T he perceptions and rationale that Heisenberg and many other Germans accepted before and during the war had enabled them to continue their work and daily lives under the circumstances of the German Reich at war. The rationale and perceptions suddenly ceased to function once the circumstances no longer obtained. They were replaced with a new structure based on the past as reconstructed for the world in which they now lived. The Allies, sweeping across Germany and the rest of Europe in the first half of 1945, brought the long-awaited collapse of the Nazi dictatorship. Their arrival also brought an end to German nuclear research and captivity to the German nuclear scientists. VE day in May was followed three months later by the capitulation of Japan under the shadows of the mushroom clouds of Hiroshima and Nagasaki.
The postwar era brought with it the realization of two terrible truths. The first came with the disclosure to the world of the utter depravity of the Nazi regime, exemplified by the unspeakable horrors of the Nazi death camps. The second truth to be faced was the awesomely destructive fury of nuclear weapons, a fury unleashed through scientific research. Both of these truths had ramifications that went far beyond the immediate experience of the war, changing forever our perceptions of human progress and human potential. They taught us to be skeptical of so-called modern, enlightened societies, however cultured, and to be wary of modern science, however promising. While each person, and especially each nuclear scientist, struggled after the war to come to terms in his or her own way with one or both of these terrible lessons,
Heisenberg having the most to explain, took a leading role in publicly articulating the reactions of leading German scientists.
As newspapers around the world blazoned reports of Nazi atrocities uncovered by Allied troops during the spring of 1945, the public remained unaware of nuclear weapons until they were used on Japan in August. The German nuclear scientists, who thought their research equal to, if not ahead of, Allied research, supposed that the Alsos mission that captured them in early May was merely an attempt by the Allies to tap Germany’s superior knowledge. The day after Heisenberg arrived at the Alsos outpost in Heidelberg, he was ushered to an interrogation on his work by his erstwhile colleague, Samuel A. Goudsmit, the scientific head of the Alsos mission.
Heisenberg and Goudsmit had last seen each other in Ann Arbor shortly before the war. Much had happened since. Now, as Goudsmit faced the man he had looked up to as a young physicist but who had apparently made little or no effort to rescue his parents from a Nazi death camp, the German physicist seemed to him despicably haughty and self-involved. Heisenberg, for his part, seemed to welcome the attention the Allies accorded him for his wealth of nuclear knowledge. The extraordinary efforts that Pash had made to arrest him had no doubt reinforced such pretensions. When asked about his nuclear research, Heisenberg was so confident of its significance that he offered to instruct the Americans on uranium fission. 1 Goudsmit, knowing of Allied progress, though not about an imminent bomb, politely thanked him for the offer.
On impulse, Goudsmit repeated his question of six years earlier: “Wouldn’t you want to come to America now and work with us?” Heisenberg repeated the answer he had given earlier: “No, I don’t want to leave. Germany needs me.” 2 To Goudsmit, this seemed further evidence of Heisenberg’s overweening self-importance. But with most of Germany in ruins and her economy near collapse, Goudsmit could hardly have expected any other response at that point from a man so attached to his country.
Heisenberg was interned. Of the fourteen leading nuclear physicists rounded up in the flurry of Alsos strikes, four were sent — willingly or not — to the United States to help with American research. Goudsmit remanded the rest — including Hahn, Laue, Weizsacker, Bothe, and Harteck — to American military authorities, who held them incommunicado for two months in a series of prisoner-of-war camps in France and Belgium. Their families had to fend for themselves. Heisenberg, Diebner, and Gerlach joined their seven fellow prisoners at a camp near
Versailles, known as “Dustbin.” Despite this inauspicious omen, the Allied military treated its scientific prisoners astonishingly well, providing them with adequate food, English-language newspapers, weekly physics colloquia, and a jogging track. 3 Nevertheless, the reason for their internment in the first place — to allow the Allies “to catch up” — seemed to the scientists hardly sufficient to keep them so long. Laue in particular could not understand why he, who had not worked on fission, should be held against his will. To their inquiries, a British officer replied only that they were “detained for His Majesty’s pleasure.” 4 Thereafter they called themselves the “detainees.”
Scottish physicist R. V. Jones, professor of natural philosophy in Aberdeen and head of intelligence for the British Air Staff, had been following German science since the start of the war and had assisted the Alsos mission on both occasions when it landed in Europe — the first in Italy, the second in Britain. But America’s irksome decision in the last months of the war to exclude the other Allies from sharing the mission’s nuclear booty inspired Jones and his staff to begin looking out for their own interests. When an American general reportedly expressed the opinion that the best solution to the problem of German nuclear physics was to shoot all the German nuclear physicists, Jones took action. 5 Not only were executions, or even war-crimes trials, out of the question, but the British seemed in awe of the prestigious detainees. Jones graciously offered to relieve the Americans of responsibility for the physicists. Apparently wanting not the physicists themselves but only their silence, the Americans agreed — on condition that the scientists be kept out of Russian or French control. The Russians and especially the French were already diverging from the British and Americans on postwar policy toward occupied Germany.
Fearful that the prisoners would be captured by the other Allies or sent to the United States if they remained on the continent, Professor Jones decided to move them to Britain. As an intelligence chief, he knew of a country safe house in the tiny village of Godmanchester near Cambridge and a large Allied air base. The house had been used by MI-6 agents as a staging area for parachuting into German-occupied territory. In early July, after outfitting the house with secret microphones, Jones had his ten German scientists flown under heavy military guard from their camp in Belgium to their new home in England. There they remained until Jones figured out what to do with them.
The British knew they could not hold the scientists forever, but they did not want to turn them loose in England for fear that they might learn too much about British research from less security-conscious
colleagues. By the end of the year, the British had decided that only a revival of the German economy and a measure of political and cultural autonomy in the British zone of occupation were consistent with British commitments and German social and political stability. Science and technology were envisoned as crucial elements of the intended revival. With the dust of the atomic blasts now settled and the British zone firmly under British control, on January 3, 1946, a British transport plane flew the detainees to less restricted detention in a northern German town in the British occupation zone. There they could move about during the day, but they had to return to British quarters at night; Within several months, they were all released. Most, including Heisenberg, settled in the undisturbed university town of Gottingen, intended by the British authorities to be a crystallization point for the revival of West German science.
The detainees could hardly complain of their Godmanchester prison. The jail actually consisted of a sumptuous English country manor, known as Farm Hall, which was located on a rolling grassy estate surrounded by flowering hedges, large trees, and an unobtrusive fence. For their leisure-time pleasure, several tennis courts were located in the rear; a well-tuned grand piano stood in the parlor; and they had books, newspapers, game paraphernalia, and a radio — even the Physical Review. The prisoners whiled away their hours with relaxation, lectures to each other on their nonnuclear work, and walks about the grounds. Two British officers, carefully chosen for their ignorance of Allied research, watched over the prisoners, providing them with new clothes, shoes, and hearty English meals. The royal treatment prompted one ungracious officer to comment that the prisoners were living better than the average English family — to say nothing of the average German family or the average family across most of war-torn Europe. 6
The only real complaint of the detainees was that they were not permitted to communicate with their wives and families. All contact with the outside world was prohibited until the evening of August 6, 1945, when they were abruptly made aware of the reason for His Majesty’s pleasure. On that evening, the British officers joined the scientists as usual in the manor dining room where the evening meal was served punctually at 7:45 P.M. Dinner conversation, however, was far from usual. The British officers calmly told the scientists that the Americans had reportedly dropped what they called an atom bomb on Japan. A brief BBC radio message seemed to confirm this. Pandemonium reigned. The shocked and disbelieving scientists huddled around the radio at 9:00 to hear a more detailed report from the BBC — but those
crumbs of information only deepened their perplexity. If the Allied scientists had really been successful — and it seemed they had — then German nuclear superiority had been a mere fantasy.
The news was devastating. Each man responded to it in his own way. Walther Gerlach, the last Reich physics head, behaved like a routed general and apparently suffered a nervous breakdown of sorts. Heisenberg and Weizsacker, who shared a bedroom next to Gerlach’s, feared he might attempt suicide and looked in on him that night to assure themselves of his safety. The angered younger physicists, long chafing at the bottom of the power hierachy, accused their elders of mismanagement; Hahn and Laue, initially shaken by the news, washed their hands of the whole affair; Heisenberg set to work calculating. 7 According to Jones, he concluded that the bomb would have to have contained several tons of uranium — quite a load for a plane to deliver. Heisenberg thought that the bomb might in fact have been a hydrogen bomb. 8 Apparently, he had never determined in detail the actual size of an explosive.
The news of a successful Allied bomb turned a glaring public spotlight on two painful issues for the Germans — one acutely embarrassing, the other more profoundly distressing. Transcripts of conversations recorded that evening and the next day by Jones’s hidden microphones — and hitherto released only in very brief excerpt and faulty translation — quote Hahn at the dinner table succinctly summing up the first problem: “If the Americans have a uranium bomb, then you’re all second-raters. Poor old Heisenberg.” 9 As Laue expressed it to his son the next day: “The main question is naturally why we in Germany did not achieve a bomb.” 10 Why was the German achievement, whether or not they were ultimately aiming for a bomb, so slight in comparison? The second question has been asked ever since: In view of the incredible death and destruction wrought by both the bomb and the Hitler regime, what moral scruples, if any, did German nuclear scientists bring to their wartime work? It is a question that can be asked of both sides of the war. 11
British news reporters were already formulating their own anti-German answers to these questions, which the detainees found appalling both for their inaccuracies and for the damage they were doing to German reputations. The scientists spent the entire day after Hiroshima pondering and debating their position — an indication that they had never jointly articulated one during the war. Some of their conversations were recorded, others were not. Heisenberg put together his response with the diplomatic Weizsacker, his closest and most trusted colleague
among the scientists, while strolling unmonitored on the grounds after lunch. By evening they had settled on their positions, and in view of negative press reports, the older scientists decided to present their side of the story in a press release. Gerlach and Wirtz assisted Heisenberg in drafting the statement, an early version of which, in Heisenberg’s hand, survives on the pages of an English military school exercise book. 12 The following day, a final draft was formulated, typed, signed by all, and handed to their captors. It was probably never released to the public.
One of the younger physicists, Erich Bagge, wrote in his diary that, “the story [in the press statement] found wide-ranging but not complete acceptance.” It had been signed by all only after difficulties with the younger physicists had been resolved. 13 Apparently some, including Bagge and his superior, Diebner, objected to the statement’s special pleading and facile exoneration of the older scientists. Nevertheless, Max von Laue, who remained aloof from fission research, apparently joined the other elders in endorsing the statement. He repeated the gist of the argument in a letter on August 7 to his son, who was sequestered in Princeton to avoid the German draft. In late September, he forwarded a copy of the statement to his son for distribution in the United States. 14 The Farm Hall statement has served ever since as the foundation of the German scientists’ position regarding their wartime work, what one historian has called a self-serving apologia. 15
To explain why Germany never achieved even a chain reaction, let alone an atomic bomb, Heisenberg and the Farm Hall elders argued that under wartime conditions in Germany, their economic, technical, and material resources were woefully insufficient and that no one wanted to demand more aid since they did not believe they could achieve their goal before the war ended. Under the conditions of total war, the regime would invest massive resources only if it were assured of immediate success. When the German effort in the context of the uneasy relationship between science and government in Germany is compared with the enormous Allied effort and the close collaboration between scientists and the military on the Manhattan Project, the argument is a relatively accurate statement of the reason the German project was so unsuccessful. It would have been enhanced by acknowledgment of the damage done to German science by Nazi policies — as the physicists themselves had argued during the war.
The German scientists were not satisfied with this explanation. With moral issues being raised by British reporters and their competence at stake, they regarded short-sightedness as indismisable and material conditions as insufficient for their failure. They now added a moral dimen
sion. According to General Groves’s excerpts from the Farm Hall transcripts of August 7, Weizsacker had insisted over Hahn’s objections that they had been driven by moral scruples to concentrate on building a machine rather than a bomb. As quoted by Groves, Weizsacker declared: “I believe the reason we didn’t do it was because all the physicists didn’t want to do it, on principles. If we had wanted Germany to win the war we could have succeeded.” 16
There is no evidence to support Weizsacker’s claim. Perhaps speaking only for himself, Max von Laue nevertheless echoed the ethical sentiment of the resulting Farm Hall statement in a letter to his son that same day: “All of our uranium research was directed toward the achievement of a uranium machine as an energy source, first because no one believed in the possibility of a bomb in the foreseeable future, and second because fundamentally no one of us wanted to put such a weapon in Hitler’s hands.” 17 The Farm Hall statement is far less explicit on the second issue, but the syntax implies the influence of scruples nonetheless. After describing the difficulties of 1942 that led them to give up any hope of a bomb, the next sentence of the statement simply reads: “The further work therefore concentrated on the problem of the machine, for which in addition to uranium ‘heavy’ water is necessary.” 18 There was no mention of efforts at large-scale isotope separation or of the plutonium alternative.
To comprehend more fully the position Heisenberg and his compatriots presented in their Farm Hall statement and its derivatives — “so violently debated in all scientific circles ever since,” as Groves put it — one needs the perspective afforded by hindsight. 19 First of all, whatever their failings as scientists and as citizens, German scientists were not solely responsible for the moral character of their country. It is true that, as noted earlier, the mere fact that these world-renowned scientists continued to live and work in Germany after the moral and political affronts of early years left them already politically and morally compromised and lent the regime an unwarranted and false credibility. They compounded their failing by continuing to seek out and to accept collaborative accommodations with the regime — a regime that continually demonstrated its utter contempt for decency of any sort from the very beginning and clearly held the scientists and their science in outright contempt. Nevertheless, Heisenberg and his colleagues were not any more — or any less — responsible than other Germans for the unspeakable atrocities of the Third Reich.
Nor were they alone in their unprincipled eagerness to prove their value to their government by creating the weapons of war. Ever since Archimedes built catapults for the king of Syracuse, ever since Bacon
declared that knowledge is power, science has been the handmaiden of every nation’s economic, military, and political interests. Not until after World War II — after the advent of weapons of mass destruction and after the example of German scientists so willingly working for their government — have moral scruples really played any role in the willingness of scientists to arm their respective nations. Recent studies of the ways in which American physicists allowed themselves to be manipulated to serve cold-war military aims suggest that fundamental moral or ethical issues — those beyond feelings of patriotism and the desire to defend one’s culture — still do not play a significant role in contempo-' rary weapons research. 20
The postwar quandary of Allied scientists points up the dilemma. Some of the Allied scientists who had devoted their best efforts to the creation of not one but two atomic bombs were profoundly shocked by the destruction they had wrought, and they suffered great moral and emotional anguish because of it. For instance, like many others, Heisenberg’s alter ego, J. Robert Oppenheimer, the scientific head of the Manhattan Project, was driven as much by desires to succeed in building the bomb and proving the value of physics to his government as he was in defending the world against Nazism. Even after he and his collaborators had built the weapon and proved the utility of physics and even after Germany had been totally defeated, he willingly helped select the Japanese cities to be targeted. But no sooner had the radioactive dust settled on Hiroshima and Nagasaki than he and others began to realize what they had done and to experience moral pangs about it. Many of the scientists immediately joined in an effort to control nuclear weapons, and Oppenheimer now joined with several others in an effort to oppose the building of an even more destructive weapon, the hydrogen bomb, largely on moral grounds. 21
A number of Allied scientists consoled themselves with the reflection that they had built the bomb to counter the far greater evil of a bomb in Hitler’s hands. While certainly valid, this rationale could not disguise the fact that their efforts had resulted in the deaths of hundreds of thousands of civilians. The Smythe report, the official account submitted to Congress on the Allied nuclear effort, attempted to counter congressional criticism by stating the obvious: “This weapon has been created not by the devilish inspiration of some warped genius but by the arduous labor of thousands of normal men and women for the safety of their country.” 22
Amidst the throes of their own moral anguish, many of those men and women were simply appalled to perceive a conspicuous lack of any
similar soul-searching among those on the other side. They perceived a shocking failure on the part of the German scientists to acknowledge that they too had been working as well as they could on nuclear fission for their country and, like scientists everywhere, had been willingly exploited by their leaders. 23 On the contrary, the Germans had the audacity to congratulate themselves for the fact that they had not built the bomb! They were even beginning to claim that they had avoided building the bomb out of principle, apparently unconcerned by the fact that, apart from the question of a bomb, they had been working nonetheless for one of the most depraved regimes that ever existed. American physicist Philip Morrison probably spoke for many of his colleagues in 1947: “No different from their Allied counterparts, the German scientists worked for the military as best their circumstances allowed. But the difference, which will be never possible to forgive, is that they worked for the cause of Himmler and Auschwitz, for the burners of books and the takers of hostages.” 24
With the help of his fellow detainees, Heisenberg expounded the Farm Hall position in the months and years following their return to Germany. The story became sharper as it spread farther. In December 1946 British authorities allowed Heisenberg to publish a summary of German nuclear research. An article appeared in the German journal Naturwissenschaften, with a partial translation in the British journal Nature. Beginning in 1947, Heisenberg sat for a series of interviews by German newspapers and by the science editor of the New York Times in response to Goudsmit’s reports on German war research and the Alsos mission 25
In each of Heisenberg’s accounts, early 1942 is depicted as the turning point. During the previous year, 1941, Heisenberg’s Leipzig team had proved that an atomic bomb was possible in principle, and his Berlin team had learned that a reactor could breed plutonium for a bomb. But the technical hurdles to be overcome were still enormous and costly. By 1942, as the war situation worsened, the Army Ordnance Office had decided to forgo most of its nuclear research effort, since the office could not be sure that the effort would lead soon to a weapon. Because of that decision, as well as the reduced capacities of German industry and the technical obstacles still to be surmounted, “all hope of making bombs was given up,” Heisenberg told the New York Times. 26 Although Heisenberg had tantalized Reich officials in early 1942 by hinting that a running reactor would produce equally fissionable plutonium, after the war he insisted that he only wanted to ensure their continued support. He dampened any expectation of an imminent weapon by stressing the
technical difficulties. The strategy worked, he said — even though such a strategy was unnecessary, since he seems to have believed that the difficulties really were enormous.
For Heisenberg, the decisive meeting occurred with Speer on June 6, 1942. After the meeting, Speer ordered that the project be continued only on a modest scale but that the researchers should work, in Heisenberg’s postwar words, for “the only attainable goal”: “to build an energy-producing uranium burner for powering machines.” 27 Of course, the production of a burner to power, say, submarines would have been no small contribution to the war effort. But in his 1946-1947 accounts, Heisenberg also seems to imply the Farm Hall ethic — that the scientists had made a conscious decision not to build a bomb for Hitler and to deter the regime from ordering them or anyone else to do so. As he put it in the pages of Nature: “The German physicists had consciously worked from the very beginning toward maintaining control over the project, and they used . . . their influence to direct the work in the sense depicted in this report.” 28 Beyond that, even if they had not decided against building a bomb, they were still immune from postwar moralism. Since the project had never progressed much beyond its status in 1942, Heisenberg wrote in 1946, he and his colleagues were therefore conveniently spared “the difficult moral decision” of whether or not to build atom bombs for Hitler. 29 Scruples, whether invoked or not, were simply unnecessary.
Heisenberg’s preposterous account parallels but overinterprets actual events. He especially did try to maintain scientific control over the project. He was also aware of the theoretical possibility of a nuclear explosive by late 1941, he did not demand a crash research and development program to build one, and he did seem content to work for the rest of the war on the more modest goal of building a reactor. It is difficult to assess his intentions and motives beyond that. But from what we know of his activities and research, there is nothing to support the notion that Heisenberg actually hindered the project in any way to keep an explosive out of Hitler’s hands or even that he himself had that much control of the situation. Moreover, the feverish effort at the end of the war to construct a reactor must be attributed to both curiosity and the plain desire to succeed. Had they succeeded earlier in producing a chain reaction, Heisenberg and his coworkers would surely have advanced to the next step: extracting weapons-grade plutonium from their machine. 30
The perceived technological and industrial difficulties, and Heisenberg’s assessment that the war would be over before they could develop
a bomb, seem far more decisive than any scruples he may or may not have had. If he did not inform the authorities in 1943 of the possibility that a working reactor would produce weapons-grade plutonium, it seems to have been solely to protect himself and his project from orders to build the bomb immediately. Failure to do so could have been construed as sabotage of the war effort — with obvious consequences.
In a draft version of his 1946 report for the German and British journals, Heisenberg implied more overtly that the control exercised by his group over the project was intended to keep it out of the hands of “other less scrupulous physicists” — as publicist Robert Jungk later called them — who “might in different circumstances make the attempt to construct atom bombs for Hitler.” 31 This is the courage that many of Heisenberg’s supporters saw in his taking control of the project. No doubt Heisenberg was referring to his chief rivals in fission research, Kurt Diebner and Diebner’s supporters: Esau, Schumann, and the Army Ordnance Office (HWA). As indicated in Chapter 24, an administrative turning point of the project also occurred in 1942 when the Kaiser Wilhelm Society regained de facto control of the Kaiser Wilhelm Institute for Physics from Diebner and the HWA, and Esau’s days as head of physics research in the Reich Research Council (RFR) were numbered. 32
If these were the “less scrupulous” physicists Heisenberg had in mind, the argument does not cohere. If Heisenberg had concluded that a bomb was unattainable before the end of the war, then what did he have to fear from his rivals? Even if the more technically adept Diebner and his supporters had somehow managed to exclude Heisenberg entirely from fission research, it is difficult to imagine them moving significantly faster than Heisenberg and his collaborators to develop a reactor, much less a bomb. Before 1942, Heisenberg perhaps did have more cause to fear his rivals, but competition concerned more general administrative and ideological issues, not the direction of one particular project. At that time, he was pursuing his strategy of using uranium research to enhance the prestige of modern physics and himself in the eyes of the regime; losing control of his research teams would defeat that strategy. But his control over Reich uranium research was never actually as complete as he could have wished. Before 1942 the HWA exercised its military authority through Diebner, who was its representative. Later, it was Mentzel and the RFR who oversaw uranium research through their representative, Gerlach, and right up to the end, Gerlach chose to give equal support to the Diebner and Heisenberg research teams.
After the war, Heisenberg and his colleagues had good reason to portray their project as they did. To reestablish German science, to
ensure that scientists could never again be disregarded and abused by their government, and to counter public criticism of their wartime behavior, it was essential that they acquire as much influence as possible, first in the British zone, then within the emerging West German government. Emphasizing again the prestige and utility of nuclear research and technology was the surest means of establishing themselves as vital to Germany’s science and to her economic revival. To realize their goal, suspicions of their having worked to arm Hitler with nuclear weapons had to be addressed. The Allied occupation forces had placed denazification and the control of nuclear energy at the top of their priorities list. Heisenberg, not a party member and ideologically victimized by Stark, sought and gained the confidence of the occupation authorities in the matter of denazification.
In addition, after the war Heisenberg and his supporters took great pains to distance themselves from former Army Ordnance researchers and from anyone else who openly admitted working toward the goal of an atomic bomb under Hitler—even if actual work never proceeded beyond the prereactor stage. During the late 1940s, Heisenberg’s circle also began an intensive public campaign to establish a German nuclear power program, a campaign that continued until the rescinding of Allied science control laws and the granting of sovereignty to the West German Federal Republic in 1955 as part of the NATO alliance. With West German self-rule imminent after 1950, Heisenberg and the nuclear scientists pushed for the establishment of a cabinet-level ministry for nuclear energy policy. At the same time, they now acted to mobilize public opinion against the acceptance by the German government of NATO plans to equip the West German army with tactical nuclear weapons.
The scientists succeeded on both scores. While ensuring that the West German army would remain nonnuclear, they successfully negotiated with Washington for permission to begin a full-scale nuclear reactor program, a program that by the late 1960s was the most successful in the world. West Germany was then the leading exporter of nuclear technology. Heisenberg later wrote with satisfaction in his memoirs: “The fact that in wartime no attempt was made in Germany to construct atom bombs, although knowledge of the principles existed, probably had a favorable effect on these [Washington] negotiations.” 33
If no actual attempt was made to construct an atom bomb in Germany (regardless of whether a reactor was or was not intended as the first step in that direction), a strong difference of opinion emerged
between German and American scientists as to why the attempt was not made. The loudest and most divisive debate occurred between Heisenberg and the former Alsos science head Samuel A. Goudsmit, then professor of physics at Northwestern University. Goudsmit ofFered his highly influential views in a series of articles and in a monograph, widely read among American scientists, entitled Alsos. Their debate raged through the pages of the New York Times and in an exchange of long and fascinating letters. 34
In many ways Goudsmit was bitterly disillusioned concerning Germany, German science, and one German scientist in particular, Werner Heisenberg. Moreover, the broader concerns that he and his colleagues faced regarding science in the United States were quite different from those the Germans were facing. As the cold war deepened, the paramount issues for American scientists were those of secrecy, administration, and the relationship between science and the military. Goudsmit expressly intended his account of the failed German project — “failed” apparently because it did not produce an atomic bomb — as a case study of what can go wrong, an example of “how incompetent control (which is not restricted to totalitarian countries) can kill scientific progress in a short time.” 35 If Heisenberg was arguing the competence and success of the German scientists in perserving their science and their scruples under Hitler, Goudsmit was arguing just the opposite — each, in part, for his own contemporary audience. And indeed each audience has tended ever since to subscribe to the respective views Goudsmit and Heisenberg offered.
According to Goudsmit, a variety of factors caused the death of science in Nazi Germany. Nazi racial doctrine removed essential personnel from the laboratory and the classroom and weakened the scientists’ adherence to fundamental scientific theories. The organization of German science and its support systems was disastrous in its lack of coherence and cooperation. The scientists themselves, who had grown accustomed to leading the world in modern science, became convinced that their superiority was absolute and therefore grew complacent: if they could not make an explosive uranium-235 bomb, neither could the Allies. And finally, said Goudsmit, the German scientists indulged in an excess of hero worship, such as that practiced by “the smug Heisenberg clique,” that overlooked less heroic but more practical-minded technicians, such as Diebner or the self-made Manfred von Ardenne. 36
The German researchers had concentrated on a reactor because they believed that, uncontrolled, it would eventually explode. But even then,
they believed that the Allies were far behind them. In Goudsmit’s opinion, the Germans had completely missed both fast-neutron fission and the plutonium alternative. If they had seen them, they, like the American scientists, would have pressured their government for more support. Thinking themselves far ahead, wrote Goudsmit, in actuality German scientists had only the vaguest notions of how a uranium bomb or even a reactor actually works, as shown by the lack of control rods in their experiments. They were obviously far behind the Allies in such technical efforts as isotope separation and moderator testing and production.
Heisenberg vehemently objected to Goudsmit’s account on nearly every score. In long exchanges with Goudsmit, in letters to and interviews with the New York Times, and through C. F. von Weizsacker and B. L. van der Waerden, then in the United States, Heisenberg vigorously maintained the advanced state of German war research. 37 Possibly through his American uncle Karl, who had lived in New York, Heisenberg gained the backing of Waldemar Kaempffert, the German-American science editor of the New York Times. In an interview by Kaempffert in response to Goudsmit’s Alsos, Heisenberg, speaking “with an objectivity that is convincing,” insisted that the destruction of German industry and unresolved technical problems forced the German scientists to give up “the idea of devising an atomic bomb and to concentrate on the development of atomic power for industry.” 38 Three days after the interview appeared, Goudsmit wrote a letter to the Times taking issue with Heisenberg’s account. “Heisenberg stresses the lack of industrial resources during the second half of the war. The book, ‘Alsos,’ points at the lack of vision of the German scientists.” Kaempffert angrily replied that “liars do not win the Nobel prize” — a remark that prompted Goudsmit’s publisher to inquire of Einstein whether in fact Nobel laureates do lie. 39
Of course, there were glaring errors in Goudsmit’s sometimes angry and sometimes oversimplified account of the German wartime research effort, but Heisenberg in particular was concerned that the research effort should be seen not only as ethically untainted but also as greatly successful. He had made it his personal mission to preserve the high quality of modern physics in Germany despite the adverse conditions. He and his colleagues could not afford to appear to be incompetent fools if they were to be influential in West German science affairs; the more they were thought to have known about atomic bombs, the more noble they would seem to contemporaries for not having attempted to
build them. He defended the obvious hero worship, the formation of a clique around himself, as a means of excluding “unscrupulous persons” from influence on the course of uranium research. Heisenberg’s 1941 visit with Bohr was now described as an effort to convey to the Allies that the Germans knew about the bomb but would not pursue it. They would work on nuclear energy only to gain funding and recognition and to save young physicists from the draft. 40
Bohr’s views on that visit now became crucial to Heisenberg’s case, and Uncle Karl again assisted his nephew. He had earlier befriended Bohr during one of Bohr’s many fund-raising trips to the United States. With his uncle’s help, Heisenberg managed to reestablish contact with Bohr and received permission — from both Bohr and the British — to travel to Copenhagen in 1947. With his wartime motives and behavior in question abroad, Heisenberg apparently wanted to discuss the situation with the influential Bohr, but more importantly, to learn what Bohr remembered of their controversial 1941 encounter. Accompanied by an Allied control officer, Heisenberg made the trip just as Goudsmit’s book appeared in the United States. 41
After all that had occurred in Denmark during the war, and probably still angry that Heisenberg had led him astray during the 1941 visit, a cordial Bohr proved less supportive than Heisenberg had expected. Bohr flatly refused to discuss the details of the visit, and Heisenberg did not report much of what transpired during this encounter. Bohr had taken the 1941 meeting, Heisenberg reported, merely as an indication of German progress on nuclear fission research. 42 Brushing Heisenberg off, Bohr told him to get in touch with Goudsmit; Heisenberg would have to refute Goudsmit without Bohr’s backing. A year later, the diplomatic B. L. van der Waerden, Heisenberg’s selfappointed “attorney,” composed an English aide-memoire on the German position and presented it to Bohr. 43 There is no record of a response. Bohr’s relationship with Heisenberg was civil but strained thereafter.
Heisenberg did get in touch with Goudsmit. Although it is unclear how much, if any, Heisenberg read of the book, soon after Alsos was published Heisenberg wrote to Goudsmit attempting to explain the difficult psychological situation the Germans had to face during the war. 44 It was a terrible moral dilemma. On the one hand, he claimed, the German scientists were well aware of the “horrible consequences” that a German victory would mean for Europe; on the other hand, they did not wish to see Germany defeated — not because of patriotism but because of “the hate that National Socialism had sown” — a compro
mising statement at best. The dilemma led the scientists to pursue “a more passive and modest posture,” he argued. This was a reference to the position outlined in his earlier essays “Active and passive resistance” and “The order of reality” — to help on a small scale where it is possible and otherwise to do work that will perhaps prove useful later. 45
Heisenberg’s letter elicited an angry five-page, single-spaced typed response from Goudsmit, repeating many of the arguments in his book. Active opposition, Goudsmit told the German physicist without ado, was simply a self-serving rationalization, fabricated ostensibly for the pursuit of an impossible goal — the mere preservation of relativity and quantum theory under Hitler. “How could you ever hope to be successful? How could you ever think that these were important issues?” 46 The two argued back and forth in public and private exchanges over the following year. Heisenberg consistently maintained Germany’s scientific success, despite Nazi policies, and the German scientists’ moral dilemmas, while Goudsmit was unrelenting on Germany’s scientific failure and the scientists’ compromising position toward the Hitler regime.
In 1948, at the request of American occupation authorities, Heisenberg and Wirtz published a technical account of the German project in a series of U.S. Army reports on German science and technology. 47 They argued, of course, that Germany had been well advanced in reactor engineering, but they did not even hint at any broader issues. The report enabled Heisenberg to reexamine available research reports, and at Heisenberg’s insistence Goudsmit reexamined copies of the captured reports in Washington.
As a result of this exercise, Goudsmit corrected his most obvious errors, conceding that the Germans had, in fact, been aware that a bomb differed from a reactor and that they had also been cognizant of the plutonium alternative. But, Goudsmit wrote in the New York Times, Heisenberg’s claims of advanced theoretical knowledge notwithstanding, the reports “show clearly that their scientists had only a very vague notion of the working of the atomic bomb, and their ideas about a uranium pile were in a very preliminary stage.” The reason for their meager progress was, again, their lack of vision. And their lack of vision was the direct result of “the stifling atmosphere in which scientists work under a totalitarian regime.” 48
This, of course, had been Goudsmit’s fundamental point all along. Again and again Goudsmit made the same point to Heisenberg and his emissaries: what he really wanted to see from Heisenberg, Hahn, and other leading scientists was articles about the frustration of scientific
progress under a totalitarian system of government. 49 He insisted that they should stop extolling the greatness of German science and acknowledge its decimation by the Nazis — a demand that they were hardly in a position to fulfill. In fact, their position was almost impossible to maintain under any circumstances: trying to distance themselves from the Nazi regime while at the same time claiming that they had done great but harmless work under it.
That Heisenberg would even attempt to defend the pursuit of decent science under the Nazi regime, or believe such were possible, seemed outrageous to many American scientists. Goudsmit had already declared of Heisenberg: “He fought the Nazis not because they were bad, but because they were bad for Germany, or at least for German science.” 50 Carl Friedrich von Weizsacker learned of this outrage firsthand when, in 1949, he met in Chicago with emigre physicists James Franck and Maria Goeppert-Mayer, both of whom — in view of the increasing secrecy, military control of nuclear research, and the decision to build the hydrogen bomb — were very concerned with ethical issues. Franck was especially critical of the German scientists, Weizsacker reported to Heisenberg. In Franck’s view, even the defense of decent physics and the acquisition of support and draft deferments could not justify the compromises Heisenberg had made with the Nazi regime. 51
Goudsmit and Heisenberg never did settle their quarrel. Years later the two men, now old, met one last time in an attempt to heal old wounds. During his last trip to the United States, in the spring of 1973, Heisenberg lectured at the Smithsonian Institution in Washington, D.C., and Goudsmit, who had long since moved to the Brookhaven National Laboratory on Long Island, traveled to Washington to meet him. 52 Goudsmit once again admitted the technical errors in his Alsos portrayal of a backward German project and apologized for any personal injury he had caused the German physicist. A complete reconciliation, however, was impossible. Heisenberg died three years later.
In his obituary of Heisenberg for the American Philosophical Society, Goudsmit offered his assessment of their controversy after decades of reflecting on it. In Goudsmit’s view, Heisenberg had failed to realize that German physics was already in precipitous decline relative to physics in other nations even before the Nazis came to power. The United States in particular was rapidly outpacing Germany. The American research system of cooperative university departments, large-scale industrial research, and close collaboration between experimentalists and theorists was much more conducive to the progress of contemporary
physics, especially nuclear physics, than was the German tradition. Thanks in part to American fascination with European science, which made possible Heisenberg’s own many trips to the United States, American physics was already surpassing German physics when the Nazis began driving many of their best scientists from Germany. Heisenberg’s efforts to maintain an illusory German lead in contemporary physics were thus completely misplaced. “If Heisenberg had realized this,” wrote Goudsmit, “he would not have taken the German failures so personally.” 53 Perhaps he would not have been so willing either to enter into the debilitating compromises he endured by convincing himself that he was indeed personally responsible for the preservation of leading German physics.
The concern of many scientists in the United States during the late 1940s over the issue of government control of research was soon settled to their disappointment in the tightened secrecy criteria of the cold-war era, and in the government-mandated H-bomb program. 54 Whatever the lessons of the past, some scientists would work nonetheless to fashion weapons of mass destruction that were becoming ever more prevalent and ever more powerful. The prospect of “mutually assured destruction” became more assured indeed with the invention of intercontinental ballistic missiles, which could carry the instruments of destruction to any spot on the globe within minutes. Concern for moral issues and the social responsibility of the scientist mounted everywhere, especially in the United States. Some American scientists felt satisfaction that at least they were building bombs not for a Hitler but for the protection of American democracy.
The satisfaction was soon challenged by the publication of Robert Jungk’s history of the atom bomb, Brighter Than a Thousand Suns, which appeared in German in 1956 and in English in 1958. 55 Those years were ones of vehement debate in West Germany over nuclear weapons and reactor technology, and Jungk’s book took up the German scientists’ case. In accounting for the meager success of the German wartime project, Jungk went beyond the issues of inadequate support, insufficient industrial resources, and faulty management to “the actual personal attitudes of the German experts in atomic research.” These, he claimed, had not been discussed hitherto for reasons of “discretion and tact.” 56 He even quoted from a letter he had received from Heisenberg, in which Heisenberg reiterated the argument of “active and passive resistance,” to show how close he was to his sources. 57
According to Jungk’s account, the German scientists — meaning those around Heisenberg — so distrusted the regime and other less
scrupulous physicists that, pursuing their active resistance, they continued to work on the project but secretly sought “to divert the minds of the National Socialist service departments from the idea of so inhuman a weapon.” 58 They gladly welcomed the authorities’ conclusion that an atomic bomb could not be made under wartime conditions in Germany and were content to concentrate on trying to build a reactor, while awaiting the inevitable defeat. Meanwhile, Jungk continued, the Americans worked feverishly on an atomic bomb and succeeded in providing their government with a weapon of awesome destruction that was promptly used on Japan. The implication was clear: the Americans were morally inferior to the upright Germans. 59 It was the old, apologetic Farm Hall story carried to its ultimate conclusion.
Heisenberg and Weizsacker, heavily involved at that time in the scientists’ dual campaign against weapons and for reactors, had helped Jungk reach this conclusion and privately professed agreement “by and large” with his book. 60 The book naturally provoked a new round of debate about German wartime research. German physicist and editor Paul Rosbaud, who by much later postwar accounts had supplied the Allies with inside information on the German uranium project during the war, wrote in his review of Jungk’s book for Discovery : “Out of all of the theory [of the A-bomb] emerges a strange picture in which it sometimes appears that the German physicists alone have no actual or moral guilt for the A-bomb.” 61
Max von Laue, who in the meantime had reconsidered the Farm Hall story that he had once so strongly supported, wrote to Rosbaud denying the moral element in the story and repudiating Jungk’s portrayal of a morally driven Heisenberg. Referring to the discussions on August 7, 1945, he wrote: “The version was developed that the German atomic physicists really had not wanted the atomic bomb, either because it was impossible to achieve it during the expected duration of the war or because they simply did not want to have it at all. The leader in these discussions was Weizsacker. I did not hear the mention of any ethical point of view. Heisenberg was mostly silent [his emphasis].” 62 Why they would not want to have it at all is unclear, but ethics for Laue were an ex post facto invention.
In 1964 science students at Cornell University, after reading Jungk’s book, asked their mentor, Hans Bethe, to give a talk on the social responsibilities of scientists and engineers. In his talk, which was later published in the newsletter of the Society for the Social Responsibility of Science, Bethe reviewed the public record of the Goudsmit-Heisenberg controversy and noted its seeming lack of focus on moral issues:
“Neither Goudsmit nor Heisenberg indicated that conscience played any part in the German failure to develop the atomic bomb.” 63 Their debate had revolved around the failure of German science.
Without access to the full record, Bethe had apparently overlooked the strong moral argument that Heisenberg was making, as indicated, for instance, in his letter to Goudsmit on the German scientists’ dilemma. Bethe’s talk brought an objection from Heisenberg, who again emphasized his moral scruples. In his letter to Bethe, Heisenberg acknowledged that German physicists were morally no better or worse than their American counterparts, but he still maintained that they did not build bombs because they did not want Hitler to win the war. On the other hand, certain that Germany would eventually lose, they did not “wish a total and obliterating defeat of Germany.” Apparently this sentiment, voiced earlier, was their justification for working to build a reactor to power the German economy before and after defeat. Again Heisenberg claimed that the controversial 1941 meeting with Bohr proved their moral concern. With the technological and administrative turning points in 1942, they were thus relieved that they could concentrate on developing a reactor without fear that they would be ordered to build a bomb. 64 Jungk’s overemphasis on morality apparently inspired all parties to stress moral scruples when telling their stories.
The 1967 publication of David Irving’s account of the German project, published as The Virus House in Britain and as The German Atomic Bomb in the United States, again revived the debate. 65 Irving, a British author, offered the first historical account of the German project to take advantage of a wealth of available, though obscure, primary sources. A number had been only recently declassified. Irving’s overall portrayal was sympathetic and unemotional, yet he too doubted that moral scruples played a role at any stage of research. He believed that curiosity drove the German scientists in their work and would have driven them all the way to a bomb, had circumstances allowed it.
This prompted Heisenberg to offer another round of interviews and book reviews, in Germany and the United States, on the German project. 66 Heisenberg expressed satisfaction that “Irving’s investigation confirms the German report in all important points,” in the pages of the Bulletin of the Atomic Scientists — the magazine of concerned American physicists — and in the influential Frankfurter Allgemeine Zeitung. But he believed that Irving’s interpretation of motives was faulty. Irving “does not recognize sufficiently how deep a mistrust could exist, yes, often has to exist, between human beings in a totalitarian state, even
between those who work closely together.” Because of this, since the war situation prevented large-scale projects, “German physicists did not insist on pursuing, by means of practical measures, a path which could not have led to success during the war.” 67
In a preface to Heisenberg’s review of Irving’s book, Bulletin cofounder Eugene Rabinowitz took direct issue with Heisenberg’s contention that distrust, hence scruples about the use of their work, had determined the scientists’ behavior. He conceded that distrust of the regime probably did exist and probably did make the German scientists reluctant to provide weapons to Hitler. But the possibility that Germany might lose the war and that defeat would mean the end of the great revival of the German nation begun by the Nazi regime at first made the scientists much less reluctant. This changed after 1942. “As the war dragged on, and the likelihood of German defeat loomed more and more ominously for all who retained a modicum of rationality, the scruples of the leading German physicists became stronger, and the alibi of developing not an atom bomb, but a postwar reactor, actually became reassuring. 68
The controversy continues in full force to this day. 69 To a large extent, Goudsmit, Rabinowitz, Irving, and others are correct. We (in the American tradition, at least) do feel there was a profound failure by Heisenberg and others to be completely candid about their attitudes during Hitler’s rule and especially during the war—a failure to explore their errors as well as their successes, to point out the human frailty as well as the human resilience of the scientist and the citizen in this encounter with the nightmare world of genocidal dictatorship, to debate not merely the stifling of science by governments but the stifling of the human spirit itself. Certainly it was unacceptable for Heisenberg and colleagues to claim that they had consciously delayed the project because of moral scruples; it was not much better for Heisenberg to say that he might have built the bomb, had it been attainable during the war, but otherwise to absolve himself of any moral failing. After all, had he and they not worked on reactors to power the German war machine? Had he and they not allowed themselves to be exploited by a monstrous regime? How this all came about, how these highly educated scientists, blessed with the best culture and learning and the highest ideals of scientific inquiry, could find themselves in this situation, are questions that they themselves, through candid reflection, could perhaps have helped us to answer better than could any postwar biographer. Perhaps it was too much to expect a soul-searching confession from Heisenberg
rather than an apology carefully tailored to the changing postwar situation. How many American scientists who have worked and who continue to work today on instruments of mass destruction have bared their souls to us?
What is remarkable in Heisenberg’s case is that despite their frustration with him, many of Heisenberg’s severest American critics remained sympathetic and more than politely cordial toward him, even while publishing the most devastating repudiations. It was as if they recognized how much they shared his difficulties, as if they only wanted him to admit what has become common knowledge since World War II: that scientists everywhere, no matter how devoted they may be to the search for truth and universal understanding, will work for their governments, whether worthy or loathsome, and that many will serve their governments by fashioning the weapons of war and destruction.
The closing paragraph of Samuel Goudsmit’s obituary of the man he had so admired and so reviled expresses the frustration as well as the pity that many others must have experienced. “Heisenberg was a very great physicist, a deep thinker, a fine human being, and also a courageous person,” he wrote. “He was one of the greatest physicists of our time, but he suffered severely under the unwarranted attacks by fanatical colleagues. In my opinion he must be considered to have been in some respects a victim of the Nazi regime.” 70
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