FREE Icon Books eBook Sampler E-Book

Greg Grandin

• Herausgeber: Icon Books
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 405

Veröffentlichungsjahr: 2013

Beschreibung

Icon Books is an independent British publisher which publishes popular and engaging non-fiction for adults. We're proud to be part of the Independent Alliance in the UK, publishing companies who share a common vision of editorial excellence and original, diverse publishing. This ebook sampler – available free on Kindle, in EPUB and as a PDF download from our website – covers subjects from popular science to sports biography to philosophy. The sampler includes extracts from: Atomic by Jim Baggott; Crashed & Byrned by Tommy Byrne; Fordlandia by Greg Grandin; God's Philosophers by James Hannam; The Lives and Times of the Great Composers by Michael Steen; Love, Sex, Death and Words by John Sutherland and Stephen Fender; A Mind of Its Own by Cordelia Fine; Proust and the Squid by Maryanne Woolf; Quantum by Manjit Kumar; Sex, Botany and Empire by Patricia Fara; The Real Oliver Twist and A Time to Dance, A Time to Die by John Waller. From Proust and the Squid, a fascinating exploration of the science of the reading brain – 'We were never born to read,' begins Maryanne Wolf – to Greg Grandin's Fordlandia, the riveting story of the American town Henry Ford tried to build in the Brazilian Amazon and Manjit Kumar's BBC Samuel Johnson prizewinning Quantum, these books represent the best of over 20 years of non?fiction publishing from Icon Books.

Leseprobe

First published in the UK in 2013 by

Icon Books Ltd,

Omnibus Business Centre,

39–41 North Road,

London N7 9DP

email: [email protected]

www.iconbooks.net

This electronic edition published in the UK in 2013 by Icon Books Ltd

ISBN: 978-184831-639-3 (digital edition)

Text copyright © 2013 Jim Baggott, Tommy Byrne with Mark Hughes, Greg Grandin, James Hannam, Michael Steen, John Sutherland and Steven Fender, Cordelia Fine, Maryanne Wolf, Manjit Kumar, Patricia Fara, John Waller

No part of this book may be reproduced in any form, or by any means, without prior permission in writing from the publisher.

Typeset in Minion by Marie Doherty

Contents

Title page

Copyright information

About Icon Books and this sampler

1. Atomic

2. Crashed & Byrned

3. Fordlandia

4. God’s Philosophers

5. The Lives and Times of the Great Composers

6. Love, Sex, Death and Words

7. A Mind of Its Own

8. Proust and the Squid

9. Quantum

10. Sex, Botany and Empire

11. The Real Oliver Twist

12. A Time to Dance, A Time to Die

About Icon Books and this sampler

We’ve put together a selection of carefully selected sample chapters from twelve of Icon’s very best books to serve as an introduction to our books.

From Proust and the Squid, a fascinating exploration of the science of the reading brain – ‘We were never born to read,’ begins Maryanne Wolf – to Greg Grandin’s Fordlandia, the riveting story of the American town Henry Ford tried to build in the Brazilian Amazon, these books represent the best of over 20 years of non-fiction publishing from Icon Books.

Icon Books is an independent British publisher formed in 1992 which publishes popular and engaging non-fiction for adults. We’re proud to be part of the Independent Alliance in the UK, publishers who share a common vision of editorial excellence and original, diverse publishing.

Icon are known for a series of illustrated, witty but intelligent guides to subjects such as Freud, Postmodernism and Einstein. Originally called … for Beginners, and now Introducing, the series is known throughout the world. See more at introducingbooks.net.

However, we combine our series with stand-out individual titles – from witty, erudite Sunday Times number one bestsellers such as Mark Forsyth’s The Etymologicon to the authoritative, dazzling BBC Samuel Johnson Prize-shortlisted Quantum. We hope you enjoy what’s here and it inspires you to find out more about us.

@iconbooks

Iconbooks.net

Atomic

Jim Baggott

ISBN: 9781848310827

The first fully realised popular account of the race between Nazi Germany, Britain, America and the Soviet Union to build atomic weapons.

Drawing on declassified material such as MI6’s Farm Hall transcripts, coded Soviet messages cracked by American cryptographers and interpretations by Russian scholars of documents from the Soviet archive, Jim Baggott’s monumental book spans ten historic years, from the discovery of nuclear fission in 1939 to ‘Joe-1’, the first Soviet atomic bomb test in August 1949.

It includes dramatic episodes such as the sabotage of the Vemork heavy water plant by Norwegian commandos and the infamous meeting between Niels Bohr and Werner Heisenberg, the subject of Michael Frayn’s stage play Copenhagen.

Baggott also tells of how Allied scientists were directly involved in the hunt for their German counterparts in war-torn Europe following D-Day; and brings to light the reactions of captured German scientists on hearing of the Allied success at Hiroshima.

Atomic is an epic story of science and technology at the very limits of human understanding; a tale barely believable as fiction, which just happens to be historical fact.

Chapter 10

Escape from Copenhagen

January–November 1943

Despite receiving numerous invitations to visit America shortly after the Nazi occupation of Denmark, Niels Bohr had nevertheless decided it was his duty to remain. He wanted to do what he could to preserve the scientific institutions which he had helped to build, and the scientists who worked within them. And, indeed, the work did continue. Bohr and his team had access to a cyclotron* and high-tension apparatus suitable for fission experiments. The lack of materials, especially metals, was alleviated somewhat by the Carlsberg Foundation, a generous sponsor of Denmark’s greatest physicist, which loaned Bohr’s institute a supply of metals from the Carlsberg brewery. Bohr probably thought he could sit out the war if not in comfort or free of concern, then at least in relative peace.

Eric Welsh thought rather differently. The veteran British SIS operative had figured that Bohr would be a valuable addition to Tube Alloys. Late in 1942 Tronstad had received a message indicating that Bohr would welcome the opportunity to see him again – interpreted as a hint that Bohr was ready to leave Denmark. Welsh talked to ‘C’,† Sir Stewart Menzies, the head of the SIS, and they agreed that an approach to Bohr should be made to sound him out about coming to Britain.

Shortly afterwards, in January 1943, Chadwick was approached by the SIS in Liverpool and asked if he would draft a letter of invitation to Bohr. Once the details of the proposed escape, or ‘ex-filtration’ plan had been explained, Chadwick agreed. His letter, dated 25 January, offered a warm welcome should Bohr decide to leave Denmark, freedom to work on any scientific problems of interest, and a veiled request for Bohr’s support on the atomic programme. ‘Indeed I have in mind a particular problem in which your assistance would be of the greatest help’, he wrote.

The letter was reduced to a microdot and smuggled to Bohr hidden in the hollow handle of a key, stored on a ring alongside a number of other keys. A second key on the ring contained a duplicate microdot. Bohr was alerted to the imminent arrival of the message by Captain Volmer Gyth, an officer in the information division of the Danish general staff with connections to the Danish resistance. Gyth passed him a set of instructions to the effect that: ‘Professor Bohr should gently file the keys at the point indicated until the hole appears. The message can then be syringed or floated out onto a microscope slide … It should be handled very delicately.’ Perhaps somewhat uncertain of his own abilities in the tradecraft of a spy, when Gyth offered to recover the microdot and provide him with a written version of the letter, Bohr gratefully accepted.

Bohr’s judgement of the situation was, however, unchanged. His desire was to remain in Denmark and continue his work at the institute. As far as he understood, the possibility of extracting U-235 from natural uranium in sufficient quantities to make a bomb was completely impractical. He gave his reasons in a reply but he also left open the possibility of coming to Britain, recognising that his circumstances could easily change. ‘However,’ he wrote, ‘there may, and perhaps in a near future, come a moment where things look different and where I, if not in other ways, might be able modestly to assist in the restoration of international collaboration in human progress.’ Gyth reduced Bohr’s letter to millimetre dimensions, wrapped it in foil and arranged to have it inserted in the hollow tooth of a courier, hidden beneath a filling.

Further correspondence ensued, though the manner of transmission of subsequent messages was rather more conventional. Bohr explained in more detail why he thought a fission bomb was impossible.

Separate ways

After successfully completing their sabotage mission, the Norwegian commandos of Swallow and Gunnerside went separate ways, as Falkenhorst and Reichskommisar Josef Terboven ordered a massive search. Rønneberg led Idland, Kayser, Strømsheim and Storhaug north towards the Swedish border. They arrived on Swedish soil fifteen days later, exhausted from a 250-mile trek that had not been without incident but which had been relatively straightforward. On reaching London they were greeted warmly and given a nice cup of tea.

Poulsson and Helberg headed for Oslo, intending to lay low for a while before making contact with the Norwegian underground. From Oslo, Poulsson escaped into Sweden before returning to Britain for a short while. Helberg, who had done time in a Swedish prison and was therefore known to the authorities, planned to head back to the Hardanger Plateau when the dust had settled. Acting on incorrect advice, on 25 March 1943 he arrived back in an area that was still crawling with German troops. Realising he had been spotted, he set off on skis as three German soldiers gave chase. Two gave up after an hour. After two hours, Helberg turned and faced his pursuer. The German emptied his Luger, missing with every shot. Now it was Helberg’s turn. He gave chase, bringing the German down with a single shot from his Colt .32.

More adventures were to follow. In darkness, Helberg fell over a precipice and broke his left shoulder. He reached his destination, a house he knew in the village of Rauland, only to find it full of German troops. He bluffed his way through the next two nights, drinking and playing cards with the troops, and even managed to get medical attention for his shoulder. He moved to a hotel in Dalen, where he was unfortunate to get caught up in an altercation between Terboven, who was staying in the next room, and a young, attractive Norwegian woman who had spurned Terboven’s amorous advances. Helberg was rounded up with the other Norwegians in the hotel on the orders of a now incensed Terboven, and was told they were all to be sent to Grini concentration camp. Helberg jumped from the bus on the way to Oslo, avoiding grenades and pistol shots. He eventually managed to get to Sweden, avoided imprisonment, and boarded a plane bound for Britain on 2 June.

Haugland and Skinnarland moved their makeshift wireless operation to a location high in the mountains. They took cover under the snow and watched the German troops make a mess of the search on the Hardanger Plateau. Haugland completed Skinnarland’s wireless training before joining his brother, whom he was surprised to find leading the resistance in Oslo. He provided the resistance with further SOE-style training in the use of explosives.

Haukelid and Kjelstrup headed west on the Hardanger Plateau, where they stayed for much of the summer of 1943. Kjelstrup’s health began to suffer, and he returned to Britain to recuperate.

Somewhat improved apparatus

The loss of heavy water production from the Vemork plant was a major setback to the German programme. The loss was to prove temporary, however. Tronstad and Brun had believed that the destruction of the high concentration cells would halt production for a few years. But the damage was already repaired by 17 April 1943, and the plant was again producing small quantities of heavy water by the end of June.

By this time, the German War Office had ceased to take any interest in the programme. Diebner and his research team were transferred back to the broader Uranverein under the auspices of the Reich Research Council, although the team was allowed to continue working at the Army Ordnance laboratory in Gottow. The two million Reichsmarks that had been promised by the War Office never materialised, and the Reich Research Council was left with the task of finding the money for itself. Speer remained an enthusiastic patron, however, and adequate funding was forthcoming.

Diebner may not have been a leading light in German theoretical physics, but he was an accomplished experimentalist. The reactor experiments that had been carried out so far under Heisenberg’s overall guidance had relied on configurations in which uranium metal plates and quantities of the heavy water moderator were organised in layers. Diebner had devised an alternative configuration based on a three-dimensional lattice of equally spaced cubes of uranium oxide or uranium metal immersed in a volume of moderator. Ingeniously, he further figured that he could do without an enveloping container of aluminium by freezing the heavy water moderator solid. In effect, the ‘heavy ice’ would function both as moderator and support structure.

He set up such a configuration in the low-temperature laboratory of the Reich Institute for Technical Chemistry. Reactor G-II consisted of about 230 kilos of uranium in the form of cubes and 210 kilos of heavy ice, arranged in a sphere about 75 centimetres in diameter. No self-sustaining­ chain reaction was generated but there was clear evidence for neutron multiplication, about one and a half times greater than the corresponding neutron multiplication in L-IV. Diebner was convinced that a self-sustaining­ chain reaction would be achieved with sufficient uranium and heavy water.

Heisenberg, however, made light of Diebner’s achievements. In a conference held in Berlin on 6 May he acknowledged the results from Diebner’s group but declared that the latter’s ‘somewhat improved apparatus’ had ‘yielded the same result’ as the previous year’s L-IV design. Heisenberg was planning a large-scale reactor experiment and had no intention of moving away from the layer configuration.

Subsequent experiments at the Gottow laboratory bore out Diebner’s conviction. The team repeated the uranium–heavy ice experiment with the same quantities of materials but this time with a lattice of uranium cubes suspended on fine alloy wires in a volume of liquid heavy water at normal laboratory temperatures. A further experiment with over 560 kilos of uranium and nearly 600 kilos of heavy water yielded even more promising results. It was clear that the lattice design was superior to anything that had yet been produced in Berlin or Leipzig.

Diebner started to draw up plans for an even larger reactor, but now ran into conflict with the demands of Heisenberg’s experiments. Heisenberg preferred to continue with the layer configuration despite the evidence suggesting that the lattice arrangement might work better. At issue here was the very different experimental philosophies adopted by the two research groups. Heisenberg was content to build understanding of the physics through a series of reactor experiments designed to allow measurement of the values of fundamental nuclear constants. As Heisenberg later confided to Harteck, he preferred the layer configuration because the theory was much simpler.

Diebner was less concerned about the theory and wanted to build a working reactor as quickly as possible. When subsequent theoretical studies pointed to the superiority of Diebner’s lattice configuration, Heisenberg remained stubborn. Professional pride may have been a factor, but the simple truth was that for Heisenberg the nuclear project was no longer his major preoccupation.

More ominously, perhaps, Heisenberg had so far perceived no need for cadmium control rods of the kind that had been used in the Chicago uranium­–graphite pile, although he understood that these would be required in a working reactor. In truth, without control rods an experimental nuclear reactor reaching criticality would precipitate a major disaster­.

A lot of experience in microfilm work

‘Oh, I think that is true’, Oppenheimer said, in answer to Pash’s question concerning other groups interested in the work going on at the Rad Lab. ‘But,’ he went on to say, ‘I have no firsthand knowledge. I think it is true that a man, whose name I never heard, who was attached to the Soviet consul, has indicated indirectly through intermediary people concerned in this project that he was in a position to transmit, without danger of leak, or scandal, or anything of that kind, information which they might supply.’

Oppenheimer explained that, speaking frankly, he was ‘friendly’ to the idea that the Russians – as allies of America in the war against Nazi Germany – be advised of the American work on the atomic bomb, but that he would not want this kind of information to get to the Soviets through the ‘back door’.

Pash was all ears.

‘Could you give me a little more specific information as to exactly what information you have?’ Pash enquired. ‘You can readily realise that phase would be, to me, as interesting, pretty near, as the whole project is to you.’

‘Well, I might say,’ replied Oppenheimer, ‘that the approaches were always to other people, who were troubled by them, and sometimes came and discussed them with me.’ He went on: ‘[T]o give more … than one name would be to implicate people whose attitude was one of bewilderment rather than one of co-operation.’

In Oppenheimer’s reply, the Chevalier incident had suddenly become one of several approaches, to several physicists working on the programme. Two of these physicists, Oppenheimer explained, were working with him at Los Alamos, and the other was a Rad Lab physicist who had departed, or was about to, for the Oak Ridge facility in Tennessee. It was, as he later admitted, a ‘cock and bull story’, designed – if Oppenheimer’s flustered response could be called that – to throw Pash off the scent.

Oppenheimer had already named Eltenton, who, he now explained, was to arrange contact with someone from the Soviet consulate ‘who had a lot of experience in microfilm work, or whatever the hell’. But Oppenheimer did not want to name Chevalier, who he believed had acted as an innocent messenger. When pressed by Pash to name his friend, Oppenheimer replied: ‘I think it would be a mistake. That is, I think I have told you where the initiative came from and that the other things were almost purely accident … The intermediary between Eltenton and the project thought it was the wrong idea, but said that this was the situation. I don’t think he supported it. In fact, I know it.’

Pash pressed him further, but other than reveal the fact that the intermediary was a member of the Berkeley faculty, Oppenheimer refused to give a name. ‘I want to again sort of explore the possibility of getting the name of the person on the faculty,’ Pash cajoled, ‘not for the purpose of taking him to task but to try to see Eltenton’s method of approach.’ Oppenheimer did not budge, and tried to downplay the significance of the incident. Surely, the transmission of information vital to America’s allies was something that should in any case be happening through formal channels. The fact that this transmission was not happening meant that information passed through the ‘back door’ was obviously treason in substance, though, perhaps, not in spirit.

These were all sentiments that had been expressed by many in Oppenheimer’s circle of ‘leftwandering’ friends and colleagues. They were not, however, the sentiments expected of the head of the Los Alamos laboratory, a leading contributor to one of America’s most secret war programmes. Worse, Oppenheimer had started to spin a web of deceit, making the classic error of elaborating a lie in the mistaken belief that it would lend it authenticity. He had not yet been caught in this lie but, unknown to him, it had been caught on tape.

The meeting ended as it had begun – amicably. Pash arranged for a transcript of their conversation to be produced and sent it to Groves with a covering note. It made no difference.

By this time the FBI had received a rather extraordinary anonymous letter. The letter was dated 7 August 1943 and was written in Russian. It named Zarubin (Zubilin), Kheifets and Kvasnikov and many others as Soviet spies. It also accused Zarubin of involvement in the March 1940 massacre of nearly 15,000 Polish prisoners of war in the Katyn forest‡ and, rather bizarrely, of spying on the United States for the Japanese. The author clearly hated Zarubin, and urged the FBI to expose him to the Soviet authorities as a traitor, whereupon he would be summarily executed by Vasily Mironov, whom the anonymous author claimed was a Soviet diplomat and a loyal NKVD agent. Inevitably, the FBI was suspicious and didn’t know quite what to make of the letter, but there were enough independently verifiable references in it to make them pay attention.§

The FBI eagerly agreed to put Eltenton under surveillance. In early September a short note was intercepted from Weinberg to ‘S’ (presumed to be Steve Nelson), requesting that he, Weinberg, should not be contacted. A sure sign, Pash argued, that Oppenheimer had tipped him off. Peer de Silva added his own voice to the growing chorus. He wrote to Groves on 2 September: ‘The writer wishes to go on record as saying J.R. Oppenheimer is playing a key part in the attempt of the Soviet Union to secure, by espionage, highly secret information which is vital to the United States.’

However, the intense surveillance of the radical young physicists at the Rad Lab had turned up no further evidence of espionage. The physicists were nevertheless removed from the programme and its proximity. Lomanitz had been drafted. Friedman was fired shortly after being given a position teaching physics to army recruits at Berkeley. Both Lomanitz and Friedman perceived their predicament to be a direct result of their union activity, and nothing more.

At Lomanitz’s farewell party, Weinberg speculated that their troubles might be the result of something else, but held back from telling them that he might actually be the cause. In the meantime, Weinberg was left on the Berkeley campus under close surveillance in the hope that he would expose more of the Soviet intelligence network.

Oppenheimer had asked Bohm to join him at Los Alamos but Groves intervened, advising Oppenheimer that the transfer could not be sanctioned, giving the rather obscure reason that Bohm had relatives in Germany. Weinberg and Bohm took positions as teaching assistants at Berkeley, presenting the course on quantum theory that Oppenheimer had once taught.

Lansdale interviewed Oppenheimer again on 12 September 1943, in Washington. Lansdale explained that in his position he could do little else but base his suspicions on past associations. What was he to make of:

… the case of Dr J.R. Oppenheimer, whose wife was at one time a member of the Party anyway, who himself knows many prominent Communists, associates with them, who belongs to a large number of so-called ‘front’ organisations, and may perhaps have contributed to the Party himself, who becomes aware of an espionage attempt by the Party six months ago and doesn’t mention it, and who still won’t make a complete disclosure.

But Lansdale also confessed that he believed Oppenheimer to be innocent of any wrongdoing: ‘I’ve made up my mind that you, yourself, are OK,’ he said, ‘or otherwise I wouldn’t be talking to you like this, see?’

‘I’d better be – that’s all I’ve got to say’, Oppenheimer replied.

Thin Man and Fat Man

By the autumn of 1943 the road to the atomic bomb was clear to Oppenheimer and the team of physicists at Los Alamos, but no less fraught with difficulty.

Two huge facilities were now under construction at Oak Ridge for the large-scale separation of U-235. One of these, called Y-12, was an electromagnetic separation plant based on Lawrence’s calutron design. Lawrence had estimated that to separate just 100 grams of U-235 per day would require about 2,000 calutron collector tanks, each set vertically between the pole faces of thousands upon thousands of tons of magnets. The tanks and magnets were organised in oval units – nicknamed ‘racetracks’ – with each racetrack consisting of 96 tanks. Groves believed 2,000 tanks – twenty racetracks – to be beyond the capabilities of the construction company, and cut the number back to 500, or five racetracks, anticipating that advances in the technology prior to completion would increase production rates and compensate for the difference.

The facility required a vacuum system and magnets that had never before been built on this, truly Lawrencian, scale. The magnets were 250 feet long, and weighed between 3,000 and 10,000 tons. Their construction had actually exhausted America’s supply of copper, and the US Treasury had loaned the project 15,000 tons of silver to complete the windings. The magnets required as much power as a large city and were so strong that workers could feel the pull of magnetic force on the nails in their shoes. Women straying close to the magnets would occasionally lose their hairpins. Pipes were pulled from the walls. Thirteen thousand people were employed to run the plant. The first racetrack – Alpha I – began operation in November 1943. It promptly broke down.

Despite the enormous scale of Y-12, Groves had remained largely ambiguous about the prospects for electromagnetic separation. This was very new technology and therefore uncharted territory. About eight miles south-west of Y-12 a gaseous diffusion plant, called K-25, was being constructed. This plant was to be housed in a huge U-shaped building measuring half a mile long by 1,000 feet wide. At the time of its construction it was the largest building in the world. The plant would employ another 12,000 people. This was, at least, more familiar technology. But it was still all a gamble. The gaseous diffusion process itself was still the subject of intense research at Columbia University, and the problems with corrosion by uranium hexafluoride had yet to be solved.

The uncertainties over the separation of U-235 were to some extent compensated for by a growing degree of confidence that the gun method would work and, moreover, that a transportable weapon could be built.

An ordnance expert acting as adviser to the project had identified a flaw in the physicists’ logic not long after the inaugural lectures at Los Alamos in April. The physicists had based their rather pessimistic estimates of the size of the gun that would be required on conventional gun designs. But these conventional designs had to take account of the need for the gun to be fired repeatedly. The gun firing the shy into the sub-critical mass of U-235 at the other end of a bomb would obviously have to fire only once, after which it would be reduced to atoms. This meant that the weight of the gun could be substantially reduced.

For U-235 the basic bomb mechanism was no longer the main problem. All they needed was enough fissile material.

But the Manhattan Project physicists were also backing another horse. Fermi’s successful demonstration of a self-sustaining chain reaction in December 1942 had led directly to the creation of a much larger-scale reactor to produce plutonium at ‘Site W’ in Hanford, south-central Washington state. Construction had started in March 1943, with a 45,000-strong labour force. The first nuclear reactor, named the B-reactor or 105-B, began construction in August based on Fermi’s uranium–graphite design. It would take a year to build the plant, and plutonium was not expected to be available in sufficient quantities for a bomb until early 1945.

However, unlike U-235, it was not at all clear that the gun method would be effective for a plutonium bomb. Too little was known at this stage about this new element’s physical properties for any conclusions to be drawn, particularly in regard to spontaneous fission and problems of pre-detonation. If plutonium exhibited a greater tendency to pre-detonate, then the muzzle velocity from the largest gun would be insufficient. The plutonium shy would be fired too slowly to prevent the bomb from just fizzling out.

In contrast to the gun method, implosion offered the possibility of assembling a critical mass much faster and more reliably. Even better, Teller now realised, a very violent shockwave could compress a sub-critical mass of plutonium to super-criticality. Implosion would literally squeeze the mass to a super-critical density which would then explode, without the need to assemble a larger super-critical mass of normal density from a hollow sphere made up of separate components.

However, implosion would not be workable unless a spherical shockwave could be created with conventional explosives packed around the outside of the bomb core. The mathematical physicist John von Neumann had demonstrated that, to be effective, an implosive shockwave would need to be spherically symmetrical to within a tolerance of just 5 per cent. In early July, Neddermeyer had set to work with modest implosion experiments set up on a mesa south of the Los Alamos laboratory, across Los Alamos canyon. These involved detonating conventional explosives wrapped around short lengths of pipe, so that the pipes would close in on themselves to form flat metal bars. Early results looked distinctly unpromising, the pipes emerging bent and twisted, indicating that the shockwaves thus generated were far from symmetrical.

A uranium or plutonium bomb based on the gun method would be long and thin – about seventeen feet long with a diameter of about two feet. Serber named this design ‘Thin Man’, after the 1933 Dashiell Hammett detective story and the series of movies it had spawned. It was estimated that a plutonium implosion bomb, if implosion could be shown to work, would be a little over nine feet long and five feet in diameter. Serber named it ‘Fat Man’, for Kasper Gutman, the character played by Sidney Greenstreet in the movie The Maltese Falcon.

Experiments to investigate how bombs with such dimensions might be dropped from a B-29 bomber began in August 1943. The plane, which was just beginning large-scale production for the American war effort, would need to be modified to carry the bombs to their target, and the experiments were designed to discover precisely what modifications would be required. To preserve security, in their phone conversations air force personnel would refer to these modifications as though they were being made to the planes in order to carry Roosevelt (Thin Man) and Churchill (Fat Man).

Slept most of the way

By August 1943 the situation in Denmark had changed. The terms of Danish government co-operation with the German occupying forces had included protection for Denmark’s 8,000 Jews. The growing boldness of the Danish resistance, and the increasing frequency of demonstrations, strikes and acts of sabotage, led German forces to declare martial law and re-occupy Copenhagen on 29 August. The Nazis started to arrest prominent Danish Jews.

On 28 September, Bohr received word from a sympathetic German woman working in the Gestapo offices in Copenhagen. She had seen the orders for Bohr’s arrest. A cable from Chadwick and Cherwell advised him that his escape from Copenhagen had been granted priority by the British war cabinet. Bohr contacted members of the Danish resistance, and an escape route was prepared.

In early evening the next day, Bohr and his wife Margrethe walked to the Sydhavn quarter of Copenhagen close to the shores of the Øresund, the strait that separates Denmark from southern Sweden. They joined about a dozen others, including Niels’ brother Harald and Harald’s son Ole, in a small Kolonihavehus, not much more than a large garden shed, and waited for darkness to descend. At a pre-arranged time they crawled towards the beach, Bohr feeling rather self-conscious, and boarded a fishing boat that took them out across the Øresund. They then transferred to a large trawler and made their way to Linhamn, near Malmö in Sweden. They spent the rest of the night in the cells of the local police station in Malmö. Bohr travelled by train to Stockholm the next day, leaving Margrethe to await the arrival of their sons, who would shortly take the same escape route. Gyth was among those waiting at the station.

Gyth had alerted the SIS to Bohr’s dramatic escape, and was told to advise Bohr that he should come to Britain as soon as possible. There were believed to be many Gestapo agents in Stockholm and Bohr was one of the most widely known scientists in Scandinavia. To evade watchful eyes, Bohr was escorted by Gyth in a taxi to a building used by the Swedish intelligence services. They climbed to the roof, crossed to the roof of a neighbouring building, descended and took another taxi. Once safely installed at the home of Oskar Klein, one of Bohr’s colleagues from some years previously, Gyth passed on the message from the SIS and told Bohr that an unarmed Mosquito bomber was available at Stockholm’s Bromma airport to transport him to England.

But Bohr was concerned for the fate of the 8,000 Jews he had left behind in Denmark. On the evening of Bohr’s escape, two German freighters had arrived in Copenhagen harbour to transport the Jews to concentration camps in Germany. When he realised that the Swedish government had no plans to protest against the German intentions, Bohr made a personal plea to King Gustav V of Sweden.

In the meantime, a remarkable series of events had taken place. News of the impending deportation of Danish Jews had spread rapidly through the Jewish community. Within a few days virtually the entire Jewish population was hidden away, as offers of support flooded in from the general public. They hid in strangers’ apartments or cottages, in their homes, in churches and in hospitals, among the patients. In the midst of tragedy, the people of Denmark had risen to the aid of their fellow citizens. Fewer than 300 Jews were caught by the German sweep, which began on the evening of 1 October.

The Swedish protest was broadcast on radio on 2 October, signalling to Danish Jews that there was safe haven to be found in Sweden. A mass evacuation followed, supported by the Danish resistance, local fishermen, the Swedish coastguard and even a German naval commander who declared that his fleet of coastal patrol vessels was in need of repair and could not put out to sea. Over the following two months, 7,220 Danish Jews escaped to Sweden.

With the crisis averted, Bohr left for Britain on 5 October on board a twin-engine Mosquito bomber. There was room in the empty, unpressurised, bomb bay for only a single passenger. Bohr had talked incessantly prior to take-off and had paid little attention to the instructions the pilot had given him. As the plane climbed to 20,000 feet to avoid the risk of anti-aircraft fire as it passed over the Norwegian coast, the pilot instructed Bohr to switch on his oxygen supply.

Unfortunately, the Nobel laureate’s head was too large for the helmet he had been given. As the message was relayed via headphones in the helmet, Bohr didn’t hear this instruction and promptly passed out through lack of oxygen. Sensing that something was wrong, the pilot descended steeply over the North Sea. By the time the plane landed, Bohr had recovered consciousness and appeared fine. He explained that he had slept most of the way.

Bohr was flown to Croydon airport near London, where he was met by Chadwick and an officer of the SIS. He was subsequently installed at the Savoy Hotel, where Chadwick informed him of the Frisch–Peierls memorandum, the MAUD report, Tube Alloys and the American bomb programme. Bohr was completely astounded. He may also at this time have been able to set the record straight regarding Lise Meitner’s telegram. The reference to maud ray kent, to which Cockcroft had given such an ominous interpretation and which had led the MAUD Committee to be so named, was not a coded message at all. Maud Ray was a former governess to the Bohr children, now living in Kent.

Bohr dined with Anderson that evening. Anderson, who had been appointed Chancellor of the Exchequer in September following the unexpected death in office of Sir Kingsley Wood, explained that he would welcome Bohr as a member of Tube Alloys, part of a mission that was to be sent to join the American programme.

The impasse on Anglo-American co-operation on the atomic bomb had been resolved. A series of meetings through the summer months had helped to clear up misunderstandings about British post-war intentions. Britain’s desire was for an independent atomic deterrent against an anticipated Soviet atomic arsenal of the future. It was not Britain’s intention to acquire know-how at the American taxpayer’s expense for commercial exploitation after the war. This appeared to do the trick: Stimson and Bush were mollified. At Churchill’s request, Anderson had then drafted an agreement governing collaboration which Churchill subsequently amended.

In the meantime, Roosevelt himself had come to a decision, on the advice of Hopkins. He had decided that it was incumbent on him to honour the commitments regarding co-operation he had made to Churchill over a year before. Anderson and Bush talked Conant round. So, when Churchill tabled the draft agreement at the Quebec summit conference on 19 August, it was quickly (and, from the Americans’ perspective, rather too hastily) signed. The first four articles were virtually those of the Anderson–Churchill draft. A fifth article set out the structure of a Washington-based Combined Policy Committee with representation from America, Britain and Canada. In the agreement Britain and America committed never to use the bomb against each other, never to use it against a third party without each other’s consent, and never to communicate any information about atomic weapons to third parties without mutual consent. This agreement would cause considerable trouble later, but for now it meant the resumption of full collaboration.

The Americans accepted that the Manhattan Project should become the main focus of Anglo-American efforts to develop the atomic bomb, and that this should be supported by a British scientific delegation, or ‘mission’. Anderson wanted Bohr to join the 30-strong British contingent that was now due to travel to America.

Bohr’s son Aage, himself a promising young physicist, joined him in London a week later, and took the role of his father’s personal assistant. The rest of the Bohr family stayed in Sweden.

Raid on Vemork (2)

Tronstad was greatly concerned by the news that the Germans had managed to get the Vemork heavy water plant working unexpectedly quickly after the successful SOE raid in February. Skinnarland, reporting from a makeshift radio station on the Hardanger Plateau, had estimated that the plant would achieve full production in mid-August. Tronstad was also concerned that a new ‘combustion’ method of separation could, if adopted at Vemork, lead to production at a much accelerated rate. The job that the SOE had set out to do with operations Freshman and Gunnerside was clearly not yet completed. Production was again delayed by small, limited acts of sabotage, in which vegetable oil was added to the distillation vats. But it was again obvious that this could not continue indefinitely. The Vemork plant had to be taken out of commission.

Tronstad tried to devise further large-scale sabotage operations, but the defences at the plant had been greatly strengthened. Vemork was now surrounded by barbed wire fences and minefields, and the garrisons at Vemork and Rjukan had been substantially increased. A further commando raid seemed out the question. The only alternative appeared to be a bombing raid. Tronstad and Wilson remained firmly opposed.

But Groves was insistent. He did not trust the British. He had not been informed of the failed Freshman raid until after it had ended in disaster. He had learned of the Gunnerside raid through a casual remark made by Akers in January. In the new spirit of Anglo-American collaboration embodied in the Quebec agreement, he now urged the British representatives of the Combined Policy Committee to agree appropriate action.

In fact, an SOE memorandum of 20 August 1943 had acknowledged that a bombing raid was the only viable option and should be given active consideration. The memo also advised that the Norwegian High Command and Norwegian government-in-exile should not be informed of such plans. By mid-October, a full-scale ground assault or a further sabotage raid had been firmly ruled out.

Groves was not prepared to take the risk that the German programme might be successful in producing, if not a bomb, then perhaps some sort of radiation weapon. Bohr’s recollection of his discussion with Heisenberg in September 1941, and the diagram of a bomb that Bohr believed Heisenberg had drawn for him, merely compounded the situation. Groves ordered a bombing raid, his first combat decision after a lifetime in uniform.

A force of about 300 B-17 Flying Fortresses and B-24 Liberators of the American Eighth Air Force took off from airfields in East Anglia just before dawn on 16 November 1943, in poor weather conditions. Part of this force headed for targets near Stavanger and Oslo to divert German fighters away from the main force heading for Vemork. The raid had been carefully timed to coincide with the lunch break, between 11:30am and noon, when most of the plant’s workforce would be off-site.

No fighters were encountered and the bombers arrived at the Norwegian coastline twenty minutes too early. The commander, Major John M. Bennett, ordered the fleet to circle back out over the sea and return for the bombing run at the right time. The decision traded civilian casualties for military: as the bombers returned to the coastline, one was shot down by anti-aircraft fire from the now fully alert coastal defences. The crew of a second parachuted into the sea as their plane spun out of the air with an engine on fire.

From their vantage point on the Hardanger Plateau, Haukelid and Skinnarland both watched as: ‘Scores of American bombers were flying across Norway in broad daylight as if no German anti-aircraft defences existed. They began to circle over us and then proceed in an easterly direction, towards Rjukan.’

In the first wave of the attack about 145 bombers dropped more than 700 1,000-pound high-explosive bombs on the Vemork plant. Fifteen minutes later a second wave of about 40 bombers dropped 295 500-pound bombs on Rjukan. But in the Second World War so-called precision bombing was far from precise. The bombs fell everywhere. The plant itself received just two hits, damaging the top floors but leaving the electrolysis cells, in the basement, completely unharmed. The plant’s power station was hit, as was the nitrate plant in Rjukan. Twenty-two civilians were killed.

The Norwegians were absolutely furious, and lodged formal protests with both the British and American governments. They argued that the attack ‘seems out of all proportion to the objective sought’. Tronstad pointed out that he had given all the reasons why a bombing raid would not be successful four months before.

And yet the raid was successful, if not quite in the manner intended. The Germans had finally got the message that the Vemork plant was not safe, that the Allies would continue to attack it until it was utterly destroyed. Production of heavy water at Vemork was stopped and plans were laid to build a plant in Germany.

Oath of allegiance

Frisch was asked by Chadwick in November 1943 if he would like to work in America. ‘I would like that very much’, was his reply. ‘But then you would have to become a British citizen’, Chadwick warned. ‘I would like that even more.’ Within a few bewildering days he had pledged his oath of allegiance to the British Crown.

Chadwick had been eager to recruit the best scientists in Britain to join the delegation to America. To give the mission the best possible chance of success, he also sought to recruit nuclear physicists from outside Tube Alloys. Chadwick was well aware of Lise Meitner’s discomfort in Stockholm, and asked if she was willing to join her nephew in America. Meitner was unambiguous: ‘I will have nothing to do with a bomb’, she replied.

British Nobel laureate Paul Dirac had acted occasionally as a consultant to the MAUD Committee on aspects of isotope separation and bomb physics. Keen to have such an eminent physicist in the delegation, Anderson telephoned Dirac in Cambridge and asked him to call into his office when next in London. Dirac agreed. As an afterthought, Anderson asked how often Dirac actually came to London. He replied: ‘Oh, about once a year.’ Dirac, too, refused to join the British mission.

All selections were subject to scrutiny by Groves, who had insisted that only British citizens would be accepted, and that they should arrive with full security clearance. Frisch’s enthusiasm for British citizenship was not shared by Rotblat, however, who was adamant that he would remain a Polish citizen and return to Poland to rebuild physics there when the war was over. Rotblat judged this mission to be more important to him than working on the Anglo-American bomb programme. Chadwick made personal representations to Groves on Rotblat’s behalf, giving assurances of Rotblat’s integrity. By this time Chadwick had managed to build something of a rapport with the notoriously blunt, anti-British head of the Manhattan Project. Groves accepted, and Rotblat joined the delegation as a Polish citizen.

Chadwick, Frisch and Rotblat were to go to Los Alamos, with British physicists William Penney and James Tuck. Oliphant was to join Lawrence’s team at the Rad Lab in Berkeley. Peierls and Fuchs were to head for New York to join the work on gaseous diffusion.

Fuchs had already pledged his oath and taken British citizenship a year earlier. British intelligence gave him a security clearance after a rudimentary background check. He advised his Soviet contact Sonja of his impending move. NKVD and GRU atomic intelligence activities had been consolidated with the NKVD First Chief Directorate under the umbrella of ENORMOZ just a few months earlier. Sonja moved quickly. At their next meeting she advised him that his controller in New York would have the cover name Raymond, and gave him a series of coded recognition signals he should use to make contact.

Barely a week after being approached by Chadwick, Frisch found himself at Liverpool docks, part of a group of about 30 scientists, some with their families. They were to board the Andes, a luxury liner that had been converted to bring American troops to Britain. Frisch had forgotten his ticket but Akers waved him through. He found he had an eight-berth cabin all to himself. ‘Some of us got seasick,’ Frisch wrote after the war about the delegation’s journey to America, ‘but otherwise the journey was uneventful, and the ship arrived safely, with perhaps the greatest single cargo of scientific brain-power ever to cross the ocean.’

And in their midst was a Soviet spy.

Niels and Aage Bohr headed for America on the Aquitania, early on the morning of 29 November, accompanied by an armed detective. When they arrived they were given the cover names Nicholas and James Baker.

Arlington Hall

In June 1942, the US Army Signals Security Agency had moved into new premises, a former private girls’ school set in 100-acre grounds on Arlington Boulevard, Arlington, Virginia. The school had been named the Arlington Hall Junior College for Women, and the name Arlington Hall (or, sometimes, Arlington Hall Station) was retained. In many respects, Arlington Hall was the American equivalent of Britain’s Bletchley Park.

By October 1943 the analysts at Arlington Hall had identified at least five different variants of the Soviet cipher system. One was used primarily for trade messages originating from Amtorg, the Soviet trade agency, and the Soviet Purchasing Commission which supervised Lend-Lease aid from America. A second was used by Soviet diplomats. The remaining three systems were being used by Soviet spies belonging to the NKVD, the GRU and the Naval GRU.

Lieutenant Richard Hallock had worked as an archaeologist and had studied the ancient languages of Babylonia before joining Arlington Hall. Now he was charged with studying a vast pile of paper consisting of about 10,000 coded Soviet trade and diplomatic messages – page upon page of apparently random and meaningless groups of five letters. But, of course, the groups of letters were not meaningless. Penetrate the cipher system and the coded messages would be revealed. Acquire a codebook or somehow break into the code and the messages themselves could be read. He confronted the stubborn question: where to begin?

He figured that at the beginning of each message there might be a reference to the subject matter that followed, a pattern that would, perhaps, be repeated for every message, much like addressing conventions in personal or business letters. He arranged for the clerks at Arlington Hall to produce punch cards containing the first five five-letter groups, converted to five-number groups, for all 10,000 messages. When these punch cards were run through a sorter, he noticed that seven messages conformed to a pattern. Although unrelated, the messages appeared to have been encrypted using the same cipher key.

For some unknown reason, some of the one-time pads had in fact been used more than once.

* Which the German physicists had not dared to touch.

† This was a convention that dated back to Mansfield Cumming-Smith, the first head of the SIS, who would initial papers that he had read with a ‘C’, written in green ink. Ian Fleming would later adopt a similar convention for his fictional ‘M’.

‡ More recent estimates put the death toll at over 21,000.

§ It seems the author of the letter was Mironov himself. He also sent a letter to Stalin denouncing Zarubin as a double agent, and both Zarubin and his wife were recalled from Washington in the middle of 1944. Zarubin was able to demonstrate that all his contacts with Americans were legitimate and both he and his wife were cleared. Mironov was then recalled to face charges of slander, but was discovered to suffer from schizophrenia and was subsequently discharged from the NKVD.