Shulou(Shulou.com)11/24 Report--

Yang Zhenning drove to New York to see T.D.Lee.

It was the best season in New York in late April or early May 1956, with warm winds blowing and flowers and leaves in full bloom. He picked up T.D.Lee at Columbia University and went nearby to look for food. They walked to the White Rose Cafe and discussed over coffee; out of the cafe they went to a Chinese restaurant and argued over lunch; finally they went back to T.D.Lee 's office and wrote on the blackboard, and by the end of the day, they already knew what they needed to do-rummaging through all past experiments on weak interactions to see if there was any evidence of parity conservation.

Memory bifurcates here.

Yang Zhenning (left) and T.D.Lee (right) | sciencephoto.com many years later, T.D.Lee remembered that he had thought of the key point first, inspired by his previous discussion with colleague Steinberg, as evidenced by several experimental physicists who did parity nonconservation analysis only thanked him in the paper. Yang Zhenning was strongly opposed at first, and after listening to his analysis, Yang Zhenning was convinced and joined the research.

Yang Zhenning remembers that he thought of the key point first, inspired by his two papers published in 1948 and 1954. T.D.Lee did not believe it at first, and it was he who persuaded T.D.Lee.

Different participants have diametrically different memories of the same thing. This is not uncommon. Memory is not something that lies quietly somewhere in the brain and can be completely taken out and put back. Instead, every time I recall it, I "reconstruct" it in my head. Each time it is reconstructed, it is more or less distorted by the present state of mind. Yang and Li must have recalled this period of history countless times, and their memories have gone farther and farther away in their respective reconstruction.

In 1956, when the discussion took place, Yang Zhenning remembered that he and T.D.Lee visited each other regularly every week. He went to Columbia University to see T.D.Lee every Thursday, and T.D.Lee went to Princeton to see him every Tuesday. T.D.Lee remembers that the two had already had a knot at that time, did not conduct cooperative research, and did not see each other very often, and the weekly exchange of visits began after the publication of parity non-conservation.

When Li Yang discussed the Chinese restaurant, Yang Zhenning remembered it as a Shanghai restaurant and T.D.Lee remembered it as a Tianjin restaurant.

Who wrote the first draft of the Nobel Prize paper of parity non-conservation? Yang Zhenning remembered that he had severe back pain and was bedridden, so he dictated the paper and asked his wife du Zhili to write the first draft-of course, the complex formula was added by Yang Zhenning himself. The first draft was handed over to T.D.Lee, and T.D.Lee made several changes, which were later typed and submitted by a secretary at Yang Zhenning's Brookhaven laboratory.

T.D.Lee remembers that the first draft of the paper was written by T.D.Lee himself, and T.D.Lee 's secretary was responsible for turning the manuscript into a typed manuscript. After receiving the first draft of the paper, Yang Zhenning only changed the title to a question. However, the "physical Review" of the receiving paper did not appreciate the question title, so it still used T.D.Lee 's title "query on parity conservation in weak interaction".

Yang and Li, two scientists, jointly ascended the Nobel Prize podium because of this discovery, and severed diplomatic relations because of this discovery. Many people had hoped that they would get back together in their lifetime. But some people think that Yang Li's personality is so strong and the relationship is so close that they will go their separate ways sooner or later.

The Nobel laureates Yang Zhenning (left) and T.D.Lee (right) | nobelprize.org have two birthdays when they have children such as Yang Da Tou.

On September 22, Yang Zhenning mistakenly wrote his birthday on his certificate when he went to study in the United States, and the same date was used when the Nobel Prize was written on the official website of the Nobel Prize.

October 1st, this is his real birthday. Yang Zhenning was born in Yang's compound in Hefei, Anhui Province on October 1, 1922. According to his seniority, he is the "Zhen" generation. That year, his father Yang Wuzhi taught middle school mathematics in Huaining County, so he chose the name "Ning" in the place name.

Coincidentally, the two most important papers in Yang Zhenning's life were also published on October 1.

Questioning parity conservation in weak interactions, which won him the Nobel Prize, was published on October 1, 1956.

Perhaps his most important discovery, isospin conservation and isospin gauge invariance, was published on October 1, 1954.

In November 1922, when Yang Zhenning was a month old, Einstein traveled to China and learned in Shanghai that he had won the 1921 Nobel Prize in Physics-not 1922, because the 1921 Nobel Prize in Physics was delayed by one year. The real 1922 Nobel Prize in Physics was awarded to Bohr.

In 1922, the Nobel Prize for Physics was awarded twice. Yang Zhenning was 0.1 and Einstein was 43. In 27 years, they will become colleagues at the Princeton Institute for Advanced Studies. They will also have one thing in common: the research that won the Nobel Prize in physics is not the most important discovery they have made. And the most important discovery they made is the existence that can be compared.

But we don't have to wait until so many years later, Yang Zhenning's talent has already been revealed. The first thing he noticed was his father, Yang Wuzhi, who found that Yang Zhenning had no difficulty in studying and wrote a sentence on the back of a childhood photo of Yang Zhenning, "Ning'er seems to have something special."

In 1929, Yang Wuzhi went to Tsinghua University as a professor of mathematics. Yang Zhenning also lived in Tsinghua Garden with his parents. At that time, he was nicknamed "Yang Da Tou", first because his head was really big, and second because he was a child's head. Yang Zhenning is the eldest son, and his younger brother and sister are quite different in age, so he sometimes takes on the responsibility of disciplining his younger brother and sister. If the younger brother and sister behave well, he will remember a red star for them. At the weekend, a red star can be exchanged for a peanut. However, after Yang Zhenning went abroad, some peanuts were not cashed, which can be called a Yang's scam.

Yang Zhenning is the kind of "other people's children". Xie Xide, a female physicist and former president of Fudan University, remembers that when she was a child, her father, Xie Yuming, taught them not to be playful and to study hard. Once Yang Wuzhi quarreled with Hua Luogeng and said, "I can't catch up with you in math all my life, but my son must surpass you in the future."

In 1938, when the Anti-Japanese War began, Tsinghua University, Peking University and Nankai established Southwest Associated University in Kunming. Yang Wuzhi went to teach there, and Yang Zhenning went to Kunming with him.

The legend of "Yang Big head" continues. At the age of 16, Yang Zhenning, a sophomore in high school, directly applied for the Southwest Associated University, with 20,000 candidates nationwide, and he ranked second. When he signed up, he had not even studied high school physics, so he applied to the Chemistry Department of Southwest Associated University, but later found it interesting to come into contact with physics, so he quickly transferred to the Physics Department.

Yang Zhenning's university admission card | wikimedia commons Southwest Associated University has only existed for eight years and graduated more than 3, 000 people. Among these more than 3,000 people, there are many world-class scholars. In addition to Yang Zhenning, there are T.D.Lee, Deng Jiaxian, Zhu Guangya, Huang Kun. Wait. The professors of Southwest Associated University gathered together. Zhu Ziqing, Wen Yiduo, and Wang Li taught Yang Zhenning, while Zhou Peiyuan, Zhao Zhongyao, and Wu Youxun taught him physics. The professors took turns in class, talking about the part of me that studied the most deeply and learned most.

Yang Zhenning's bachelor's thesis was written under the guidance of Wu Dayou, who drew his attention to the principle of symmetry. His master's thesis was written under the guidance of Wang Zhuxi, who drew his attention to statistical mechanics. Symmetry and statistical mechanics are the direction of Yang Zhenning's deep ploughing all his life. It can be said that a scientist is extremely lucky to be exposed to a lifelong subject at the beginning of his research career.

At Southwest Associated University, Yang Zhenning is still famous for being good at reading-100 in physics and 99 in calculus, the best in the school. Xu Yuanchong, a translator who took classes with Yang Zhenning at Southwest Associated University, remembers that he was second in writing English essays at that time. Yang Zhenning is the first place.

He Zhaowu, a historian who is also a student at Southwest Associated University, has also seen Yang Zhenning and Huang Kun, who were already famous talents at Southwest Associated University, talking in a teahouse. Huang Kun asked, "what do you think of the article recently published by Einstein?" Yang Zhenning waved his hand and said with disdain: "there is no originality (innovation). It is an old fool."

At that time, he Zhaowu secretly thought to himself whether this guy was arrogant or not, but he also felt that maybe he had to have this kind of boldness in order to surpass his predecessors.

Huang Kun later won the Boxer Indemnity to stay in the UK, returned home after completing his study, and became one of the top figures in China's semiconductor industry.

Physicist Huang Kun and his student wikimedia commons Yang Zhenning can be said to be extremely lucky in terms of "small environment". His parents are very affectionate, his younger brother and sister are friendly, and they are surrounded by mentors. He recalled that he was also born at the right time in scientific research. China's modern science has taken three big steps from scratch in the past 30 or 40 years. During the May 4th Movement in 1919, China hardly had its own natural science research career. By the time he was born, there were already Chinese students coming back from abroad to set up universities in various places. By the time he was in primary school, China had been able to train undergraduates on a par with foreign undergraduates. By the time he was in middle school, Qingbei and other famous schools had already had a number of doctorates coming back from abroad, and they were able to train master's degree students at the same level as foreign countries. By the time he attended the Southwest Associated University, the Southwest Associated University had been able to train doctoral students of the same level as foreign countries.

However, in terms of the country's "general environment", Yang Zhenning is in the "long night". The broken shadows of mountains and rivers are always caged on the heads of him and his family. Before the age of 6, he and his mother lived in Hefei (his father was studying for a doctorate in mathematics at the University of Chicago). When the warlords fought in Hefei, they had to hide in hospitals run by the countryside or foreign churches. He even remembers coming back when he was 3 years old and saw a bullet hole in the corner of his home. When he grew up in Kunming, he often encountered air raids by the Japanese aggressors. In the fall of his 18-year-old, the Japanese air raids blew up the Yang family's house. Fortunately, the whole family took refuge in the air-raid shelter in time, safe and sound, but the belongings were gone. A few days later, Yang Zhenning went back to dig the ruins of his home with a shovel and dug up a few books that could still be used. There was no entertainment at that time, so Yang Zhenning worked with his playmate Xiong Bingming (who later became a painter) to make local movies. Xiong Bingming painted comic books, and Yang Zhenning installed an installation-- a light bulb in an old biscuit tube and a magnifying glass at the mouth of the tube. When the comic book was drawn in front of a magnifying glass, a moving picture appeared on the wall. They made a local movie about the destruction of families caused by the bombing of Japanese planes.

Yang Zhenning later named his collection "Dawn Collection" and "Morning Collection", meaning that the Chinese nation finally finished that long night.

A thousand years of shame has snowed in the end. The sight of enemies is like smoke. But our country is old and old, old and new.

Yang Wuzhi once taught Yang Zhenning a song "Chinese Man":

"Chinese men, Chinese men, want to hold one hand to the sky.

Sleeping Lion Millennium, Sleeping Lion Millennium.

Yang Zhenning often sings this song. So people around him remember one thing: Yang Zhenning sings loudly and badly.

After graduating from the Southwest Associated University in the Temple of Physics, Yang Zhenning was admitted as a Boxer indemnity to study in the United States. August 28, 1945, was the day when he left.

Early that morning, Yang Zhenning left home, his younger brother and sister were reluctant to part, his mother was very calm and did not shed tears, and his father accompanied him to the bus stop.

After getting on the bus, Yang Zhenning began to discuss the flight route with his classmates who went to the United States. After waiting for more than an hour, the car hasn't started yet. Someone signaled Yang Zhenning to look out of the window, but he was surprised to find that his father had been waiting there and did not leave--

"he had a shapely figure, a long robe and gray hair on his forehead. Seeing his anxious face, I held back the tears all morning and burst into tears. I couldn't help myself."

At that time, the Yang Zhenning family had a very tortuous journey to the United States. Yang Zhenning first flew from Kunming to Calcutta, India, where he waited for more than two months before boarding a US Navy transport ship. The ship had to carry thousands of American soldiers back to the United States from Southeast Asia, leaving one or two hundred beds for ordinary people. Yang Zhenning and his classmates were one of the "ordinary people."

On November 24, 1945, three months after leaving Kunming, Yang Zhenning finally disembarked at a dock on the Hudson River in New York. He spent two days familiarizing himself with the environment and buying some daily necessities, and on the third day, he went to Columbia University to find his idol, physicist Fermi. It came as a bolt from the blue that Fermi was no longer at Columbia University. Yang Zhenning asked around and chased him from New York to Princeton, then from Princeton to the University of Chicago, and finally to Fermi.

When he was at Southwest Associated University, Yang Zhenning had already formed a taste for scientific research. Not all great scientists have a style that he admires. For example, he can't resonate with Heisenberg, who discovered the uncertainty principle. He most appreciated Einstein, Dirac and Fermi, who went straight to the point and extracted the simple spirit from complex phenomena and expressed them mathematically.

Yang Zhenning has considered the situation of all three: Einstein is old and hardly recruits graduate students, Dirac is still in Cambridge, England, but Fermi has arrived in the United States to escape Italian anti-Semitism. Fermi is the nameter of neutrinos, one of the designers of the atomic bomb, and is a top-notch scholar in theory and experiment. For very complex physical problems, he can put aside the details, analyze the nature, and add a few quantitative estimates to give a clear idea of solving the problem in half an hour-this method of quickly estimating the number of difficult problems is now called "Fermi estimation". At that time, in the Los Alamos Laboratory in the United States, Fermi and Von Neumann were two famous "sages", and other physicists could ask them no matter what problems they encountered. When the United States tested the first atomic bomb, Fermi waited at the base 9 kilometers away, holding some scraps of paper in his hand. As soon as the flash of the explosion appeared, he let the piece of paper fall-without the shock wave, the piece of paper would have fallen at his feet, but when the shock wave of the explosion arrived, it would have caused the piece of paper in the air to shift by a few centimeters. Fermi accurately estimated the energy of the atomic bomb about 20, 000 tons of TNT based on his distance from the explosion point and the distance the paper was pushed.

In 1946, Yang Zhenning succeeded in chasing stars and met Fermi at the University of Chicago. Fermi also recognized Yang Zhenning's physics skills, and sometimes Fermi went on business trips and even asked Yang Zhenning to teach graduate students on his behalf. But for political reasons, Yang Zhenning can't be Fermi's graduate student.

At that time, the University of Chicago had not yet built a cyclotron for particle physics experiments. Fermi is doing experiments at Argonne National Laboratory in the United States, where the Manhattan Project is carried out in the United States. There are many secrets, and basically only American researchers are accepted. Yang Zhenning, a Chinese newcomer, is absolutely impossible to go there to do research.

Science has no national boundaries, but scientists have their own country. The next time Yang Zhenning was keenly aware of this, it was after 1950 that China and the United States had bad relations, and President Truman ordered that all people who obtained doctorates in the United States should not return to China. The moment he left China, it never occurred to him that it would take him 26 years to set foot on his native land again.

Back in 1946, Fermi recommended Yang Zhenning to Professor Edward Taylor. Taylor is characterized by rich imagination, strong intuition, lots of ideas and daring to speak. How many ideas are there? At that time, he participated in the atomic bomb program of the United States, but the idea was too divergent. One idea today and another new idea tomorrow, the people who worked with him complained incessantly. Oppenheimer gave full play to the art of management, leaving Taylor to make a hydrogen bomb on his own-as a result, Taylor became the father of the hydrogen bomb.

Although 90% of Taylor's instincts may be wrong, he is not afraid to make mistakes. A 10% correct breakthrough is enough anyway.

Fermi is Taylor's confidant and translator. At the seminar, it was often Taylor who spoke about his instincts and thoughts, and then Fermi stood up and added, "what Taylor is trying to say is this."... "

Yang Zhenning later recalled, "the difference between Taylor and Fermi is that Fermi's opinions are usually right, while Taylor's opinions are mostly wrong." According to Chinese tradition, if you don't fully understand a problem, don't talk nonsense. People think that talking nonsense is bad, and people who talk nonsense must be unreliable. Taylor has a lot of opinions and always speaks out. But if you point out that he is wrong, he will accept it immediately and go in the right direction. "

Fermi wikimedia commons, an Italian-American physicist, followed Taylor for a while. Yang Zhenning's mind fluctuated again and said to Taylor, "I have to go back to China. I think what China needs is experimental physics, so I want to do this work."

So Yang Zhenning went to Samuel Ellison's laboratory, which was building a 400,000 electron volt accelerator to do some low-energy nuclear physics experiments. Yang Zhenning participated in the construction of the accelerator and subsequent experiments.

In Allison's laboratory, Yang Zhenning had two insights: one was to understand what experimental physicists were doing, and the other was to realize that it was not very good to do it yourself.

Speaking of which, Yang Zhenning was not very good at craftsmanship when he was a child. Once he made a chicken out of mud and showed it to his parents. The parents said, "well done, is it a lotus root?" When you grow up to do experiments, it is also "harming others and harming yourself". There was even a joke in Allison's lab that said, "where there is ping-pong, there must be Where there is a bang, there is Yang."

An American classmate named Joan Hinton later moved to China and changed his name to Han Chun. On one occasion, when Yang Zhenning was doing an experiment, he accidentally touched Han Chun's hand with a device with high voltage. Han Chun left a scar on his hand since then, and he was a little afraid to see Yang Zhenning doing the experiment.

At that time, there was often something wrong with the accelerator circuit and air leakage. A classmate named Arnold often found the air leak in two minutes, but Yang Zhenning could not find it in two hours. Yang Zhenning asked Arnold about the trick Arnold was looking for, but Arnold couldn't explain it. In the end, Yang Zhenning had to give up and say, "some people have an intuitive understanding of the experiment, but I don't."

After working in Allison's laboratory for a year and a half, Yang Zhenning did not produce any results, but noticed that Taylor had an intuitive guess, which could be expressed by group theory in mathematics, and wrote a simple proof manuscript to Taylor in his spare time.

Taylor asked him if the experiment was not very successful. Yang Zhenning admitted that he was. 'or you can write a theoretical physics paper based on the previous proof, and you can still graduate with a PhD, 'Mr. Taylor said.

Yang Zhenning went back and thought painfully for two days and decided to accept the proposal. He was relieved, and so did his friend, saying that it was probably the luck of experimental physics.

Yang Zhenning went back to write a three-page paper and showed it to Taylor. Taylor says this paper is good, but should it be longer as a doctoral thesis? how about you popularize it? A few days later, Yang Zhenning handed in a seven-page paper. Taylor couldn't help saying, could you be more specific? A few days later, Yang Zhenning handed in a 10-page paper.

Taylor hesitated. Although the paper was still short, it was really excellent. In 1948, Yang Zhenning received a doctorate in physics from the University of Chicago.

Yang Zhenning's tutor Taylor wikimedia commons's doctoral thesis, from parity nonconservation to Yang-Mills gauge field theory, is actually about symmetry.

Before that, he met teachers who could preach textbooks. After that, he began to meet more and more people who rewrote textbooks. He learned from the "gods", accepted the challenge of the "gods", and eventually became a member of the "gods".

The most beautiful scenery in Princeton, Yang Da Tou, the eldest son, treats his younger brothers as a "protector" in a sense.

Deng Jiaxian was 2 years younger than Yang Zhenning. The two met when they were studying at Chongde Middle School in Beijing, chatted together, listened to Beethoven's "Symphony of Heroes" together, read Newton's "Mathematical principles of Natural philosophy" together, and were successively admitted to the physics department of Southwest Associated University. In 1948, Yang Zhenning's younger brothers Yang Zhenping and Deng Jiaxian went to the United States together, both of whom went abroad at their own expense, so they were very short of money. It only took Deng Jiaxian more than a year to finish his doctorate at full speed. Nine days after getting his doctorate, he returned home by boat.

Yang Zhenning had just received his doctorate and stayed at the University of Chicago as a lecturer with a monthly salary of $375. He helped Deng Jiaxian apply to Pudu University and funded some funds for Deng Jiaxian to go abroad. For his younger brother, he earns 1/3 of his monthly salary as living expenses for Yang Zhenping. Yang Zhenping himself feels that Yang Zhenning treats him as "an eldest brother like a father." Later, Mills, who worked with Yang Zhenning on the Yang-Mills equation, said something similar: "Frank (Yang Zhenning's English name) treats me like a father."

In the fall of wikimedia commons1946, 20-year-old T.D.Lee came to the United States to study as a graduate student. His brotherly days with Yang Zhenning began.

Yang and Li have no contact in China, but they can be regarded as brothers of the same teacher. In 1942, Wu Dayou instructed Yang Zhenning to write a bachelor's thesis. In 1945, the year Yang Zhenning left for the United States, a fat teenager introduced himself to Wu Dayou, who was T.D.Lee. Wu Dayou found that T.D.Lee was indeed a physics genius, so he recorded him in Southwest Associated University, and when T.D.Lee was a sophomore, he recommended him to study in the United States. T.D.Lee first accompanied Wu Dayou's wife to the University of Chicago to find Yang Zhenning. Soon after arriving there, T.D.Lee also went to graduate school at the University of Chicago. Like Yang Zhenning, T.D.Lee soon showed his talent and diligence, and he was eager to learn from Fermi-unlike Yang Zhenning, he succeeded. Fermi was erudite and modest and was an excellent teacher, and T.D.Lee benefited a lot under his guidance.

At that time, T.D.Lee used to associate with three graduate students-Steinberg, who also studied under Fermi; Rosenblues, who studied with Taylor but shared an office with T.D.Lee; and Yang Zhenning, who studied with Taylor. In 1949, T.D.Lee published his first paper, which was co-written with Yang Zhenning and Rosenblues. Yang Zhenning and T.D.Lee also joined several other graduate students in the physics department to participate in a crossword puzzle competition held by a Chicago newspaper. The first prize was $50, 000. This group of top students sang triumphantly all the way to the final round, and found that there was a rule ambiguity in the title, which could be explained in two ways. So they put forward two sets of solutions according to two explanations-- as a result, they proposed too many solutions. Lost his qualification for the competition and lost his bonus.

One year off, Yang Zhenning, T.D.Lee, and another Chinese student, Ling Ning, bought a light green second-hand Chevrolet. Yang Zhenning first went to Rosenblues to teach him how to drive, and then he taught T.D.Lee and Ling Ning. Finally, all three of them took the driver's license and immediately drove this car to take a self-driving trip to the western United States. They drove all the way from Chicago to San Francisco and then to the Grand Canyon, where they almost had an adventure.

T.D.Lee 's recollection of this is that before leaving, Yang Zhenning suggested that the trio should pay proportionately for the car, and when they came back, T.D.Lee would pay for the car alone. T.D.Lee readily agreed and returned Yang Heling's money to them when he came back from the trip. Later, Yang Zhenning mentioned this "car bought by three people" in his biography. T.D.Lee recalled the events of that year and thought about the taste again.

There's a follow-up to this. When we got together again almost 40 years later, Rosenblues told Yang Zhenning that he didn't have a driver's license when he taught him to drive.

In 1949, Yang Zhenning had the opportunity to visit the Princeton Institute of Advanced Studies.

When Yang Zhenning went there, the dean of the institute was Oppenheimer, the "father of the atomic bomb". There were about 20 lifelong research professors, and Einstein was one of them.

Fermi once said to Yang Zhenning, "the Princeton Institute of Advanced Studies is very good." but it's not suitable to stay there for a long time. Because it is a bit like an ancient monastery, the research direction is too theoretical, it is easy to change to formalism, and finally has nothing to do with the practical problems of physics. "

Yang Zhenning thought Fermi had a point, then spent 17 years at the Princeton Institute for Advanced Studies and made some of the most important findings of his life.

After two years at the Princeton Institute, Yang Zhenning also sent T.D.Lee to the Princeton Institute of Advanced Studies.

By that time T.D.Lee had graduated from Fermi with a PhD and his thesis was "hydrogen content of White Dwarfs". After graduation, he first went to the observatory in Wisconsin and did research with Chandrasekhar, who was later a Nobel laureate. It was said that he was not very happy. Chandrasekhar is such a person: if students knew he was in the office, they would not take a shortcut through his office, but would rather take a farther way. Steven Weinberg, who later won the Nobel Prize, said he was afraid to go to the bathroom when T.D.Lee gave a speech when he was a graduate student at Columbia University. S.C.C.Ting, who also won the Nobel Prize later, also remembers that he met T.D.Lee in 1963 and told him about his doctoral thesis. T.D.Lee listened for a few minutes and told S.C.C.Ting that there was not much physics in the work you did.

Two people with a bad temper have been together for eight months. T.D.Lee moved to the University of California, Berkeley, and Yang Zhenning also wrote him a letter of recommendation at that time. Not long after, Yang Zhenning recommended T.D.Lee to Oppenheimer, so T.D.Lee came to the Princeton Institute of Advanced Studies. The two live next to each other. The Yang family lives in 3F Goodman Road and the Li family lives in 3e. The two worked together and soon co-authored two papers on statistical physics. The two children also played together and took a picture of the eldest son of the two families taking a bath together.

In October 1957, the two collaborative papers written by Yang and Li at the Princeton Institute for Advanced Studies also attracted Einstein. Einstein read the two papers on statistical physics and took the initiative to ask them for some details.

Yang Li finally made an appointment with Einstein for the first time. Previously, they were so careful not to disturb the divine physicist that Yang Zhenning did not even take a picture with Einstein himself, but his eldest son Yang Guangnuo once met with Einstein.

It was an idol meeting for fans. Yang Zhenning was so emotional at that time that he could hardly remember what he had talked about with Einstein. All he remembered was that Einstein spoke in a low voice, with an accent in English and a lot of German words.

T.D.Lee, on the other hand, remembered more details of the conversation. He had intended to ask him to sign a copy of Einstein's work, the meaning of the Theory of Relativity, but did not do so, regretting it for a long time. At parting, Einstein shook his hand and said, "I wish you success in physics in the future." Einstein's hands were big and warm. Also, Yang Zhenning later recalled the meeting and forgot that T.D.Lee went with him. It was really interesting.

Oppenheimer was trying to reform the Princeton Institute for Advanced Studies at the time, and he didn't like the fact that the institute was always littered with lonely old men, silently wandering about their own problems. He hopes that one is to recruit more young people, and the other is to promote cooperation and exchanges within the institute.

Yang and Li are the ideal picture of Oppenheimer. Oppenheimer once said that he was proud to see Yang Li walking together. Two extremely smart young Chinese were together, talking very fast and fiercely, deducing with blackboards and paper pens, and even calculating through the air with their fingers. Many physicists are impressed by this scene.

This kind of close cooperation continued until they won the Nobel Prize together for parity nonconservation.

Parity nonconservation should not only talk about "parity nonconservation", but also from "the riddle of θ-τ particles".

In the 1950s, experimental physicists bombarded various substances with high-speed protons, and then recorded the various "strange particles" produced. This is how theta particles and tau particles were discovered. From a variety of experimental data, theta particles and τ particles have the same properties, their lifetimes are similar, their masses are about the same, their charges are the same, and so are their spins.

However, the theta particle decays into two pions. The tau particle decays into three pions.

Is there two kinds of decay of the same particle, or are there almost identical "twin particles" in nature?

Yang Zhenning used an analogy. At that time, all physicists fumbled for an exit in a dark room. Everyone firmly believed that there must be an exit, but in which direction did they look for it?

Yang Zhenning and T.D.Lee groped for the direction that the physics "gods" had thought of, but did not believe that they would succeed.

Yang Zhenning and T.D.Lee discuss the problem in the office of the Institute of Advanced Studies in Princeton IAS. To be honest, physicists hope that the two particles are the same, but according to the widely accepted laws of physics at that time, they will come to the conclusion that "it can't be the same particle" anyway.

In the "widely accepted laws of physics at that time", there is "parity conservation", which can be understood as "the physical process obeys mirror symmetry". A physical system and its mirror image should be able to abide by the same laws of physics, the process of forming left and right symmetry.

Yang Zhenning used an analogy of "the man in the mirror". If a person lives in the mirror world, his heart grows on the right side, other internal organs grow on the opposite side of us, and the molecules that make up his body are also mirrors of our world molecules. Then his body should be able to obey the same laws of physics and operate as effectively as our bodies.

It is only natural that the mirror image is symmetrical. In numerous previous physical experiments, "parity conservation" has never disappointed physicists. Pauli, a famous poisonous tongue physicist who won the 1945 Nobel Prize, said, "I don't believe that God is left-handed." The famous Feynman also advised Norman Ramsey, who wanted to do an experiment to test the rule, "it was a crazy experiment, so don't waste your time on it."

Contrary to most physicists, it takes enough courage to propose that parity may not be conserved. What is more difficult is how to prove that "parity is not conserved"?

This is the flash of inspiration of Yang Zhenning and T.D.Lee.

They thought that there were four basic interactions in the world-gravitational interaction, electromagnetic interaction, strong interaction (the force that holds nuclei together) and weak interaction (the force that causes radioisotopes to decay). Previous experiments that support "parity conservation" are related to the first three basic functions.

They spent three weeks doing a lot of calculations and found that the terms that might reflect "parity nonconservation" were eliminated in weakly interacting decay experiments. Now we only need to do some new experiments to know whether the weak interaction obeys the parity conservation or not.

It took only about two months from that dinner in New York to writing the Nobel Prize paper "questioning parity conservation in weak interactions". The paper was written at the end of June 1956 and published at the beginning of October. In the paper, Yang and Li list a lot of detailed descriptions of experiments and show that these experiments may prove parity non-conservation. Now, what they need is experimental physicists waiting for discerning eyes to prove or negate their guesses with experimental results.

If a hero knows a hero, it belongs to C.S. Wu.

C.S. Wu, a colleague of T.D.Lee 's physics department at Columbia University, had already booked cruise tickets for family trips during the Christmas season, but she realized the importance of verifying parity non-conservation with her intuition in physics. So she asked her husband to take a cruise ship alone, while staying to do the experiment with her colleagues.

In 1958, C.S. Wu heard about it at Columbia University | Smithsonian Institution @ Flickr Commons Pauli. He worked with C.S. Wu and respected the scientist who "has an unimaginable interest in nuclear physics." so he said to another physicist, G. M.Temmer, "A good experimental physicist like C.S. Wu should find something important to do." You shouldn't waste your time on such an obvious thing. Everyone knows that parity must be conservative. "

In fact, after looking in the right direction, the experiment advanced very quickly. On Friday, January 4, 1957, the traditional "Chinese lunch Day" of the physics department of Columbia University, T.D.Lee excitedly announced that C.S. Wu called him in front of a dozen physicists. said her preliminary data showed an "amazing effect".

T.D.Lee 's colleague Leon M. Lederman couldn't help thinking that he was absent-minded at the dinner that day. As soon as he returned to the lab, he began to do another experiment that could verify parity non-conservation, and it took only three days to get the results-- too simple, too clear, too successful, even more significant than C.S. Wu's experiment. it's a pity that his name was answered, but it was a step behind.

At 6: 00 a. M. on January 8, Ledermann called T.D.Lee and said, "Yuzheng is finished."

Of course, the "mystery of θ-τ particles" is also easily solved-they are the same kind of particles, but they decay into different parity products. At this point, however, the riddle itself is less important.

The news spread like wildfire among physicists, making them restless. Oppenheimer sent a telegram to Yang Zhenning, "out of the door"-referring to Yang Zhenning's analogy of "groping in the dark room." Julian Schwinger, the chief theoretical physicist at Harvard University, asked, "I want to pay homage to nature!" On January 15, Columbia University's physics department held an unprecedented press conference on the discovery, at which Nobel laureate Isidor Rabi solemnly declared that "a fairly complete theoretical structure has been fundamentally broken, and we do not know how these fragments can be put together again in the future."

Even Pauli had to throw in the towel. On January 27, he wrote to his student, Victor Weisskopf, a physicist at MIT, saying, "fortunately, I didn't really bet, or I might lose a lot of money... God may be left-handed. However, when he expresses himself strongly, he is still symmetrical."

Physicist A.Salam used an analogy to describe how incredible parity non-conservation is. "when writers describe Cyclops, they always put that one eye in the middle of their forehead. Parity non-conservation is equivalent to physicists shocked to find that space is a weak left-eyed giant."

Yang and Li won the Nobel Prize in 1957-just over a year after their flash. Feynman said it was "the fastest Nobel Prize to be awarded", a record that has not yet been broken.

Yang Zhenning believes that the most important significance of winning the Nobel Prize is to "help change the psychological role that Chinese people feel inferior to others."

When Yang and Li won the Nobel Prize, they were both of Chinese nationality.

T.D.Lee (left) and Yang Zhenning (right) won the Nobel Prize in Yang Mills' normative field theory at the scene of the Nobel Prize is of course Yang Zhenning's highlight moment. But what is unknown at that moment is that another discovery made by Yang Zhenning a few years forward is of even more far-reaching significance.

To talk about "parity asymmetry", we should start with "the riddle of θ-τ particles". To talk about Young-Mills theory, we should start with Newton, Maxwell, Einstein and Emmy Noether.

Nott, a first-rate mathematician, lived in an age when female researchers were under pressure and died at the age of 53 after a postoperative infection. She has done numerous outstanding mathematical work in her life, and the Nott Theorem she proved is the cornerstone of today's theoretical physics.

There is only one sentence in the Nott Theorem-- every continuous symmetry corresponds to some conservation. And vice versa.

For example, the laws of physics are established today, tomorrow, and as long as they take. This is the symmetry of time.

The laws of physics hold true in Beijing and New York, no matter how far they move. This is the symmetry of space.

Time symmetry corresponds to the conservation of energy.

Spatial symmetry corresponds to the conservation of momentum.

Rotational symmetry corresponds to the conservation of angular momentum.

Some kind of symmetry of potential energy corresponds to the conservation of charge.

The reason why there are all kinds of conservation is that the world itself has various symmetries.

Nott's theorem is really a very beautiful theorem.

Nowadays, "aesthetics" has become the driving force of modern physics research. Physicists are surprised to find that the lowest foundation of the universe is beautifully designed. If there are two equations that can describe natural phenomena, physicists will always choose the more beautiful and symmetrical one. Einstein's creation of general relativity began with the introduction of "symmetry of generalized coordinates". Legend has it that Einstein lost interest in an equation as soon as he thought it was ugly.

Yang Zhenning is also a member of the "aestheticism". His ideas are even bolder--

Symmetry dominates conservation as well as interaction. Perhaps the equation describing the strong interaction between particles can be directly derived from some kind of conservation and using the appropriate symmetry.

The conservation chosen by Yang Zhenning is "isospin conservation".

With regard to isospin, there is an analogy-isospin is like a label, marking particles with different charges but otherwise the same. Imagine a pair of identical twin brothers who look exactly alike, except that the elder brother is wearing a coat and the younger brother is not. Once my brother took off his coat, he couldn't tell them apart. In the "strong interaction" force, protons and neutrons are like such twins, as long as the "charge coat" is removed, there is no difference between the two particles from the point of view of strong interaction. In a sense, neutrons and protons are two "quantum states" of the same particle. This "quantum state" is described mathematically as isospin.

With this intuition, he thought for many years, and the calculation was so complicated that he always got stuck. But after a while, he couldn't help thinking again and got stuck in the same place. It's been stuck for at least seven years.

In the summer of 1953, Yang Zhenning spent some time at the Brookhaven Lab on long Island, New York, where he shared an office with a graduate student, Robert Mills, who was still a doctoral student.

Robert Mills / Peter A. Frisch / wikipedia Yang Zhenning began to discuss many physical problems with Mills, including some failed attempts he had made. In one discussion, they suddenly came up with a mathematical method that could solve a large number of complex quadratic and cubic terms generated later in the calculation.

This is the birth of the Yang-Mills equation. It is equivalent to the Newton equations in classical mechanics and the Maxwell equations in electromagnetism.

Particle physicist Christine Sutton described Yang Zhenning's encounter with Mills-"like a rare planetary arrangement, briefly in the same time and space." The coexistence of this field gives birth to an equation that will be the cornerstone of A theory of everything, the holy grail of physics. They soon split up on different paths, but the Yang-Mills equation ensured that their names would never be separated again. "

The Yang-Mills theory was so advanced that at first it was only regarded by other physicists as a beautiful but useless math game. For example, a particle with an electric charge but no mass is predicted in the theory, but how can such a particle exist? When Yang Zhenning returned to the Princeton Institute of Advanced Studies in February 1954 to report on the new theory, the only person he was interested in was the venomous Pauli.

Pauli actually made almost the same attempt as Yang Zhenning, but he also encountered the same problem, zero-mass field particles. So Pauli just asked, "what is the mass of this field particle?"

'We 've studied it, but it's too complicated and we haven't reached a definite conclusion yet, 'Mr. Yang said.

Pauli said sternly, "this is an unjustifiable excuse."

Yang Zhenning didn't know what to do, so he stopped talking and sat down.

Or Oppenheimer came out to play round and said let Yang go on.

Pauli didn't ask any more questions that day, but he sent a note to Yang Zhenning the next day.

Dear Yang: I'm sorry, what you said at the meeting made it impossible for me to discuss it with you any more. have a good day. Sincere Pauli. February 24th. "

Strict Pauli | wikimedia commons Yang Zhenning debated for a long time whether or not to publish this theory, but finally decided to publish it, because the theory itself is really beautiful.

As a result, there are two classic papers jointly published by Yang Zhenning and Mills, "isospin conservation and isospin gauge invariance" and "isospin conservation and a generalized gauge invariance".

Physicist Xu Yihong wrote in awesome Symmetry, "Yang Zhenning and Mills' paper is not to explain phenomena that could not be explained in the past, but to pay tribute to a completely symmetrical God. This paper seems to say, 'look, this is the most beautiful theory that the human mind can dream of. If nature does not use this theory in her design, physicists will only be disappointed in nature.'"

It turns out that nature did not disappoint physicists. Yang-Mills theory is an extremely useful tool. The heavy photons found in 1983 prove that the Yang-Mills equation is not only a beautiful theory, but also more consistent with the experimental results. Even many of the later Nobel prizes in physics were made within the framework of Young-Mills theory.

The unified theory of electric weakness, which won the prize in 1979, is based on Yang-Mills theory.

The prize in 1999 is about the correctability of Yang-Mills theory.

The award in 2004 is about the asymptotic freedom of Yang-Mills theory.

There is also the award-winning Higgs particle in 2013, which is actually an important complement to Young-Mills theory. The problem of zero-mass particles is solved, and the Higgs mechanism can give zero-mass particles mass. Since then, Yang-Mills theory has no weakness and has really become the cornerstone of today's standard model of particle physics, "the Theory of everything". All basic interactions can be brought into the framework of Yang-Mills theory.

Physicist Dyson commented on Yang Zhenning in an article entitled "Birds and Frogs": "the view that symmetry determines interaction is Yang Zhenning's greatest contribution to physics. This contribution is the contribution of a bird who soars high above the rainforest with small problems, and most of us spend our lives in the rainforest."

Four high-spirited theoretical physicists: Pais, T.D.Lee, Yang Zhenning, Dyson Princeton IAS physicist Gross, said, "Symmetry dominates interaction, while Yang Zhenning dominates symmetry."

Today, there are four theories considered to be the brightest pearls of physics-Newton's theory of gravity, Maxwell's theory of electromagnetism, Einstein's theory of general relativity, and Young-Mills theory.

Yang Zhenning also found that many concepts of "gauge field" in physics can correspond to many concepts of "fiber bundle" in mathematics. The study of the physics of all things is the same as the mathematics of pure reason.

As a result, Yang-Mills theory has also brought about some advances and breakthroughs in mathematics. Part of the result of the 2019 Abel Prize (the equivalent of the Nobel Prize in mathematics) is the extension of the Yang-Mills equation.

On one occasion, Yang Zhenning talked about this exact correspondence with the great mathematician Shiing-Shen Chern. Yang Zhenning said,'I didn't expect you mathematicians to come up with these concepts out of thin air. Shiing-Shen Chern immediately retorted that these concepts were not imagined, but were natural and real.

Gains and losses know that Yang Zhenning has selected several papers from 1945 to 1980, compiled a collection of essays of his own choice, and added comments.

On the title page of the collection of essays, it is du Fu's poems that he translated into English.

A piece of literature

Is meant for the millennium.

But its ups and downs are known

Already in the author's heart.

The article goes through the ages, knowing every inch of its gains and losses.

The poem was also engraved on the 90th birthday gift given to Yang Zhenning by Tsinghua University in 2012. it is a black marble square with du Fu's poem engraved on the top and Yang Zhenning's 13 important contributions in four fields of physics on four sides.

Statistical mechanics

Phase transition theory in 1952

Boson many-body problem in 1957

1967 Young-Baxter equation

Exact solution of boson in 1-dimensional δ function repulsive potential at finite temperature in 1969

Condensed matter physics

Theoretical explanation of magnetic flux quantization of superconductors in 1961

Non-diagonal long program in 1962

Particle physics

Parity nonconservation in 1956

Three discrete symmetries of time inversion, charge conjugation and parity in 1957

Theoretical discussion on High Energy Neutrino experiment in 1960

Phenomenological framework of CP nonconservation in 1964

Field theory

Yang-Mills gauge field theory in 1954

The integral form of gauge field theory in 1974

The correspondence between gauge Field Theory and Fiber Bundle Theory in 1975

Feynman once asked the question, "if there is a catastrophe and all scientific knowledge is destroyed, how to convey the most information to future human beings with the least words?"

Feynman's own answer was, "everything is made up of atoms."

Now, physicists think that in addition to the word atom, it's best to add--

"symmetry determines the law of conservation."

The work done by Yang Zhenning, known as the "king of symmetry" (Lord of Symmetry), will be handed down forever with this sentence.

reference

[1] by Yang Jianyu. Yang Zhenning biography. Beijing: commercial Press, 2020

[2] Jiang Caijian. Yang Zhenning biography of the beauty of norms and symmetry in 2011 a new revision. Guangzhou: Guangdong Economic Publishing House, 2011.05.

Yang Zhenning, Weng Fan. Dawning set [M]. . Life Reading New knowledge Sanlian Bookstore, 2008

Yang Zhenning, Weng Fan. The Dawn Collection [M]. Commercial Press, 2018.

Xu Yihong, awesome Symmetry: exploring the Beauty of Modern Physics [M]. Tsinghua University Press. 2013

[6] Ji Cheng. T.D.Lee biography [M]. International Cultural Publishing Company, 2009.

[7] T.D.Lee, broken parity

C.N. Yang:Selected Papers 1945 TV 1980 with Commentary

[8] Shi Yu. The beauty of physics: Yang Zhenning's 13 important scientific contributions [J]. Physics, 2014, 43 (01): 57-62.

[9] Shi Yu. The Beauty and Truth of Physics: Yang Zhenning's Scientific contribution [J]. World Science, 2021 (12): 50-58.

[10] Jeremy Bernstein,A Question of Parity, New Yorker, Vol.38,49-104, May 12, 1962

[11] long tail Technology, depth: what does Yang-Mills Theory say? Why is this Yang Zhenning's contribution beyond his Nobel Prize? . (2021). Retrieved from https://zhuanlan.zhihu.com/ p/55922673

[12] The Feynman Lectures on Physics Vol. I Ch. 1: Atoms in Motion. (2021, July 12). Retrieved from https://www.feynmanlectures.caltech.edu/I_01.html

[13] Farmelo, Graham. It must be beautiful: great equations of modern science. London: Granta, 2002. Print.

This article comes from the official account of Wechat: fruit Shell (ID:Guokr42), author: Youyou Editor: small towel Review: steed

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.