The First War of Physics (23 page)

Serber recalls their reaction:

At this point something remarkable happened. Teller brought up the idea of the Super, a fusion weapon, not a fission weapon, which was to be a detonation wave in liquid deuterium set off by being heated by the explosion of an atomic bomb. Well, everybody forgot about the A-bomb, as if it were old hat, something settled, no problem, and turned with enthusiasm to something new.

The figures were astonishing. If a thermonuclear reaction could be triggered, just twelve kilos of liquid deuterium could be expected to explode with a force equivalent to one
million
tons of TNT. Then Teller realised that a fission bomb might trigger other kinds of fusion reactions as well. Specifically, he figured that an atomic bomb would heat the atmosphere so intensely that fusion reactions involving nitrogen, constituting 80 per cent of the earth’s atmosphere, would be triggered. Simply put, exploding an atomic bomb would set fire to the air.
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Oppenheimer was sufficiently perturbed by Teller’s conclusions to seek an emergency meeting with Compton, who was holidaying in Michigan. Bethe, however, was immediately suspicious. He quickly spotted the unjustified assumptions that had propelled Teller’s calculations to these stark conclusions. Teller was mollified and the possibility of catastrophe receded.

The group then realised that deuterium fusion reactions would proceed too slowly to support an explosive release of energy and, as the summer wore on, alternatives were discussed. These included reactions of deuterium with tritium, the heaviest isotope of hydrogen which contains one proton and two neutrons, and of deuterium and an isotope of lithium, Li-6, which produces tritium on bombardment with neutrons. At the end of their deliberations, Teller was left with the firm impression that the Super represented the ultimate prize and that the fission bomb had been reduced to a mere ‘engineering problem’. However, this was not an impression that was shared by Serber, Bethe and Oppenheimer. For them the Super was, perhaps, an interesting possibility, but as it required a fission bomb to initiate it, this was a possibility that could be explored once a fission bomb had been built.

By the end of the summer the study group had done much to sharpen the thinking about both the fission and fusion bombs. In August 1942 Oppenheimer reported that a U-235 bomb would require 30 kilos of the isotope but ‘should have a destructive effect equivalent to the explosion of over 100,000 tons of TNT’.
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This was much, much more than the 1,800 tons claimed by the MAUD Committee physicists the previous year. The study group further claimed that by surrounding a fission bomb with 400 kilos of liquid deuterium, the destructive force would be greatly enhanced, to ten million tons of TNT equivalent, which would devastate an area of more than 100 square miles.

On hearing of these results, the S-l Committee was stunned. Of course, the discovery of the possibility of a thermonuclear fusion weapon did not change the immediate priorities of the S-l programme, which was to build a fission bomb. But it did change dramatically the scale of the enterprise. The Committee alerted Bush, and Bush alerted Secretary of War Henry Stimson.

Whether it was just an interesting possibility or not, the Super was now firmly on the radar.

The biggest sonovabitch

Bush’s decision to involve the Army Corps of Engineers in the S-l programme led to an inevitable culture clash just a few months later. This clash was, in part, precipitated by a notable shift in the balance of power within the programme. Despite the exceptional circumstances, and the ever-present threat that German physicists might get there first, the work on the American bomb project had to this point proceeded more or less democratically. The physicists had agreed to work together, to pool their knowledge and resources, and to each take tasks befitting their areas of expertise.

Now the physicists were losing control. A more authoritarian organisation was in place, issuing orders from Washington, and they were no longer involved in making key decisions. The involvement of the army and the introduction of formal management structures had increased bureaucracy. Communication between the physicists was being restricted in the interests of preserving secrecy through ‘compartmentalisation’, ensuring that very few individuals involved in the S-1 programme had the full perspective of it. This was not the way the physicists were used to working, and Szilard was convinced that this was not the best way to conduct the project. He proceeded to make a nuisance of himself.

The clash spilled over into confrontation over the design of the reactor cooling system. The engineering contractors brought in by the Army Corps of Engineers were more used to designing roads and bridges. The physicists were alarmed by their level of ignorance and incompetence.
Compton’s efforts to impose his authority by reading a parable from the Old Testament to an assembly of Met Lab scientists did not help.

On 21 September, Szilard summarised his discontent, and his concerns for peace after the war, in an eleven-page memorandum. After noting how easy life could be if they all followed orders and just carried out the tasks assigned to them, he wrote:

Alternatively, we may take the stand that those who have originated the work on this terrible weapon and those who have materially contributed to its development, have, before God and the World, the duty to see to it that it should be ready to be used at the proper time and in the proper way.

It had become clear to Bush in August that the division of the S-1 programme between the civilian OSRD and the army was not working. He raised the issue with General Brehon Somervell, head of the Army Services of Supply. Bush had been trying to work out a solution that would allow him to retain some civilian oversight, but Somervell thought to put the Army Corps of Engineers in charge of the whole programme.

Things were about to change and, from the scientists’ perspective, not for the better.

Somervell needed a dependable individual to lead what was about to become a military programme, and he thought he knew just the man for the job. At the time, Colonel Leslie Groves was ‘probably the angriest officer in the United States Army’. A West Point graduate, he had just agreed to accept an assignment overseas, having grown weary of the bureaucratic headaches associated with directing military construction projects with budgets of tens of millions of dollars (he had recently overseen construction of the Pentagon). His superiors leaned on him heavily. ‘If you do the job right,’ Somervell advised him, ‘it will win the war.’

Groves’ spirits fell. He could only answer: ‘Oh, that thing.’

The entire budget for the S-1 programme was less than Groves would typically spend in a week. He set about taking control of the programme in a forthright manner. One of his subordinates, Lieutenant Colonel
Kenneth Nichols, another West Point graduate with an engineering Ph.D., remembered Groves as ‘the biggest sonovabitch I’ve ever met in my life, but also one of the most capable individuals … I hated his guts and so did everybody else but we had our form of understanding.’ Groves’ first meeting with Bush was not an auspicious one. ‘I fear we are in the soup’, Bush wrote.

Groves may not have been noted for his tact and diplomacy, but he did move quickly. At the behest of Joliot-Curie in Paris and Henry Tizard in Britain, in 1940 Union Minière had shipped to the US over a thousand tons of pitchblende ore rich in uranium oxide from its mines in the Belgian Congo, to keep them out of German hands. The ore had been sitting at Port Richmond on Staten Island for six months. Groves had heard about the intention to appoint him to head the S-l programme on 17 September. The very next day he despatched Nichols to New York to buy the pitchblende ore. That same day he approved the requisition of what was to become known as Site X, 56,000 acres of land near Oak Ridge in eastern Tennessee, where large-scale facilities for the separation of U-235 and the production of plutonium were to be built. At this point, a self-sustaining nuclear chain reaction had to be demonstrated.

Newly-promoted to Brigadier General, Groves took up his post formally on 23 September, and the programme finally kicked into high gear. The Army Corps of Engineers had referred to its contribution to the S-l programme as Manhattan Engineer District, after its North Atlantic Division headquarters on Broadway, near New York City Hall. With the Army Corps of Engineers now in charge, the name was adopted to describe the whole programme. What was eventually to become known as the Manhattan Project was born.

But the compulsion for the American project remained the threat of a German atomic bomb. If Compton’s estimates were correct, then Szilard’s concern that they might not be ready ‘before German bombs wipe out American cities’ was an alarming prospect. German progress depended critically on access to heavy water. Groves added his voice to the growing demand for Allied action against the Vemork plant.

The Grouse party had parachuted onto Norway’s Hardanger Plateau on 18 October. Operation Freshman was launched a month later.

Gliding to disaster

Operation Freshman went wrong virtually as soon as it began. Combined Operations decided that the target was sufficiently important to warrant a doubling of the personnel for the mission. Two Halifax bombers left Skitten airfield in Caithness, Scotland, on the night of 19 November. Each bomber towed a Horsa Mk. 1 glider flown by two pilots in which an officer, a sergeant and thirteen other ranks drawn from the Royal Engineers of the First Airborne Division sat huddled. This made a total of 34 men, all volunteers. Three days later, the British newspapers reported the following:

On the night of November 19–20th, two British bombers, each towing one glider, flew into Southern Norway. One bomber and both gliders were forced to land. The sabotage troops they were carrying were put to battle and wiped out to the last man.

One of the Halifaxes had got into difficulties as it approached Egersund, about 125 miles from the landing zone, and the glider was unexpectedly released. The glider crashed into a mountain near Helleland, killing two on board and severely injuring a third. The Halifax managed to climb above this mountain range, but then crashed into the next, killing the crew of seven.
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Two of the survivors of the glider crash managed to get to a nearby farmhouse and local civilians hurried to warn them of the approach of German troops. The survivors must have decided that there was little choice but to surrender and sit out the war in a German prisoner-of-war camp.

But Hitler, infuriated by the success of British sabotage operations, had just a few weeks before issued a new order. No quarter was to be granted to saboteurs, on principle, even if they were in uniform at the time of their capture. They were instead to be interrogated and then shot.

The survivors were rounded up by German troops and taken to a camp near Egersund. They were first interrogated and then taken into nearby woods where they were executed by firing squad, one after another. The bodies of all seventeen were buried in a trench in the sand dunes of Brüsand.
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At the landing zone, Haugland heard the drone of at least one bomber overhead. The night sky was cloudy but the moon was out and it was not particularly dark. But the noise of the plane died away. Running low on fuel and unable to identify the landing zone, the pilot of the second Halifax had decided to return to base. The plane and its glider were approaching the Norwegian coastline when the tow line froze solid and snapped, sending the glider hurtling to the ground. It crashed into mountains near Fyljesdal, north-west of Stavanger. Seven on board were killed instantly. One survivor managed to crawl away from the crash site but died of exposure and loss of blood. When German troops arrived on the scene, the bodies were buried in shallow graves.
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Of the nine remaining survivors, four were badly injured. All nine were taken to Stavanger county jail, where a dispute erupted between the Wehrmacht and Gestapo as to which of them had jurisdiction over the prisoners. By this time the hasty execution of the commandos from the other glider had come to the attention of General Wilhelm Rediess, head of the Gestapo in Norway, who angrily noted that Hitler’s order did not preclude full interrogation of the prisoners first.

The four injured were taken for questioning by the Gestapo. Three of them were beaten and strangled with leather straps, and their chests and throats were crushed. They were then killed by injecting air into their bloodstreams. The fourth was executed by a single shot to the back of the head. The bodies were taken out to sea, weighted with stones and thrown overboard. They were never recovered.
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The five uninjured were imprisoned at Grini concentration camp, north of Oslo. They were advised that their rights as British soldiers under the Geneva Convention would be respected. However, on 18 January 1943, after much questioning, the five were taken from their cells by a ‘Special German Delegation’, blindfolded and shot.
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From maps and other documentation salvaged from the crashed gliders and, no doubt, from the Gestapo’s brutal interrogation of the crash survivors, the Germans learned all they needed to know about the target of Operation Freshman. They fortified their positions in Rjukan and laid a minefield around the Vemork plant.

Now in great jeopardy, the four-man Grouse party vanished into the depths of the Hardanger wilderness.

The new world

Laura Fermi organised a party for the ‘metallurgists’ at the Met Lab early in December 1942. As the guests began to arrive, they were effusive in offering their congratulations to Enrico. ‘Congratulations?’ Laura asked, puzzled. ‘What for?’ Nobody took any notice of her.

Her persistent questions received evasive answers or no answer at all. ‘Nothing special,’ said one, ‘he is a smart guy. That’s all.’ ‘Don’t get excited,’ said another, ‘you’ll find out sometime.’

Just a month before, Fermi had come to a difficult decision. Workers employed by the army contractors responsible for the construction of a new reactor building had gone on strike, delaying construction indefinitely. Fermi proposed to Compton that, rather than wait any longer, they instead make use of the squash court which had thus far been used to house the experimental piles.