Chapter 25 Chen Ning Yang's inspiration

Yang Zhenning received a bachelor's degree from Southwest Associated University in Kunming in 1942 and a master's degree in 1944. He went to Chicago around Christmas in 1945 and officially enrolled in Chicago University as a graduate student in January 1946. , 1957 and Li Zhengdao won the Nobel Prize in Physics.The English version "Selected Papers 1945-1980 With Commentary" (Selected Papers 1945-1980 With Commentary), which was published in English for more than a year, has 585 pages, and the first 82 pages are "commentaries" written by him to each article in the book, vaguely reviewing most of his life His mental journey is both lyrical and plain, and his English is clean and charming, reminiscent of the elegant writing style of modern Western physicists.Einstein's literary talents have long been known, and the papers, speeches, and letters he wrote in his life are not dull and touching; James Watson wrote "Double Helix Chain", although he talked about the discovery of DNA The whole book reflects the whole atmosphere of Britain after the Second World War, and the reflection of personal character and cultural tradition is everywhere, and the rational presentation and emotional expression are just right; I edited the Chinese translation of this book more than ten years ago, Reading Chinese and English word by word, it is really like a spring breeze, and I am worried about the future for those who study liberal arts!It was no surprise that the book was a bestseller in the West.Yang Zhenning said in the "Commentary" of "Selected Papers" that in every creative field, taste plus academic ability, temperament and opportunity determine the level of style and the size of contribution.Physics was originally a subject that objectively studies all phenomena of matter. It may sound unbelievable at first to say that the taste and style of physicists have a profound influence on their contributions to physics; The concept of perception, the biased love and dislike of thousands of characteristics in it, is the reason for personal appreciation and taste.Therefore, Yang Zhenning said that it is not surprising that taste and style are so important to scientific research, just like literature, art and music.

Physicists' articles make good use of metaphors and similes, which can set off rigorous logical deduction and turn abstraction into concreteness.Austrian-American physicist P.Frank said that he once talked to Einstein about a physicist with mediocre research achievements, saying that he always liked to deal with some extremely difficult problems, but unfortunately there was no result.After hearing this, Einstein said: "I admire this kind of person; I most dislike those scientists who are only willing to find the thinnest and easiest place to punch holes in a piece of wood." This anecdote was quoted in the paper "Elementary Particles: A Brief History of Atomic Physics" written in one year.The part of the thesis that talks about the principle of symmetry in physics uses Chinese lattice windows, the bronze ware of the Southern Dynasties, Fang Ge, and the pattern of warriors riding horses by the Dutch artist Escher as metaphors, which are vivid and interesting.German-American mathematician Herman Wahl talked about the Austrian physicist and philosopher Ernest Maha experimenting with the magnetic needle parallel to the wire, the deflection direction of the magnetic needle will be determined by the direction of the current, and it is also used to sandwich two piles of the same The donkey in the straw pile is likened to a magnetic needle. It is said that the donkey "has no reason to decide to go left or right", which hits the nail on the head!Yang Zhenning appreciates such inspiration.

When Li Zhengdao and Yang Zhenning began to study the problem of left-right symmetry in the principle of symmetry, it seemed that it was the time when the confrontation between the left and the right in China was fierce. These two physicists chose this topic in physics to do research. It is because of their taste and style. The rest of the political consciousness is at work, and the imagination is thus redoubled.Yang Zhenning once pointed out that in daily life, the left and the right are very different, but the laws of physics often show that the left and right are completely symmetrical. Therefore, quantum mechanics has the theory of conservation law or parity conservation; The family is likened to a person who is trapped in a dark room and cannot find the door.In the summer of 1956, he and Li Zhengdao finally came to an anti-traditional conclusion, thinking that the symmetries C, P, and T were conserved in the dominant interaction between elementary particles, and violated the old theory in the weak interaction. Say.In other words, in the weak interaction, the left-right symmetry has been proved by Wu Jianxiong et al.'s experiments and does not obey the left-right symmetry law.Yang Zhenning immediately sent a telegram to the American physicist Oppenheimer who was on vacation in Virgin Island. Oppenheimer called back and said: "Get out of the room", sincere, relevant and funny!The Austrian-American physicist W. Bowley did not believe that the strong interaction of elementary particles would show symmetry and the weak interaction would show asymmetry at first. Afterwards, he said that he finally had to marvel that "God is really a weak left-handed person"!However, Yang Zhenning still said in a speech: "It seems that when God created the universe, he also wanted certain symmetries to be generally and imperfectly observed." The words are determined to be "nature has not fully revealed herself"!

After Yang Zhenning became a U.S. citizen in 1964, he was still worried about it, fearing that his father would never forgive him for abandoning his country and country.The decision to become an American came after several hesitation; in his "Commentary", he used a small episode to point out the history of blood and tears of overseas Chinese in the United States: "One night in the early 1960s, I took a train from New York City via Paseo I went to Brookhaven. The night was very dark. The rickety car was almost empty. I chatted with an old man sitting behind me. He was born in Zhejiang in about 1890 and lived in the United States. He has been doing laundry for fifty years, not necessarily. He has never been married, and has always lived alone in a room. He always has a smile on his face; does he really have no resentment in his heart? I don’t know. I understand. I watched him stagger through the dimly lit aisle in the carriage and get off at Wanbin Station. He was old and hunchbacked, a little trembling, and my heart was full of grief and indignation." In January 1961, Yang Zhenning watched TV. At Kennedy's inauguration, the poet Frost recited "The Cif Outright" (The Cif Outright), and if he had an epiphany, he began to apply for citizenship.However, in this "Selected Papers", he said that his appreciation of physics was developed when he was a student in Kunming; there are four Chinese characters on the title page of this book: "Dedicated to Mother".