**:Intelligentsia.
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Written by丨Shi Yu
Subrahmanyan Chandrasekhar (1910-1995, Fig. 1) was an Indian-American theoretical astrophysicist who shared the 1983 Nobel Prize in Physics for his work on the physical processes of star structure and evolution. He received his Ph.D. from the University of Cambridge in 1933 and spent four years as a postdoctoral fellow in Cambridge before joining the Yerkes Observatory at the University of Chicago (Williams Bay, Wisconsin).
Figure 1 Subrahmanyan Chandrasekhar
There is a legend about Chandrasekhar, Yang Chenning, and Lee Tsung-do, which is widely circulated. Peter Freund, a professor at the University of Chicago, told in "Passion for Discovery" that Chandrasekhar was going to take classes from Yerkes to the University of Chicago campus, and there were only a few students who chose the course, and after a few classes, there were only two students left, namely Lee Tsung-dao and Yang Zhenning, and the head of the department was willing to cancel the course, but Chandra himself insisted on taking it, because the students were very good, and he was happy to continue talking. Later, the whole class and the teacher won the Nobel Prize.
I asked Mr. Yang by email on January 25, 2013 and June 7, 2014 to verify this story, and Mr. Yang said, "Correct in spirit, but not in the details." ”
On July 22, 2014, we discussed this matter again in a long face-to-face conversation.
Me:"Legend has it that Chandrasekhar went to Chicago from the Yerkes Observatory to take classes, and there were only two students, you and Tsung-Dao Lee. Aren't you too right to say the details? ”
Yang Zhenning:"This story was later written by someone who was a very famous man named Osterbrock, who was a brilliant astrophysicist who was at Yerkes at the same time as Tsung-Dao Lee, and he later wrote an article to study this matter in detail, and the result was that the meaning of this was right, and the specific thing was wrong. Later, Lee went to Yerkes and had a confrontation with Chandrasekhar. Later, Chandrasekhar went to Tsung-Dao Lee's 60-year-old meeting, so Tsung-Dao Lee was very happy. ”
Me:"It is a seminar about 30 years of non-conservation of the universe and the 60th year of Lee Tsung-do. Tsung-Dao Lee's own report, chaired by Chandrasekhar, began with an introduction to the grand occasion of the University of Chicago, mentioning the names of many teachers and students of that year, and calling Tsung-Dao Lee "a student of the past and a master of physics today." Just now you said, Chandrasekhar gave you a lesson, 'the meaning is right, the specific is not right', do you mean that it is not really a class or something? ”
Yang Zhenning:"It's class. It was snowing heavily, and Chandrasekhar drove a car and walked for an hour and a half to Chicago for this lesson, and very few students attended. These are all right. But it's not just us. And neither of us took this class, we both sat in on it. ”
Me:"The legend is dramatized. ”
Mr. Yang provides new information here, and there has been a time (or several times) that it has "snowed heavily". This made a deep impression on him. In fact, Chandrasekhar's classes were for a semester, and there was certainly more than one time when it snowed heavily.
On the 24th, I consulted K c.Chandrasekhar's biography Chandra (published in 1991) written by Wali and Chandrasekhar's autobiography edited by Wali. The biography reads: "There is a famous story that Chandra often traveled from Williams Bay to Chicago to take a class with only two students. April 22, 1975, President of the University of Chicago, John TIntroducing Chandra's Ryerson report to the audience, Wilson said: 'In today's cost-effectiveness and its frequent misuse in higher academics, I can't help but tell you that Chandra has provided an excellent example to the troubled provosts in defending the educational heritage of our university. In the mid-to-late 1940s, Chandra often drove hundreds of miles a week between the Yerkes Observatory in Williams Bay and the university to meet a class of two students. Even at the time, people might have raised the question of the relative value of time and effort, but I suspect he didn't even think of it. When the Nobel Prize in Physics was awarded in 1957, it was awarded to the class, Mr. Lee and Mr. Yang. There's a slip of the tongue or a clerical error, but the fact is that Yerkes is only a hundred miles from Chicago.
But Wali added a note to the text: "Before 1983, the 'whole class' referred only to these two students, Lee Tsung-dao and Yang Chen-ning. Since 1983, the term has also included teachers. I must point out that the historical accuracy of this story has been questioned. Apparently several other people (such as Donald Osterbrock and Enrico Fermi) also attended, but not regularly. ”
When Wali wrote this biography, Chandrasekhar gave him a copy of a notepad and said that after his death, if Lady Chandra and Wali were interested, they could publish it. Wali later edited the notebook into The Autobiography of Chandrasekhar, which was published in 2010.
Chandrasekhar's autobiography says: "I lecture on radiation transfer on campus. There were only two people in my class, Li and Yang. The entire class of 1948 went on to win Nobel Prizes! It seems that the words of the rector in 1975 misled the memory of Chandrasekhar himself.
Chandrasekhar recalls the spring of 1950 and mentions: "Lee Tsung-do had already joined my research team at Yerkes by this time. This refers to the first eight months of 1950, when Lee Tsung-dao was a postdoc at Chandrasekhar.
On the 25th, I found several more Osterbrock reminiscences, and Figure 2 is the first page of one of them.
Figure 2 Donald E osterbrock
One of these articles is the one mentioned in Mr. Yang's conversation that he had read the draft but did not know where it was published [ D e. osterbrock, j. astrophys. astr.17, 233-268 (1996)], the article systematically describes Chandrasekhar's teaching and mentoring of students, in which it is written: "There were several students in the class, and neither Fermi's postdoctoral fellow Yang Zhenning nor Fermi's student Tsung-Dao Lee were formally selected. Among those who audited were they, Fermi, Marcel Schein (professor of physics who studies cosmic rays), and several other young faculty, postdocs and graduate ......As the semester progressed, the number of auditors dwindled, but Fermi, Schein (who often slept and snored in the first row, causing Chandra's obvious but unspoken displeasure), Yang and Lee persevered until the end, and there were probably a few others I can't remember clearly. Chandra's signed transcript shows that six students have officially enrolled in the course. 3 of them, another Fermi student, Richard LGarwin, later Professor of Physics at Tufts Arthur Uhlir JrAnd I, both stayed in Chicago to get my Ph.D. The fourth, John Goddard, died shortly after, not completing his degree. Garwin, Uhlir, and I all took the lessons seriously and learned a lot, and I think Goddard did too, although Wilson's story made it clear how easy it is to remember long after the incident, and the value of what was recorded at the time. Yang and Lee's memories match mine's memories (as well as records); Young told Walter Sullivan, the author of Chandra's obituary in The New York Times, that there was a class, but there were more than two people. ”
Later in the article, it is stated: "Lee Tsung-do completed his Ph.D. on white dwarfs on a university campus, under the guidance of Fermi, and Chandra was an astronomy consultant." He then spent two semesters at the Yerkes Observatory, in the spring and fall of 1950. The brilliant young postdoc (then 23 years old) regularly attends theoretical presentations and plays an important role in the discussions. Their styles were very different, Chandra's style was much more mathematical, while Lee was more physical, and the fur could fly was very heated as they tried to understand the turbulence and come to different conclusions. But they were polite, and the next day they discussed whether the average turbulent energy density was approximately equal to the average turbulent magnetic energy density (Lee's theory) or a mean square expression containing the curl of the magnetic field (Chandra's result). Sometimes it seems like a repetition of the debate between Eddington and the illustrious young Chandra over the internal structure of white dwarfs more than a decade ago, now in the quiet halls of the Yerkes Observatory, rather than at a meeting of the Royal Astronomical Society. ”
On the evening of the 25th, Mr. Yang and I had another discussion.
Yang Zhenning:"Did Osterbrock elaborate on that snowfall? ”
Me:"We don't talk about snow, but we talk about the norm of going from the observatory to the university. ”
Yang Zhenning:"I was under the impression that he gave me his draft. I haven't seen the whole published article. ”
Me:Published in an astronomical journal in India. I checked, Osterbrock studied at the University of Chicago campus for 3 years, came to the Yerkes Observatory in 1949, the supervisor was Chandrasekhar, graduated with a Ph.D. in 1952, went to Princeton University as a postdoctoral fellow for 1 year, during which he used von Neumann's computer at the Institute for Advanced Study, and in 1960 he visited the Institute for Advanced Study for 1 year. He passed away in 2007. ”
Yang Zhenning:"What year was at the Institute for Advanced Study? ”
Me:"1960-1961. ”
Yang Zhenning:"I must have seen him at the time. Even though he's at the Institute for Advanced Study, he's on the side of the astronomy guys. All I know is that he was a very successful theoretical astronomer. People in Yerkes must have had a deep impression of the quarrel between Lee Tsung-do and Chandrasekhar, because quarrels with Chandrasekhar are rare. ”
Me:"Chandrasekhar is a difficult person, and the students are afraid of him and avoid meeting him, right? ”
Yang Zhenning:"Yes, he's more difficult. ”
Me:"He's also a neat, quiet, shy, private guy, isn't he? ”
Yang Zhenning:"Yes, it has something to do with the fact that he is Indian. Indians, I think, are easy to be discriminated against in the United States because they are darker, and they have been ruled by the British for many years. In fact, many years ago, there was a young man in the United States who was writing a Bose biography. I don't know if the biography of Bose was published later, but when he wrote it, before it was finalized, he wrote an article, and I read it, and it said that Bose told the man who wrote the biography that the British had been in India for hundreds of years, and that its policy was to make the Indians feel that they were inferior to the British. ”
Me:"A lot of the last successful people in India came from aristocratic families, and Chandrasekhar was Raman's nephew, right?
Yang Zhenning:"Yes. ”
Me:"Chandrasekhar was bullied by Eddington in England, does it have anything to do with him being Indian? ”
Yang Zhenning:"It had something to do with that, but more importantly, I think Eddington was a bit strange at the time. Did you know that Eddington later invented a theory? ”
Me:"137 That, huh? ”
Yang Zhenning:"Yes. ”
Me:Later, Dirac also felt that the number 1 137 of the fine structure constant was important, and he was dissatisfied with quantum electrodynamics because he could not explain this number. ”
Yang Zhenning:"He had a guess that the number had changed over time. ”
Me:"Yes, the big number assumption. ”