The First War of Physics (41 page)

The captured physicists were unco-operative, but a more detailed picture of the German bomb programme emerged from files taken from Weizsäcker’s office which Goudsmit read eagerly, by candlelight. Among the papers was a letter that Weizsäcker had written to Heisenberg, dated 15 August 1944, criticising some of the latter’s calculations. The letter had been torn up and never sent (a more moderate version of the same letter was subsequently recovered from Heisenberg’s files). To Goudsmit’s eyes, the subject matter was astonishingly basic at so late a stage in the German programme:

We found references to ‘special metal’, which was obviously uranium, memos about the difficulty of obtaining the ‘special metal’ in slabs instead of in powdered form, letters confirming our information that it was the Auer Company that produced the metal for the German experiments. We learned that ‘large scale’ experiments were being performed at an Army proving ground near Berlin. We found parts of computations which clearly applied to the theory of a uranium pile.

A pile, not a bomb. ‘We’ve got it!’ Goudsmit declared.

‘I know we have it, but do they?’ Pash misunderstood.

‘No, no!’ Goudsmit said. ‘That’s it. They don’t!’

These documents, Goudsmit believed, accurately reflected the state of the German programme towards the end of 1944. Hitler had been advised of the possibility of a ‘super-weapon’ more than two years previously, but it seemed that experiments carried out as recently as August had not advanced much beyond a preliminary phase. The general lack of secrecy supported this conclusion – the documents quite clearly revealed the whereabouts of the Uranverein scientists, in Tailfingen, Hechingen and Haigerloch.

The documents recovered from Strasbourg were studied by scientific advisers to the Manhattan Project and the OSRD. Groves wondered if the information had come rather too easily. Reconnaissance photographs
of the Hechingen area had revealed what looked like an Oak Ridge-sized isotope separation plant.
⁸
But, as far as the Alsos team was concerned, the evidence was indisputable.

‘Isn’t it wonderful that the Germans have no atom bomb?’ Goudsmit enquired of Furman.

Furman’s answer surprised him. ‘Of course you understand Sam,’ Furman said, ‘if we have such a weapon, we are going to use it.’

The objectives of the Alsos mission now shifted to accommodate what had been discovered. As Soviet forces advanced on eastern Germany, the Alsos mission became a race to capture the German physicists and whatever materials could be recovered to keep them out of Soviet hands.

Assassination plan

Donovan met Eifler at OSS headquarters in Algiers in June 1944. Eifler was preparing to proceed with the mission to kidnap Heisenberg, but Donovan now advised him that the mission had been scrubbed. Donovan broke the news gently, but the truth was that Eifler had lost the confidence of Groves, Furman and Donovan himself. There was no way Eifler’s crazy plan could be executed without leaving behind a considerable mess.

Eifler was off the mission, but despite what Donovan had told him, the mission was still very firmly on.

In November, Berg was briefed about Paul Scherrer, director of the Physics Institute at the Eidgenossische Technische Hochschule (the ETH) in Zurich. Scherrer was well connected with the European physics community and had a reputation for organising well-attended lectures by visiting scientists, including German nuclear physicists. He also gathered intelligence for the SIS and the OSS. The OSS bureau chief in Bern, Allen Dulles, valued Scherrer highly as a source of intelligence.

Word reached the OSS office in Bern that Heisenberg was to give a lecture at the ETH sometime around 15 December. Berg headed for Paris, arriving on 10 December. It is not clear precisely who briefed Berg about his next mission. Furman was in Washington, but Goudsmit was in Paris and spent several days with Berg. Goudsmit was aware of Heisenberg’s scheduled lecture, and gave Berg a small container of heavy water as a gift for Scherrer. No official documentation of a combined Alsos-AZUSA mission exists, but Berg wrote notes during his briefing. ‘Gun in my pocket’, he wrote. ‘Nothing spelled out, but – Heisenberg must be rendered
hors de combat
.’

Some years later Berg related sketchy details of the mission to an OSS colleague, Earl Brodie. ‘If anything Heisenberg said convinced him the Germans were close to a bomb,’ Brodie later explained, ‘then his job was to shoot him – right there in the auditorium. It would probably have cost Berg his life – there would have been no way to escape.’

Berg arrived at the ETH in Zurich on 18 December 1944 together with another OSS agent, Leo Martinuzzi. He used several cover stories. In one he was a Swiss physics student (barely plausible, as this was his 42nd birthday). In another he was an Arab businessman. In a third he was a French merchant from Dijon. He carried in his pocket a small pistol and a deadly cyanide pill. The cyanide pill was for his own suicide, in the event that he was compromised, or as his only means of ‘escape’ after he had killed Heisenberg.

Berg passed himself off convincingly. He followed Heisenberg’s lecture intently, understanding little of the S-matrix theory that was being discussed. He used the time to make copious notes, including a detailed description of the man he might yet have to kill. He spotted Weizsäcker in the audience, and on a seating plan of the auditorium that he had sketched he wrote ‘Nazi’ next to Weizsäcker’s name.

He might not have understood the physics, but he understood enough to realise that there appeared to be no immediate threat. This left him in an uncertain position. He wrote: ‘As I listen, I am uncertain – see: Heisenberg’s uncertainty principle – what to do to H.’

The lecture ended without incident. Berg introduced himself to Scherrer and presented him with the gift from Goudsmit. Scherrer was aware that Berg was an OSS agent but was unaware of his mission, though he knew of the Allies’ interest in Heisenberg. Scherrer had been ambiguous about his
German colleague, but having spent several days in his company prior to the lecture he had come to the conclusion that Heisenberg was anti-Nazi. Heisenberg was deeply distressed that, in the fall-out from the failed plot to assassinate Hitler on 20 July, Max Planck’s son Erwin had been sentenced to death.
⁹
Scherrer now passed these conclusions on to Berg, who wondered if Heisenberg should be invited to come to America. Scherrer thought this a good idea, and in turn invited Berg to join the group at his home for dinner later that week.

But even as Scherrer painted his sympathetic portrait for Berg, Heisenberg was once again busy betraying a distinct lack of tact and diplomacy. Over dinner with his Swiss colleagues after the lecture, he eagerly consumed news reports of Rundstedt’s offensive against Bastogne in Belgium, in what would come to be known as the Battle of the Bulge, declaring triumphantly that ‘they’re coming on!’

Heisenberg accepted Scherrer’s invitation to dinner on the understanding that he would not discuss politics. But his fellow guests had no such understanding, and he was soon bombarded on all sides by questions and challenges. When asked to admit that Germany had all but lost the war, Heisenberg replied in familiar style: ‘Yes, but it would have been so good if we had won.’

Berg overheard the remark. For him, this was the final confirmation he needed that the Germans were nowhere near to developing an atomic ‘super-weapon’. If they were, why would the programme’s leading physicist openly declare that the war was lost?

Berg arranged to leave dinner at Scherrer’s home at the same time as Heisenberg, and together they made their way through the city’s dimly-lit streets. This would have been a perfect opportunity for murder. Instead, as they walked, Berg continued to question Heisenberg about his views of the German regime. Berg’s Swiss-accented German aroused no suspicions.

Eventually, they parted company. Berg’s pistol had remained in his pocket. Heisenberg had no idea he had come so close to death.

¹
Groves learned too late that
alsos
is the Greek word for grove.

²
The full extent of Rosbaud’s intelligence activities remain buried in classified SIS files. In 2006 campaigners secured the services of Cherie Booth QC, wife of former UK Prime Minister Tony Blair, in an attempt to get Rosbaud’s files declassified. However, this is not going to happen anytime soon. In April 2008, the Investigatory Powers Tribunal concluded that it was legal to withhold records beyond 30 years and, therefore, to neither confirm nor deny the records that they hold. See
http://www.cabinetoffice.gov.uk/about_the_cabinet_office/080425meeting.aspx

³
This was not as far-fetched as it might now seem with the benefit of hindsight. The Allies frequently used carefully staged events to feed disinformation to the Germans and disguise real intentions. For example, the Allied invasion of Sicily was, in part, successful because plans recovered from the body of a major in the Royal Marines found floating in the sea off the Spanish coast indicated the imminent Allied invasion not of Sicily, but of Greece. The plans, together with personal letters which helped to authenticate the identity of the body, were all fabrications produced by British naval intelligence.

⁴
In the autobiography of her life with Heisenberg, his wife Elisabeth wrote of the reaction of her father to reports of mass executions of Polish Jews that Heisenberg had shown him: ‘So this is what it has come to, you believe things like this! This is what you get from listening to foreign broadcasts all the time. Germans cannot do things like this. It is impossible!’: Heisenberg, Elisabeth, p. 49.

⁵
Frank was found guilty of war crimes at the Nuremberg trials and executed on 16 October 1946. In his testimony to his defence lawyer, Frank said: ‘A thousand years will pass and still Germany’s guilt will not have been erased.’ See:
http://www.law.umkc.edu/faculty/projects/ftrials/nuremberg/franktest.html

⁶
Originally thought to be visualisable literally as a bit of negatively-charged matter spinning on its axis as it orbits the positively-charged nucleus, it was subsequently accepted that electron spin is an entirely relativistic quantum-mechanical phenomenon with no counterpart in classical physics.

⁷
Roosevelt had agreed that de Gaulle’s Free French would enter the city first. The American forces had halted just outside the city limits.

⁸
It was actually a plant designed to squeeze desperately-needed oil from a seam of shale.

⁹
Erwin Planck was hanged at Plötzensee Prison in Berlin on 23 January 1945.

Chapter 14

THE FINAL PUSH

January–June 1945

F
risch had settled into accommodation in one of the original Los Alamos school buildings, a large blockhouse constructed from huge tree trunks known as the ‘Big House’. He had been greeted cordially on arrival by Oppenheimer, wearing jeans, open-necked shirt with sleeves rolled up, and his trademark pork-pie hat. Oppenheimer tended to greet all the members of the newly-arrived British delegation the same way: ‘Welcome to Los Alamos, and who the devil are you?’ Frisch was amazed at the scientific talent gathered on the Hill. He had the impression that if he struck out on any evening in any direction and knocked on the first door he came to, he would find interesting people inside.

Working in the Critical Assemblies Group in G Division, Frisch busied himself with various small projects mostly involving the development of experimental instruments. However, he also continued to nag at the problem of critical mass in uranium. Despite the progress that had been made, the physicists were still largely ignorant of the precise experimental conditions under which uranium enriched with U-235 or pure U-235 would form an explosive super-critical mass. Frisch was surrounded by theoretical physicists of the first order. Some, like Ulam, had confessed to Frisch that they had now sunk so low as to include actual numbers in their
calculations instead of just abstract mathematical symbols. But still, to a seasoned experimentalist like Frisch, theory was one thing, practice quite another.