Q&A: Tito Pontecorvo, oceanographer and son of nuclear physicist Bruno

Bruno Pontecorvo’s fingerprints are all over neutrino physics. Most notably, in 1969 with Vladimir Gribov, he predicted that neutrinos oscillate. He also proposed that supernovae emit neutrinos, realized that electron and muon neutrinos are distinct, and thought up methods to detect neutrinos.

In 1950 Pontecorvo, who had lived in Italy, France, the US, Canada, and the UK, mysteriously defected to the Soviet Union. He continued to make significant contributions in neutrino physics, but he was seen in the West again only decades later. Historians still debate whether Pontecorvo was a Soviet spy (see box below).

Born in 1944, Pontecorvo’s second son, Tito Nils (named after Yugoslav communist leader Josip Broz Tito and physicist Niels Bohr), was only six years old when he arrived in the Soviet Union. Growing up outside Moscow, in Dubna, where his father worked at the Joint Institute for Nuclear Research, he met many scientists and foreigners. Those connections served him well as an adult, when he repeatedly found himself looking for ways to play the Communist Party system. Tito’s first career was as an oceanographer; later he bred horses. In 1997 he immigrated to the US with his wife, Natasha, and 75 horses.

Physics Today‘s Toni Feder visited Tito and Natasha in July at their home in Seguin, Texas. A whimsical life-size ceramic bust sits in the dining room; it was made by Russian physicist Pyotr Kapitsa, who gave it to Bruno. Over several hours, Tito and Natasha told stories about the elder Pontecorvo and themselves.

PT: What do you remember about your family’s move to the Soviet Union?

TITO: The KGB looked at anyone coming from another country with a magnifying glass. They even lived in our house in Dubna for quite some time to “protect us.” There was a lot of bullshit. That is how it worked in the Soviet Union. And that’s one reason I hated it.

NATASHA: When they crossed the border into the Soviet Union, the kids and their mother were temporarily separated from Bruno. The kids started crying. Tito remembers the KGB gave them chocolate, and that quieted them down.

PT: Did you hate the Soviet Union the whole time? Even as a child?

TITO: Yes. I hated the Soviet Union, the communists, yes. But not Russia or Russians. Very early, even when I was seven years old, I understood that people were scared. My friends’ parents were scared, especially to say what they thought about communism and about America. I always wanted to leave.

PT: Would you say Bruno and your mother, Marianne, had a good life in the Soviet Union?

TITO: Of course they had a good life. The KGB tried to make them have a good life. They had many friends, including physicists Pyotr Kapitsa, Arkady Migdal, and Andrei Sakharov. They had friends in the arts. Bruno was engaged in scuba diving, tennis, and other things. But for people like Bruno, freedom is the main thing. And he was not free.

PT: Did he continue his scientific work?

TITO: Yes. But the KGB was commanding. And people were not allowed to talk about their experiments. Bruno would ask why it had to be secret. The KGB authorities understood they needed to make him shut up. That’s why he wasn’t allowed to do experiments. And they didn’t let him go abroad. The KGB wanted Bruno, of course. They needed him. They could say “Bruno came to the Soviet Union. He is for the communists.”

PT: Do you know if he regretted the move to the Soviet Union?

TITO: He never showed it. In the family, never. Now I understand, he was scared for us. And he knew I might be more aggressive. That’s why he was very careful and didn’t complain about conditions.

The curious disappearance of Bruno Pontecorvo

Bruno Pontecorvo was the youngest of the “Via Panisperna boys,” the group of scientists at the Sapienza University of Rome led by Enrico Fermi. Their 1934 experiment with slow neutrons led to the discovery of nuclear fission. Pontecorvo then spent a few years in Paris working in the lab of Irène and Frédéric Joliot-Curie, during which time he joined the French Communist Party. In 1940, as the Nazis closed in on Paris, Pontecorvo, who was Jewish, fled to the US.

In Oklahoma he developed a method to prospect for oil by analyzing how neutrons interact with underground rock formations. The method is still in use, says Pontecorvo biographer and Oxford University physicist Frank Close. Pontecorvo then moved to Ontario, Canada, to work on a UK–Canada heavy water–moderated reactor in Chalk River, a collaboration that was folded into the Manhattan Project. In 1949 Pontecorvo relocated to the UK, where he continued work on reactor development at the Harwell Atomic Energy Research Establishment.

In 1950 Pontecorvo planned to move to the University of Liverpool, where he could consult for Harwell but wouldn’t represent a security risk to the lab. That arrangement was sought by the laboratory, Close says, as a precaution in the wake of Klaus Fuchs’s arrest for espionage; Pontecorvo’s and Fuchs’s careers had intersected on the Manhattan Project and at Harwell. With the arrest, evidence of additional spies, and the intensifying of the Cold War, government agencies began scrutinizing other scientists. In the US, the hunt for communists, driven by Senator Joseph McCarthy, created further fears and suspicions.

Pontecorvo went to Italy on vacation before his impending move to Liverpool. But instead of returning to the UK, Pontecorvo and his family flew to Sweden (where his wife, Marianne, was from), crossed Finland, and defected to the Soviet Union. He was a communist. But was he a spy?

From his research, Close surmises that Soviet Union officials put the squeeze on Pontecorvo. “If I had to guess,” he says, Pontecorvo delivered “harmless, nonmilitary information” to Igor Kurchatov, the head of the Soviet atomic bomb project. Before the war, the two scientists had been aware of their mutual interest in nuclear isomerism, Close adds.

Pontecorvo did not work on nuclear weapons, says his biographer. But, he adds, “to my knowledge he never denied passing information about nonmilitary aspects of work in Canada or at Harwell.” It is known that Kurchatov had agents snooping into the Canadian reactor project and that he was aware Pontecorvo was involved in the project, Close says. It’s also known that the reactor blueprints found their way to Moscow before Pontecorvo did.

As Close imagines it, Kurchatov might have conveyed a request through one of those agents along the lines of “Comrade, can you help me design a nuclear reactor for the good of the Soviet people?” Although the reactor work was not primarily military, it was classified, and sharing details about it would have been enough for Soviet officials to blackmail Pontecorvo, says Close, who believes that Pontecorvo “panicked.” He was afraid he’d be sent to the US, Close explains, where McCarthy’s Red Scare was in full swing.

Pontecorvo’s son Tito dismisses the scenario sketched by Close. Bruno was a pacifist, he says, and would never have met with Kurchatov. The elder Pontecorvo moved to the Soviet Union because he believed in communism, says Tito, adding, “He refused to work for war, which brought him troubles in the Soviet Union.”

During the vacation before they defected, Tito recalls, the family got together with relatives, including one of Bruno’s brothers, the film director Gillo Pontecorvo. Tito later learned—at a family gathering in Italy in the 1980s—that Bruno didn’t tell them anything because he didn’t want to put them at risk. “But there is no doubt the move to the Soviet Union was planned,” Tito says.

At the time, the synchrocyclotron at the Joint Institute for Nuclear Research in Dubna, about 120 kilometers north of Moscow, boasted the highest energy of any such facility in the world. Close reckons that Pontecorvo “decided to check it out.” Given that Pontecorvo’s cousin Emilio Sereni traveled in and out of the Soviet Union, he continues, the physicist didn’t see his visit as a one-way trip. “But Stalin did.”

Pontecorvo and his family disappeared without a trace. In the West, nothing was heard about them again until 1955 when Nikita Khrushchev—who succeeded Joseph Stalin as first secretary of the Communist Party of the Soviet Union—formally announced that Pontecorvo was at Dubna.

Pontecorvo was not permitted to leave the Soviet Union for decades. The first time he went abroad was in 1978; late in life, he went to Italy and spent time at CERN. He died in Dubna in 1993 at age 80.

PT: Describe your path to oceanography.

TITO: The ocean was my dream. And in the Soviet Union, if you were 18 you had to go into the army unless you were studying at some institute. I hated the army and all that stuff, but I was bad at school. When I turned 18, I frantically searched for an institute. I found one where it was easy to pass the entrance exams: the Moscow State University of Geodesy and Cartography. Even there I was a bad student, and they threatened to kick me out. I switched to oceanography and finished my studies at Lomonosov Moscow State University, and then I started to do what I really wanted to do.

PT: What was that?

TITO: I wanted to go and work on a ship. I went to Vladivostok and worked at the Research Institute of Fisheries and Oceanography. We were studying underwater mountains near Hawaii—the currents, chemistry, and practical aspects. I went out on voyages for months at a time with ichthyologists and other scientists. We all worked together.

PT: What was your research topic?

TITO: The theoretical part of my thesis had to do with the currents near underwater mountains and what happens with the chemistry as the water flows up and down. The practical part was that I learned to tell at what time you need to put a net down 300 meters for just a few minutes to pull up tons of fish. You see, if the currents change, the local chemistry changes. Phytoplankton come, and after that come the fish. In Soviet times, a PhD required a practical result.

After that, captains of fishing boats were dreaming to meet with me. We would meet and drink a lot of vodka. I told them everything I knew about catching fish—where to go and how to put their nets in. It worked, and they pulled out many tons of fish.

PT: How long did you stay in oceanography? And why did you quit?

TITO: At that time, the Soviet rules were that you could not be in any type of top position unless you were a member of the Communist Party. But the Communist Party was not for me.

I was already the scientific chief of a huge expedition, and the Communist Party bosses would come to me and say, “Tito, you need to be a member.” At first I would say, “Yes, yes. Of course I am dreaming of that.” But after many times of this, they became more aggressive, and I became less sweet. I was mad.

After 13 years at the institute, they caught me. That was in Vladivostok, on the beach. It was not easy to catch me, because I was at sea on expeditions for eight, nine months of the year. They said, “Tito, you want to be in the Communist Party, now sign.” Well, I looked at them with my mouth open and said what I thought about them. The next day I found out that I would not be allowed to go on any more scientific expeditions on the ocean. I was kicked out.

NATASHA: They offered him a position as a theoretical oceanographer, an office job. But he needed the ocean.

PT: What did you do next?

TITO: I didn’t know what to do. For me, not being able to work on the ocean was a serious tragedy. I went to Dubna, where my family lived. I didn’t want to see anybody. I was crying. After a week, maybe two weeks, I started to get mad at myself. I said to myself, “Tito, think about what you like. Think, what do you want to do?”

I loved horses, and I decided to work with them. And while I worked with horses, I wrote my PhD in oceanography. That was in 1979.

PT: You had been chief of a division at the institute without having completed your PhD?

TITO: Yes. I had written lots of articles, and I had all the information. I was not ambitious; I didn’t need to write the PhD. But my friends and many other people said, “Tito, write your PhD.” So I sat down and wrote it in three weeks.

PT: How did you make the transition to working with horses?

TITO: In Soviet times, horses, like trucks, belonged to the government. Private people were not allowed to have a truck or a horse. Russian Roma had traditionally worked with horses, and they were an exception—they were allowed to have them. I had a lot of friends among the Roma because of my lifelong love for horses. And they made me false documents saying I was Roma.

I started by buying horses from Roma. But then I wanted better ones.

PT: How did you have the money to buy them?

TITO: I had money because when I worked on the ocean, I earned it. When the ships returned, I immediately spent my earnings. But the last time, when I lost my job, I didn’t spend it, so I had money. Later I made money buying and selling horses. And in the winter I took people on sleigh rides.

NATASHA: In the Soviet Union, you couldn’t buy a horse, but there was a special government association whose members could buy meat. So Tito bought “meat.” And he found a way to buy the best racing horses.

TITO: I would go to official government stables, and they found a way through crooked documents to sell me 500 kilograms of meat. I would get a document that said the name and pedigree of the “meat.” There were strange ways of making things work in the Soviet Union.

I started with Roma horses, then I went to special breeds—English thoroughbreds, Hanoverian, Trakehner, Arabs, and so on. Then I saw my first Akhal-Teke. It was something else. I was amazed. They differ from other breeds in many details of their conformation and their movements. They have soft movements and stamina and can work without stopping for long times. The Akhal-Teke breed was created in the territory of modern Turkmenistan, supposedly about 5000 years ago.

After a while, I had more than 250 pureblood Akhal-Tekes. In 35 years, I produced more than 1500 foals.

PT: So despite the law prohibiting private individuals from owning horses, you were able to make a living breeding them?

NATASHA: He did not officially work with horses. In the Soviet Union, you work or go to jail. He formed an equestrian club for children in Dubna. It was not an official job, but it was something. It was an international club, because people from many countries were involved in scientific research in Dubna.

TITO: I was teaching many children in my club, around 200 of them. We were riding and doing other things. We became friends. They asked me many questions, and I said what I thought—not what their parents would say. And the Soviets knew that if they touched my club, I would open my mouth and tell the foreigners. That protected me, because I didn’t officially work.

PT: So how did things develop?

NATASHA: In the mid 1980s Tito had quite a few horses, and he needed a stable. He spent all the money he inherited from his Swedish grandparents to design and build it. The children from the equestrian club and their parents—most of whom worked at the Joint Institute for Nuclear Research—helped workers build the stable; it was beautiful.

Some authorities wanted to take the stable away and use it for other purposes. The whole town of Dubna was divided in two parts. A friend of Bruno’s told us that Sakharov came to town, and before he would shake hands with somebody, he asked if they were for horses or against them. He shook hands only with people who were for horses.

TITO: Dubna was a special town, a nuclear center, with a lot of bright scientists. If it weren’t for the foreigners and Sakharov, I would probably have gone to jail because of the stable. Or the Soviet officials could have taken the horses and stable away from me. But the officials didn’t want to make a bad impression on the foreigners.

Later I built a bigger stable. My stable was visited by high-level Communist Party members—each month we would invite different Communists, not everyone at once. We prepared good food and drank lots of vodka. In that way I kept a balance—they didn’t touch me, even though they could have sent me to jail.

PT: How did things change after the collapse of the Soviet Union?

NATASHA: People from more than eight embassies came periodically to our stable for weekends. They stayed at our stable hotel and rode horses. They came to have fun.

TITO: The bosses were still the bureaucrats, the Communists. They were aggressive and not pleasant. Some of them became criminals. The idea was, if you were rich, you needed to pay them. They would kill people.

I had understood that I could lie to the Soviets—it worked because my huge stable helped the top Soviet scientists, and it helped the foreigners. But after the collapse of the Soviet Union, the bosses got tired of my lying. They said things like “We know you love your dog” and “We know you love your wife.” I knew they would come with a pistol. I understood it was time to escape. I sold many horses, and I escaped to the US with 75 Akhal-Tekes.

PT: How did you leave?

TITO: First, I learned the details of whether it was allowed to take horses. There were no laws that prohibited it. But when I came to the border between Russia and Poland, I was scared to death. In Russia, many Soviet rules were still in place, so I was scared they would stop me and take away the horses.

The horses were driven in three large trailers to the Netherlands. From there they were flown to New York and then driven to La Crosse, Wisconsin—a sister city to Dubna—and then on to Texas. It took a couple of weeks. I was with them all the time.

We had help from diplomats. Without help from many people from all over the world, I would never have been allowed to leave with the horses. Never. And I’m sure the Russians were happy to be rid of me. They were probably thinking, “After all the trouble with him, let him go.”

PT: Why Texas?

TITO: We were invited to Canada. I was born there, and on a visit to Sweden I secretly got my Canadian passport. But when we visited Montreal in early 1997, it was cold.

NATASHA: A friend from Texas heard we were in Canada and invited us to visit San Antonio. In February it was 72 degrees, birds were singing, there were flowers. And Tito said, “I will never live in Canada. It’s as cold as Russia! We are going to Texas!”

PT: What have you done since moving to Texas?

TITO: I bought some land and built a small barn for stallions—you need to keep them separately. The mares were in the pasture. I created a children’s riding club. I experimented with breeding, and my Akhal-Tekes got better and better. I studied their lines, and I sold some and kept and bred the best ones. Many of my Akhal-Tekes won competitions all over the world.