Who discovered the theory of "parity non-conservation under weak interaction conditions"?

Zhenning Yang, a Chinese-American physicist. A native of Hefei, Anhui. In 1956, he and Lee Tsung-dao discovered the parity non-conservation theorem under weak interaction conditions. In 1957, they both won the Nobel Prize in Physics.

The greatest influence on Yang Zhenning in his early years was his good family environment and the good education he received at Southwest Associated University. Yang Zhenning’s father, Yang Kechuan, was originally a middle school teacher. Later, he studied abroad at the University of Chicago in the United States for five years and returned to China after obtaining a doctorate in mathematics. Yang Zhenning was only two years old when his father left. Yang Zhenning is talented and intelligent. He began to read when he was 3 years old. Under the guidance of his mother, he learned 3,000 Chinese characters in only one and a half years.

In 1937, Japan launched a full-scale war of aggression against China. Soon, Peiping fell. Yang Zhenning's family fled to Hefei and later arrived in Kunming. Yang Zhenning was only 16 years old at the time and was in his second year of high school, but he was admitted to Southwest Associated University with equivalent academic qualifications the following year. The conditions of the Southwest Associated University during the war were extremely poor, but the teaching staff was extremely strong. Because it is a joint venture between Peking University, Tsinghua University and Nankai University, there are many famous professors. Famous teachers such as Zhu Ziqing, Wen Yiduo, Wang Li, and Luo Changpei all taught him Chinese. Celebrities in physics such as Zhao Zhongyao and Zhou Peiyuan also gave them lessons in person. His bachelor's thesis was written under the guidance of Professor Wu Dayou, and his master's thesis was written under the guidance of Professor Wang Zhuxi.

Professor Wu Dayou guided him to learn group theory and symmetry principles, and Professor Wang Zhuxi guided him into the field of statistical mechanics. In future work, these aspects have always been Yang Zhenning's main areas of focus. The influence of these two famous teachers on him cannot be underestimated.

While Yang was studying for a master’s degree at Southwest Associated University, he highly admired the research styles of Einstein, Fermi and Dirac. The three of them have the same characteristic: they can extract substantive things from very complex physical phenomena, and then express them with mathematical formulas through in-depth research and thinking. The articles written by the three of them were straight to the point, to the point, and never made empty words.

Yang Zhenning secretly made a vow that he must go to the United States and become his mentor to one of the three of them. However, it is not easy for an ordinary Chinese to have a world-famous physicist as his teacher. When Chen Ning Yang and his teacher talked about this idea, they both thought it was not practical. However, Chen Ning Yang still refused to give up easily.

After coming to the United States, he went straight to Columbia University to look for Fermi, but the secretary of the school’s physics department actually said that he had never heard of such a person in their school. In desperation, Yang Zhenning had to go to Princeton to find his former teacher, Professor Zhang Wenyu, for help. After Professor Zhang's efforts and recommendations, in January 1946, Yang Zhenning finally got his wish and sat in Fermi's research class. When he directly proposed to do a doctoral thesis with Professor Fermi, Fermi told him: "I can't supervise your doctoral thesis because I am engaged in a highly confidential research work. But I can introduce you to a professor at the University of Chicago. A very talented professor." This professor was Edward Teller, who was later called the "Father of the Hydrogen Bomb" by Americans.

One of the characteristics of Edward Taylor's physics courses is that he likes to express his opinions outspokenly. He believes that even if more than 90% of this view is wrong, as long as 1% is right, it has reference value for students. This teaching method is very helpful in developing students' thinking.

When Yang Zhenning first came to the United States, he wanted to be an experimental physicist. He believed that the real joy of learning physics can be found in experiments, and only in experiments can there be real innovation. When he told Fermi about this idea, Fermi believed that it was impossible for a foreigner to enter the Argonne Laboratory. So Fermi introduced him to Professor Allison's accelerator laboratory.

However, Yang Zhenning was not successful here and always seemed clumsy in the laboratory. There was a joke in the laboratory at that time: "Wherever there is an explosion in the laboratory, there must be Chen Ning Yang!" After Taylor learned about the situation, he decided to let him give up and switch to theoretical physics.

After staying in the laboratory for nearly 20 months, Yang Zhenning decided to give up after careful consideration. Although this period of laboratory life was not very successful, it laid the foundation for his later work. When he and Li Zhengdao came up with the conclusion that "parity is not conserved under weak interaction conditions", they once designed an experiment from the perspective of experimental physicists to test the correctness of their theory.

It can be said that this period of life in the laboratory laid a solid foundation for him to combine theory and experiment.

After years of hard work, Yang Zhenning’s hard work finally paid off. In 1956, he and Li Zhengdao discovered "parity non-conservation under weak interaction conditions". In 1957, this conclusion was experimentally proved by Ms. Wu Jianxiong, a Chinese-American scientist. This year is an unforgettable and historic year for Yang Zhenning. His achievements have been recognized by the world. Together with Li Zhengdao, he won the highest honor in the hall of science - the Nobel Prize in Physics.

After winning the award, Yang Zhenning was still not satisfied and continued to work selflessly. After the establishment of diplomatic relations between China and the United States, he visited China many times, promoting Sino-US exchanges and the development of China's scientific undertakings.