Bohr Plain language. All right, so here we are, walking along the street once more. And this time I’m absolutely calm, I’m listening intently. What is it you want to say?
Heisenberg It’s not just what I want to say! The whole German nuclear team in Berlin! Not Diebner, of course, not the Nazis—but Weizsäcker, Hahn, Wirtz, Jensen, Houtermanns—they all wanted me to come and discuss it with you. We all see you as a kind of spiritual father.
Margrethe The Pope. That’s what you used to call Niels behind his back. And now you want him to give you absolution.
Heisenberg Absolution? No!
Margrethe According to your colleague Jensen.
Heisenberg Absolution is the last thing I want!
Margrethe You told one historian that Jensen had expressed it perfectly.
Heisenberg Did I? Absolution .… Is that what I’ve come for? It’s like trying to remember who was at that lunch you gave me at the Institute. Around the table sit all the different explanations for everything I did. I turn to look … Petersen, Rozental, and … yes … now the word absolution is taking its place among them all …
Margrethe Though I thought absolution was granted for sins past and repented, not for sins intended and yet to be committed.
Heisenberg Exactly! That’s why I was so shocked!
Bohr You were shocked?
Heisenberg Because you did give me absolution! That’s exactly what you did! As we were hurrying back to the house. You muttered something about everyone in wartime being obliged to do his best for his own country. Yes?
Bohr Heaven knows what I said. But now here I am, profoundly calm and conscious, weighing my words. You don’t want absolution. I understand. You want me to tell you not to do it? All right. I put my hand on your arm. I look you in the eye in my most papal way. Go back to Germany, Heisenberg. Gather your colleagues together in the laboratory. Get up on a table and tell them: ‘Niels Bohr says that in his considered judgment supplying a homicidal maniac with an improved instrument of mass murder is …’ What shall I say? ‘ … an interesting idea.’ No, not even an interesting idea. ‘ … a really rather seriously uninteresting idea.’ What happens? You all fling down your Geiger counters?
Heisenberg Obviously not.
Bohr Because they’ll arrest you.
Heisenberg Whether they arrest us or not it won’t make any difference. In fact it will make things worse. I’m running my programme for the Kaiser Wilhelm Institute. But there’s a rival one at Army Ordnance, run by Kurt Diebner, and he’s a party member. If I go they’ll simply get Diebner to take over my programme as well. He should be running it anyway. Wirtz and the rest of them only smuggled me in to keep Diebner and the Nazis out of it. My one hope is to remain in control.
Bohr So you don’t want me to say yes and you don’t want me to say no.
Heisenberg What I want is for you to listen carefully to what I’m going on to say next, instead of running off down the street like a madman.
Bohr Very well. Here I am, walking very slowly and popishly. And I listen most carefully as you tell me …
Heisenberg That nuclear weapons will require an enormous technical effort.
Bohr True.
Heisenberg That they will suck up huge resources.
Bohr Huge resources. Certainly.
Heisenberg That sooner or later governments will have to turn to scientists and ask whether it’s worth committing those resources—whether there’s any hope of producing the weapons in time for them to be used.
Bohr Of course, but …
Heisenberg Wait. So they will have to come to you and me. We are the ones who will have to advise them whether to go ahead or not. In the end the decision will be in our hands, whether we like it or not.
Bohr And that’s what you want to tell me?
Heisenberg That’s what I want to tell you.
Bohr That’s why you have come all this way, with so much difficulty? That’s why you have thrown away nearly twenty years of friendship? Simply to tell me that?
Heisenberg Simply to tell you that.
Bohr But, Heisenberg, this is more mysterious than ever! What are you telling it me for? What am I supposed to do about it? The government of occupied Denmark isn’t going to come to me and ask me whether we should produce nuclear weapons!
Heisenberg No, but sooner or later, if I manage to remain in control of our programme, the German government is going to come to me! They will ask me whether to continue or not! I will have to decide what to tell them!
Bohr Then you have an easy way out of your difficulties. You tell them the simple truth that you’ve just told me. You tell them how difficult it will be. And perhaps they’ll be discouraged. Perhaps they’ll lose interest.
Heisenberg But, Bohr, where will that lead? What will be the consequences if we manage to fail?
Bohr What can I possibly tell you that you can’t tell yourself?
Heisenberg There was a report in a Stockholm paper that the Americans are working on an atomic bomb.
Bohr Ah. Now it comes, now it comes. Now I understand everything. You think I have contacts with the Americans?
Heisenberg You may. It’s just conceivable. If anyone in Occupied Europe does it will be you.
Bohr So you do want to know about the Allied nuclear programme.
Heisenberg I simply want to know if there is one. Some hint. Some clue. I’ve just betrayed my country and risked my life to warn you of the German programme …
Bohr And now I’m to return the compliment?
Heisenberg Bohr, I have to know! I’m the one who has to decide! If the Allies are building a bomb, what am I choosing for my country? You said it would be easy to imagine that one might have less love for one’s country if it’s small and defenceless. Yes, and it would be another easy mistake to make, to think that one loved one’s country less because it happened to be in the wrong. Germany is where I was born. Germany is where I became what I am. Germany is all the faces of my childhood, all the hands that picked me up when I fell, all the voices that encouraged me and set me on my way, all the hearts that speak to my heart. Germany is my widowed mother and my impossible brother. Germany is my wife. Germany is our children. I have to know what I’m deciding for them! Is it another defeat? Another nightmare like the nightmare I grew up with? Bohr, my childhood in Munich came to an end in anarchy and civil war. Are more children going to starve, as we did? Are they going to have to spend winter nights as I did when I was a schoolboy, crawling on my hands and knees through the enemy lines, creeping out into the country under cover of darkness in the snow to find food for my family? Are they going to sit up all night, as I did at the age of seventeen, guarding some terrified prisoner, talking to him and talking to him through the small hours, because he’s going to be executed in the morning?
Bohr But, my dear Heisenberg, there’s nothing I can tell you. I’ve no idea whether there’s an Allied nuclear programme.
Heisenberg It’s just getting under way even as you and I are talking. And maybe I’m choosing something worse even than defeat. Because the bomb they’re building is to be used on us. On the evening of Hiroshima Oppenheimer said it was his one regret. That they hadn’t produced the bomb in time to use on Germany.
Bohr He tormented himself afterwards.
Heisenberg Afterwards, yes. At least we tormented ourselves a little beforehand. Did a single one of them stop to think, even for one brief moment, about what they were doing? Did Oppenheimer? Did Fermi, or Teller, or Szilard? Did Einstein, when he wrote to Roosevelt in 1939 and urged him to finance research on the bomb? Did you, when you escaped from Copenhagen two years later, and went to Los Alamos?
Bohr My dear, good Heisenberg, we weren’t supplying the bomb to Hitler!
Heisenberg You weren’t dropping it on Hitler, either. You were dropping it on anyone who was in reach. On old men and women in the street, on mothers and their children. And if you’d produced it in time they would have been my fellow-countrymen. My wife. My c
hildren. That was the intention. Yes?
Bohr That was the intention.
Heisenberg You never had the slightest conception of what happens when bombs are dropped on cities. Even conventional bombs. None of you ever experienced it. Not a single one of you. I walked back from the centre of Berlin to the suburbs one night, after one of the big raids. No transport moving, of course. The whole city on fire. Even the puddles in the streets are burning. They’re puddles of molten phosphorus. It gets on your shoes like some kind of incandescent dog-muck—I have to keep scraping it off—as if the streets have been fouled by the hounds of hell. It would have made you laugh—my shoes keep bursting into flame. All around me, I suppose, there are people trapped, people in various stages of burning to death. And all I can think is, How will I ever get hold of another pair of shoes in times like these?
Bohr You know why Allied scientists worked on the bomb.
Heisenberg Of course. Fear.
Bohr The same fear that was consuming you. Because they were afraid that you were working on it.
Heisenberg But, Bohr, you could have told them!
Bohr Told them what?
Heisenberg What I told you in 1941! That the choice is in our hands! In mine—in Oppenheimer’s! That if I can tell them the simple truth when they ask me, the simple discouraging truth, so can he!
Bohr This is what you want from me? Not to tell you what the Americans are doing but to stop them?
Heisenberg To tell them that we can stop it together.
Bohr I had no contact with the Americans!
Heisenberg You did with the British.
Bohr Only later.
Heisenberg The Gestapo intercepted the message you sent them about our meeting.
Margrethe And passed it to you?
Heisenberg Why not? They’d begun to trust me. This is what gave me the possibility of remaining in control of events.
Bohr Not to criticise, Heisenberg, but if this is your plan in coming to Copenhagen, it’s … what can I say? It’s most interesting.
Heisenberg It’s not a plan. It’s a hope. Not even a hope. A microscopically fine thread of possibility. A wild improbability. Worth trying, though, Bohr! Worth trying, surely! But already you’re too angry to understand what I’m saying.
Margrethe No—why he’s angry is because he is beginning to understand! The Germans drive out most of their best physicists because they’re Jews. America and Britain give them sanctuary. Now it turns out that this might offer the Allies a hope of salvation. And at once you come howling to Niels begging him to persuade them to give it up.
Bohr Margrethe, my love, perhaps we should try to express ourselves a little more temperately.
Margrethe But the gall of it! The sheer, breathtaking gall of it!
Bohr Bold skiing, I have to say.
Heisenberg But, Bohr, we’re not skiing now! We’re not playing table-tennis! We’re not juggling with cap-pistols and non-existent cards! I refused to believe it, when I first heard the news of Hiroshima. I thought that it was just one of the strange dreams we were living in at the time. They’d got stranger and stranger, God knows, as Germany fell into ruins in those last months of the war. But by then we were living in the strangest of them all. The ruins had suddenly vanished—just the way things do in dreams—and all at once we’re in a stately home in the middle of the English countryside. We’ve been rounded up by the British—the whole team, everyone who worked on atomic research—and we’ve been spirited away. To Farm Hall, in Huntingdonshire, in the water-meadows of the River Ouse. Our families in Germany are starving, and there are we sitting down each evening to an excellent formal dinner with our charming host, the British officer in charge of us. It’s like a pre-war house-party—one of those house-parties in a play, that’s cut off from any contact with the outside world, where you know the guests have all been invited for some secret sinister purpose. No one knows we’re there—no one in England, no one in Germany, not even our families. But the war’s over. What’s happening? Perhaps, as in a play, we’re going to be quietly murdered, one by one. In the meanwhile it’s all delightfully civilised. I entertain the party with Beethoven piano sonatas. Major Rittner, our hospitable gaoler, reads Dickens to us, to improve our English .… Did these things really happen to me …? We wait for the point of it all to be revealed to us. Then one evening it is. And it’s even more grotesque than the one we were fearing. It’s on the radio: you have actually done the deed that we were tormenting ourselves about. That’s why we’re there, dining with our gracious host, listening to our Dickens. We’ve been kept locked up to stop us discussing the subject with anyone until it’s too late. When Major Rittner tells us I simply refuse to believe it until I hear it with my own ears on the nine o’clock news. We’d no idea how far ahead you’d got. I can’t describe the effect it has on us. You play happily with your toy cap-pistol. Then someone else picks it up and pulls the trigger … and all at once there’s blood everywhere and people screaming, because it wasn’t a toy at all .… We sit up half the night, talking about it, trying to take it in. We’re all literally in shock.
Margrethe Because it had been done? Or because it wasn’t you who’d done it?
Heisenberg Both. Both. Otto Hahn wants to kill himself, because it was he who discovered fission, and he can see the blood on his hands. Gerlach, our old Nazi co-ordinator, also wants to die, because his hands are so shamefully clean. You’ve done it, though. You’ve built the bomb.
Bohr Yes.
Heisenberg And you’ve used it on a living target.
Bohr On a living target.
Margrethe You’re not suggesting that Niels did anything wrong in working at Los Alamos?
Heisenberg Of course not. Bohr has never done anything wrong.
Margrethe The decision had been taken long before Niels arrived. The bomb would have been built whether Niels had gone or not.
Bohr In any case, my part was very small.
Heisenberg Oppenheimer described you as the team’s father-confessor.
Bohr It seems to be my role in life.
Heisenberg He said you made a great contribution.
Bohr Spiritual, possibly. Not practical.
Heisenberg Fermi says it was you who worked out how to trigger the Nagasaki bomb.
Bohr I put forward an idea.
Margrethe You’re not implying that there’s anything that Niels needs to explain or defend?
Heisenberg No one has ever expected him to explain or defend anything. He’s a profoundly good man.
Bohr It’s not a question of goodness. I was spared the decision.
Heisenberg Yes, and I was not. So explaining and defending myself was how I spent the last thirty years of my life. When I went to America in 1949 a lot of physicists wouldn’t even shake my hand. Hands that had actually built the bomb wouldn’t touch mine.
Margrethe And let me tell you, if you think you’re making it any clearer to me now, you’re not.
Bohr Margrethe, I understand his feelings …
Margrethe I don’t. I’m as angry as you were before! It’s so easy to make you feel conscience-stricken. Why should he transfer his burden to you? Because what does he do after his great consultation with you? He goes back to Berlin and tells the Nazis that he can produce atomic bombs!
Heisenberg But what I stress is the difficulty of separating 235.
Margrethe You tell them about plutonium.
Heisenberg I tell some of the minor officials. I have to keep people’s hopes alive!
Margrethe Otherwise they’ll send for the other one.
Heisenberg Diebner. Very possibly.
Margrethe There’s always a Diebner at hand ready to take over our crimes.
Heisenberg Diebner might manage to get a little further than me.
Bohr Diebner?
Heisenberg Might. Just possibly might.
Bohr He hasn’t a quarter of your ability!
Heisenberg Not a tenth of it. But he has ten times the eagerness t
o do it. It might be a very different story if it’s Diebner who puts the case at our meeting with Albert Speer, instead of me.
Margrethe The famous meeting with Speer.
Heisenberg But this is when it counts. This is the real moment of decision. It’s June 1942. Nine months after my trip to Copenhagen. All research cancelled by Hitler unless it produces immediate results—and Speer is the sole arbiter of what will qualify. Now, we’ve just got the first sign that our reactor’s going to work. Our first increase in neutrons. Not much—thirteen per cent—but it’s a start.
Bohr June 1942? You’re slightly ahead of Fermi in Chicago.
Heisenberg Only we don’t know that. But the RAF have begun terror-bombing. They’ve obliterated half of Lübeck, and the whole centre of Rostock and Cologne. We’re desperate for new weapons to strike back with. If ever there’s a moment to make our case, this is it.
Margrethe You don’t ask him for the funding to continue?
Heisenberg To continue with the reactor? Of course I do. But I ask for so little that he doesn’t take the programme seriously.
Margrethe Do you tell him the reactor will produce plutonium?
Heisenberg I don’t tell him the reactor will produce plutonium. Not Speer, no. I don’t tell him the reactor will produce plutonium.
Bohr A striking omission, I have to admit.
Heisenberg And what happens? It works! He gives us barely enough money to keep the reactor programme ticking over. And that is the end of the German atomic bomb. That is the end of it.
Margrethe You go on with the reactor, though.
Heisenberg We go on with the reactor. Of course. Because now there’s no risk of getting it running in time to produce enough plutonium for a bomb. No, we go on with the reactor all right. We work like madmen on the reactor. We have to drag it all the way across Germany, from east to west, from Berlin to Swabia, to get it away from the bombing, to keep it out of the hands of the Russians. Diebner tries to hijack it on the way. We get it away from him, and we set it up in a little village in the Swabian Jura.
Bohr This is Haigerloch?
Heisenberg There’s a natural shelter there—the village inn has a wine-cellar cut into the base of a cliff. We dig a hole in the floor for the reactor, and I keep that programme going, I keep it under my control, until the bitter end.
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