Their names are in the history of science

That's what Pontecorvo said

22 August marks the 110th anniversary of the birth of Academician Bruno Maksimovich Pontecorvo. In the preface to his book "The Life and Ideas of Bruno Pontecorvo", published by the Moscow publishing house "Eksmo" at the end of 2021, the famous experimental physicist, JINR chief researcher Mikhail Sapozhnikov wrote: "The life story of Bruno Pontecorvo waits for its film director. He can make a biopic about a great scientist whose ideas have received recognition in the form of six Nobel Prizes. He can shoot a big family saga about the fate of a wealthy family of textile manufacturers from Pisa in the era of Mussolini, a detective about Bruno's escape with his entire family in the USSR, a drama of a real communist losing his ideals in the era of glasnost and perestroika…"

Parting words of E.Fermi

After a job interview with B.Pontecorvo, E.Fermi said:

"Unfortunately, today, physicists are divided into two categories - theorists and experimenters. The requirements for theorists are very high. If a theoretical physicist is not at a very high level, his work is meaningless. In this regard, there is an analogy, say, between the profession of a theoretical physicist and the profession of an Egyptologist. If the Egyptologist did not turn out to be an exceptionally bright scientist, it means that he simply made a mistake in choosing a profession. As for experimental physicists, here even for a person of average abilities there is always the possibility of being useful. An experimenter can, say, measure the density of various substances. It will be a very necessary job, although it does not require a great mind.

Bruno was sent to experiments.

Even the great Fermi could not imagine what a huge practical application the physical effect, discovered, literally, as a result of experiments on the laboratory table, would receive.

End of physics

In 1934, Fermi believed that physics was over, nothing interesting would be discovered anymore and all that was left was to do a few boring calculations. Pontecorvo recalls: "Even now there are people who say something like that, they talk about some kind of desert, an area of high energies where nothing new can happen. But I don't believe in it. I do not believe that physical problems will disappear. I won't believe it even if I see it."

About Joliot-Curie

Pontecorvo identifies two qualities of Joliot as a scientist:

"... a powerful scientific fantasy and as the Italians say, spreguidicatezza (impartiality), the ability to recognize as possible even the most incredible and strange fact. It was thanks to these qualities that Fr?d?ric Joliot, in collaboration with Irene Curie, whose critical mind sometimes served as a healthy antipode to her husband's enthusiasm, managed to discover the phenomenon of artificial radioactivity (awarded by the Nobel Prize), despite the fact that they had at their disposal less experimental means than those with which scientists of America and England disposed. It can even be said that in America and England the phenomenon of artificial radioactivity was certainly observed, but it was not discovered due to the lack of this ability that Joliot possessed, to consider the most incredible possible.

Gillo Pontecorvo about life in Paris in 1936-1940

"For me, coming to Paris was an important experience, it was a turning point in my life. I came from Italy, where in every bar there was a sign saying "We don't talk about politics or high matters here." I had no idea what democracy was. I was lucky that there were many emigrants and Bruno, from whom I learned a lot."

Gillo Pontecorvo about his brother

"Bruno became a communist because he believed that communism could create a New Man. Better than there were people before and better than those that exist today. And many Italian intellectuals believed it, too. For example, I was also a communist. We thought that a society not divided into classes could create a New Man. This was the basic point that led him to communism, as well as many other Italian intellectuals."

Laura Fermi about Bruno

"Bruno was extraordinarily handsome. Perhaps it was the amazing proportionality of his figure that attracted everyone. Everything about him was just right, nothing should be added or subtracted either in the width of the shoulders and chest, or in the length of the legs or arms. Maybe he learned to be so dexterous and coherent on tennis courts, where he had become a champion early. And good manners were his natural gift.

Bruno Pontecorvo about E.Fermi's attitude to the possibility of neutrino detection

"In 1946, it became clear to me that the development of nuclear reactors would revolutionise the search for neutrinos. At that time, scintillation counters had not yet been invented and I proposed the radiochemical method of recording neutrinos that is currently used to register solar neutrinos. Now, I would like to point out that long after my proposal the attitude of public scientific opinion towards possible neutrino detection did not change (even after I had constructed an extremely low-background, high-gain counter for registering rare ³⁷Ar decay events).

I distinctly remember that when I spoke to Enrico Fermi in 1949, he was very interested in the methodological aspects of the counters I considered as a by-product of my attempt at a neutrino detector and my investigations of the L-capture of ³⁷Ar and the tritium spectrum, yet remained rather indifferent to the neutrino detector problem."

The key Conversi - Pancini - Piccioni experience,
the results of which predetermined Bruno's scientific interests

"As soon as I read the paper by Conversi et al... I was literally captivated by the particle we currently call the muon. It was indeed an intriguing particle: 'ordered' by Yukawa and discovered by Anderson, it was, as Conversee et al. discovered, actually nothing like the Yukawa particle!

I felt myself swept by the anti-dogmatic wind and started asking a lot of questions like:

- Why does the spin of a muon have to be integer?

- Who says that the muon should decay into an electron and a neutrino, but not into an electron and two neutrinos or an electron and a photon?

- Is the charged particle emitted in muon decay an electron?

- Are particles other than the electron and neutrino emitted in muon decay?

- What form is energy released in when a muon is captured by the nucleus?"

On moving to the USSR

"I emigrated to the USSR both as a scientist and as a "comrade" for ideological reasons. I knew that in the Soviet Union there were all the opportunities to work as a nuclear researcher, I felt the heat of the Cold War and as a specialist I sided with the USSR. This was my choice, to which I had every right and about which I have never regretted and do not regret. Russia became my second homeland, I found real and sincere friends, comrades in work, creative work, research in the field of application of my knowledge. Of course, I was guarded in the USSR, but it was formal. What espionage could we talk about if I lived in the Soviet Union, gave it all my knowledge, was on a par with other leading scientists in the USSR? I have nothing to justify myself. I lived always according to my conscience and openly. That's all my "espionage".

La Repubblica newspaper 26.02.1996.

"Yesterday Fermi and Pontecorvo received a posthumous acquittal from the FBI that on the basis of documents declassified for the first time and obtained by the Washington Post, offers what appears to be the final judgement in the case. It is a surprising judgement: it was not Italian scientists that passed the secrets of the bomb to the USSR, but two little-known and brilliant American students. One of them would be Theodore Alvin Hall, a seventy-year-old scientist living in England: at the time of the events he was 19 years old, a brilliant Harvard student, gifted enough to be called upon to co-operate in atomic bomb research. His code name was 'Junior' that is Russian for 'boy'... Another spy that carried the code name 'Star' was Hall's classmate, Savile Sacks."

First impressions of the USSR

"When I arrived in Moscow, I felt like a Jew seeing the promised land." (B.Pontecorvo, in M.Mafai's Il lungo freddo).

First impressions of Dubna

"I remember well how in October 1950, M.G.Meshcheryakov showed me the Dubna synchrocyclotron, the most powerful accelerator in the world at that time. It made a great impression on me... At that time, research at the Dubna accelerator was only in its initial stage and the measuring pavilion, I remember, was practically empty. But in a few years, the situation changed significantly. I remember how foreign guests that visited Dubna for the first time in 1955, were shocked not only by the accelerator, but also by the huge amount of first-class equipment in the synchrocyclotron's measuring pavilion.

Experiments at DLNP of JINR

"Here in Dubna, I developed a rather clear idea that there is a contradiction between the long lifetime of particles that are currently called strange particles and the high probability of their production. This problem allowed us to formulate independently and a little earlier than Pais the principle of associative birth of strange particles. This principle was not recognised at that time and there was even an experimental paper by Schein et al. that -hyperons are born alone in the reaction ^- + p + ⁰. Therefore, a large group of collaborators, among whom I will mention Balandin, Zhukov and Selivanov, searched our synchrocyclotron for the single production of -particles in collisions of nucleons with nuclei. The result was negative that showed the fallacy of Schein's work and fully satisfied our philosophy about the associative birth of strange particles... In general, our philosophy about particles that today are called strange, was absolutely correct, but we lacked the intelligence to come up with the quantum number S - strangeness".

Hunting for discoveries

"I would like to note Fermi's complete lack of scientific dogmatism. This is a rare phenomenon for such physicists as Fermi was, with such a huge erudition and amazing ability to use the "immutable" laws and foundations of science. By the way, it seems to me that one of the most characteristic features of Fermi is his demand for a "golden mean" or if you like, the necessity of fighting on two fronts in science: basic principles are extremely important, but prejudice is harmful; long live the new, but let the new be legitimized only when the old has been proved worthless; physics moves forward through discoveries, but not only through discoveries; it is very good if a physicist manages to discover a new phenomenon or predict an unexpected regularity, but physics is not done by hunting for discoveries; originality and scientific imagination are good only in combination with deep knowledge."

Farewell to graduates of the Department of Elementary Particle Physics at MSU

"You have chosen a profession in which it is impossible to get satisfaction, that is, to achieve success in scientific research, without daily, hard and painstaking work. On the other hand, if you have achieved them, it is difficult to find another field of human activity that brings such pleasure as scientific work."

Asking the right question

"Bear in mind, when they say that an experimenter has good hands, they mainly mean that he has a good head... More than 70 per cent of the major experimental discoveries were not only made by experimenters, but the task itself was set by them. It is very important for modern research to ask oneself the right question. And in this the experimenter is no worse than the theorist".

From a report at the meeting of the staff members of Department of Weak
and electromagnetic interactions of DLNP

"The leader in a research group is a typical researcher, a little older and more experienced than the others, but less able to perceive new things... A leader should not demand from his subordinates to be like him. Example: there can be such a leader that is very good at engineering implementation of difficult experiences, but who does not have a very deep theoretical base or poor imagination to come up with new arrangements of experiments. It will be bad if such a leader looks with arrogance at the desire of an employee with a great theoretical orientation, say, to be in the library often.... There are people that like to work day and night in the first building¹ (the most striking example of it was Y.D.Prokoshkin²). This is very good, but no one has proved that all people should be of this type and that this is the only way for a researcher to be successful. In fact, a leader should just use the different characters and inclinations of the employees. The power of the group, especially today, when the experiments have become complex, is precisely based on the complement of the various qualities..."

How to get an employee to write a dissertation

"The arrangement between B.Pontecorvo and M.Balandin:

М.P.Balandin undertakes from 1 November 1970 not to come to work in the laboratory at all, in order to write his thesis at home. As an exception, he is allowed to visit the library...

In January 1971, the thesis must be completely printed or, if not completely, then almost completely. B.Pontecorvo and G.Selivanov may judge the meaning of the word almost.

If these points are not fulfilled, the promises by B.Pontecorvo to M.Balandin will lose force".

To journalists at Fiumicino Airport, first arrival in Italy in 1978.

"Now I will tell you a terrible secret: I have never worked on a bomb, neither in the West, nor in Russia, nor in China."

From the book Il lungo freddo by M.Mafai

Mafai: What do you think is your main quality?

Bruno: I don't know. Only flaws come to mind. I'm shy, I've never been able to deal with my shyness. Ah, I'm also naive. But it's better to be naive than a scoundrel, isn't it?

M: When you left the West, did you imagine that it would be almost thirty years before you could return to Italy?

B: I guess, I have never thought about any exact time.

M: During your life in the USSR, did you ever regret getting on that plane from Rome at that time?

B: I have never considered the problem so rigidly. Of course, sometimes I thought about it when I saw things I didn't like. But I always thought they could change. And actually, when I left, I didn't have a return ticket. And I knew that.

M: And do you regret today that you made that choice forty years ago?

B: I've thought about it a lot. You can imagine how much I have thought about that choice. But I can't answer.

M: If I say: your country, what would you think of the USSR or Italy?

B: Italy.

The editorial board thanks Mikhail Sapozhnikov for preparing this material and the biographical book about the life and work of Bruno Maksimovich.

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¹ The first building is the building where the synchrocyclotron of DLNP JINR is located.

² Yu.D.Prokoshkin - (1929-1997), Academician of the Russian Academy of Sciences of the USSR, carried out a range of nice experiments at the JINR synchrocyclotron. In 1963, he headed the Department of Experimental Physics of the Institute of High Energy Physics (Protvino).

Evgeny MOLCHANOV