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Tsung-Dao Lee benefited from opportunities throughout his life and also "opened doors" for others.

Text丨Zeng Menglong
Editor: Qian Yang

Tsung-Dao Lee stood at the side of the podium, half sideways, with his face slightly tilted upward, looking a little arrogant and conceited. This is how a student who had taken Tsung-Dao Lee's physics course recalled in Beijing in 1979.

At that time, Tsung-Dao Lee gave a seven-week course at the Beijing Friendship Hotel to introduce the international academic frontier. However, the domestic academic community had been out of touch for a long time, and most people could not understand what he was talking about. But they remembered Tsung-Dao Lee's bright eyes when he talked about physics, and they also remembered him saying, "The most important things in science are simple, and the complicated things are all side issues."

Tsung-Dao Lee is an undisputed genius. He once concluded that he had been engaged in physics research all his life and that the vitality of his life came from the "challenges of physics."

He got up at three or four o'clock every day to work. Physics became his way of life. He did not think it was strange, nor did he think it was hard. In 2011, the 85-year-old Tsung-Dao Lee officially retired from Columbia University as a professor. He often reread his papers from his youth for fun, but later he was too old to understand his old works. He read university physics textbooks and still enjoyed solving problems.

Due to health problems, he never returned to China after retirement. In 2014, Tsung-Dao Lee moved from New York, where he had lived for 61 years, to San Francisco to be near his children and grandchildren. Tsung-Dao Lee has two sons, seven grandchildren and one great-grandson. He often bathes in the California sunshine and walks alone on the beach by the Golden Gate Bridge.

In the early morning of August 4, 2024, local time, Tsung-Dao Lee passed away at his home in San Francisco, USA, at the age of 98.

He was born in a wealthy family in Shanghai, but encountered war and lived a life of displacement. He did not have a diploma, but relying on his talent, he was admitted as a graduate student by the University of Chicago. In 1957, 31-year-old Tsung-Dao Lee and Chen-Ning Yang won the Nobel Prize in Physics for discovering the phenomenon of "parity non-conservation". He also became the first Nobel Prize winner from China and the fourth youngest in history.

Tsung-Dao Lee not only fully utilized his talent, but also was eager to give more Chinese people the opportunity to display their talents. Concerned about the lack of education and scientific talent in China, he suggested the establishment of the "Junior Class", the "China-US Joint Training Program for Physics Graduate Students" (CUSPEA), the postdoctoral system, the National Natural Science Foundation, etc. These programs and mechanisms have cultivated countless talents in science, technology, and business.

He also helped China enter the Internet age faster. The book "The Language of Heaven and the Way of Things: A Critical Biography of Tsung-Dao Lee" states that in the early 1990s, the Beijing Electron-Positron Collider experiment urgently needed to cooperate with high-energy physics laboratories around the world through the Internet. All things are difficult at the beginning. Tsung-Dao Lee worked hard to coordinate the government leaders and scientific and technological personnel of both China and the United States, and in March 1993, he created China's first international Internet service system using the Internet communication protocol. Xu Rongsheng, a researcher at the Institute of High Energy Physics who led the project, wrote in an article that without Tsung-Dao Lee's efforts, the beginning of China's Internet age would have been delayed for several years.

In 1950, Tsung-Dao Lee married his wife, Qin Hui-yi. 46 years later, Qin Hui-yi passed away. In memory of his late wife, he donated to establish the "Zheng-Dao Fund" in 1998 to support Chinese students' scientific research internships, benefiting thousands of young scholars.

In his later years, Tsung-Dao Lee thought about and advocated the combination of science and art, believing that "art and science are like two sides of a coin. They originate from the noblest part of human activities and both pursue profundity, universality, eternity and meaning." He created many poems and paintings to mourn his late wife, and also encouraged researchers to broaden their knowledge as much as possible, "reading more miscellaneous books will make your mind more flexible."

He often combined life with science, saying "Symmetry shows the beauty of the universe, asymmetry generates the reality of the universe", "Life has no geometry, life has no algebra. We must cherish life, cherish life, work hard, and make more contributions."

"I can understand how the universe evolved and what laws everything in the world follows, but ants cannot."

On November 24, 1926, Tsung-Dao Lee was born into a fertilizer merchant family in Shanghai. He attended the private Qingxin Middle School (now Shinan Middle School) for primary school, where he received a modern education that emphasized both Chinese and English. He was picked up and dropped off by a driver every day.

The war interrupted Tsung-Dao Lee's happy childhood. In August 1937, the Battle of Shanghai broke out, and Tsung-Dao Lee fell into a life of displacement. He first fled to the British Concession in Shanghai with his family. After the outbreak of the Pacific War in 1941, Tsung-Dao Lee and his second brother were separated from the rest of the family. After hundreds of kilometers of exile, the two brothers came to Ganzhou, Jiangxi Province via Fujian, and were taken in by a local refugee relief organization.

But Ganzhou was not a peaceful place. The Japanese often came to bomb, and the citizens had to flee the city to take refuge in the air-raid shelter. In order to survive, the 16-year-old Li Zhengdao risked staying in the city and looked after the teahouse during the bombing. The leftovers of the teahouse customers were his reward. Once, he even saw a Japanese pilot wearing a helmet and glasses, but fortunately he hid well and escaped.

During the war, Tsung-Dao Lee did not give up studying and entered Ganzhou Lianzhong with his hard work. Since the college entrance examination was mainly divided into test areas based on geography at that time, he planned to travel hundreds of kilometers to apply for Zhejiang University, which was then moved to Guiyang, Guizhou. In order to raise enough money for the trip, Tsung-Dao Lee worked as a middle school physics and mathematics teacher for a while. In Ganzhou, he found the textbook "General Physics" written by Sa Bendong, the former president of Xiamen University, in the library. Tsung-Dao Lee also systematically taught himself physics for the first time.

"Self-study" is the characteristic of Tsung-Dao Lee's study and research. This characteristic is related to the fragmentation of his early education. From elementary school, middle school to university, Tsung-Dao Lee was almost unable to attend classes completely and could only rely on self-study. Self-study also became the source of meaning that supported him to survive during the war and later to enjoy research.

Li Zhengdao once recalled: "In war and famine, people were dying everywhere. Death and life are very close. There must be a motivation to make you feel the need to live. What was the motivation for me? I read the university textbooks published by the Commercial Press and learned that there are laws in nature! So I think it is very interesting to study this in life."

"During those lonely and helpless years in Ganzhou, on the road of escape under enemy bombing, no matter how dangerous and difficult the environment was, I still tried to encourage myself to survive. How to encourage myself? Every person has a meaning of survival. (Although) we are all living things, I am different from ants. I can understand how the universe evolves and what laws all things in the world follow, but ants cannot."

Finding the laws of nature, or calculating and solving difficult problems, became a lifelong hobby that Tsung-Dao Lee cultivated during the war. For example, he recalled that he often went to Wu Dayou's house to ask for difficult physics problems. Later, Wu Dayou simply gave him a physics textbook used by senior students in the physics department of an American university and asked him to do all the exercises in the book. As a result, Tsung-Dao Lee solved all the problems in less than two weeks. Wu Dayou was quite surprised and found that his problem-solving ideas were unique and the steps were simple, and "his thinking was much more agile than that of ordinary people."

"He asked me, 'You have only studied physics for one year, and many exercises in this book require a lot of knowledge that you have not learned to solve. Where did you learn it from?' I told Teacher Wu that my mind was full of physics problems all day long, and when I couldn't figure them out on my own, I would look for books to read. When I was doing exercises or researching problems, I never asked others how to solve the problems, nor did I apply other people's problem-solving methods. I always solved the problems and sought answers on my own," said Tsung-Dao Lee.

Norman Christ, a student of Tsung-Dao Lee, recalled to Sanlian Life Weekly: "He really wanted to understand everything by himself. He didn't read other people's papers. If he heard about some problems, he would try to solve them himself. He believed that nothing was superficial, and everything needed to be started from scratch to achieve complete understanding. So he often saw things that others didn't see."

Li Zhengdao's son Li Zhongqing recalled that his father once suddenly asked him: "Do you usually dream?" Li Zhongqing said that he sometimes had nightmares. Li Zhengdao said that he had never had a dream with a plot in his life, and he only saw geometric figures of different shapes in his dreams.

Talent, diligence and opportunity——"Opportunity may be the most important, but also the most difficult to control"

In 1957, 31-year-old Tsung-Dao Lee and four-year-old Chen-Ning Yang won the Nobel Prize in Physics for discovering the phenomenon of "parity non-conservation". Since both of them were Chinese at the time, they also became the first Chinese Nobel Prize winners. In terms of age, Tsung-Dao Lee is the fourth youngest Nobel Prize winner in history. Younger than him are Malala (17 years old), Lawrence Bragg (25 years old) and Heisenberg (30 years old).

Tsung-Dao Lee (left) and Chen-Ning Yang in front of the blackboard in their office. Image courtesy of the Shelby White and Leon Levy Archives Center.

How did he achieve such success? Li Zhengdao himself said: "Genius and diligence are the two major factors that play a leading role in achieving excellent results and outstanding achievements." In addition, opportunity is also important - "perhaps the most important and the most difficult to control."

"The most important opportunity in my life was that I was very lucky to meet three important teachers when I was very young and received their guidance and help. The enlightenment of teacher Shu Xingbei, the education and cultivation of teacher Wu Dayou, and the formal professional training of teacher Fermi all directly influenced and affected my future work and achievements. My life is inseparable from their influence on me."

After being admitted to Zhejiang University in Guizhou, Li Zhengdao met his teacher Shu Xingbei, who called him the "light source of enlightenment" for his physics. At Shu Xingbei's suggestion, Li Zhengdao transferred to Southwest Associated University to study with Wu Dayou. At that time, there were also Rao Yutai and Ye Qisun at Southwest Associated University. Like Shu Xingbei and Wu Dayou, they were physicists who returned to China after training in famous Western universities (such as Harvard and Princeton). Although the war was continuous, the young genius was carefully cultivated by the most internationally-minded scholars in China at that time.

Another university that did not waste Tsung-Dao Lee's talent was the University of Chicago, which recruited talents in an unconventional way. In 1945, the government of the Republic of China sent three scientists, Wu Dayou, Hua Luogeng, and Zeng Zhaolun, to the United States to learn the technology of making atomic bombs. Each scientist could bring two assistants, and Wu Dayou chose 19-year-old Tsung-Dao Lee and Zhu Guangya, who was already a teacher (later awarded the "Two Bombs and One Satellite Medal of Merit"). However, the United States did not open atomic bomb technology to the Chinese, so they had to study abroad separately.

Because he did not complete his studies, Tsung-Dao Lee did not have a diploma and was rejected by many universities. Only the University of Chicago offered him trial status. In the quantum mechanics class of Edward Teller, the "father of the hydrogen bomb," Tsung-Dao Lee solved a difficult problem that impressed Teller. Teller recommended Tsung-Dao Lee to Enrico Fermi (1938 Nobel Prize winner in Physics). Fermi was also amazed by his talent and successfully lobbied the school to make Tsung-Dao Lee his official graduate student. In 1950, Tsung-Dao Lee received his doctoral diploma, which was his first diploma.

Historian Wang Fan-sen wrote an article titled "Why do geniuses come in groups?" He said that many important academic advances were made by a "pushing" of a small force to move a large object. This "pushing" came from a person developing ideas and knowledge from a group of people in endless discussions. A group of people "pushing" up the academic efforts of a person. Examples include the coffee houses in Vienna, the intellectual capital of Europe in the 19th century, the development of Russian literature in the 19th century and the literary and artistic circles centered on Belinsky, etc.

Compared with his fellow teachers and friends who returned to China after graduation (such as Zhu Guangya and Wu Ningkun), Tsung-Dao Lee chose to continue his research in the United States. His achievements were also inseparable from the brilliant academic circle he was in at the time. The dean of the Institute for Advanced Study at Princeton at the time was Robert Oppenheimer, the "father of the atomic bomb." Oppenheimer and Fermi were good friends, and on Fermi's recommendation, Tsung-Dao Lee joined the Institute for Advanced Study in 1951.

It was at the Institute for Advanced Study in Princeton that Tsung-Dao Lee began to collaborate with Chen-Ning Yang, who had arrived two years earlier. Lee's paper also attracted the attention of John von Neumann, the "father of computer science" and "father of game theory", and Albert Einstein, the idol of many physicists, who were also at the Institute for Advanced Study. Einstein even invited Lee and Chen-Ning Yang to his home for a discussion.

Li Zhengdao recalled that he saw a copy of Physical Review spread out on Einstein's desk, and the manuscript next to it was filled with calculation results to verify their papers. Einstein spoke with a German accent and asked some questions about statistical mechanics. At the end of the conversation, the 75-year-old Einstein shook hands with them and said, "I wish you success in physics in the future."

Einstein died in 1955 and did not live to see the two receive the Nobel Prize two years later, but his wish came true.

"This rare opportunity changed my life... I hope more similar opportunities can come to young people"

Tsung-Dao Lee once expressed that, in some ways, the China-U.S. Joint Training Program for Physics Graduate Students (CUSPEA) is more meaningful than his Nobel Prize-winning work on "Parity Violation."

From 1979 to 1989, more than 900 Chinese students received full scholarships to study physics at American universities through CUSPEA. Because China did not have TOEFL and GRE exams in the early 1980s, CUSPEA was almost one of the few ways to study abroad. This program has trained countless talents in physics, technology, finance, etc., including 15 scientists who have become academicians in China, the United States, Canada, Europe and other places, and more than 400 successful high-tech inventors and entrepreneurs. For example, Yang Bo (nicknamed "Abei"), the founder of Douban, who is well-known to the public, benefited from this.

At that time, Tsung-Dao Lee was already a world-renowned Nobel Prize-winning physicist, but in the past ten years, he was willing to devote one-third of his time to CUSPEA to help Chinese students communicate with the universities they wanted to attend. From sending letters to universities in China and the United States three times a year, to the application materials for each round of students, to the study and life of each student, these were all things that Tsung-Dao Lee, his wife, and his secretary had to worry about.

In 1950, Tsung-Dao Lee and his wife, Hui-Chen Qin, got married in front of the Chicago City Hall. Image from: Tsung-Dao Lee's popular science book Symmetry and Asymmetry.

Many people cannot understand why Tsung-Dao Lee put so much energy into CUSPEA. He once explained: "With the recommendation of Professor Wu Dayou, I received a scholarship from the Chinese government to study in the United States and continue my studies in physics. This rare opportunity changed my life. There are many factors that contribute to a person's success, among which 'opportunity' is perhaps the most important and the most difficult to control. Although the opportunity for success cannot be predetermined, its probability can be greatly increased. Through Professor Wu, I was able to get this opportunity. My cherishment of this opportunity is one of the main reasons that prompted me to organize the CUSPEA exam in recent years. I hope that more similar opportunities can patronize young people."

Another reason was responsibility. In 1972, after leaving China for 26 years, Tsung-Dao Lee was allowed to return to China to visit scientific research institutes. He was worried about the scientific research situation in China at that time, so he decided to return to China to give lectures and introduce the frontiers of foreign physics. From May to July 1979, Tsung-Dao Lee got up at 3 a.m. every day to prepare for the course, and gave a full 7-week course at the Beijing Friendship Hotel. After the lecture, he realized that it was far from enough to just give lectures in China to make up for the lessons.

"From my own experience of growing up, I deeply feel that we must create opportunities for systematic learning and development for a group of young people in our country as soon as possible, especially to enable them to go to the world-class research institutes and universities in the United States for systematic study. This is a long-term strategy for cultivating talents and it is also my unshirkable responsibility," Li Zhengdao wrote in the article.

CUSPEA is just one of Tsung-Dao Lee’s creative solutions to China’s lack of education and scientific talent. In addition, he also suggested to leaders in the 1970s to set up “junior classes”. In 1978, the University of Science and Technology of China established the first “junior class”, and later Fudan University and other universities also established them. Over the past few decades, the “junior class” has trained many scientific research and business talents, such as Liang Jianzhang, the founder of Ctrip.

However, the junior class also faces controversy such as forcing students to grow too fast. Li Zhengdao said that he proposed the junior class as a stopgap measure. He believed that "the education system was severely damaged at that time, and it would not be restored overnight, but starting from primary and secondary schools might be a feasible solution." CUSPEA, a separate selection exam, is also a similar measure for special periods.

Later, Li Zhengdao's suggestions on talent training became more conventional and institutionalized. For example, he suggested that China set up postdoctoral institutions, the National Natural Science Foundation, and other systems, establish a Chinese advanced science and technology center, and promote China's basic research to focus on fundamental scientific issues.

Looking back, Tsung-Dao Lee was able to make these contributions thanks to the "honeymoon period" of Sino-US relations. His projects and suggestions were supported by China's top leaders, the overseas Chinese scholar community facilitated the smooth progress of the projects, and the top leaders of the United States were also happy to accept Chinese students. The most classic example in this regard was in 1978, when China asked the United States whether it could send 5,000 people to study abroad. Former US President Carter said to his scientific adviser: "Tell Deng Xiaoping that he can send 100,000 people."

Many people also believe that Li Zhengdao knows how to exert his influence, is good at handling interpersonal relationships and persuading others, which is one of the reasons why he can get things done. For example, he helped American students obtain project funding totaling 15 million US dollars.

However, Li Zhengdao is a low-key and generous scholar who is good at exerting influence but does not like to be in the limelight, wants to accomplish things but is unwilling to form a school of thought, and wants to maintain his reputation but is not willing to talk too much.

Li Zhongqing recalled, "My father rarely took the initiative to keep in close contact with CUSPEA students. He had a very pure sense of responsibility in dealing with students." Just like the obituary of Li Zhengdao by Shanghai Jiaotong University, which quoted Du Fu's poem, "To study physics carefully, one must enjoy life, why bother with fame and fortune?"

The public is keen to discuss the feud between Tsung-Dao Lee and Chen-Ning Yang, and both sides have said some harsh words. His son, Chung-Ching Lee, once told Sanlian Life Weekly that his father was in poor health in his later years and rarely met outsiders. When he accidentally heard the three words "Chen-Ning Yang", he would often be silent for a moment, and then say, "He is a very outstanding physicist." Chen-Ning Yang has repeatedly said that the breakdown of their relationship was the biggest regret of his life.

How to judge the disagreement between these two physics geniuses and superstars is ultimately a task for the history of science. As Oppenheimer recalled, the young Tsung-Dao Lee and Chen-Ning Yang discussing issues on the lawn of the Institute for Advanced Study in Princeton was a pleasing sight.

Title image source: Visual China

Some references:

1. Symmetry and Asymmetry, by Tsung-Dao Lee, translated by Zhu Yunlun and Liu Huaizu, published by CITIC Publishing Group in April 2021.

2. "The Language of Heaven and the Way of Things: A Critical Biography of Tsung-Dao Lee", written by Zhao Tianchi, published by China Planning Press in December 2017.

3. "Tsung-Dao Lee: Opening a Door for Geniuses", cover feature, Sanlian Life Weekly, June 17, 2024.

4. Deeply mourn the passing of Mr. Tsung-Dao Lee

https://news.sciencenet.cn/htmlnews/2024/8/527648.shtm

5. Tsung-Dao Lee: Dedicated himself to cultivating talents for the motherland

https://mp.weixin.qq.com/s/-fGbc3Yxp6eQf07KXp6vgA