contributors.


I am very much astonished…That’s the first time I hear about it. I really didn’t know that. When I spoke about anti-Semitism, I thought more of the political situation in the student group. But of course by 1925 I knew about it, because in the meantime there had been the incidents in Berlin. And I had studied in Berlin, I went and wanted to see what it was like. And of course I also remembered 1920.