The detailed process of Li Zhengdao's break with Yang Zhenning.

In the 1940s, Li Zhengdao was a sophomore at National Southwest Associated University. After the victory of the Anti-Japanese War, Chiang Kai-shek thought the atomic bomb was very important and wanted to build it. He approached Zeng Zhaolun, a professor of physics and chemistry, and Hua, a professor of mathematics in The National SouthWest Associated University, and said to them: I will give you 10 million dollars to build an atomic bomb in an auditorium as a workplace.

They said that if Wu Dayou wants to build an atomic bomb, it must first train talents, and suggested that some people should be sent to study in the United States.

Li Zhengdao was selected and came to the United States on 1946. However, because the United States does not open up the technology of atomic bomb manufacturing, the investigation team can only be dissolved. According to the instructions, they can use the funds obtained to continue their studies in the United States. Therefore, Li Zhengdao went to the University of Chicago to study theoretical physics from Fermi.

At that time, Yang Zhenning had been working as a teaching assistant at the University of Chicago. He received a notice from Wu Dayou and reserved a room for Li Zhengdao and them in the University International Apartment. Yang Zhenning is also an alumnus of The National SouthWest Associated University, but he is two grades higher than Li Zhengdao. This is Li Yang's first meeting.

In the same school, communication naturally begins. The two began to publish papers together and became close friends in life.

Shortly after Li Zhengdao entered school, he bought a second-hand car because he had two scholarships and was relatively well-off financially. /kloc-in the summer of 0/947, He, He drove this car to travel to the west. In addition to the story of the Grand Canyon in distress, the book revealed that Li Zhengdao also talked about an interesting detail: before leaving, Yang Zhenning proposed that the three people pay the fare in proportion, and Li Zhengdao would pay the fare after returning. What exactly does Yang Zhenning's proposal mean? Later, Li Zhengdao thought about it. He was moved by Yang Zhenning's clever calculation. After graduating from Ph.D., from 65438 to 0950, Li Zhengdao worked at the University of California, Berkeley as a teaching assistant in the Department of Physics. At that time, the Korean War broke out and the local anti-China arrogance prevailed in California, so Li Zhengdao was unhappy in California.

Previously, in the autumn of 1949, Yang Zhenning came to Princeton Institute for Advanced Studies as a visiting member. He knew the situation of Li Zhengdao in California, so they discussed that Li Zhengdao would also come to Princeton to do research together.

According to this book, Yang Zhenning found Dean Oppenheimer and asked him to send an invitation letter to Li Zhengdao. Therefore, in September, Mrs. Li Zhengdao came to Princeton Institute for Advanced Studies.

Li Yang's two families live next to each other and have close contacts. Yang Zhenning is studying the calculation of magnetization of two-dimensional Ising model, and he hopes Li Zhengdao can join in. "This is the real beginning of their cooperation." Ji Cheng wrote.

195 1 autumn, they wrote two papers on statistical mechanics, and gave strict definitions of different thermodynamic functions for the first time. On this basis, they found that different thermodynamic functions could not be analytically generalized under the condition of phase transition-this discovery turned a new page in the study of statistical mechanics.

The papers of two young China scholars attracted the attention of physicist Einstein. 1952 One day, they were invited to see Einstein. The conversation was long, and Einstein asked many questions, which were very detailed. Finally, he stood up and shook hands with Li Zhengdao, and sincerely said to him, "I wish you success in physics in the future."

The cooperation and outstanding achievements of two young people in Princeton, as well as their close relationship with two families, were suddenly passed down as a much-told story. Oppenheimer once said that it is a pleasing sight for Li Zhengdao and Yang Zhenning to sit on the lawn of Princeton Institute for Advanced Studies and discuss problems. Li Zhengdao worked in Princeton, which was both successful and enjoyable. But at this time, the dispute happened, starting with the signature order of the two papers they jointly wrote.

The general title of these two papers is the equation of state and the statistical theory of phase transition. The first is the "cohesion theory" of Yang Zhenning and Li Zhengdao, and the second is the "Ziggy and Ising Model" of Li Zhengdao and Yang Zhenning.

Ji Cheng wrote that after the completion of the first paper, according to the usual practice, the names of collaborators should be arranged in alphabetical order, which should be "Li Zhengdao and Yang Zhenning". However, Yang Zhenning hinted that if Li Zhengdao didn't mind, he would like to rank first because he was four years older than Li Zhengdao. Li Zhengdao was surprised at this request and reluctantly agreed.

When signing the second document, Li Zhengdao persuaded Yang Zhenning to make amendments in accordance with international practice.

The signature problem brought a rift to the two men, and Li Zhengdao decided not to cooperate with Yang Zhenning any more. After that, although he worked at Princeton for another year and a half, they didn't write a paper together.

The signature of the paper worried Li Zhengdao. At that time, his unknown wife (the eldest daughter of Du, a senior Kuomintang general) was also involved. As I recall, I wanted to put it at the top of the signature order of the above two papers, because Li's scientific research career has been unsatisfactory since graduation, and I wanted to help him, but I stopped him according to the "woman's sixth sense" and said that it was not worthy of his trust.

Li Zhengdao decided to leave Princeton University and become an assistant professor at Columbia University. Three years later, 1956, at the age of 29, he became the youngest professor in the history of Columbia University. Li Zhengdao left Princeton Institute for Advanced Studies because he wanted to stay away from Yang Zhenning. An accidental event made them cooperate again.

1953, worked in Brookhaven National Laboratory for one year, and published the paper Isospin Conservation and Isospin gauge invariance in cooperation with Mills, in which the later famous Young-Mills gauge field equation was put forward.

However, at that time, Li Zhengdao had serious doubts about whether the starting point of this paper was correct. Once, when he came to Columbia to give the right way, Li told Yang his opinion. After a heated discussion, Yang agreed with Li and signed his name on * * *. After Li Qianyang, he published a paper "Conservation of Heavy Particles and Transformation of Universal Norms".

This incident enabled them to cooperate again, which was also a romantic and magical period in their physics career. In the article Breaking Parity, it is described as follows: "From 1956 to 1962, Yang and I wrote 32 papers, ranging from particle physics to statistical mechanics? Close and fruitful cooperation, competition and coordination. Let's work together and give full play to each of our abilities. The results of cooperation are much more than everyone can achieve by working alone. "

It was during this period that they won the Nobel Prize.

The discovery of parity non-conservation is called the revolution of physics in the 20th century. According to Li Zhengdao's biography, this discovery was first discovered by Li Zhengdao:

1956 is about a morning in late April and early May. Drive from Long Island to Columbia, then to Zhengdao, and discuss it in Li's office. Soon, Yang Zhenning wanted to move his car parked in the street, so they walked into the street. After parking the car, because the restaurant was not open yet, they discussed it over coffee at the White Rose Cafe on125th Street and Broadway. Li Zhengdao told Yang Zhenning about his recent work and the breakthrough idea of parity non-conservation.

Yang Zhenning strongly opposes everything Li Zhengdao said. But after repeated discussions, he was gradually persuaded. After lunch, they returned to Li Zhengdao's office. Yang was completely convinced and expressed his willingness to cooperate with Li. He also put forward a very important suggestion, that is, to persuade Li not to rush to publish the above paper. He said that this is a very popular breakthrough and should occupy the whole weak area at once at the fastest speed. This is more complete and meaningful.

Li Zhengdao thinks it makes sense, and thinks that if Yang Zhenning participates, the whole thing will be done better.

The two started a friendly match. They finished all the beta decay analysis in about two weeks. This requires a lot of calculation. Both of them have equal computing power and both contribute.

A month later, they finished the analysis of these processes and wrote a paper. This paper was written by Li Zhengdao and signed by Li Zhengdao. This is a paper that won the Nobel Prize 1957 after a sensation. 1957 10 In June, the Royal Swedish Academy of Science announced that it would award the physics prize of that year to Li Zhengdao and Yang Zhenning.

165438+ 10, Li Zhengdao will go to Stockholm to receive the prize. They all write speeches and speeches. At that time, in the notice of the Nobel Prize Committee and all media reports, the order of the two names was the same as the signature of the winning paper, with Li Zhengdao in the front and Yang Zhenning in the back.

"I didn't expect this," the book says. When they arrived in Stockholm, Yang Zhenning suddenly suggested that according to the age order, he hoped to win the prize before Li Zhengdao, and his wife Du Zhili hoped that the king would be accompanied at the dinner party, that is, when entering the dinner party, she had to go ahead, and Yang Zhenning came second, accompanied by the queen.

Li Zhengdao was surprised by this and did not agree to do so. However, Yang Zhenning went to ask Qin Gui, the wife of Li Zhengdao. Qin Hui told Li Zhengdao that it was shameful for foreigners to joke about it. So Li reluctantly agreed.

This is an episode. Although Li Zhengdao was unhappy, he was soon diluted by the glory of the Nobel Prize. However, an article soon divided them-The New Yorker published in May 1962 published the Sidelights of Parity written by Bernstein, which told the story of Li Yang's cooperation in discovering the non-conservation of parity.

At that time, Li Zhengdao had returned to Princeton Institute for Advanced Studies. In April, he received the proof of Bernstein's article, and did not make any changes. However, Yang Zhenning put forward many opinions. He said that there are "some painful places" in the article, which should be discussed with Li Zhengdao.

Yang Zhenning suggested that in some places in the article, he wanted his name to be written before Li Zhengdao, and his wife Du Zhili's name should also be put before Qin Hui, because Du Zhili was one year older than him. The next day, I went home and asked, "Did Li and Yang write?" Add a note in all places, indicating that it is out of the habit of alphabetical sorting.

Li Zhengdao is tired of Yang Zhenning's demands. That evening, Yang called again and said that those notes could be omitted, but the article should be written as "Yang and Li".

Li Zhengdao was disappointed and had to advise them not to cooperate in the future. According to this book, Yang Zhenning immediately became very excited and began to cry, saying that he was very willing to continue cooperation. But Li Zhengdao felt helpless. Finally, everyone agreed to suspend cooperation.

In June of the same year, Li Zhengdao submitted his resignation to Oppenheimer. Oppenheimer feels very sorry for this. He pointedly pointed out that Li Zhengdao should stop studying high-energy physics and Yang Zhenning should see a psychologist. Of course, this is just the expression of Li Zhengdao. In Biography of Li Zhengdao, the author Ji Cheng also tried to introduce Yang Zhenning's expression to achieve a balance.

Yang Zhenning wrote in the anthology published in 1982 and 1983, in the article "Understanding Li Zhengdao": "He is brilliant and studious. We got along well and soon became good friends. ? Fermi is the tutor of his thesis, but he always asks me for guidance. Therefore, in those years in Chicago, I actually became his physics teacher. "

In the postscript of the last cooperation with Li Zhengdao, Yang Zhenning summed up their cooperation: "I treated him like a brother. In the field of particle physics and statistical mechanics, I became famous in the early 1950s. In our cooperative relationship, I am a senior party. Keenly aware that I shouldn't stand in his way, I will consciously lean back and try my best to support his career. At the same time, I will keep a strict silence on the essence of our cooperative relationship in public? "

In the postscript of "The Generation of Nobel Prize Papers" written by 1982, Yang Zhenning's version is completely different from Li Zhengdao's: "Our discussion focuses on the mystery of θ-τ. At a key point, I thought that the symmetry of production process should be separated from the decay process. So, if people assume that parity is conserved only in strong interaction, but not in weak interaction, then θ and τ are the same particle, and the conclusion that spin and parity are 0- (inferred from strong interaction) will not encounter difficulties? Li Zhengdao first opposed this view. I tried to convince him. Later he agreed with me. " The feud between Li Yang has gone far beyond personal category and extended to the future development of basic disciplines in China.

From 65438 to 0972, Yang Zhenning and Li Zhengdao visited China successively, which had a far-reaching impact on China's scientific career. Ji Cheng wrote that around the development of high-energy physics, China has always had different opinions. However, since Li Yang, two Chinese Nobel Prize winners, returned from outer space and visited China one after another and intervened in it, this disagreement has a strong personal passion and has become a struggle between Li Yang and other places.

There are many examples: Li Zhengdao advocates building a high-energy accelerator, while Yang Zhenning opposes it; Li Zhengdao advocates attaching importance to basic science, while Yang Zhenning advocates applied science. Li Zhengdao created a special examination method to help China students study in the United States, which Yang Zhenning called "humiliating the country", and so on.

"He didn't put forward any specific suggestions on the development of high-energy physics in China, and even advocated freezing the funds for basic research, saying that it was for the benefit of the whole nation, and advocated that the Academy of Sciences should focus on developmental research, thus' production first, production first, production first'." This book sums up Yang Zhenning's attitude.

Ji Cheng wrote: "By extension, it seems that as long as Li Zhengdao agrees, Yang Zhenning opposes it. Yang Zhenning's personal spirit goes far beyond the field of high-energy physics. The source of passion lies entirely in Yang Zhenning. On the contrary, Li Zhengdao did not express his personal feelings about what Yang Zhenning did after returning to China. People can't see the phenomenon that' as long as Yang Zhenning advocates it, Li Zhengdao opposes it'. "

Ji Cheng told this reporter: "I wrote their grievances with an objective attitude and described the facts without prejudice or conclusion."

"The difference between them is a question of the history of science. Its merits should be judged by history and studied by historians of science. As for the conclusion, I am afraid that no one or institution can get it. " Ji Cheng said.