15 October 2012

PLOT AGAINST HITLER

(Atomic fantasy in 2 acts)

All characters are invented. Any similarity with historical events is purely incidental.

Eduard Roth

1 .

2 ACT I: THE WAR YEARS

Main characters

WERNER HEISENBERG: German physicist NIELS BOHR: Danish physicist ALBRECHT SPEER: German minister for armament KURT DIEBNER: Phycisist in charge of the nazi atomic program HENDRIK CASIMIR: Dutch physicist

ROBERT OPPENHEIMER: Physicist in charge of american atomic program ROBERT SERBER: collaborator of Oppenheimer HANS BETHE: collaborator of Oppenheimer GENERAL GROVES: general in charge of american atomic program MERKADA: Argentinian physicist working in the nazi atomic program HORST KORSCHING: collaborator of Heisenberg

GENERAL BECK: German general in charge of the plot against Hitler COUNT STAUFFENBERG: German colonel in charge of killing Hitler GENERAL VON KLUGE: Commander of german armies in France GENERAL VON STUPNAGEL:¨ collaborator of the former COLONEL VON HOFACKER: collaborator of the former

PAUL SCHERRER: Swiss physicist CIA AGENT: member of the american secret services GREGOR WENTZEL: German physicist

3 Scene 1 - Copenhaguen - 15 september 1941, morning - Seminar room of Niels Bohr Institute (full of hidden microphones) - Present: Heisenberg and audience.

Heisenberg: Alone in Copenhaguen and far from dark zipped eyes, I weep in my outcast state and curse my fate. I wish I could be like you, with friends possess’d and from dark earth I sing this hymn at heaven:

If west would join anzip And Russia could defeat Anzip would plot against nazip Forces of the west unite And with anzip collaborate

Audience: Heisenberg, you dont know what you are saying ! You are totally crazy ! You are the victim of the nazi madness ! Heisenberg: I am anzip. Audience: Nazi ! Traitor !

Note: nazip=nazi, anzip=antinazi, zip=svastica. Heisenberg wants to re- move Hitler from power and make an alliance between a democratic Germany and western countries against Russia.

Scene 2 - Copenhaguen - 15 september 1941, afternoon - Close to Bohr’s house - Present: Heisenberg and Bohr.

Heisenberg: Niels, look at this plot. We are designing at Dahlem a uranium reactor with heavy water. Bohr: Werner, I dont want to know anything about it. Heisenberg: Just take a look. Bohr: Werner, you already destroyed France, Holland, the Balkans. Now you want to destroy Russia ! And what then, the whole world ? Heisenberg: You should take a look and deliver the plot to your foreign friends.

4 Bohr: Werner, you are mad ! mad !

Note: Heisenberg wants to contact the Allies and make a deal: he will only de- velop a uranium reactor but the Allies must not attack Germany with atomic bombs, in case they succeed to fabricate them. Niels Bohr rejects the project of Heisenberg because the deal implies an alliance against Russia, and Bohr is very left-wing oriented. The invasion of Russia started in june 1941. The Americans will enter the war in december 1941.

Scene 3 - Berlin, Reich Chancellery, Wilhelmst. - February 1942 - Present: Speer, Heisenberg and Diebner.

Heisenberg: There are two uranium isotopes, 238 and 235. The first is abso- lutely dominant nowadays but it used not to be so in the past. The second is nowadays scarce. However, if a critical mass of 235 is achieved, it can produce an enormous explosion and destroy a large town. Speer: How much 235 is required ? Heisenberg: Only a very small and well determined quantity. Speer: So we go ahead. Which name for the project ? Heisenberg: Uranverein.

Note: Heisenberg wants money to construct a reactor (he calls it an ’engine’), but tries to sell it to the minister of armement as a bomb to get the money.

Scene 4 - Eindhoven, Philips Laboratories - October 1943 - Present: Heisenberg and Casimir.

Heisenberg: It has always been the historic mission of Germany to defend the West and its culture against the hordes of the Eastern. Neither France nor

5 England have been sufficiently strong to play a leading role in such a defense and so, perhaps a Europe under german leadership might be the lesser evil. Casimir: I cant believe what you said, Werner. Can you repeat it in German ? Heisenberg: Da w¨are vielleicht doch ein Europa unter deutscher F¨uhrung das kleinere Ubel.¨ Casimir: Did you make a pact with the Devil, Werner ? Heisenberg: No need Henk, Ich bin das kleinere Ubel.¨

Note: There are several famous ambiguous statements by Heisenberg that can be misinterpreted and suggest that he is a nazi. But it is obvious that he is not a nazi as can be demonstrated later. The origin of these misunderstanding is that Heisenberg is very anticommunist and does not want to see Germany invaded by the Russians.

Scene 5 - Oppenheimer’s office at Los Alamos - unspecified day in December 1943 (morning) - Present: Oppenheimer (Opie), Serber (Roby) and Bethe (Ansi).

Roby: Hello Opie, What are the news ? Opie: Look at this drawing (see figure 1). It slipped out of Niel’s pocket yesterday. Roby: It looks like a bottle of cognac. Opie: Cant be. Look at the letter z. It must be anis, it was called ouzo in ancient greek. Roby: What about a bottle of porto ? Opie: Not possible. The shape is certainly a novel late vintage, like those in my bar, but there is no z in the translation to any hindustanic, semitic or arabic language. Roby: What about xerez ? there is a z and it looks spanish. Opie: Very good guess, but you know very well that Spain is occupied by the fascists and Niels would never drink xerez under these circumstances. Ansi: Guys, this is a heavy water reactor. I just did my calculation on the

6 back of an envelop. It will never produce enough fast neutrons to yield a nuclear explosion.

D O 2

z

Z

Figure 1: Bohr’s plot.

Scene 6 - Oppenheimer’s office at Los Alamos - same day as before (afternoon) - Present: Oppenheimer, Groves.

Groves: Doctor, can you explain to me the meaning of this plot ? Oppenheimer: General, this is a false fission reactor. Groves: How should we call it ? Oppenheimer: Call it falsos, that means groves in ancient greek. Groves: That sounds good, ‘Falsos Mission’. Oppenheimer: Yes, but never say I passed you this name. Groves: Doctor, you are a genius. I swear I will never put in doubt your loyalty.

7 Note: The Americans understand that Heisenberg is only trying to construct a reactor and not a bomb, but they want to be sure by sending a spy to inspect the german atomic sites.

Scene 7 - Berlin, Kaiser Wilhelm Institute, Dahlem - January 1944 - Present: Heisenberg, Merkada (Mercader), Korsching

Heisenberg: So you come from Argentina. Merkada: Yes, from University of La Plata. Heisenberg: A funny name for an Argentinian. Merkada: In reality I come from Palo Alto (Stanford). Heisenberg: And you work with professor Rolenz (Lawrence)? Merkada: Yes, on separation of U-235 with a spectrometer. Heisenberg: What a coincidence, we have a spectrometer too. Merkada: May have a look at it ? Heisenberg: Sure, make a tour with my talented young colleague Host Ko- rsching. But dont forget to pay him 500 000 pesetas and give to him a good position at La Plata at the end of the war. Merkada: Thanks a lot. I will inform about your hospitality the argentinian ambassador in Madrid. (possibly this was the nickname of Colonel Hohen- thal, The american spy chief in Spain)

Note: The University of La Plata had no interest in atomic physics at the time. The presence of an argentinian physicist coming from La Plata Uni- versity to inspect the german atomic sites is certified by the Farm Hall tran- scripts. Most probably he is a spy sent by the Americans to confirm that Heisenberg is not trying to build a bomb.

8 Scene 8 - Meeting of the Bavarianvereingemainesanzip (BVGA) - - Unspecified day in 1943 (but it was a wednesday) - Present: Heisenberg, Beck, Stauffenberg

Beck: So today we are talking again about chimpanski ? Heisenberg: Naturlich, Herr General ! Beck: Did you succeed to complete your calculations ? Heisenberg: The energy in the sun is very complicated to calculate, Herr Gen- eral ! That needs to be renormalized. There are infinities of higher orders. What are the news from Erwin Rommel? Beck: He will join us as agreed.

Note: General Beck was in charge of a plan to kill Hitler (nicknamed ’chim- panski’). The conspirators used to meet every two weeks on wednesday. Heisenberg used to attend these meetings and was therefore informed about the plans to kill Hitler. This demonstrates without any doubt that Heisenberg was an antinazi. Erwin Rommel was also involved in this plot as commented later.

Scene 9 - Meeting of the BVGA - Heisenberg’s house in Berlin - 19 july 1944 - Present: Heisenberg, Beck, Stauffenberg.

Beck: Werner, what’s your talk about ? Heisenberg: The production of energy in the stars. Beck: And the tittle ? Heisenberg: What are the stars. Beck: In German, please. Heisenberg: Was sindt die Sterne. Beck: Say it again, please. Heisenberg: iter ws Steren. Beck: Again, please. Heisenberg: Hitler muss sterben (Hitler must die).

9 Beck: OK, now you can go ahead.

(Heisenberg gives his talk) Beck: When do you leave for Haigerloch ? Heisenberg: Tomorrow morning, good luck.

(Heisenberg leaves for the Swiss border with telegrams from Scherrer in his pocket. His family is waiting for him.) note: next day, On July the 20th 1944, Stauffenberg tried unsuccessfully to kill Hitler by placing a bomb in the meeting room of his headquarters in Eastern Prussia. On july the 17th, Rommel was severily injuried by a plane attack in the front of Normandy. Rommel was supposed to transfer to Berlin by air troops from Normandy to take control the city. Rommel was replaced by general von Kluge who tried unsuccessfully to negociate with Eisenhower.

Scene 10 - Headquarters of the Supreme Field Commader West, in La Roche-Guyon, close to Paris - 20 july 1944 - Present: General in Chief of Army Group B Von Kluge, general Von St¨ulpnagel, colonel Von Hofacker.

St¨upnagel: I have already arrested all SS-units in Paris. Hofacker: You should mobilize your army against the nazis and contact im- mediately the Allies to negociate a cease-fire. Kluge: I can only do that wenn das Schwein tot w¨are.(If the pig is dead). Hofacker: Can you repeat that again ? Kluge: Wenn weisnchre sitot. Hofacker: Once more ? Kluge: Wenn Eisenhower stimmt (If Eisenhower agrees). Hofacker: OK, I understand now. St¨upnagel: What are the news from Berlin ? Kluge: Confusing. Keitel says Hitler is alive and Beck that he is dead.

10 Scene 11 - Video-conference between Berlin and Z¨urich. - Early 1944 - Present: Heisenberg, Scherrer.

Scherrer: Hello Werner, how is life in Berlin ? Heisenberg: Hello Paul, just a bit noisy at night and smoky during the day. Scherrer: If you knew, Werner, how peaceful life is is Switzerland ! By the way, did you receive my telegrams inviting you to come to Z¨urich ? Heisenberg: Yes Paul, its very kind. May I know the reason for these invita- tions ? Scherrer: We are really interested in your S-Matrix theory. I am sure the future of physics will depend on it. Heisenberg: I am very pleased to learn that, but you know I am essential here in Berlin for the plot of a new generator. Maybe I can escape next july.

Note: Paul Scherrer was a renowned physicist working at Zurich. He was both a good friend of Heisenberg and close to the american secret services in Switzerland. He was therefore the ideal contact between the Americans and Heisenberg.

Scene 12 - ETH, Z¨urich, Seminar room - 18 December 1944 (morning) - Present: Heisenberg, audience (mixture of nazi and CIA agents).

Heisenberg: (After drawing some plots on the blackboard, see figure 2) Now is the winter of our discontent made glorious summer by my S-matrix invention. When after so many cries I see the black zip evaporate And in front of so many spies Info is lost in outcast state I hoped that my own art Nazip, nazip could defeat While I fulfill my part Forcing my reactor to sleep

11 But brute force did prevail And I reached the fate That all my plots did fail They closed the only gate Wars only destruction bring Atomic power is the king

a s a nsch n m n a z S−Matrix l z S−Matrix o i i p a p k g e

Figure 2: Heisenberg’s plot (Anschlag=attempt to kill Hitler).

12 Scene 13 - Streets of Z¨urich - 18 December 1944 (afternoon) - Present: Heisenberg, CIA agent.

Heisenberg: Heischen. Agent: Berg. Heisenberg: Why no response to my messages ? Agent: Churchill said yes, Roosevelt said no. Heisenberg: Why sabotage of the heavy water ? Agent: Because of Roosevelt. Heisenberg: Bombings on Germany ? Agent: Only conventional. Heisenberg: F¨uhrer ? Agent: Grosse Ubel.¨ Heisenberg: F¨uhrung ? Agent: Kleine Ubel.¨ Heisenberg: Uran-Verein ? Agent: Safety guaranteed by Churchill and colonel Hohenthal. Heisenberg: Berk. Agent Eley.

Note: Sherrer organized a contact between Heisenberg and the american spy Morris Berg from OSS (Office of Strategic Sevices). Morris Berg attended the morning lecture by Heisenberg with a gun in his pocket. It’s a pure legend that he intended to kill Heisenberg during the lecture.

Scene 14 - Scherrer’s house in Z¨urich - 18 December 1944 (night) - Present: Heisenberg, Scherrer, Wentzel.

Heisenberg: I dont want to talk about politics. Just science, please. Scherrer: Yes, this was our agreement. Wentzel: But Werner, you should admit now that you have lost the war. Heisenberg: It would have been so beautiful If we had won !

13 Wentzel: I cant believe what you said, Werner, can you repeat that in Ger- man? Heisenberg: Es w¨are so sch¨on gewesen wenn wir gewonnen h¨atten. Wentzel: Again ? Heisenberg: DIE NAZIS haben den Krieg verloren. Es w¨are so sch¨on gewe- sen wenn WIR gewonnen h¨atten. (The NAZIS lost the war, it would have been so beautiful if we had won, UNDER THE COMMAND OF GENERAL BECK)

Note: Here again we have an ambiguous statement by Heisenberg that makes him look as a convinced nazi. The misunderstanding comes because he is very anticommunist and cannot accept that Germany is invaded by the Russians.

Scene 15 - Oppenheimer’s office at Los Alamos - June 1945 - Present: Oppenheimer, Groves.

Oppenheimer: Where are they, general ? Goves: In Dwight’s bin. Oppenheimer: Why such an ugly name for a beautiful house ? Goves: You have a better place, doctor ? Oppenheimer: Farm Hall. Goves: So False-Heisenberg-Operation ? Oppenheimer: Call it epsilon operation. Goves: I know you are a red, doctor. But I swear I will never betray you.

Note: At the end of the war, Heisenberg and seven other german physicists working in the german atomic program were detained in Farm Hall for six months. Otto Hahn and Max von Laue were added to complete the list of ten. The presence of these last two physicists is absurd: they were antinazis and had no relation with the german atomic program (just Hahn a little bit).

End of Act I

14 ACT II: THE FARM HALL TRANSCRIPTS

Main characters (Farm Hall detainees from july 3, 1945 until january 3, 1946)

WERNER HEISENBERG: German physicist, Nobel Laureate KURT DIEBNER: In charge of german atomic program PAUL HARTECK: Worked on german atomic program WALTER GERLACH: Replaced Diebner in 1944 ERICH BAGGE: Collaborator of Heisenberg HORST KORSCHING: Collaborator of Heisenberg KARL WIRTZ: Collaborator of Heisenberg CARL FRIEDRICH VON WEIZSACKER:¨ Collaborator of Heisenberg MAX VON LAUE: German physicist, Nobel Laureate OTTO HAHN: German chemist, Nobel Laureate at the end of 1945

All action takes place in Farm Hall, a bugged house in Godmanchester, Eng- land, near Cambridge.

Note: When in 1981 the historian of science Gerald Holton asked to see, for scholarly reasons, the Farm Hall transcripts, he received a reply from the Foreign Office saying: ‘It is, as you probably know, the general policy of the British Government, to release documents to the public 30 years after their date of origin. But there are exceptions, we do not release documents which contain information about individuals which could cause distress or embar- rassment to themselves or immediate descendents. I am afraid there can be no doubt that the Farm Hall transcripts fall into this category.’ On december 20, 1991, the Royal Society asked Lord Mackay to release the transcripts, which were finally released.

15 Scene 1 - 6 july 1945 - Present: Heisenberg and Diebner.

Diebner: I wonder whether there are microphones. Heisenberg: Oh no, they’re not as cute as that. They are not as the Gestapo. They are a little bit old fashioned. Diebner: What are they going to do with us ? Heisenberg: Of course it is possible they will agree to ask us whether we want to stay in England or go to America, but we cannot stay in Germany. Diebner: Why ? Heisenberg: They cannot take any risk that we fall in russian hands.

Scene 2 - 18 july 1945 - Present: Heisenberg, Witz and Harteck.

Heisenberg: If our colleagues who know something about the business - Goudsmit for instance- were clever, they would put another article in the newspaper about antinazis. It could start with Winston Churchill and colonel Hochenthal. Wirtz: Goldsmit doesn’t want to help us, he lost his parents. Harteck: Goudsmit cannot forget we killed his parents. Heisenberg: One day in 1943, I received a letter from Coster saying that Goudsmit’s parents were in great danger. I wrote a letter to Coster saying that ‘I would be very sorry if they experienced any difficulty in Holland’, but I admit, it was too late. Harteck: What happened then ? Heisenberg: When the letter arrived, they had already been deported. Wir haben nicht seine Eltern umgebracht, aber Hilfe angebracht haben. Harteck: Do you know of similar cases? Heisenberg: One day Scherrer wrote to me a letter saying that the mathe- matician Shouder leaving in the polish town of so-and-so was in great danger, under the false name of so-and-so. Of course the letter was opened by the Gestapo at the border and I never heard of Shouder any more. Wirtz: We murdered all Jews in Poland. Heisenberg: What could we do about it ?

16 Scene 3 - 21 july 1945 - Present: Bagge, Diebner, Korsching

Korsching: Well Diebner, we’ll go to Argentina. I know Merkada. He came to KWI and to Haigerloch and made detailed inspections of our installations. He came from La Plata. Nowadays you can also work in a uranium machine of your own at La Plata.(Merkada, or Mercader, the supposed argentinian physicist who inspected the german atomic sites, was possibly an american agent coming from Berkeley University and not from La Plata, an argentinian university without any interest in atomic physics). Bagge: We should approach the argentinian ambassador. Korsching: But not in England, you will only succeed with the argentinian ambassador in Madrid (colonel Hohenthal, the american spy chief in Madrid). If I go to La Plata, I will tell them: ‘I am a scientist, and I want to build a laboratory myself. It will cost 500 000 pesetas. Otherwise I can always work on cosmic rays.’ Bagge: Actually, you derived no benefit from your patent either. Korsching: Because I did not tell them it was a patent. It’s still now in Zehlendorf (Berlin) but hidden so the Russians can’t find it. But if they let me go to La Plata and pay the 500 000 pesetas they promised, I will let them know the place where it’s hidden.

Note: The british agents added the following comment on the transcripts: ‘Korsching is a complete enigma’. Enigma is the name of a machine used by the British Intelligence during WW II to decode german secret messages.

Scene 4 - 21 july 1945 (continuation) - Present: Bagge, Diebner, Korsching

Bagge: I am sure the Anglo-Americans have used their last 3 months to im- itate our experiment. Korsching: They probably used their uranium blocks to see if our engine was running or not. Bagge: What about future research in Germany ?

17 Korsching: They dont want to destroy Germany but England wants to weaken her, otherwise they will never achieve hegemony in Europe. Bagge: They seem to plan a United States of Europe. Korsching: If Russia does not interfere. If the Russians put a spy in my room, I will make an experiment without this fellow noticing it. I will just work on saturday nights. Bagge: There is also the question of what the Commander wants. Korsching: He told us ‘I assure on my word of honor’, but nothing written, ‘that (sentence erased in the transcripts)’.

Scene 5 - 4 august 1945 - Present: Heisenberg, Hahn

Hahn: Did you get any information from the american atomic program ? Heisenberg: I had a special man who sent me amazing information from Switzerland. Of course, I burned all the correspondence and I have forgotten his name. Hahn: I understand you dont want his name to be known by the Americans. Heisenberg: At that time I knew exactly what was being discussed in the Scherrer Institute regarding uranium. Apparently he was often there when Scherrer lectured and knew what they were talking about. Nothing very exciting, but for instance, he once reported that the Americans had just built a new heavy water plant and that sort of things.

Note: The source information of Heisenberg was Scherrer himself.

Scene 6 - 4 august 1945 (continuation) - Present: Heisenberg, Hahn

Heisenberg: On the other hand, for the whole water business, I did everything I could not to produce an explosion.

18 Hahn: Can you develop that further ? Heisenberg: Well, I was absolutely convinced of the possibility to make our engine, but I never thought we would make the bomb and at the bottom of my heart I was really glad that it was to be an engine and not a bomb. I must admit that. Hahn: And what did the Americans ? Heisenberg: About a year ago, the Außenministerium warned me that the Americans had threatened to drop a uranium bomb over Dresde if we didn’t surrender. This was contrary to our agreements with the Americans, and I replied that it was not possible. Hahn: And what happened ? Heisenberg: Between 13th and 15th february 1945, some 1300 heavy bombers from RAF and USAF dropped more than 3900 tons of high explosives and incendiary bombs on Dresde, causing at least some 50 000 casualties. Hahn: What was the reason for this bombing ? Heisenberg: There was no strategical reason for it. They just said: we agreed with you not to drop any atomic bombs on Germany, but this is not atomic, just conventional.

Note: The effect of the Dresde bombing was equivalent to the effect of a ura- nium or plutonium bomb. Probably the americans wanted to compare the effect of a conventional bombing to the effect of a nuclear bombing.

19 Scene 7 - 6 august 1945 (day of Hiroshima attack) - Present: Heisenberg, Hahn, Gerlach

Gerlach: We will be looked upon as the ones who have sabotaged everything. We won’t remain alive long there. You can be certain that there are many people in Germany who say that it is our fault. Please, leave me alone. Hahn: I am thankful that we were not the first to drop a uranium bomb. Heisenberg: Look Walter, we sabotaged many more things than you can imagine. But nobody will ever know about it. Gerlach: They were our enemies, although we sabotaged the war. There are some things that one knows and one can discuss together, but one cannot discuss in the presence of Englishmen. Hahn: I must honestly say that I would have sabotaged the war if I had been in a position to do so. Heisenberg: Dont tell this to Walter, he is close to suicide.

Scene 8 - 8 august 1945

Statement: As the press reports during the last few days contain partly incorrect state- ments regarding the alleged work carried out in Germany on the atomic bomb, we would like to set out briefly the development of the work on the uranium problem. 1) The fission of uranium was discovered by Hahn and Strassmann at KWI- Berlin in december 1938. 2) In 1941, work started to produce a uranium engine, not a bomb, using heavy water. 3) Heavy water was produced at the Norsk Hydra plant in Rjukan (Norway) but production was stopped in 1943 due to aircraft bombing. 4) At Freiburg an Celle, experiments were made to avoid use of heavy water by using U-235. 5) The engine at KWI-Berlin and Haigerloch was about to work successfully at the end of the war.

20 Signed: O.Hahn, W.Gerlach, P.Harteck, K.Witz, H.Korsching, M. von Laue, W.Heisenberg, C.F. von Weizs¨acker, E.Bagge, K.Diebner.

Scene 9 - 11 august 1945 - Present: Hahn, Gerlach, Bagge

Hahn: In Germany they could prepare a few grams of ionium per year. Gerlach: No, we prepared 60 kg of pure ionium. Hahn: That’s impossible. Where, in Germany ? Gerlach: No, in Belgium. It’s part of some espionage affair. An indian secret agent came to me and asked help to know where the ionium came from. It was at the end of 1944. Can one make a bomb of pure ionium ? Hahn: I dont know.

Note: Ionium is possibly a code name for the propellant or the explosive of V1 and V2 rockets used by the Germans to attack London from Belgium since june 1944. The British Intelligence Services wanted to know how the the Germans were able to fabricate large quantities of such material. They asked help to Uranverein members, according to Gerlach.

Scene 10 - 14 august 1945 (Lecture by Heisenberg) - Present: Heisenberg, Bagge, Diebner, Gerlach, Hahn, Harteck, Korsching, von Laue, von Weizs¨acker, Wirtz

Heisenberg: When we consider an explosion due to chain reaction of fast neutrons inside a fissible material like U-235, we need the cross-section, −24 2 σt = 4 × 10 cm , where the fraction of fission is 40% and the fraction of scattering is 60%. The mean free path for neutrons for fission is lf =1/(nσf ), where n is the density of atoms, and the mean free time τf =1/(nσf v), where v is the neutron speed. In a fission process, the typical kinetic energy of neu- trons is 1 MeV, corresponding to v =1.4 × 109 cm/s. The density of U-235

21 is n = ρ NA/Mu = 19 NA/235 where NA is the Avogadro number. We obtain −8 in this way lt =5.1 cm, lf = 13.7 cm and τ = 10 s. Assume now that the neutron distribution is a continuum function N(r, t). This function will obey the diffusion equation, also called Frick’s equation ∂N ν − 1 − D∇2N = N ∂t τ for r < R and N = 0 for r > R, where R is the radius of the bomb. The diffusion coefficient is D = ltv/3, and the right hand side of the equation is the neutron flux created inside the bomb by the chain reaction. The coefficient ν is the average number of neutrons created in a fission reaction, and must be larger than 1 in order to produce a chain reaction. The value of ν for fissible materials like U-235 or Pu-239 is about 2.2. We have a solution for the equation of the type

ν′t/τ N(r, t)= N0(r)e and by substitution in the equation with the boundary condition N0 = 0 for R> 0 we find

sin(πr/R) ′ 2 2 N0(r)= with ν =(ν − 1)(1 − R /R ) r c 2 2 − where Rc is called ‘critical radius’ and obeys Rc = π Dτ/(ν 1). If R > Rc the neutron yield increases exponentially inside the core of the bomb and the explosion occurs. There is no explosion otherwise. Now I will calculate the critical mass. For U-235 and using the values above, Rc = 13.8 cm, so 3 Mc =4/3 πRcρ = 200 kg of U-235. Note however that the interaction length of neutrons is comparable with the critical radius, so the approximation is not very accurate. The correct critical mass, once all effects are taken into account, is of the order of 50 kg. If one considers a tamper around the bomb (neutron reflector) then Mc ≈ 15 kg for U-235 and Mc ≈ 5 kg for Pu-239.

Note: The calculations we have written before are not actually those by Heisen- berg, but those extracted from the book ’LOS ALAMOS PRIMER’.

22 Scene 11 - 7 september 1945 - Present: Heisenberg, Blackett, Laue

Heisenberg: Everything concerning the bomb should be made public. Blackett: I think the arguments in favor of that are very strong. Heisenberg: When are we going to be liberated ? Blackett: My own views are that the majority of you are going to be liberated very soon. And there is the possibility for some of you to work in England or America. Laue: Some of our younger colleagues have the wish to go for one or two years to America or England. Is that possible ? Blackett: Who ? Laue: Bagge for example. Heisenberg: Weizs¨acker is very interested in astrophysics. Blackett: Is he extremely good ? Heisenberg: Yes, but he wants to stay in Germany. Blackett: What about Korsching ? Heisenberg: He is a very good experimentalist and had a nice idea on the separation of isotopes. Blackett: Wirtz ? Heisenberg: He is also very good. Blackett: Is there any political problem about him ? Heisenberg: No, he was politically always on the good side, on our side, the same as Korsching. Only Diebner and Bagge were members of the nazi party. By the way, Patrick, can you investigate where is the corpse of my talented colleague Hans Euler ? Blackett: Where did he die ? Heisenberg: In a plane accident over the Azov Sea. Blackett: Sure Werner, I will exploit my russian connections.

Note: Patrick Blackett was a future Nobel Laureate and a leading experimental physicist in postwar England. He was left-wing oriented and an important consultant for the new Labour Cabinet. He was in addition a good friend of Heisenberg.

23 Scene 12 - 12 november 1945 - Present: Harteck, Hahn, Laue

Hahn: The Daily Telegraph has announced that I have been awarded the Nobel Prize for chemistry. I think the info is reliable. Laue: You got it to put pressure on our liberation. Hahn: If they allow me to go to Sweeden, the world will know how we are treated here. It’s a shame on England and America to treat us like that. Harteck: They wont let you go, unless you promise not to say where and with whom you are.

Scene 13 - 1 january 1946 - Present: Heisenberg, von Weizs¨acker

Weizs¨acker: Werner, tell us was really happened ! Heisenberg: (Plot of the plot against hitler appears on a screen, see figure 3) A reactor painted with zips Was the object of my passion True plots are not equipped Unless added by fashion But when the plot’s not false My very attention is gazed. Fast, fast neutron yield increases Till turning point arises Perfect were you first created Til your plane fire spitted And me by thee defeated My action can’t be admitted But your’s made for destruction So let’s all hide our action

Note: On january 3, 1946, 6 months exactly after arriving to Farm Hall, the 10 german scientists were flown to L¨ubeck in the british zone of accupied Germany.

24 BH

s

z h

S h z H=Grosse Ubel P M h= Kleine Ubel h z=zorro

Z

Figure 3: Plot of the plot against Hitler

B=Berlin, M=Munich, S=Stuttgart, P=Paris, Z=Zurich H=Hitler, h=Heisenberg, z=zorro=Rommel, s=Stauffenberg

General Beck was in charge of assassinating Hitler and replacing his gov- ernment in Berlin by an anti-nazi government with Rommel as minister of defence. This government would negotiate a peace accord with the british and the americans, but not with the russians. Churchill was in favor of this plan, but not Roosevelt. The attempt to assassinate Hitler occurred on July 20th, 1944, while Hitler was in his headquarters in East Prussia, but it failed. However, the plan included to send by air german troops from the Normandy front to Berlin, in order to take control of the city. The commander of these troops was to be Erwin Rommel. Unfortunately, Rommel was severely in- juried by a spitfire attack, just 3 days before the attempt to kill Hitler, and

25 the plan to send german troops to Berlin from Normandy failed. The attempt to kill Rommel was probably a mistake because the allies believed that Rom- mel was against the plot. We know with total certainty that Rommel was in favour of the plot, since he was forced to commit suicide once the plot failed. Heisenberg was in contact with the americans via Paul Scherrer, a renowned physics professor at Zurich. Scherrer was both a good friend of Heisenberg and close to american secret services. Most likely, Heisenberg agreed with the americans, via Scherrer, that no atomic bomb would be used against a ger- man town, and in exchange the German would not develop any atomic bomb, but just a reactor. Merkada (Mercader) was possibly an american agent sent to Berlin to inspect the german atomic sites, with the consent of Heisenberg and his close collaborators. It is clear that the americans knew everything about the german atomic program, and therefore the detention of Heisenberg and another 9 german physicists at Farm Hall was nonsense, unless the americans wanted to know more about the plot against Hitler on july 20th, 1944. They expected that Heisenberg would tell the whole story to Otto Hahn or Max von Laue, who were anti-nazis and had no or little relation with the german atomic program. Heisenberg decided to say nothing (except maybe in encrypted form), because he did not want to be considered a traitor in post-war Germany.

Scene 14 - 1 february 1946

Telegram from G¨ottingen to La Plata HAVE DESIGNED MACHINE TO KILL NAZIS .STOP. CAN TEST IT ON SATURDAY NIGHTS .STOP. COST ONLY 500000 PESETAS .STOP. KORSCHING .STOP.

Telegram from La Plata to G¨ottingen NOT INTERESTED .STOP. WE ARE NAZIS OURSELVES .STOP. MOD- IFY TO KILL REDS .STOP. TELLER .STOP. ALVAREZ .STOP. LAWRENCE .STOP.

end of the play

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