The mystery of the disappearance of the genius physicist Majorana. What happened before he disappeared?

There are several types of scientists. Second-rate or third-rate scientists try their best and still get nowhere. First-rate scientists make important discoveries that promote scientific progress. They are all geniuses, such as Galileo and Newton. And of course Majorana - Fermi

On Saturday, March 26, 1938, Antonio Carrelli, Dean of the School of Physics at the University of Naples Federi II But he didn't have the leisure of a rest day at all. At 11 o'clock in the morning, he received a telegram signed by Majorana: "Don't be nervous, the letter will arrive soon." He was confused about this. Why should he be nervous? Carelli certainly knew who sent him the telegram, and it all started with Majorana.

1. Majorana

Figure 1: Italian genius——Majorana

Majorana’s full name is Ettore ·Ettore Majorana was born in Catalia, Sicily, Italy in August 1906. The year before he was born, Albert Einstein published five shocking papers in one breath, not only He laid the foundation for the special theory of relativity and proposed the concept of light quanta, which revolutionary extended Planck's theory and created a new situation for quantum mechanics. Like Wolfgang E. Pauli, Werner Karl Heisenberg, Enri Fermi, Paul Adrien Maurice Dirac and others, their generation has caught up with a boom in physics. The era of development is also an era of rapid changes in the world pattern.

Although Majorana’s father is a businessman, he has a strange physicist uncle, Quirino Majorana. The most outstanding deed is that he believes that Einstein's theory of relativity is nonsense and has been committed to falsifying the theory of relativity, but his experiments always prove that Einstein is right. This seems to be a typical Sicilian style, never caring about what the whole world thinks. It seems ridiculous but is actually similar to the qualities of a physicist, as in Richard Phillips Feynman's autobiography "Why Do You Care What Others Think?" 》as described. It's just that Quirino's luck was not good. The Muse was not on his side, just like Einstein in his later years, and this magical fate finally befell Majorana himself.

In 1923, Majorana entered the University of Rome to study engineering. At this time, some changes occurred in the Italian physics environment. In 1926, Orso Mario Corbino, head of the Institute of Physics at the University of Rome, realized Fermi's talent, recruited him, and recruited a large group of young people to conduct physics research together, focusing on the atomic nucleus. physics. The Institute of Physics at that time was located on Via Panisperna in Rome. This street was named after the famous nearby San Lorenzo Monastery. Every day, young people walked through the monastery to arrive at the Institute of Physics to study the truth of the universe. This was actually in line with the mysticism of physics at that time. The thoughts are inexplicably consistent. This group of young people is also known as "Via Panisperna boys". In addition to Coribin and Fermi, the main members include Edoardo Amaldi (the pioneer of Italian aviation), Emilio Gino Segrè, Bruno Pontecorvo ( Bruno Pontervo, Oscar D'Agostino, Fran Rasetti and others.

In 1928, Majorana could no longer stay at the School of Engineering for various reasons, so Segre introduced him to Fermi, "You will definitely be very happy with those geniuses." In 1929, Fermi decided to change the research institution to the research direction of modern physics, focusing on various currently popular theories. People at the time commented that this was the greatest group of physicists in Italy after Galileo.

Majorana's first paper was an early application of the statistical model of atomic structure proposed by Fermi, and he and his colleagues conducted research on atomic spectra. In 1932, Majorana continued his efforts and published a paper on the spectrum of atoms under time-varying magnetic fields. I.I. Rabi and others were also studying this problem at the same time, thus starting atomic physics. An important new branch - the radiomagnetic spectrum. In the same year, the Curies, their daughter Irène Joliot-Curie and her son-in-law Frédéric Joliot-Curie discovered A new particle suspected to be gamma rays, Majorana studied it and believed that this new particle should remain electrically neutral and have a mass similar to that of a proton, that is, a neutron; Fermi suggested that he write an article and publish it, but Majorana refused. Later, James Chadwick confirmed this through experiments and won the 1935 Nobel Prize in Physics. But this incident did not change Majorana's style, and he even intensified his practice of only researching without publishing.

In 1933, at the request of Fermi, Majorana left Italy and came to Germany. Majorana met Heisenberg in Leipzig. He is a smart scientist and will be his lifelong best friend. He also went to Copenhagen to work with Niels Henrik David Bohr, a master of physics and Heisenberg's mentor. At that time, the Nazis had just gained power in Germany, and Majorana studied Heisenberg's theory and Bohr's atomic model.

That summer Majorana returned to Rome with illness. For the next four years, he retreated behind closed doors to cultivate himself. Anxin’s research was still never published, but today we know that his research directions include: geophysics, Electrical Engineering, Mathematical Analysis and Theory of Relativity. We know about him today all because of Majorana fermions. This is a paper that Majorana suddenly published in 1937 - he rewritten the Dirac equation to get the Majorana equation, which can describe The particle has a spin of 1/2, so the particle that satisfies this equation is its own antiparticle, that is, the antiparticle of the Majorana fermion is itself, but the antiparticle of the Dirac fermion is not itself. It is said that this was just one of his many papers chosen at random because he suddenly wanted to find a job.

Figure 2: "Via Panispernaboys" in 1934, from left to right: D'Agostino, Segre, Amaldi, Rassetti and Fermi

2. The mysterious disappearance

Because of this paper and his previous reputation, Majorana was exempted from the examination and applied for a full-time professorship at the University of Naples. In Carelli's opinion, Majorana should be on the way here. At two o'clock in the afternoon on the 26th, Carelli received a letter from Majorana: "I have made up my mind that this is not selfish, although I know that my sudden disappearance will cause inconvenience to you and your students. I therefore ask for your forgiveness for betraying your trust, especially for your concern over the past few months, and for conveying this message to those in the hospital whom I know and admire, especially Sciuti: I will keep their best memories until 11 o'clock tonight, maybe even longer." The letter was dated the 25th, and Carelli couldn't help but feel nervous.

The investigation found that Majorana wrote two text messages at the Albergo Bologna Hotel in Naples on the 25th. One was the official letter received by Carelli, and the other The letter was a personal letter to a family member but was left in the hotel room instead of being sent. The letter read: "I don't want you to wear black for me. If you must bow to the guests, I also hope that your grief will not exceed three days. After that, if you are willing, please remember me in your heart." , and forgive me." On the day he finished writing the letter, he boarded a letter ship bound for Palermo, the capital of Sicily. According to the itinerary, the ship would arrive at dawn the next day.

Both letters, at least literally, foreshadow a bad ending. Majorana's colleagues Segre and Amaldi firmly believed that Majorana planned to commit suicide. Segre believed that Majorana planned to go to Palermo just to meet him, who was teaching there, but unfortunately he was in California at the time.

In fact, the original text of Majorana is sparire, which means both "disappearance" and "death" in Italian. Wear black has multiple meanings. Three days and the like may also just mean "disappearance" and "death". It’s just in line with the tradition of Majorana’s home island of Sicily. In short, semantic ambiguity is the opposite of confidence and firmness in writing. The writer Leonardo Sciascia commented on this: "I have seen many suicide notes, even in terms of writing, they are more or less different from ordinary ones, and of course they are usually more irregular and sloppy. Majora Not so with Na..." He examined various situations in "The Mystery of Majorana" and focused on criticizing the theory of suicide. Of course, Xia Xia's own claim did not receive any more response. He thought unbelievably that Majorana was trying to escape from the monastery. It was unknown whether it referred to the mysterious realm of metaphysics or the place where their group of young physicists worked. .

The difficulty with the suicide theory is that it cannot explain the third letter. In fact, later on the 26th, Carelli received another letter from Majorana, written in Albergo The letter on the Albergo Sole Hotel proves that Majorana did land in Palermo on the morning of the 26th. Carelli speculated that the telegram was actually written before this letter, telling him not to worry, but for some reason it arrived earlier than the first letter. The letter read: "I hope that the letter and the telegram have reached you. The sea has rejected me, and tomorrow I will return to the Albergo Bologna Hotel, maybe this letter will still travel with me. However, in any case, I will Decided not to teach anymore. Don't think of me as Ibsen's heroine, I am in a completely different situation." This letter seems to indicate that Majorana did intend to commit suicide. But gave up again.

The ship back to Naples set sail on the night of the 26th. According to the shipping company's records, Majorana did purchase a ticket. If he is on board, he will arrive on Sunday morning (27th). There were two people in the same cabin as Majorana. One of them swore that Majorana was still sleeping in the bed when he got off the ship. If the testimony is reliable, this is not a good sign. After all, he seems to have just come out of a slump, but at this time he is curled up in a small cabin like a baby in need of care. No matter what he encountered, he seemed ready to give up.

The strange fact is that from then on, he disappeared as if he had evaporated from the world. Various literature, dramas, and animations also put forward their own opinions on this. Some people think that he became a beggar and lived on the streets. Some people think that he was just dissatisfied with his personal life in Argentina. Some even said that he was abducted by aliens. The latest A science fiction novel awarded him a Nobel Prize in Physics.

Although physicists believe that his contributions deserve a Nobel Prize, and they jokingly call his disappearance like "Schr?dinger's cat," many physicists believe that Majorana It is possible that he was kidnapped or even killed because he was unwilling to participate in the development of nuclear weapons. This explanation seems reasonable at present, but without sorting out the development of physics at that time, especially particle physics and nuclear physics, it will be difficult to restore the entire historical scene.

3. The most likely explanation

Joao Magueijo, a cosmological physicist and popular science writer, wrote in "A Brilliant Darkness: The Extraordinary" "Life and Mysterious Disappearance of Ettore Majorana, the Troubled Genius of the Nuclear Age" restores the development of the entire physics at that time. We can clearly feel the pulse of physics and the pulse of the entire era.

Germany was undoubtedly the center of physics at that time. Among Majorana’s contemporaries, Pauli proposed the Pauli matrix and the Pauli exclusion principle, and Dirac proposed the Dirac equation. Heisenberg proposed matrix mechanics, which they both studied in Germany. Majorana also went to Germany to study on Fermi's recommendation.

We don’t know what kind of atmosphere Majorana felt in Germany, but in 1935 Pauli had keenly noticed the shift in political trends and left Germany. Dirac returned to England early, and even Bohr, who was close to Germany, also became an American citizen after World War II. Only Heisenberg insisted on staying in Germany and began studying nuclear physics in 1938.

As a later ally of Germany, Italy's "Via Panisperna boys" were in a very similar situation. As mentioned earlier, Segre was visiting the University of California in 1938. When he returned home, he found that Mussolini had enacted the Anti-Semitic Act, so he stayed in the United States. Later, he and Owen Chamberlain discovered the antiproton and won the Nobel Prize in 1959. Bell Prize in Physics.

To some extent, these people formed a physics network at that time. For example, taking the discovery of neutrinos as an example, in 1930 Pauli proposed a hypothesis to explain the energy loss problem in beta decay. In 1934 Fermi first proposed the concept of "neutrino" (meaning "tiny electrically neutral particle" in Italian) in 1937. When Majorana fermions were first proposed in 1937, it was generally believed that neutrinos should be like this. The first antiparticle is its own particle (there is still controversy, but it is tended to be that neutrinos are not Majorana fermions). In 1957, Pontecorvo proposed the neutrino oscillation hypothesis, which believed that neutrinos can come from a One type transformed into another, and later it was further discovered that neutrinos have different flavors. Another example is the field of nuclear physics. As we all know, since the discovery of radioactivity in 1896, people have successively discovered a variety of natural radioactive elements. In 1919, the first artificial nuclear reaction was achieved by bombarding helium with alpha particles. The emergence of accelerators in the 1930s further accelerated related research. The two most important discoveries were the aforementioned discovery of neutrons and the discovery of artificial radionuclides by Curie and his wife in 1934. . The discovery of neutrons not only provides the necessary prerequisite for the study of nuclear structure, but also because it is uncharged and not repulsed by nuclear charges, it can easily enter the nucleus and cause neutron nuclear reactions. It has become an important means to study the nucleus and is an important tool for understanding the relationship between nuclear fission and nuclear fission. The basis of nuclear fusion. Fermi won the 1938 Nobel Prize in Physics for his research on neutron bombardment. In 1942, under his leadership, the world's first fission reactor was built.

In the book, Maguyo recalled a conversation between Majorana and Fermi. Majorana said: "I like Galileo because he knows what fear is... people will only See what they want to see." Another quote from Majorana is: "Physics has gone astray, and we have all gone astray.

"Maguyou and others all believed that this was Majorana's inner fear of nuclear physics and nuclear weapons. This genius who foresaw neutrons but was unwilling to publish them has always been uneasy about his discovery. However, Majorana's disappearance did not There was no inspiration for Fermi. After going abroad to receive the Nobel Prize in 1938, he did not return to Italy. Instead, he went to the United States. A year later, he contacted the U.S. Navy and hoped that the United States would develop atomic weapons. Maguyu was not without regrets. Quoting Mayorana's fellow countryman Luigi Pirandello (the famous Italian dramatist and novelist, who won the 1934 Nobel Prize for Literature), he commented: "The dead are the pensioners of remembrance."

Perhaps Pontecorvo’s deeds can serve as another footnote to Majorana. He “defected” from the United Kingdom to the Soviet Union in 1950. As Maguyu’s subtitle writes, he was just another person in the nuclear field. He is just a genius with unclear ideas. Therefore, Maguyou gave Majorana a very high evaluation, thinking that he is a scientist with a strong humanistic background. This kind of compassion may bring a touch of warmth to the cold science.

The Italian media recently reported that someone witnessed Majorana in the 1950s, and confirmed this news through comparison of some physical features, but just like countless previous observation cases, there have been many Questioning. Majorana had never had a girlfriend in his life. He was called a mysterious figure by those around him at the time. The truth of his disappearance was as mysterious as the person he was. We may never know what happened; he was kidnapped. Even the assassination was due to personal morality or fear, and it was still shrouded in the fog of history. For physicists, the search for Majorana fermions is the best way to commemorate him; for the public, all kinds of things. The interpretation in culture also gives it a sense of immortality. To a certain extent, history is a summary of the facts that have happened, and we hope that similar tragedies will never happen again.