Half Life: The Divided Life of Bruno Pontecorvo, Physicist or Spy, by Frank Close

A biography of a secretive scientist comes with a cast worthy of a le Carré novel, says Jon Turney

March 12, 2015

At the midpoint of the last century, memories of two world wars were receding but the mutual suspicions of two great power blocs threatened a third. When Bruno Pontecorvo, a physicist at the UK government’s secret atomic laboratory at Harwell in Oxfordshire, disappeared while holidaying in Europe in the summer of 1950, the press opted for the simplest explanation: he was a spy who had fled to the Soviet Union. He surfaced five years later in Moscow, explaining his abrupt departure as a result of misgivings about work on nuclear weapons, along with harassment by the authorities. But the spy story still seemed a better fit.

Pontecorvo, who lived and worked in the USSR until his death in 1993, never admitted to espionage. Nor was he ever formally accused. But his career had much in common with those of spies such as Klaus Fuchs, who began passing information to the Soviet Union while working at Los Alamos on the first atomic weapons and continued when he, too, moved to Harwell. The similarities between Pontecorvo and the likes of Fuchs include a life deeply marked by the turbulence of the mid-20th century, scientific brilliance that led to a close involvement with secret work and military research, and long, tangled relationships with the security services of several countries.

Some of the records of those services have become more accessible since Pontecorvo’s death, and they help Frank Close to revisit tantalising questions about his life. Was he a spy? Will we ever be sure? And does it really matter? Close is equally interested in his subject’s scientific achievements, which are easier to assess, and the two aspects of this “divided life” add up to a remarkable story.

It started in Italy, where Pontecorvo began research in the 1930s with the great Enrico Fermi, already a star of the new physics. Fermi’s group was exploring unstable nuclei and particle interactions, and Pontecorvo became an expert on experimental detection and measurement of radiation, and especially on the behaviour of neutrons – soon to become a matter of intensely practical as well as scientific interest in attempts to exploit nuclear fission.

Fermi left Rome for the US in 1938, two years after Pontecorvo moved to Paris to work with Irène and Frédéric Joliot-Curie. A Jewish intellectual exiled by Italian fascism, Pontecorvo became a communist and a supporter of the Soviet Union. When the Nazis invaded Paris in 1940, his last-minute escape took him to North America.

Much of the early history of nuclear fission related here is familiar, although Close weaves it into the story skilfully. His account of Pontecorvo’s pioneering first job in the US, however, is more surprising. He turned his knowledge of radioactivity to oil prospecting. The emissions from different minerals under neutron bombardment can reveal the location of oil-bearing rock, and this is a technique still used today. By 1943 he was in Canada, working on an Anglo-Canadian project to build a nuclear reactor. The Federal Bureau of Investigation had already visited his home in the US, and noted a small library of communist literature, but somehow this was no bar to classified work.

Like the later reactor project at Harwell, the wartime effort in Canada was tightly bound to weapons development, with a reactor expected to generate new fissile materials suitable for bomb-making. It also involved a certain amount of spying, but on behalf of the British, who were supposed to be kept abreast of US research but found official channels silent. Informal contacts with other scientists, especially those at Los Alamos, kept the researchers in Canada informed.

After Pontecorvo’s post-war move to Harwell, scrutiny by the security services intensified following the exposure of first Alan Nunn May, his colleague in Canada, and then Fuchs, as Soviet agents. Pontecorvo was interviewed at length by MI5, and a new job was found for him at the University of Liverpool. He never took up the post. A letter from the British Embassy in Washington to London detailing suspicions about the physicist passed across the desk of the double agent Kim Philby, who it seems safe to assume notified the KGB. Pontecorvo’s flight, with his family, followed soon after.

It is a tale whose le Carré-esque cast of spies, double agents, couriers, intercepted messages and clandestine escapes cries out for dramatisation. Close tells it well, but eschews any novelistic invention of scenes whose details he cannot know. Just one example: what, one is bound to wonder, transpired the day in 1975 when Pontecorvo presented himself unannounced at KGB headquarters and demanded to meet Yuri Andropov, the Politburo member in charge? What, indeed, was the conversation when Pontecorvo, denied that meeting, was visited by his KGB minder to discuss freedom of movement, a concession he did not win for several more years?

His appeal to Andropov is one of many pieces of circumstantial evidence that suggest that Pontecorvo had indeed spied for the Soviets. Close patiently builds up a picture of a charismatic, clever, complicated man, who was often disingenuous and retained his faith in Soviet communism longer than most, although he became disillusioned after the 1968 invasion of Czechoslovakia. For most of his time in Russia, he did research in nuclear physics, and Close also makes a detailed case that his insights into subatomic particles, especially the elusive neutrinos, were a major contribution to what is now the standard model of particles and forces, and would have earned him a Nobel prize had he remained in the West.

That, of course, cannot be proved. On firmer ground is Close’s conclusion that, even if Pontecorvo had passed information to the Soviets before his move, his presence in Russia after 1950 was probably more valuable. The significance of such spying is sometimes minimised by arguing that the most important thing to know about the atom bomb was that it could be built, which could never be a secret. Even so, there was an enormous amount of know-how in working successfully with nuclear materials, and Pontecorvo had both formal expertise and a big store of tacit knowledge. That the Russians already had samples of uranium, and reactor designs, from the Canadian project at Chalk River where Pontecorvo worked, undoubtedly helped as well.

Even so, as Close sifts carefully through a wealth of documentation on the case, much of it still heavily redacted, it is not possible to say conclusively that Pontecorvo was personally responsible for passing secrets before his flight. Between the US and UK security services’ interest in minimising his importance after his disappearance, the large claims made by some later KGB defectors about what he conveyed, and with a background of shifting alliances and enmities between states striving to exploit the new physics, there remain many grey areas.

There is, at least, very good evidence that this state of affairs suited the physicist. As well as an agile mind and a strong belief in the Soviet cause, Pontecorvo, it is clear, had one other quality that – paradoxically – suits a spy. He was a resolute and skilful keeper of secrets. Close’s subtitle is justified in one sense. The life does divide down the middle, before and after Pontecorvo’s flight to the USSR. But “physicist or spy” seems a false antithesis. The impression the reader is left with, as Close surely intends, is that he was very likely a physicist and a spy – and very good at both.

Half Life: The Divided Life of Bruno Pontecorvo, Physicist or Spy

By Frank Close
Oneworld, 402pp, £20.00
ISBN 9781780745817
Published 5 March 2015

The author

A Peterborough boy born and raised, Frank Close confesses that he is “stuck with being a supporter of the Posh - the local football team. But I am not sure if that qualifies as a habit or a personality trait.”

Professor of physics at the University of Oxford, and formerly the head of the theoretical physics division at Rutherford Appleton Laboratory, Close lives in Oxfordshire with his wife Jill, some 50 miles away from their two adult daughters, and grandsons aged 3 and 5. “We had a cat for 20 years, most famous perhaps as having come from the same litter as Philip Pullman’s, but it’s now buried under a tree in the garden.”

As a boy he was head chorister at Peterborough Cathedral, and recalls “spending a lot of time trainspotting – which, after you’ve stopped laughing, I recommend! I shall encourage my grandsons to do this, as it made me familiar with numbers and helped to build confidence with mathematics.

“My father was an accountant and taught me tricks with numbers when I was very young – if the digits add to 3, 6 or 9 the number is divisible by three, for example. I loved reading. I started to read the non-fiction books in the local library; the return date-stamps showed which were the most popular. I then found one that had been taken out only once in 20 years: The Principles of Quantum Mechanics by Paul Dirac. I didn’t understand a word of it at the time, but have often wondered who the other reader could have been.”

His undergraduate years were spent at the University of St Andrews, where he recalls being “excited that, having been to a single-sex school, there were lots of girls (although not so many in physics). That’s where I met Jill (who had not met a physicist before, nor anyone from Peterborough). I couldn’t decide which of maths, applied maths or physics to specialise in for my final two years, so I did them all to become a theoretical physicist.”

After doctoral work at the University of Oxford and a postdoctoral fellowship at Stanford University, Close spent two years in Cern (1973-73), and would later return there to head its communications department between 1997 and 2000. Does he think it likely that there would have been scientist-spies at Cern in either period?

“There were two physicists from East Germany in the 1970s, who were husband and wife, and who wrote research papers together. The female was a strong scientist, and interacted in seminars at Cern, but the husband was by contrast very quiet. Later I learned he had been made persona non grata at Cern, having been found going through the personnel files. Looking back, I cannot recall him ever showing any evidence for being a real physicist, and with hindsight I suspect that she was his cover,” says Close.

“I think that the mid 20th century – 1940s and 1950s – was special, as intellectuals had grown up under the spectre of fascism versus communism in the 1930s. They had seen the USSR lose millions of citizens in the war against fascism, and yet these allies were excluded from the atomic bomb. If there’s any surprise, it may be that so few actively shared their know-how with the Soviets - or perhaps they did, and we only know of the handful who were exposed!”

Half-Life ends with Rudi Peierls’ words about Pontecorvo, “You can never tell”. Which is the greatest challenge for a biographer: the essential unknowability of an individual, the limitations of archival records, or the incomplete/fallible/compromised nature of other people’s reminiscences?

“All three!” says Close. “I was very much aware of this when researching my previous book, The Infinity Puzzle, which is the history of the quest that culminated in discovery of the Higgs Boson. Different individuals not only had conflicting memories, but also of the relative roles of various characters present at an event. As a result I prefaced the book with a quote from Shakespeare’s Henry V: ‘Old men forget…But he’ll remember with advantages what feats he did that day.’ There is both frustration and enjoyment when reading MI5 files in the National Archives: frustration when a critical name or fact is redacted, and much enjoyment, and ironic chuckling, when another document makes a reference, which clearly identifies the redacted information. I give one example in Half Life, but if MI5 wants me to do their work for them, they will have to read the book first, and anyway, the information is now out there!”

In 2015, after the end of the Cold War, but in a world that nevertheless is hardly politically secure or peaceful, does Close feel that readers are more likely to be accepting of a neutral, warts-and-all, but not polemic, biography of Bruno Pontecorvo, a man whom many would have seen as at worst a traitor and at best a dupe?

“Many may have seen Pontecorvo as a traitor – indeed, Alan Moorehead’s book The Traitors, written in 1952, described him as such, but one of my revelations is that there was never any solid evidence that he was involved in espionage, and that the files of the Security Services were filled more with gossip than hard facts.

“And even if he did pass secrets to the Soviet Union, they were our allies, so he was never a ‘traitor’ in the usual definition of the word. Before anyone rushes to judgements about Pontecorvo, or any of his contemporaries, it is important to note that the world in which they grew up differed radically from ours today. I repeat what I said earlier: if you were a student in the 1930s, you had a choice – to support fascism or to oppose it. I sense that people today are more ready to accept that stark reality than perhaps readers of the 1950s and 1960s, when society was much occupied with the Cold War and books denouncing ‘traitors’ first appeared.”

In Half Life, Close acknowledges the input of very many people in the writing of the book, including Pontecorvo’s family and friends - some of whom will have cared for him very much. Did he hope that his book would offer them new insights and understanding - and did he expect anyone to have been hurt by what he uncovered?

“I hope no one has been hurt, but there were some uncomfortable facts that emerged, and if one is to maintain integrity it is necessary to include them. For this reason, in part, I took great care to separate facts from speculation, and to clarify which is which. I can find it depressing sometimes to be in archives and to be reading files about people who are long dead, but whose family members who are alive; I feel as if I am going through their dirty linen, accessing information that relates to them, but which they themselves have not read and may even be unaware of.”

He adds: “It was fascinating though when, after nearly two years of research, I met two of Bruno’s sons, several nephews, and a sister, at a gathering to celebrate the centenary of his birth. We were all chatting over coffee, and suddenly it became clear that I knew more about their family than they individually did.”

Science books for a general readership are often the work of journalists rather than research scientists. Does Close think that more of the latter group should undertake such initiatives, and does a good book about particle physics mean more coming from a research-active particle physicist than even the most diligent non-specialist?

“Imagine knowledge displayed on a graph,” Close begins. “Expertise is displayed on the vertical axis; subjects are ranged along the horizontal. A great science journalist will span the entire horizontal, with a low plateau; the specialist scientist will produce a huge needle, but with very little horizontal spread. The areas in both are the same. Their popular books, as a result, may be complementary – the journalist making connections that the specialist researcher cannot, but the researcher will, by definition, have more insight into the day-to-day reality of the particular subject than the professional writer.

“Being a great researcher does not necessarily make for a good writer; editors can help – and in some cases, where a scientist whose eloquence in seminars or research papers is unremarkable produces an eminently readable book, one suspects that an editor has produced the work almost as if a ghost-writer.”

Asked to compare the situation when he was vice-president for the British Association for the Advancement of Science, and today, does he feel that we have seen significant gains in the public (and governmental) acknowledgement of the importance and social/economic value of science? Or is this a battle that must be fought at all times?

“It is certainly much easier now to get hard science, such as physics, on to mainstream media than in the past. I still recall, just 20 years ago, soon after I gave the Royal Institution Christmas Lectures, being assured by a senior television gatekeeper that ‘it’s not possible to show particle physics on television’. Thankfully that is no longer the case; Brian Cox and Jim Al-Khalili in particular have shown that it is possible to produce exciting television, which tackles hard science, while the Large Hadron Collider and the Higgs Boson have become iconic.

“On the other hand, I used to enjoy Horizon more then than I do now. Perhaps it is because I am getting older and more serious, or perhaps it is the nature of the content itself, but what used to be for me a serious engaging exposition of science too often now seems to be a tabloid piece of entertainment geared to short attention spans. I am seriously worried about the appreciation of science on a worldwide stage; three centuries after the enlightenment, scientific critical thought is under attack in some societies. And I am astonished that, in our own country, a belief in astrology can be accommodated on the Science and Technology Committee,” he adds.

Close’s many acclaimed books – he is a three-time winner of the Association of British Science Writers Award – have addressed subjects on the order of infinity, the void, nothingness, neutrinos and cosmic catastrophes. What remains to be addressed?

“I am writing a short book on my lifelong fascination with solar eclipses. The fall-out from Half Life (sorry about mixing metaphors) is that I have developed an interest in the emergence of nuclear physics in the 1940s and of the spies that it spawned. So I am researching the relationship between my former mentor, Rudi Peierls, and Klaus Fuchs – the physicist and spy, who was taken into the Peierls’ family home and then betrayed his friends, his colleagues, and the nation that had adopted him.”

And, he adds, “depending upon how my grandsons’ questions about the universe pan out, I would love to write a physics book for five-year-olds”.