Norman Moss - Klaus Fuchs - The Man Who Stole the Atom Bomb

Klaus Fuchs was in Berlin for five months, in hiding. Then, in August, he went to Paris, to attend an anti-fascist conference under the chairmanship of the French writer Henri Barbusse. The party told him to go; he said later that he was ‘sent by the party’. He had very few belongings and very little money, and when he crossed the border, he knew he could not go back.

He was only twenty-one. It must have taken strong nerves, and all the self-assurance his father had noted, to keep his head. He was exiled from his country. All the things that made up the structure of his life — family, friends, career, political activities — had vanished, and he was alone and penniless.

Outside Germany, many people felt revulsion against what was happening there. There was a fund of goodwill and sympathy towards the victims, and this came to Fuchs’s rescue. A cousin of his was engaged to a girl who was working as an au pair with a wealthy English couple, Ronald and Jessie Gunn, in the village of Clapton in Somerset. Fuchs wrote to her from Paris, telling her of his circumstances. She showed the letter to the Gunns and, generously, they wrote to Fuchs immediately, inviting him to stay with them. Fuchs always said later that the Gunns were Quakers and that he had contacted them through his father’s Quaker friends. In fact, there is no record of their having belonged to any Quaker organization; they were Communist sympathizers. It seems that in linking them to the Quakers, Fuchs was trying to protect them from any difficulty that could have arisen from their acting out of political sympathy.

He arrived by Channel steamer at Dover on 24 September 1933, one of the first of a wave of refugees from Nazism who would land on British shores, carrying his few belongings in a bundle; thin, pale and hungry. Because he was going to a village near Bristol, he told the immigration officer that he was planning to study physics at Bristol University; but this was no more than a vague hope, and an answer to give to an official question.

Fuchs went to the Bristol area only because of the fortuity of the Gunns’ invitation, but had he chosen his location he could hardly have chosen better. Bristol University was not one of the country’s biggest, but it had a large and well-equipped physics department that was the equal of any in Britain outside Oxford and Cambridge, thanks to a generous endowment from the Wills family, heirs to the Imperial Tobacco Company. Furthermore, the newly appointed head of the physics department, Professor Nevill Mott, at twenty-eight the youngest full professor in the country, had studied at Göttingen University, spoke fluent German, and also had strong left-wing sympathies. And furthermore, Mrs Jessie Gunn was a member of the Wills family, so the Gunns were in a position to introduce their young house guest to Professor Mott, which they did. They asked him whether he could find a place for Fuchs in his department.

Mott took him on as a research assistant. He was soon glad that he had done so. He found Fuchs very talented and capable although not, perhaps, gifted with the kind of profound intelligence that produces great new discoveries about the nature of things. He was also persistent; if he was given a problem, he would plug away until he had solved it. Mott had a grand scheme to apply quantum mechanics, the mathematics of the shadowy sub-atomic world, to solids, and use this to explain certain properties of the materials. Several of his research assistants worked on aspects of this.

Fuchs was now a changed personality. He was in a strange country, cut off from all his social ties, where he could not even speak or understand the language with any more than a schoolboy’s half-forgotten competence. Psychologically as well as legally, he was an alien. He developed caution, the caution of the exile, who does not know how his behaviour or his opinions will be received by the strangers about him. He became reserved, withdrawn, even cold. The political enthusiast who had addressed meetings and argued passionately now spoke very little, and kept his thoughts and feelings to himself. This was the Klaus Fuchs that the world knew from now on.

Always self-contained, as his father had noted, he learned now to do without ties to other people, and withdrew into himself. The self-reliance which had been observed in him when he was a teenager was now vital to him. He relied for assurance only on his own intellectual appreciation of the world. He was a Communist, but he had learned that this was a dangerous thing to be, so he kept it to himself. Perhaps he discussed his political views with the Gunns, who had taken him into their home as a Communist refugee and had friends among German Communists, but he did not discuss them with anyone at the university.

He studied politics, but in the privacy of his room, and he worked out his conclusions in his own mind. Previously, he had thought of Communism primarily in the context of Germany’s political situation. Now he looked at it in a worldwide framework. He studied the principles of Marxism, and the Marxist view of the historical process. Like many scientists of the time, he was attracted by Marx’s teaching that Man need no longer be at the mercy of historical forces but could now understand and control them, as he was coming to control the forces of nature. Politics was now a part of his private life rather than his public life. It was a matter of deciding what to think rather than what to do.

He did engage briefly in one overt quasi-political activity in Bristol: he did some work for a committee set up to help Spanish Republican refugees in the Spanish Civil War. Most British people may have regarded this as simply an anti-fascist humanitarian group, but so far as he was concerned it was a Communist organization and this was why he helped it.

His physics also was a cerebral activity. It was not experimental or applied, but theoretical physics: the problems were worked out in his own mind. In quantum mechanics in particular, one is working with mathematical terms that do not represent objects at all in the sense that the things in the world about us that we can see and feel are objects. The quantum world is one of paradoxes, of incompatibles, yet when the right mathematics are applied to it, it works. Some physicists are bothered by the philosophical implications of this, and the nature of the reality with which they are dealing, but Fuchs was not of this cast of mind.

He worked on the application of quantum mechanics to explain electrical resistance in the thin films of certain metals. For a while, he worked on this in collaboration with Bernard Lovell, then another young research assistant, later to be Sir Bernard Lovell and one of the founders of the new science of radio-astronomy. Lovell was a robust, cheery young man, and he did not take to his pale, weedy-looking collaborator; he found him too reticent, too bottled-up, for his taste. ‘He seems like a chap who’s never breathed any fresh air,’ he told others. And indeed he did seem rather anaemic-looking: pale-complexioned, with spindly arms and legs and a narrow chest, bespectacled, he was the image of the awkward, unsociable, bookish young scholar.

Bristol University consists of a number of Victorian buildings around the town, which weaves in and out of the fingers of water that contain or used to contain the docks, but the physics building that was built with the Wills family money was newer. The research assistants were mostly young, and keen, and convivial with graduates in other departments. Young men in blazers and pullovers, borrowing money from one another at the end of the month, they would often go to a pub in an evening, or pile into an old car to go somewhere for the weekend. At first someone or other would often ask Fuchs to join them on an outing, but he never accepted and did not encourage such invitations.