Copenhagen was the occupied capital of Denmark which Werner Heisenberg visited, watched closely by the Gestapo, one night in September 1941 to visit and talk to his old mentor and close friend Niels Bohr. It is the title of a play both historical and scientific, and the most fascinating I have ever read. It is the home of the Niels Bohr Institute, where the Copenhagen Interpretation - the new way of describing atoms, using quantum mechanics - was born, after difficult but exhiliarating years of debates and struggles between physicists all over Europe.
I love the story of those scientists. Most of them were young, and breaking new ground, and they fought to the point of tears and avoiding each other for weeks. They were spaced all over Europe, yet operating closely - "Everyone in and out of each other's departments." "Papers and drafts of papers on every international mail-train." I wish I'd been there! I feel the same way about Galaxy Zoo. I honestly believe we might change the face of science and in the long term science education. But my God I get het up if there's the slightest sign that our standards are at risk.
It was Chris's fault that I ordered a copy of this play. I read it again and again at the time - early November last year. The science was enthralling, as was the story. (I didn't feel a need to watch the play, let alone a film - the dogma that "it is always easier to understand when you see it" has never applied to me.) It took several reads to establish exactly what they were talking about, how much each character knew. Their perspectives keep flipping from past to present to future (or rather, from the 1920's to 1941 to after the war, since, in the play, they are "all of us dead and gone"), which was an added brain-teaser until I knew all the steps. It was like having to learn a piano piece or a dance back to front before I could start appreciating the finer points.
Anyway, I picked it up again somewhat absent-mindedly a couple of weeks ago. And again I was reading it over and over. Until suddenly one evening it was like being punched in the throat because what happened was so terribly sad. As a teenager, Heisenberg had had a terrifying time towards the end of the war. Aged 20, his university supervisor took him along to hear Niels Bohr speak, which was a thrilling event. "The war had been over for four years, but we were still lepers . . . in Germany we worshipped you. Because you held out your hand to us." Heisenberg challenged the mathematics Bohr was using, and Bohr came to meet him afterwards. It was the start of a seventeen-year friendship; Heisenberg was almost adopted into Bohr's family. "In the whole history of physics no two men were ever closer," wrote Thomas Powers many years later.
But in 1939 there was war again, and soon Denmark was invaded. Bohr and Heisenberg were both patriots and on opposite sides. Worse, Bohr's mother was Jewish, and in 1943 he had to escape being rounded up by crawling down the beach on his hands and knees in the dead of the night to be smuggled away on a sailboat.
"Copenhagen" looks back on an intriguing, eternally confusing event that took place in 1941: Heisenberg visited Bohr and clearly told him that Germany was working on a nuclear project. But afterwards, the two could not agree on what had been said, or even where. Heisenberg was depressed afterwards, and Bohr clearly angry with Heisenberg for the rest of his life. Heisenberg was no Nazi supporter, but he was clearly working for the regime. Bohr concluded that he wished to provide Hitler with an atomic bomb. Heisenberg claimed that he wished no such thing and was in fact trying to avoid it, perhaps even asking Bohr's advice in going about doing so. Today, many scientists and historians disbelieve Heisenberg and feel his behaviour was immoral and arrogant. What did the two of them say to each other?
That is what the characters in the play try to answer. It deliberately takes place in an unrealistic "afterlife": all three characters are dead, but get together - as they both decided not to do in real life, because trying to resolve it only made it worse - to try and work it out. They also fail to work it out in the play, but at least they explore it and at least each man gets his say.
Present in the conversation are, indirectly, the audience, who take the place of the Gestapo, and the people who subsequently interrogated Heisenberg for many years afterwards. Directly present is Bohr's wife Margrethe. In real life she and Niels were devoted to each other. She typed up all Bohr's papers and he plainly discussed all his research with her. She was less enthusiastic about Heisenberg than Bohr was, and discouraged her husband from allowing him to visit in 1941. The play opens with them debating whether or not to invite him, and they agree that he can come on the condition that they don't discuss politics. (But physics and politics, as Heisenberg remarks, are "painfully hard to separate".) Her presence requires the two physicists to use "plain language", so the audience can understand the science; and she disbelieves most of Heisenberg's explanations. "Every time he explained it became more obscure."
Much of the play is told in a sort of monologue, the characters speaking to nobody and everybody simultaneously. "We operated like a business." "Chairman and managing director." "Father and son." "A family business." It sounds as if they are taking parts singing in a choir. During pauses in the conversation, they follow each other's thoughts: "Silence. And of course they're thinking about their children again." "The same bright things. The same dark things. Back and back they come." Many times the play returns to "the same moments I [Bohr] see every day" - his eldest son, Christian, drowning in a sailing accident. Apparently Bohr and Heisenberg could finish each other's sentences, and once you're used to it, it sounds like close relatives talking. At other times, they argue about the things they and the other scientists did in the past - "shoot" each other by beating each other to it writing papers, skiing, piano-playing, hiking, and Schrödinger's visit during which Heisenberg was angry and jealous and Bohr talked Schrödinger to the point of illness. These snippets are both hilarious and some real philosophy to chew on - "that particle that goes through two slits at the same time" being compared to skiing at 70 k.p.h, and making a decision about which way to swerve when necessary!
Even during the most heated moments of the play, Frayn can suddenly make me snort with laughter, by the two men knowing each other so well. "The speed he skis," Heisenberg remarks of Bohr, "he has to do something to keep the blood going round. It was either physics or frostbite." Later, Heisenberg challenges the Bohrs to murder him as an enemy, adding that this would not be immoral in a war, and that all they have to do is tell someone what he said. At white heat, Bohr interrupts: "My dear Heisenberg, the suggestion is . . ." "Most interesting. So interesting that it never even occurred to you." Bohr was famous for saying "this is most interesting". Frayn brings it out very well how widely Bohr was loved. He has the characters mention that Bohr was dubbed "the Pope" by his students, that it is impossible for anyone to accuse him of ever having done anything wrong. I get the feeling that whatever Heisenberg hoped to gain from the Copenhagen meeting, Bohr's kindness would have been a real encouragement to go ahead with it.
That closeness, I think, is the tragedy - that for seventeen years that there was this special cooperation, the shared excitement and science and walking and talking - and then, because of the war, it died.
There is strangeness. There are differences between the characters and the real people, of course. There is eerie unease when they can't agree on what they said or where, or who did what during their science. Some of things they say sound odd. It particularly struck me early on, when Heisenberg has, in their memories, just arrived at the Bohrs' house in 1941. Bohr says: "I believe you had some personal trouble . . . I'm so sorry." It took a few reads of the commentary to establish that this meant Heisenberg had been interrogated by the Nazis for teaching "Jewish physics" (i.e. relativity). He was accused of being a "White Jew" and forbidden ever to mention Einstein in his lectures. Heisenberg's reaction is very odd: "A slight misunderstanding . . . These things happen. The question is now resolved. Happily resolved . . ." Surely he wasn't happy about it. He was still treated with suspicion, and he could hardly have been anti-Semitic or happy with the persecution taking place. In 1933, when Hitler came to power, Hans Geiger dismissed Hans Bethe from his post as assistant without the slightest regret, and Heisenberg offered Bethe a job despite the dangers he must have known this would bring. Bethe sensibly refused and went to work in the USA.
It is so obvious it is almost a cliche that Heisenberg's life, aims and activities are rather a parallel to his legacy, uncertainty. Michael Frayn is clearly fascinated by human motivation. (I read a linguistics book when I was 15 and have since been used to the idea that we have a dozen different motivations at a time for every word we say.) Frayn wrote: "He wanted to distance himself from the Nazis, but didn't want to suggest that he had been a traitor. He was reluctant to claim to his fellow-Germans that he had deliberately lost the war, but he was no less reluctant to suggest that he had failed them simply out of incompetence." Robert Butler, writing in the commentary of the student edition, points out, "The position for many 'good Germans' was that they wanted Germany to win the war and Hitler to lose it."
This is not enough for many critics of the play. Frayn writes two postscripts, in which he baldly details the criticisms, accepting some and refuting others. (He writes with the confidence of one whose work is good enough that he need not really fear any criticism.) There are many, but just as I can't mention every point in the play I liked without this blog post ending up the size of the Encyclopedia Britannicca and spoiling too much of the plot for you, I won't go through them all. I will mention the one I thought was silliest, though: apparently, there were loud calls for more condemnation of the Nazis. As Frayn points out, the evil of the Nazi regime is "a given". For goodness sake, we don't need yet another sermon on what we don't need telling; the physics and the ethical debates and the mixed-up memories are far more fresh and exciting!
Personally I think it's a sort of trendy modern hysteria. Few people alive today remember the war, so we don't know quite what it was like and therefore whether it might happen again. It's not reality to us, it's a nightmare. It must be fended off. Sadly, people are so worried about what other people think of them that one can't even mention the war without ritual condemnation of the Nazis! Tell me honestly, do you really think that unless someone goes out of their way to state otherwise, they're pro-Holocaust? An old friend of mine accused me of sounding so simply for using the word "Jewish", not in a remotely derogatory way. In my father's school days it was quite acceptable to mention the fact that someone was Jewish; it was like mentioning that I wear glasses or that Spain is sunny. (One of the mostly-Jewish school football teams dubbed themselves "The Smelly Yids"!) Another friend of mine was once warned never even to say "black coffee". Oh, and when discussing schoolkids with one another, teachers who wish to avoid trouble must say "pupil", not "boy" or "girl", because apparently any assumptions that might be made are more important than the actual information they wish to give or obtain.
I think this is wicked. To forbid mention of someone's culture and heritage is to deny them a face. It's also to subtly imply that there is something wrong with their gender or nationality or what have you, but that you personally are too smugly refined to say so. And similarly, to assume everybody guilty of sympathy with the Holocaust unless they go on and on about it is to contribute to another culture of suspicion.
(Mealy-mouthed-ness - using the correct words, or not - doesn't mean anything, anyway. Genocide goes on today and not only do we not do any more about it than we did for the Jews during the war - I doubt the victims of Darfur for example will get another country to live in - we daren't mention the fact that it does. As Amnesty International pointed out the other day, it's inadvisable to use the word "genocide" even during an admission that it is actually taking place. I'm not kidding about people "not having a face", either, or why would there have been those two films a few years ago about the "human sides" of Hitler and Jesus? Because people are so silly they actually need proof that every human has a "human side". How babyish.)
Getting back to the play, I also hugely admire Frayn's attempt to tackle very difficult science. He describes himself in the postscript as "a non-scientist" who "can't offer any opinion on the physics". He was certainly braver than the newspaper reviewers. Butler offers seven reviews mentioning the reviewer's own ignorance of science and fear that they needed a physics qualification to understand the play - fears which were mostly dispelled, it seems. It's sad that people are frightened of science. I hope citizen science will help put an end to that; we wouldn't be frightened of a play about art or music. Frayn's ability to have the characters talk understandably, but as scientists, about fission, neutrons, and quantum physics, is brilliant. He has a glossary of some of the lines used at the end of the book. For "that particle", he makes a double joke: "One of the mind-bending aspects of quantum mechanics is that when a particle is faced with the choice of going through one of two slits it appears to go through both of them. (Don't ask.)" Because, of course, "asking" - or using light to "see" the particle - would deflect its path anyway!
* * *
Frayn's masterpiece intrigued me enough to get Thomas Powers's "Heisenberg's War: The Secret History of the German Bomb". It seems impossible to get what is politically correctly termed "a balanced view" - Heisenberg has attackers and defenders. P. L. Rose's book, "Heisenberg and the Nazi Atomic Bomb Project, 1939-1945: A Study in German Culture", for example, is an attack, if that is more to your taste.
Now, like the mealy-mouthed folks I criticise, I wasn't there during the war. But I have a relative who's lived in a terrifying dictatorship abroad, and I'm a history fanatic and an Isabel Allende fan, and like most people I've had the odd instance where I've had to be sly to win a fight because to open my mouth too wide would have been disastrous - so I don't consider myself totally ignorant. I feel an intense admiration for and sympathy with Frayn's Heisenberg, and I think the things his fellow physicists and historians feel he should have done were not actually any better than what he did.
We come to a major question now, which I had never really considered before: Why didn't the Germans manage to build a bomb?
When I was younger I assumed it was simply that America was more powerful and advanced. As one learns more, one finds out that Germany had been bursting with impressive physicists - but the expulsion of the Jews, such as Einstein, sent the brains off to America and brought poetic justice. What about the physicists who stayed in Germany? One physicist, Weizsäcker, stated: "History will record that . . . the peaceful development of the uranium engine was made in Germany under the Hitler regime, whereas the Americans and the English developed this ghastly weapon of war."
Hardly. Take this review by Ian Kaplan: "Those [physicists] who remained in Germany fell into one of three categories: (1) they were Nazis, like Nobel Prize winner Johannes Stark; (2) they could not leave, for what ever reason, or (3) they were selectively blind to the regime around them and its implications . . . The evidence of the Farm Hall transcripts is morally damning. Heisenberg and his colleagues knew about the murder going on around them, but they still worked on the German nuclear program. They did not build a nuclear weapon because they did not know how."
Perhaps there was a fourth reason for not leaving Germany: that one's family and friends and students and fellow countrymen were there too, and one does not abandon all these people lightly. Do we call on all Americans to emigrate if they disapprove of the Iraq war or Guantanamo? Am I going to condemn myself to exile over Ian Tomlinson? No, there are people here besides the police and the government, and I'd rather stay and work here with them. Exile is not a happy future. If the scientists had all left, Nazis would have been put in their places anyway, and then goodness knows what would have happened.
It is possible that the scientists did not know how to build a nuclear weapon; Heisenberg claims that he had some idea, though he had actually got several points wrong. But perhaps - and if you think about it, this isn't as pathetic an excuse as it sounds - they did not want to know. Towards the end of Allende's first novel, "The House of the Spirits", a Communist in danger of being murdered by Pinochet's soldiers explains to his lover that he cannot tell her where he hides: "If they find you, it's better if you don't know anything." The German project, when found by the Allies, turned out to be very primitive, and they claimed they only wished for an energy source. If this is true, one can hardly blame them for wanting that much. People were starving and freezing.
Heisenberg claims in the play that he had hoped that physicists across the world could collectively refuse to build atomic bombs, and then mankind would be safe from the worst of destruction. This was a futile hope. There was no way the Allies would agree to that, and his team could hardly tell Hitler later that they refused to cooperate. But I got interested enough to Google the transcripts from Farm Hall, the house in which ten physicists including Heisenberg were imprisoned (though very well treated) for six months, and their horrified reactions after they heard about Hiroshima are hardly "morally damning":
HAHN: . . . For [Uranium-93] they must have an engine which will run for a long time. If the Americans have a uranium bomb then you’re all second-raters. Poor old Heisenberg.
LAUE: The innocent!
HEISENBERG: Did they use the word uranium in connection with this atomic bomb?
ALL: No. . .
HEISENBERG: Then it’s got nothing to do with atoms, but the equivalent of 20,000 tons of high explosive is terrific. . .
HAHN: At any rate, Heisenberg, you’re just second-raters and you may as well pack up.
HEISENBERG: I quite agree.
HAHN: They are fifty years further advanced than we.
. . .
WEIZSÄCKER: I don’t think it has anything to do with uranium. . .
HEISENBERG: I don’t believe that it has anything to do with uranium. . .
. . .
WEIZSÄCKER: I think it’s dreadful of the Americans to have done it. I think it is madness on their part.
HEISENBERG: One can’t say that. One could equally well say, "That’s the quickest way of ending the war."
HEISENBERG: We wouldn’t have had the moral courage to recommend to the Government in the spring of 1942 that they should employ 120,000 men just for building the thing up.
WEIZSÄCKER: I believe the reason we didn’t do it was because all the physicists didn’t want to do it on principle. If we had all wanted Germany to win the war we would have succeeded.
HAHN: I don’t believe that. But I am thankful we didn’t succeed.
. . .
KORSCHING: If one hasn't got the courage, it would have been better to give up straightaway.
[At this point, Gerlach, at who this remark was aimed, stormed out and was later found weeping in his room. Meanwhile the debate continued:]
DIEBNER: [The Reich authorities were only interested in immediate results.] They didn't want to work on a long-term policy as America did.
WEIZSÄCKER: We were all convinced that the thing [bomb or reactor? Nobody knows] could not be completed during this war.
HEISENBERG: Well, that's not quite right. I would say that I was absolutely convinced of the possibility of our making an uranium engine but I never thought that we would make a bomb
and at the bottom of my heart I was really glad that it was to be a Maschine and not a bomb. I must admit that.
WEIZSÄCKER: If you had wanted to make a bomb we would probably have concentrated more on the separation of isotopes and less on heavy water.
Why are they discussing what they are thinking now? Why not while they were working together? Well, it's suicidal to say exactly what you think in a dictatorship or war. You don't know if your neighbour might turn you over to the authorities. They were probably all trying to guess what all the others were thinking; Diebner, in "Copenhagen", is criticised as having "ten times my [Heisenberg's] eagerness [to build a bomb]". But after the bomb had exploded, they knew they had lost. It was too late, they had no more to lose now.
In "Copenhagen", Gerlach is described as "our old Government administrator". He does not seem to have been a Nazi, but was afraid of what might happen to him if he returned to Germany now, and felt responsible for the defeat and deaths of his fellow Germans. Otto Hahn, as Heisenberg said, "wants to kill himself, because it was he who invented fission, and he can see the blood on his hands". He had contemplated suicide years before when he realised what fission could do. Major Rittner, their host/warder, and the other physicists, were very worried about Hahn that night, but Hahn also found time to comfort Gerlach:
HAHN: Are you upset because we did not make the uranium bomb? I thank God on my bended knees that we did not make an uranium bomb. Or are you depressed because the Americans could do it better than we could?
Powers states at the beginning of his book that the American scientists feel no guilt at working on the atomic bomb, and Frayn reiterates this in his play - Margrethe asks incredulously, "You're not implying that there's anything Niels needs to explain or defend?" - though he later cites two Americans, including Oppenheimer, feeling revulsion at what their weapon has done. But the German scientists appear to be condemned for both having a project to do, and for failing to complete it. "Hands that had actually worked on the bomb wouldn't touch mine," Heisenberg laments in the play.
I still admit there's a lot I don't know, and I must find the courage to read the critical literature as well as the supportive. But I will say one last thing: those who judge Heisenberg and the other physicists harshly might like to read the Göttingen Manifesto.