by Mischka's War- A Story of Survival from War-Torn Europe to New York (epub)
But then came the Nazis. They were against Jews, and Einstein and many of the other German theoretical physicists were Jewish. On top of that, they were against cosmopolitan theoretical ‘Jewish physics’ and in favour of experiment-based ‘German physics’. Experimentalists like Philipp Lenard, who held the chair at the University of Heidelberg, were particularly offended by ambitious theorising like Einstein’s relativity theorem, which lacked immediate experimental demonstration; they thought of it as pure speculative fantasy that would take physics away from its true path. You didn’t have to be Jewish to come under their condemnation: the young (Aryan) German Werner Heisenberg, a pioneer in quantum mechanics (almost as objectionable as relativity theory), was berated by Nazi periodicals as a ‘white Jew’.
The result of the Nazi assumption of power in 1933 was that about a quarter of all German theoretical physicists in university posts were dismissed because they were Jews, and a large emigration of physicists followed. Einstein led the way, publicly condemning the Nazi regime and becoming the number one villain in Nazi eyes, his property being seized and eventually a price being put on his head. Berlin, Göttingen and other great centres lost their senior physicists and a whole cohort of the coming generation, including the young Edward Teller and John von Neumann, who would later join the Manhattan Project in Los Alamos and work for the United States on the production of the first atomic bomb.
The heyday of anti-modern, anti-theoretical ‘German physics’ was in the mid 1930s. By the end of the decade, it had become clear even to the Nazis that if they wanted to remain in the game of developing atomic energy, they couldn’t afford to dismiss modern theoretical physics. The nuclear fission effect identified in 1939 by Otto Hahn and Lise Meitner (now, as a Jew, exiled in Stockholm) opened up the way to the production of huge amounts of energy, once scientists had worked out how to produce and control chain reactions. This was the task of the informal group known as the Uranium Club, of which Jensen, still in his thirties, was a member. Another key participant was the somewhat older Walther Bothe (born in 1891), who was Professor of Experimental Physics at the University of Heidelberg when Mischka arrived there in 1949.
As war loomed, the Uranium Club’s activities were naturally of great interest to the German military and supported by them, but never on anything like the scale of the Manhattan Project in the United States, and without the short-term objective of building an atomic bomb. The Uranium Club physicists—whose lack of drive to invent a bomb probably reflected some disinclination to trust Hitler with such a weapon, even if less than they later claimed—focussed on building a ‘uranium machine’ (that is, a reactor) and got tied up with some false leads and technical problems along the way. On a wartime visit to Denmark immortalised in Michael Frayn’s play Copenhagen, Heisenberg tried to tell Niels Bohr in a roundabout manner that Germany was not making a bomb, but succeeded only in appalling him by the idea that it perhaps could. The young Jensen had a walk-on part in this story too, because it was he who, after a subsequent wartime visit to Copenhagen, made his colleague Heisenberg aware for the first time of the intensity of Bohr’s reaction. The Americans, meanwhile, were convinced that Germany, that world centre of nuclear physics, was well on the way to making a bomb and would naturally be trying to do so. It came as a shock at the end of the war to discover how far from the truth this was.
While ‘German physics’ was on the wane elsewhere, in Heidelberg it remained ascendant. Lenard, the experimentalist founder of the institute that Mischka entered in 1949, had held the chair at the university since 1907 and had criticised Einstein’s relativity theory as early as 1910; his antipathy to modern theoretical developments in physics predated his Nazi sympathies, which arose out of a sense of German national humiliation in the First World War. A local hero in Heidelberg, Lenard’s influence remained great even after his retirement in the early 1930s, and he insisted successfully that ‘only a master of experimental physics’ should be appointed to the chair, rejecting the candidates initially proposed as too ‘theoretical’ and one-sided. Walther Bothe was the compromise candidate, a distinguished experimentalist who, however, was not averse to modern theoretical physics. But Lenard’s supporters made Bothe’s tenure so uncomfortable that after two years, he retreated into the more congenial surroundings of Heidelberg’s Kaiser-Wilhelm Institute for Medical Research, where he built Germany’s first cyclotron.
Thanks to the efforts of some ardent Nazi disciples of Lenard’s, the Heidelberg Physics Institute was already so judenfrei in 1933 that, in contrast to the rest of Germany’s physics institutes, there was no need for a purge. The main Nazi activist was a former student of Lenard’s, Ludwig Wesch, who became a lecturer professor of technical (applied) physics at Heidelberg in 1943. It was said that one of the reasons for Bothe’s precipitate flight to the Kaiser-Wilhelm Institute was that Wesch was in the habit of organising military drills in the loft above the office where he was trying to work. Though not of the same stature as a physicist as Lenard or Bothe, he was nevertheless a real scientist rather than a charlatan on the lines of Trofim Lysenko (the opponent of genetics in the Soviet Union), working primarily on defence-related radio technology during the war. But he was and remained a staunch opponent of modern theoretical physics.
For Jensen and his fellow members of the Uranium Club, the war’s end was a dangerous time. Agents of both the Soviet Union and the United States were running around scooping up nuclear scientists they thought might be useful for work on the bomb. The British whisked a group of Uranium Club leaders, including Heisenberg and Harteck, off to a secret holding place in England, Farm House, to try to find out the real story about the (non-existent) German bomb. The Farm House contingent were released and returned to Germany in the spring of 1946, Heisenberg becoming director of the Kaiser-Wilhelm Institute (renamed for Max Planck, like other Kaiser-Wilhelm Institutes, after Planck’s death in 1947) in Göttingen. Jensen in Hanover and Bothe in Heidelberg both remained at liberty, though they had to go through a not very rigorous denazification process.
For the former ‘German physics’ proponents, the outlook was bleaker. Heidelberg was in the American occupation zone, where denazification was more stringent than in the British zone, and Lenard and Wesch were in any case notorious for their Nazi connections. The Americans decided not to prosecute Lenard because of his age, and he died, a free but embittered man, in 1947. Wesch, on the other hand, was one of the few to be convicted as a ‘major offender’ in denazification proceedings and dismissed from the university. The Physics Institute was left in a shambles, partly because towards the end of the war Wesch had removed a lot of equipment for safekeeping in a village some 70–80 kilometres away. The whole university was closed when occupation forces came in at the end of March 1945, and even when it reopened, the Physics Institute led a ghostlike existence, almost empty of furniture, equipment and personnel and without heat. Its last Nazi-era director, the experimental physicist August Becker, a close colleague and friend of Lenard’s, had his own house in Heidelberg confiscated by the military government and was dismissed from his position in February 1946. Bothe’s cyclotron was seized by the Americans as well, though as scientific booty rather than punitively; he didn’t get it back until 1949, the year of Mischka’s arrival.
It was Bothe who had the job of getting the university’s Physics Institute back on its feet, moving back from the Kaiser-Wilhelm Institute to the position Wesch and his acolytes had forced him out of before the war. But it was tough going at first. He had to get the building running again, heat and furnish it, organise the return of the institute’s scattered scientific equipment and, at the same time, hire new staff, trained in modern physics, and get rid of the Lenard/Wesch legacy. This was only partially achieved by the summer of 1949, when Mischka showed up. Memories of the Lenard era were still vivid in Mischka’s time, and he had a stock of Lenard anecdotes to prove it, mainly heard from the institute’s mechanic, a survivor of several changes of regime. One of the stories
concerned Mischka’s own office in the institute. Under Lenard’s reign, it had housed a lecturer in theoretical physics whom Lenard couldn’t get rid of, but as Lenard hated theory, he had instructed that ‘Theoretical physics apparatus’ be painted on the door. That sign was still there when Mischka arrived—he was tickled by the idea of being a piece of apparatus.
Jensen, selected in 1948 as the new professor of theoretical physics, was the key appointment, and it was after his arrival at the beginning of 1949 that things really started humming. But as a modern theorist, he met considerable opposition. Some of the Lenard group remained in Heidelberg, fighting to get their old jobs back, and there were still many in the Heidelberg university and social establishment who sympathised with them. With the establishment of the German Federal Republic in 1949, enthusiasm for outcasting and punishing former Nazis quickly waned. Becker, already of retirement age, successfully petitioned for emeritus status (which carried a pension) in 1951. Wesch, now working in industry after serving a prison term, got his ‘major offender’ conviction reduced to ‘minor offender’ on appeal and spent more than a decade agitating to get his university job back (he was turned down for a second time in 1956 after both Jensen and Bothe’s successor in the experimental physics chair threatened to leave if he were reinstated).
Postwar Heidelberg physics was surrounded by such a golden aura in Misha’s memory that I found it hard to judge how it stood, objectively, in the history of nuclear physics. Perhaps that didn’t matter for my story, but it niggled away at me. I read the classic accounts, but they are all written in terms of a teleology that leads to Los Alamos and the making of the bomb—in other words, a German–American competition to make the bomb that the Americans won. In this story, Germany loses its good physicists in successive waves of emigration, mainly to the United States. The world centre of physics moves from Europe to the United States. Once the Americans have the bomb and Germany loses the war, physics in Germany drops out of view.
All this makes a lot of sense, but teleologies tend to smooth out any deviations along the way that don’t fit the big picture. I think that’s what probably happened with postwar German nuclear physics, at least up to the mid 1950s, when another wave of emigration took yet more physicists (including Misha) to the United States. It looks to me as if Misha wasn’t deceiving himself, and there really was a minor golden age for theoretical nuclear physics in postwar Germany, with Heidelberg one of the most lively centres. The ten years after the Second World War were not a peak period of Nobel Prizes being awarded to Germans, which scarcely comes as a surprise. But then, when Germans started winning Nobel Prizes for physics again, Heidelberg scooped the pool. Walther Bothe, the Heidelberg cyclotron man, won a Nobel in 1954, and a Heidelberg-trained spectroscopist called Rudolf Mössbauer won in 1961. In 1963, Mischka’s mentor Hans Jensen was joint winner, along with the German-American Maria Goeppert-Mayer, for work on the nuclear shell model they were doing when Mischka was his student.
The excitement of those years was recalled by one of Mischka’s contemporaries, Berthold Stech, who was also Jensen’s student. Stech’s arrival in Heidelberg actually preceded Jensen’s, and he remembered the shock of Jensen’s appearance on the scene, which put them ‘suddenly in contact with modern theoretical ideas and approaches’:
It was challenging. Jensen was unconventional … [He] managed to make Heidelberg a leading center of nuclear physics in experiment and theory … Of course it was the high time of nuclear physics and the shell model. We students were witnessing an exciting period with hot and lively discussions. But even more important, we experienced the outstanding scientific and social atmosphere created by Bothe and Jensen which extended to the newcomers and students. Besides scientific competence, there was also heart. Coming back from years of war the institute became our home where we spent all day and half the night.
The centre of it all was the Tea Colloquium (Tee-Colloquium), lovingly remembered all his life by Misha. He walked in on his first one, evidently having just arrived from Hanover, when the colloquium was already in session and was admitted by Jensen’s senior assistant, Helmut Steinwedel:
There around a long combined table sat the professors, Jensen, Bothe, [Heinz] Maier-Leibnitz and some more who I did not know, the assistants Steinwedel and others, and graduate students. Steinwedel announced my name and I sat down. Suddenly, unexpectedly, I was served a chemical beaker (100 cc) with tea, and the general discussion continued. After a while a graduate student went to the blackboard and commenced to report on a paper from a recent Physical Review. Quite soon he was interrupted by questions and comments from different people, including myself. I found that whole situation exceedingly stimulating, and interesting, and informative.
Including myself is a nice touch: here was Mischka jumping in to discussion with the great men, his bags not yet unpacked and the ink still fresh on his PhD diploma. That was unconventional but in local disciplinary terms not outrageous: democracy of discussion between professors and students had been an important part of the Göttingen tradition in physics before the war too. Obviously Mischka, like Jensen, enjoyed flouting hierarchical conventions. Even in the Tea Colloquium, there were some conventions relating to seniority, but Mischka ignored them:
The traditional rule was that the newest member of that circle was supposed to prepare and serve the tea. I was blithely unaware of that and found out about it only after a new graduate student appeared and took over these duties. I felt a little uncomfortable about not having done my turn and told it to my predecessor, who said that it is perfectly OK, since I was a theorist. In fact I was quite happy about my ignorance.
Scientific life was a lot livelier in Heidelberg than in Hanover, Mischka wrote more than once to his mother: ‘Since I came here, I have got a whole lot cleverer.’ The best part was the Tea Colloquium discussions, where every aspect of the topic was clarified by ‘comments and questions, even mini-lectures’ by members of the audience in an atmosphere that was ‘light and free’ but, as far as the underlying intellectual issues were concerned, dead serious. ‘It was by far the most important learning experience I encountered throughout my career,’ Misha wrote later. The greats of the German nuclear physics world—people like Heisenberg and Fritz Houtermans from Göttingen and Hans Suess from Hamburg—would turn up at the Tea Colloquium and present their latest work. Jensen and Bothe, working hard to end Germany’s international isolation after the war, persuaded even émigrés reluctant to revisit Germany to come to Bothe’s sixtieth birthday celebration in 1951. Jensen’s collaborator Maria Goeppert-Mayer and the now US-based Hans Bethe, Eugene Wigner and Enrico Fermi were among others who visited the Heidelberg Institute in this period.
Young physicists were scarce on the ground, the war having wiped out a large part of Mischka’s age group in Germany, and no doubt they were the more valued because of it. When Mischka had been around in Heidelberg for a few months and got friendly with Steinwedel, Jensen’s senior assistant, they had a discussion one night about their prospects. Their conclusion was that ‘we are too old to come up with a discovery of the magnitude of Einstein, Heisenberg, Schrödinger. They were all 25–26 years old when they did it. We are 27, and as far from that kind of discovery now as anybody else.’ It was characteristic of the Heidelberg atmosphere that they should think in such ambitious comparative terms; probably, despite their stated pessimism, they all secretly hoped to win Nobel Prizes themselves one day. Actually none of them did (except the spectroscopist Rudolf Mössbauer, who was a bit younger than Mischka and arrived in Heidelberg after he had gone), and I think Mischka at least always felt that to be a bit of a failure. But there are cycles in science, and the great age of Nobel Prizes for German physicists was coming to an end. By the time Mischka’s cohort got into their stride for the competition in the 1960s, the buzz had moved out of their area of nuclear physics. Hans Bethe, the Sommerfeld-trained German émigré who relocated to Cornell and who won in 1967, was the last of the line.
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bsp; The question of physicists’ past Nazi affiliations was naturally a matter of interest. In Hanover, Mischka had never paid much attention to it, but once he got to Heidelberg, that changed. Jensen had been a party member, though after the war Heisenberg had vouched for his lack of enthusiasm in one of the attestations of political harmlessness known as Persilschein (after the laundry powder) that were part of the denazification process in these years. According to a memoir by Berthold Stech (one of Mischka’s Heidelberg contemporaries), Helmut Steinwedel and Mischka, when they arrived successively from Hanover, ‘told us about Jensen with great admiration, his attitude during the “Third Reich” and how he managed to survive inhuman times and still do interesting physics’. This probably came mainly from Steinwedel, who had been closer to Jensen in Hanover and had known him longer. But the question of Jensen’s Nazi past was one that Mischka gave a lot of thought to in his first months in Heidelberg. He and Jensen talked about it, at least obliquely. Quoting Jensen in a letter to Helga, Mischka set out his argument:
If you see over and over again that people whom you have trusted have thrown in their lot with the party and actually become addicted to those nationalistic resentments, and you are always being pushed against the wall, then you think: to hell with this rubbish, let’s leave, go far away from here, go to Australia; then one can at least be a free man again. But then after a while you get back your courage and start pushing back against it again. That is all you can do. So he [Jensen] didn’t go to Australia, Argentina or America.
In the same letter, Mischka assured Helga that ‘I have not the least grounds to assume, but rather all grounds against assuming, that [Jensen] was ever a Nazi … He was in the party, of course. But to put it even more strongly, it can be claimed with a probability bordering on certainty that if anybody ever joined because there was nothing else to do, that person was Jensen.’ With Mischka, such rather awkward formality of style often conveys uneasiness. But in this case it may also reflect the fact that the question of Nazi membership and general German guilt were closely linked in Mischka’s mind, and he was writing to a German girl he was proposing to marry. The big thing to understand, Mischka instructed Helga, was that Jensen, although a German, is ‘primarily a human being (Mensch), thus a cosmopolitan [first] and only secondarily also a German’. This made him even better than Obst, the German intellectual Mischka had met and briefly admired in Hanover, because with Obst it was the other way round: German first, and only then cosmopolitan (weltbürgerlich). Moreover, Jensen had the proper critical attitude towards Germans—‘shares the opinions of my mother and myself’, as Mischka put it to Helga—that Helga herself needed to adopt. Germans are arrogant because they feel inferior. They claim Germany is the country of poetry and philosophy, but this (whatever the teenage Mischka may have thought back in Riga) is actually completely unfounded. He quoted Jensen’s categorical dismissal of the claim: ‘there is one superior thinker who was an East Prussian: Kant. Otherwise the rest are no greater than their French or English counterparts.’