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

  But there was one thing Peierls did know: Pontecorvo’s presence in the USSR had been revealed in 1955. The Soviets, for reasons best known to them, had kept his defection a secret for five years, and then suddenly revealed him to the world’s media. As shocking as it was, the disclosure had actually explained very little; questions as to why he had defected so suddenly, whether he had been coerced, and whether he had anything to hide remained unresolved.

  Moreover, even after Pontecorvo’s location had been revealed, little had been seen of him. His research reports were published in Russian journals, their English translations appearing only months later. These papers were like the tip of an iceberg, the visible sign of Pontecorvo’s professional existence, while his life, and the circumstances that took him to the USSR, remained out of sight.

  In 1973 I went to Eastern Europe to attend a specialized physics school, where I met Russian scientists for the first time. Pontecorvo had been listed as one of the lecturers, but he never materialized, and one of his research collaborators stood in for him. One evening, my confidence boosted by vodka, I asked my Russian colleagues about Pontecorvo but came away little wiser. Perhaps my companions were more expert with vodka than I. Pontecorvo the scientist was easy to learn about, but the man was an enigma. Charismatic, extrovert, and life and soul of the party were the headline descriptions, sentiments that I have heard repeated subsequently by numerous other colleagues. However, as to what lay behind this exterior, I learned little.

  One of the Russians I got to know during this time was Alexei Sissakian. Alexei, who decades later would become the director of Dubna, was then, like me, a young theoretician. The tale of Bruno Pontecorvo fascinated him too. Alexei told me that he had heard Pontecorvo’s name “while still a schoolboy. Its unusually ardent ring surprised me. It was always surrounded by an aura of mystery and legend. Very little was written about him. Schoolchildren and students of my generation knew little about him. We only knew that there was a ‘secret’ professor at Dubna, who for ideological reasons had decided to transfer with his family to the USSR. . . . I think we shall never succeed in understanding the mystery of his transfer to the Soviet Union.”5

  Two years after that encounter, I was working in England, at a laboratory adjacent to the one Pontecorvo had fled. What’s more, I discovered that I was living five minutes from Pontecorvo’s former home in Abingdon-on-Thames, and was working with some of his former colleagues. Some senior members of the Abingdon tennis club remembered him: he had been a champion, always neatly dressed in white. His son would ride a bicycle around the courts while he played.6

  MY INTEREST IN PONTECORVO THE PHYSICIST WAS REAWAKENED IN 2006 following the death of Ray Davis, an American physicist who had won a Nobel Prize at the age of eighty-seven by building on one of Pontecorvo’s ideas. Pontecorvo had died in 1993, and so missed out on a share of the prize. As I researched Davis’s life, first for an obituary and then for a book about him, I discovered the extent of Pontecorvo’s own brilliant contributions to physics.

  Pontecorvo devoted much of his later career to the study of the enigmatic neutrino, a subatomic particle produced in nuclear reactors and in stars. His work inspired a new branch of science: neutrino astronomy. Pontecorvo’s lack of recognition by the Nobel committees was no fault of theirs; rather, it resulted from a combination of bad luck and Pontecorvo’s choice to live in the USSR. The vagaries of Soviet politics prevented him from performing critical experiments. His theoretical ideas were secreted for years in Russian journals, unknown in the West. Thus, instead of being one of the most famous scientists of the twentieth century, Pontecorvo is largely unknown, except as one of the “traitors” who leaked the secrets of the atomic bomb.7

  The question of whether he was in fact a spy has been a cause célèbre for more than half a century. KGB agents have named him as one, but he himself never confirmed it. The intelligence agencies of the United Kingdom, the United States, and Canada all vetted him. None found any conclusive evidence. On more than one occasion they cleared him for classified work.

  Decryptions of Soviet ciphers show that there were several spies operating in the West during the time in question, each identified by a nom de guerre, such as Elli, Kelly, and Moor, whose true identities have never been unambiguously established. For over sixty years there has been speculation as to whether Bruno Pontecorvo was one of them. Following his disappearance in 1950, the Western media claimed that he had been on the verge of being exposed as a spy, like Fuchs and Nunn May before him, and so had jumped ship. The British government, misled by their security services, attempted damage control by portraying Pontecorvo as a scientist who had never worked on the atomic bomb and, by implication, had no worthwhile secrets to give to the USSR. Meanwhile, British intelligence began a forensic investigation into Pontecorvo’s disappearance, led by Ronnie Reed, the head of counterespionage against the USSR.8

  Although Central Casting might have chosen the dashing Bruno Pontecorvo for the role of James Bond, the real-world intelligence officer could have passed for a bank clerk. Three years younger than his quarry, slightly built, with large ears, a prominent nose, and a wispy mustache, Reed was unlikely to strike fear into a suspect through his physical presence. Nonetheless, this former electronics engineer had monitored communications between secret agents during World War II, and in the war’s aftermath had proved adept at identifying fleeing Nazis who had disguised themselves as civilians. Though Reed was no scientist, he shared Bruno’s talent for methodical investigation, as well as his persistence, insightfulness, and healthy skepticism. He would need to uncover the mechanics of the Pontecorvos’ flight, but this was less important than understanding the reasons. Reed prepared to build a complete picture of his prey: his expertise, his colleagues, and his politics. To do this, he began by researching Bruno Pontecorvo’s history.

  LIKE REED, I BEGAN MY WORK BY EXAMINING PONTECORVO’S BACKGROUND. Sixty years have passed since Reed’s investigation, so I had several advantages. We now know what became of Pontecorvo, how the Soviets regarded him, and how he, in turn, regarded them. Also, being a nuclear physicist myself, I could assess Pontecorvo’s scientific value—to the international community of physics throughout his life, and to the USSR in 1950. In any case, one thing was clear to me from the start: if he was a spy, he paid a huge personal price, greater even than the price paid by Klaus Fuchs and Alan Nunn May, who each spent but a short period in jail. The Soviets placed severe restrictions on Pontecorvo’s freedom (similar to the constraints placed on on British traitors Guy Burgess, Donald Maclean, and Kim Philby, fellow émigrés to the USSR), and for years cut him off from all contact with his family in the West. They also placed restrictions on his scientific research. Nevertheless, my knowledge of nuclear physics had for some time led me to suspect that Pontecorvo’s significance to the USSR, during the final years of Stalin’s tyranny, was probably far greater than has been generally recognized. After 1950, the USSR was desperate to build nuclear reactors, as well as other equipment that would enable them to develop an arsenal of atomic weapons, and hydrogen bombs in particular. Fuchs had passed atomic secrets to the Soviets before 1950, as had other spies, but his expertise was not available to them during Stalin’s final years. Pontecorvo, however, was in the USSR, where his knowledge of nuclear science could be tapped by both the scientific community and the government.

  This possibility crystallized my personal quest to resolve the lingering questions surrounding Bruno Pontecorvo’s defection: Why did he go? What happened to him in the USSR? Did he claim, like Edith Piaf, “Je ne regrette rien”? In the 1980s I had discovered that his eldest son, Gil, who had been twelve years old at the time of his father’s defection, was now a scientist based at Dubna, and part of a team doing experiments in Geneva, at CERN, the European Organization for Nuclear Research. I too had worked at CERN, but we never overlapped. Recently, by chance, I found myself on a CERN committee that periodically reviewed the team’s progress. In 2011, after half a lifetime,
Gil and I finally made contact.

  “You want to see Volga River?”

  Thanks to the marvels of Skype, Gil Pontecorvo’s face filled the screen of my laptop. Then he turned his camera around, so that it showed the view through the window of his apartment: the Volga, four thousand miles away from my living room in Abingdon, and from the house he had left sixty years before.

  At last I could learn firsthand what had happened.

  FIRST HALF

  “Midway on our life’s journey, I found myself in dark woods, the right road lost.”

  —Dante’s Inferno

  ONE

  FROM PISA TO ROME

  MOST OF THE SCIENTISTS WHO WORKED ON THE MANHATTAN PROJECT grew up in the 1930s, in an era when fascism was on the rise. Large numbers of intellectuals rejected such tyranny; many chose to follow the red banner of communism instead. Bruno Pontecorvo was not unusual in this regard. The events that would lead to his singular role in the history of the Cold War stemmed from experiences during his youth and early manhood, and flowered as a result of the influential people he came in contact with. Their seeds lay in his family history.

  The Pontecorvos of Pisa were a wealthy and intellectually gifted Jewish family. In the nineteenth century, Pellegrino Pontecorvo introduced the spinning jenny to the Italian textile industry. His son Massimo, Bruno’s father, expanded the business, eventually owning three textile factories, which employed well over a thousand people.1

  Bruno hardly knew his grandfather, as he was only five years old when Pellegrino died. Pellegrino nevertheless established the mold within which his children, and later their children, were formed. He was active in the international Jewish community, and in the 1880s rescued Jews fleeing the pogroms in Russia. He inspired the family’s liberal ethics, which became more radical and explicitly antifascist following Mussolini’s rise to power. Bruno and several of his relatives joined the Communist Party in the 1930s.

  Pellegrino’s funeral in 1918 was a big affair. The Russian Revolution of the previous year had inspired unrest among workers throughout Europe, not least in Italy. Even though many Italian tradesmen were threatening to rise against their bosses, the community’s respect for Pellegrino was such that “laborers and industrialists alike” came en masse to his funeral to celebrate his life.2 Indeed, Pellegrino was held in such high esteem that he was given the title of Cavaliere del lavoro, similar to a knighthood in the United Kingdom, in recognition of his dedication to laborers’ rights.

  That same year marked a sea change in global politics. World War I ended; the November Revolution overthrew the German Empire; Italy was in turmoil due to high unemployment and social conflict. The Bolsheviks had taken power in Russia, and there was a real possibility of revolution in Italy too. Into the mess goose-stepped Benito Mussolini.

  In Pisa there was an antifascist demonstration in which several of Massimo’s workers were involved. The local fascist leader, Guido Buffarini Guidi, came to the factory and ordered Massimo to reveal the names of the participants, and the ringleader in particular. Massimo refused. Buffarini Guidi challenged him to a duel.3 Fortunately the duel never took place, but Massimo’s workers always remembered the support their boss had given them. Bruno’s sister Anna recalled that when one of them saw her father in the street many years later, the man threw his arms around Massimo’s shoulders and exclaimed that it was “like seeing the Lord resurrected.”4

  It was into such a family, with antifascism at its heart, that Bruno Pontecorvo was born on August 22, 1913. Bruno was the fourth of eight children—three girls and five boys. Those were days of rigid gender roles: the girls were educated in the liberal arts; the boys were encouraged toward science and technical matters. The most intelligent of the children, in their parents’ opinion, was the eldest, Guido, born in 1907. He emigrated to the United Kingdom in 1938 as part of the Jewish exodus from fascism. There, he became a distinguished geneticist, and a fellow of the Royal Society. Paolo, “the most serious,” was born in 1909. In 1938 he moved to the United States, where he worked on radar and microwaves during World War II. The eldest of the three sisters, Giuliana, born in 1911, was “the most cultured.” She became a journalist and prominent communist.

  Bruno was followed by brother Gillo in 1919, sisters Laura and Anna in 1921 and 1924, and finally, in 1926, the youngest brother, Giovanni. The children’s French governess, Mlle Gaveron, said there would be no need for her to spend time in purgatory “as she had been there already looking after the children—except for Bruno, who was heaven.”5

  IMAGE 1.1. Bruno Pontecorvo as a child. (COURTESY GIL PONTECORVO; PONTECORVO FAMILY ARCHIVES.)

  Each child was talented, so much so that Massimo and his wife, Maria, did not regard Bruno as particularly intelligent in comparison to his siblings. Years later, Bruno remembered that his parents described him as “the most gentle but the most limited.” They also said that his eyes showed him to be “sweet but not intelligent,” an opinion that left him with a shy disposition and an “inferiority complex that haunted me for the rest of my life.”6

  Bruno inherited a natural aptitude for sports. Friends recall his love for alpine skiing, underwater swimming, and, above all, tennis. Throughout his life, Bruno would recount how, at age sixteen, he had been included on Italy’s national junior tennis team and been invited to attend a training camp in France. His parents refused to allow him to go, as they regarded the activity to be a distraction from serious study and wanted him to spend his time preparing for college. The disappointment of a young boy came across in the tale, even after nearly half a century had passed. His parents consoled him. They assured Bruno that his achievements in physics were also first-rate, and that with suitable dedication he could achieve great things there too. Bruno acquiesced—sort of: “Yes, but I would also like to be the Italian tennis champion.”7

  Bruno’s mother, Maria, had grown up in a highly cultured family. Her father, Arrigo Maroni, had been the director of a hospital in Milan, enjoyed the opera at La Scala, and was well known in Milanese society. Her religious background was Protestant.8 Massimo Pontecorvo, however, was still a traditional Jew when Bruno was born. After Pellegrino’s death, Massimo continued to lead the family rituals, but attitudes toward religion in the home were changing. The younger members took part in the ceremonies, but they did so halfheartedly. Their mother was Christian, and the children were not actively Jewish. A young brother—probably Giovanni—even asked one of his older sisters about circumcision, only to be informed that she didn’t know what it was.9 There were no bar mitzvahs in the Pontecorvo family, no bris rituals, no burials in Jewish cemeteries, but nonetheless they “were Jewish enough for Mussolini.”10

  Indeed, the Pontecorvos’ privileged and idyllic life began to unravel with the onset of Mussolini’s anti-Semitic laws. The family dispersed. Guido had already settled in Britain, and in 1939, with the threat of war looming, Giovanni, Laura, and Anna, still teenagers, moved there too. The three siblings completed their education in Britain, becoming, respectively, an agriculturalist, nurse, and language teacher. Bruno’s exodus in 1936, the first of his three great upheavals, had been more gradual.

  Many Italian intellectuals—Jewish and Christian alike—believed strongly in the ideals of liberal socialism. Those Jews who foresaw the consequences of fascism from the start had adopted strong antifascist positions long before anti-Semitism became formalized. Bruno’s cousin Emilio Sereni was especially prominent in this regard.11 Sereni’s mother, Alfonsina, was Bruno’s father’s sister. Emilio, born in 1907, was a powerful intellectual, with a strong personality of almost overpowering intensity. By the age of twenty he was reading Marxist classics avidly, and he soon married Xenichka Zilberberg, the daughter of two heroes of the Russian Revolution.12 Sereni joined the Communist Party of Italy in 1927. In 1929, following in the tradition of his parents-in-law, Sereni, along with his colleague Manlio Rossi-Doria, founded an underground communist organization in Italy. The following year, the fascist police ar
rested Sereni and Rossi-Doria, and the Special Court of State Security, which the fascists had created to “defend the state,” sentenced them to fifteen years in prison. Granted amnesty and freed in 1935, Sereni fled from Italy to Paris, where he became the cultural manager of the Communist Party of Italy, and the chief editor of Lo stato operaio (The Workers’ State). It was during this period, in prewar Paris, two years after Bruno left Italy, that Emilio Sereni would begin to have a considerable influence over his younger cousin—an influence that would frame the course of Bruno’s life.

  PHYSICS IN ROME

  It was far from obvious that Bruno would end up a great physicist. Initially he followed the same route as his older brother Paolo, and at age sixteen enrolled at the University of Pisa to study engineering. After two years, he was doing well but disliked technical drawing, so he quit engineering and, in 1931, decided to concentrate on physics.

  As it happened, Bruno’s childhood coincided with the emergence of atomic physics. He was born in the same year as the insight that every atom is like a miniature solar system, in which “planetary” electrons orbit a compact nucleus at the core. He was a student when physicists realized that an atom’s ability to shed energy through radioactivity results from the instability of the nucleus and began to home in on the neutron, a still-hypothetical constituent of the nucleus. This is when his eldest brother, Guido, made a pivotal intervention.

  Guido was insistent: “For physics you must go to Rome.”13 Enrico Fermi was there, building a huge reputation. In 1926 Fermi had been appointed, at just twenty-five years of age, to a professorship at the University of Rome, funded by Orso Corbino, an influential Sicilian. At the time, nuclear physics was an exciting new field. Quantum theory was being used to build mathematical models of the properties of the nucleus, but experimentally it remained virgin territory. Fermi decided that the best way to revitalize Italian physics was to understand the atomic nucleus, in terms of both constituents and construction, and the relationships between the nuclei of different elements. With Corbino’s support, Fermi established a laboratory in the physics department on the Via Panisperna, in Rione Monti, a few minutes’ walk from the main railway station; to help in the endeavor, he gathered a team of young experimental scientists—a group that became known as the “Via Panisperna Boys.”