CORRESPONDENCE

To the Editor:

Gerald Holton’s mostly tolerant review of my play “Copenhagen” (Book Review, Dec. 31) is marred by a bizarre factual misconception.

He suggests that in the new version of the postscript to the published text, written to coincide with the play’s production in New York, I have changed my mind about a crucial point--the argument put forward by Thomas Powers in his book “Heisenberg’s War”--that Werner Heisenberg had calculated the right critical mass for a bomb and “cooked up” a false one to make building a bomb seem even less possible than it was. In the new postscript, according to Holton, “Frayn now dismisses Powers’ ” main thesis with the cutting comment, “If he [Heisenberg] had kept the fatal knowledge . . . from anyone, as Powers argues, then it was from himself.” This, he says, “raises an unsolvable problem for Frayn: If the play was initially structured in good part to reflect an idea of Powers which now has to be laid aside, what is the playwright to do?”

It would be a problem, I agree, if I had changed my mind. But I haven’t, because at no point have I ever accepted the thesis which I am now said to “confess” that I dismiss. I make precisely the same point about keeping the knowledge from himself in the original (London) version of the postscript, where almost precisely the same sentence occurs. Nowhere in my play does the fictitious Heisenberg claim, any more than the real Heisenberg did in life, that he had ever calculated the correct critical mass. The whole argument of the play stems (and has always stemmed) from Heisenberg’s own admission, as recorded during his internment at the end of the war, that he hadn’t calculated it; and the question at issue is why he hadn’t.

I have, as I explain in the new version of the postscript, modified my views on various points as a result of reading material that was not available to me when I wrote the play. I now accept that Heisenberg didn’t fully understand the principles of the calculation. But on the whole this somewhat reinforces my view that he had never thought about it as hard as he might.

Professor Holton seems for some reason to assume that, because I gratefully acknowledge Powers as the source of my initial interest in the subject, I am arguing the same case as he. I’m not, and never have.

At no point in the play do I suggest that Heisenberg made any conscious decision to sabotage the German bomb program. Indeed, as soon as Niels Bohr, in an alternative version of the conversation in 1941, persuades him to think seriously about the calculation, and he gets the answer right, the fictitious Heisenberg seems to be unable to resist the logic of going ahead and building the bomb.

I may well be wrong in accepting Heisenberg’s claim that he never made the calculation; the record is ambiguous (as I explain in the postscript) and it’s possible to read it as suggesting that he had attempted a serious calculation and simply got it wrong. But I can’t see the point of attributing to me a view which I have quite plainly never held, and which would equally plainly make a nonsense of the whole argument of the play.

Michael Frayn

London

To the Editor:

The argument in Michael Frayn’s play “Copenhagen”--that the German physicist Werner Heisenberg’s purpose in going to see his old friend and colleague Niels Bohr in 1941 was to discuss the moral problem posed by atomic bombs--holds little interest for your reviewer, Gerald Holton. His claim is that none of it happened or that whatever happened was without significance. He was not reviewing my 1993 book, “Heisenberg’s War,” but he often cited my views. He thinks I got it all wrong, and because of me Frayn got it all wrong and now, as a result, the world’s playgoers have been falsely persuaded that Heisenberg said he asked Bohr “whether or not it was right for physicists to devote themselves in wartime to the uranium problem” because he wanted to know.

But, for a historian of science, Holton seems strangely lacking in curiosity about what did happen. The only actual piece of direct evidence he cites--an angry letter written to Heisenberg by Bohr in the 1950s but never sent--is locked up until 2012, apparently on the advice of Holton. Now that to me is really surprising. Why would a historian of science recommend that? Was he trying to protect Heisenberg’s reputation? Lacking the letter, Holton says, leaves us with “half-knowledge”--is that what he wants? I, for one, would certainly like to know what Bohr thought about Heisenberg’s visit and hope Holton might now urge the Bohr family to change its mind and release the letter--perhaps at the symposium being planned for Copenhagen next spring. They listened to him once, he says; perhaps they would again.

Thomas Powers

South Royalton, Vt.

To the Editor:

I participated in the wartime Manhattan Project (atomic bomb) at Los Alamos and five other sites. After the war, I was on the staff of the U.S. Atomic Energy Commission and was the person initially responsible for evaluating wartime German atomic progress, such as it was. Thus, for more than 55 years, I have followed the supposed events and persons depicted in Michael Frayn’s play, “Copenhagen.” The purpose of my letter is not to criticize Frayn, Gerald Holton or Jeremy Bernstein but, as always, to illuminate certain critical facets of nuclear history, which suffer from Samuel Taylor Coleridge’s “willing suspension of disbelief.”

It was the fear that the Germans would achieve the bomb first which drove the joint American and British atomic bomb project. It is not generally appreciated that as early as mid-1943, the British, through extraordinary intelligence efforts, began to realize that the German atomic project would not come to fruition for many years. They imparted that knowledge, just before the 1944 invasion of Normandy to Gen. Leslie Groves, head of the Manhattan Project. Groves chose not to believe the British and created his own atomic intelligence unit to follow our invasion troops. Its mission was to capture Nazi atomic documents and the key scientists themselves. The scientists were incarcerated at Farm Hall in Godmanchester, outside of Cambridge, England, where the premises were thoroughly bugged. Forty years later, ever fascinated, I visited Farm Hall, where the bugging wires still show in the basement. A wartime Farm Hall tile serves as a paperweight on my desk.

My visit was the culmination of decades of study about what occurred at Farm Hall, a venue which has captured the imagination of many historians, including Frayn.

Most participants, such as myself, in the wartime Manhattan Project were motivated by the fear of a German atomic bomb. Groves knew that and rejected the 1944 British evaluation for he knew that if that knowledge leaked, the motivations of many scientists would have been vastly diminished. In the immediate post-war world, on the staff of the U.S. Atomic Energy Commission, it was my task to evaluate the vast collection of captured German documents. They confirmed the abysmal, though fortunate, lack of German atomic progress. Through the years, I eventually learned from British colleagues of their earlier evaluations and discussions with Groves.

And I came to meet, interview and correspond with many of the German scientists who had been interned at Farm Hall and with the British intelligence officers who had performed their evaluations for Winston Churchill. When the first reviews of the London opening of “Copenhagen” were published, I wrote to Frayn. That sparked a small drama in itself. It appears that the legacies of Farm Hall will ever prevail, in fact and in fiction.

Harvard’s Holton is recognized as the preeminent historian of science; his observations are almost always to be heeded. Nevertheless, his review of “Copenhagen” and Bernstein’s “Hitler’s Uranium Club” still does not answer the fundamental question posed by Margrethe, the wife of Niels Bohr, in the play: “Why did he [Heisenberg] come [to Copenhagen]?” Frayn fantasized the answers surrounding the circumstances of the famous meeting, in September 1941 between Bohr and Heisenberg. As Holton points out, Frayn continues to revise the answer, as criticism has mounted, even though, to quote Holton, the play “is now acknowledged to be even further from physical reality.”

The continuing mystery is why reviewers, even Holton, who is one of the few persons privileged to have seen Bohr’s explanation, sealed until the year 2012, persist in blinding themselves as to the actual purpose and course of that meeting, insisting it is an unanswered question. Contemporary documents and statements of persons closest to Bohr answered the question long ago. They made it clear that the Copenhagen visit was an intelligence mission approved and arranged (as a “cultural visit”) at the highest levels of the Reich.

Those who have created a Bohr-Heisenberg speculation “industry” sometimes give lip service to the intelligence facet, but they avoid crediting it. As Holton notes, they owe their inspiration to Robert Jungk’s 1956 “Brighter Than a Thousand Suns” (Harcourt, Brace & World). Jungk wrote that Bohr never really understood why his former pupil was there and that Heisenberg “never reached the stage of declaring frankly that he and his group would do everything in their power to impede the construction of such a weapon if the other side would consent to do likewise.”

Under Hitler?! In fairness, Jungk came to recognize that. In a December 1988 Berlin lecture, after much reflection, Jungk did confess his great mistake. Not long after that, he wrote to me that “it is true that [Carl von] Weizsacker misled and used [Jungk’s emphasis] me to propagate his version of the German A bomb history. But you [in “The Griffin,” Houghton Mifflin, 1986] make it sound as if that lie came from me, whereas I was made to believe in it by somebody I have since learned to see as an unscrupulous opportunist.” Jungk was referring to Weizsacker, who Heisenberg accompanied to Copenhagen but was not received by Bohr.

There was no moral dimension to the conversation. Immediately after the meeting, Bohr told his son Aage, who, in 1967, wrote that Jungk’s account had “no basis in the actual events” [“Niels Bohr,” North Holland Publishing Co., 1967]. So what did transpire? Robert Oppenheimer was the first person Niels and Aage saw at Los Alamos after their escape from Occupied Denmark. In a series of lectures, given in 1963 and 1964, Oppenheimer said, “Heisenberg and Weizsacker came over from Germany. . . . Bohr had the impression that they came less to tell what they knew than to see if Bohr knew what they did not. I believe it was a standoff” [New York Review of Books, Dec. 17, 1964].

The “visit” was an intelligence mission, nothing more or less. But why at that time? Credit Dr. Paul K. Schmidt, the clever and ambitious head of the German Foreign Office’s press branch. He was a favorite of the foreign minister, Ernst von Weizsacker, father of Carl von Weizsacker. On Sept. 4, 1941, Carl von Weizsacker received, from the enterprising Schmidt, a report from London, which had appeared in the Stockholms Tidningen, to the effect that: “in the United States scientific experiments are being made on a new bomb. . . . The material used in the bomb is Uranium, and if the energy contained in this element were released, explosions of heretofore-undreamed power could be achieved. Thus a five-kilogram bomb could create a crater 1 kilometer deep and 40 kilometers in radius. . . .”

That was an astonishingly accurate statement for that period. It reflected more of the British than the American thinking. Carl von Weizsacker immediately forwarded the Schmidt report to the Abwehr, the intelligence arm of the German High Command. The next day, he sent the report to Education Reichsminister Bernhard Rust, who was funding the physicist’s research. Already, Von Weizsacker had been writing, for Rust, a report on nuclear research in the United States. A fortnight later, Bohr and Heisenberg had their famous chat. Von Weizsacker, told to stand outside, was not a direct witness.

In October, Carl von Weizsacker’s father was still asking Schmidt for reports on the American uranium program. Ironically, the U.S. program did not receive a full go-ahead from Presi dent Roosevelt until Dec. 6, 1941--the day before Pearl Harbor.

Six months after the Copenhagen meeting, a young associate of Bohr’s, Christian Moeller, visited Lise Meitner in Sweden. She wrote to the Nobel Laureate Max von Laue:

“I had Dr. M with me one evening and that was very nice and pleasing. He told me much about Niels and the institute, and most was comforting and satisfactory. Half amusing and half depressing was his report about a visit of Werner and Carl Friederich. . . . I became very melancholy on hearing this; at one time I had held them to be decent human beings. They have gone astray” [Meitner papers, Churchill College].

Had Bohr and Heisenberg spoken of atomic bombs, no one would have been surprised. Had they discussed moral issues and the control of the bomb, Meitner would have been pleased. Heisenberg had asked his old friend and teacher to betray the Allies who would free his beloved Denmark from the yoke of Heisenberg’s masters. The perceived treachery, more than any other facet, real or imagined, was cause enough for the friendship to “have gone astray.” As have I, in Frayn’s judgment. He advised that “I should certainly give the play a miss, if I were you,” as he wrote to me on July 8, 1998.

Arnold Kramish

Reston, Va.

To the Editor:

I read with great interest the excellent review by Gerald Holton of Michael Frayn’s play “Copenhagen.” However it seems to me that Holton has overestimated the extent to which Frayn’s drama “reflects” or endorses Werner Heisenberg’s interpretation of his September 1941 meeting with Niels Bohr. “Copenhagen” certainly plays around with the possibility that Heisenberg’s team deliberately confounded the German effort to develop an atomic bomb during World War II, but it does so in order to explore the theme of uncertainty, not to convert Heisenberg’s claims into statements of historical fact. Holton interprets the tearful reaction of his fellow playgoers to a New York showing of “Copenhagen” to mean that they had bought into the Heisenberg legend: “At least for these playgoers,” he writes, “all ‘uncertainties’ had undoubtedly given way to a ‘knowledge’ of what really had happened on that day in September 1941 and to which side the moral victory belonged.” I too saw the play in New York and was deeply moved by it, but not out of any simplistic sense that the Allied scientists were uniformly in the wrong at the end of World War II and their opponents safely in the right. The conclusion of “Copenhagen” does remind one very powerfully of the tragic loss of life that was incurred at Hiroshima, but the play as a whole also evokes just as powerfully, albeit more indirectly, the countless lives that were lost at the hands of Nazi Germany. Perhaps the tears in the eyes of Holton’s fellow playgoers reflected not merely the first of these tragedies but a complicated combination of the two.

Malick Ghachem

Stanford, Calif.

Gerald Holton replies:

Michael Frayn’s surprising letter to the editor is best read in context. First, I note that Frayn does not take issue with the main points of my review. His play was evidently based in large part on Heisenberg’s published claim that for him an impeding moral compunction may have existed about working on atomic energy, although that claim was subsequently unmasked (e.g., by Max von Laue) to have been manufactured for public consumption, right after Hiroshima. Eventually it was admitted (e.g., by one of Heisenberg’s closest co-workers during the war, C.F. von Weizsacker, in an interview reprinted in his autobiography, “Bewusstseinswandel”) that the German scientists had in fact tried to build an atomic bomb. Nevertheless, the journalist Thomas Powers, in his book “Heisenberg’s War,” escalated the story of a claimed moral compunction into the fable that Heisenberg knew well how to make a bomb but sabotaged the work of his team by keeping that knowledge entirely to himself.

While that main thesis was contradicted by all serious historical studies, Powers’ book first aroused Frayn’s interest in his work on “Copenhagen.” And in fact Frayn’s Heisenberg is a character right out of Powers’ book. Thus, instead of acknowledging that crucial errors and omissions doomed the work of the team toward a bomb, the stage-Heisenberg insists that he “wasn’t trying to build a bomb.” He also brags that even though the Germans in 1942 were “desperate for a new weapon,” he asked the German Minister of Armament and Munitions, Albert Speer, intentionally for so little funding that Speer did not take the program seriously--and, Heisenberg adds “that is the end of the German atomic bomb.” Frayn here merely paraphrases Powers’ words: “‘He killed it.”

While the 1998 play script of “Copenhagen” was hardly changed for its new (2000) edition, Frayn’s postscript was considerably expanded, in good part because in the meantime he had read the book “Hitler’s Uranium Club” (1996, 2nd edition, 2000) by Jeremy Bernstein, whom Frayn cites repeatedly and of whom he writes: He “seems to me the best-informed and most fair-minded of all Heisenberg’s critics.” Throughout his important book, Bernstein documents how wrong it is to argue, as Powers had done, that Heisenberg sabotaged the embryonic German nuclear weapons program.

I believe any reader patient enough to compare Frayn’s postscript in the first and second version of his play will be left with no doubt that Frayn had changed his mind about Powers. In 1998, he had quoted and referred to Powers without raising any objection--indeed giving him at one point “‘the advantage” over Heisenberg’s main biographer. By contrast, Frayn’s new postscript is constructed around a markedly different idea. Now he accepts explicitly only “some view of Powers’ version of events” (emphasis in original), the “lack of zeal” of the German researchers. But from that point on, he dismisses the other, major part of Powers’ thesis, namely that Heisenberg had the fatal knowledge, yet, “as Powers argues,” kept it from his colleagues. There are several other examples of the shift from Frayn’s earlier, generous belief in Powers’ ideas. In his 2000 postscript a quite different authority is invoked--typically, “I think we have to accept Bernstein’s judgment.”

Nevertheless, now Frayn informs us in his letter that he “quite plainly never held” views identified with those of Powers. A comparison of the two postscripts shows otherwise. But happily, Frayn’s new position relieves him of any temptation to amend his stage play--one that remains, as I noted in my review, a hugely successful work of fiction, a drama of remarkable effectiveness.

As to Powers’ own letter to the editor, I would have expected him to berate Frayn for having abandoned him. Instead, after a rather incoherent set of statements, he focuses on the question why I, when shown Niels Bohr’s letter in 1985, would have “recommended” it to be “locked up until 2012.” But of course I did no such thing. On the contrary, I advised that it be preserved by having it put into Bohr’s archives (as against other possibilities, such as having it discarded). For reasons of its own, Bohr’s distinguished family later decided to embargo the letter. And I did not require Powers’ advice for me to urge the archives’ authorities that Bohr’s letter be released sooner.

Arnold Kramish, author of the fascinating book “The Griffin,” believes that, like other reviewers of the play, I have blinded myself to the true meaning of the German scientists’ visit to Denmark in 1941. As it happens, I agree with Kramish that the visit was quite possibly at bottom an intelligence mission. Many of the other details in Kramish’s letter are interesting and likely to be also correct. But my own review was intended not as a history of those terrible days but as a study of the subtle subtext of a new play.

I agree fully with Malick Ghachem’s remark that Frayn’s play is not, and should not be considered, a statement of historical fact. My review insisted on the difference, precisely because for unwary audiences, such works can have the seductive effect of passing for history. I am glad that at least for Ghachem the play evoked the horror experienced by all the victims of that period, not only those in Hiroshima. But it ought to be noted that in the play itself, the cries of those millions who died at the hands of the Nazis are not heard.