Some Personal Perceptions of Japanese Physics

Laurie M. Brown　

〈Department of Physics and Astronomy, 
Northwestern University, 
Evanston, Illinois, USA　
e-mail: lbrown＠nuhep.phys.nwu.edu〉

It is both a pleasure and an honor to be invited to contribute to this important jubilee of the Physical Society of Japan. My contact with Japanese physicists and the wonderful science they have produced in this century has been both as an historian of physics and as a theoretical particle physicist (thus most of my comments will bear on soryushiron kenkyu).

Japanese physics first impressed me in 1948 when I was a graduate student at Cornell University, working as Hans Bethe's assistant and Richard Feynman's doctoral student. We all read eagerly the first issues of Yukawa's new journal, Progress of Theoretical Physics, containing the marvelous papers of Sakata, Tomonaga,Yukawa, and their associates, written during and just after the wartime. Freeman Dyson was also a student of Bethe; a recent book has quoted his reaction to Tomonaga's work on QED at that time: “Tomonaga expressed his [theory] in a simple clear language so that anybody could understand it and Schwinger did not . . . Tomonaga set the framework in a very beautiful way. To me that was very important. It gave me the idea that this was after all simple."^*

At a Cornell colloquium I heard Yukawa speak on non-local fields, when he was a professor at Columbia University, before he received the Nobel Prize. One summer I acquired the valued friendship of the late Satio Hayakawa, who was visiting Cornell from MIT. As a Member of the Institute for Advanced Study in Princeton in 1952, I also learned to know Fellow Members Toichiro Kinoshita and Yoichiro Nambu. Their brilliant work, like that of other expatriate theorists (such as S. Okubo, B. Sakita, H. Umezawa, and other partial expatriates, like K. Nishijima and Y. Yamaguchi) has greatly influenced my own work and career. Here I will mention only a review article I wrote on quarks in 1966, in which I emphasized the important impact of the Sakata Model on the origin of the quark idea.^**

After nearly thirty years as a particle theorist, I turned my attention to the history of modern physics. I began my studies with the field of physics that I knew, and asked: “What was the origin of modern particle physics?" A clear answer emerged: the meson theory of Yukawa. With a copy of Tabibito borrowed from my good friend Nambu-san and with the assistance of a Japanese undergraduate physics student at Northwestern University, R. Yoshida, I prepared a translation to help me to understand Yukawa's remarkable achievement.^*** From this seed, there grew an extended investigation into the history of Japanese particle physics, in which I enjoyed the cooperation of many outstanding Japanese physicists.

I tried first to correspond with Yukawa himself, but at that time (1977) he was not in good health and did not answer. I then wrote for help to my old Cornell friend Hayakawa-san. He was extremely enthusiastic and proposed a joint Japan-USA project to acquire archival material and personal accounts, in order to document important Japanese contributions to the historical epoch of the birth of modern particle physics. A collaboration resulted, with Nambu and myself on the USA side, supported by the National Science Foundation, and a distinguished Japanese group, supported by the Japan Society for the Promotion of Science on the other side. The group originally included Hayakawasan and Y. Fujimoto, R. Kawabe, M. Konuma, Z. Maki, S. Nakamura, T. Takabayasi, Y. Tanikawa, and T. Tsuji. We also had the valuable collaboration of M. Kobayasi and M. Taketani. (All these names will surely be familiar to the reader.)

Professors Konuma and Maki were at that time at Yukawa Hall in Kyoto, where Maki was the Director; they both played active roles and the project was centered there. It began with a three-day workshop in 1978 at Kyoto and continued with other workshops (seven in all) and a number of interviews. A particularly outstanding workshop was held at Riken in Tokyo on 12 October 1978, where S. Tomonaga spoke for almost three hours about his early career.^**** Soon after that, unfortunately, he entered the hospital with his final illness.

Shortly after Yukawa's death in 1981, a treasure trove of documents belonging to Yukawa (notes of seminars, lectures, manuscripts, letters, etc.) were discovered in a corner of the library of the Kyoto University, Department of Physics. This became the basis of the Yukawa Hall Archival Library, zealously attended to and catalogued by Konuma and Kawabe. Other archives have been set up at Nagoya (Sakata Memorial Archival Library) and at Tsukuba (Tomonaga Memorial Room). The persons mainly responsible at Nagoya were the Committee for SMAL and Morris Low, a visiting Australian expert on Japanese physics, and at Tsukuba, the well-known physicist S. Kamefuchi.

The small space I was given for my remarks prevents a more substantive account, and thus I have presented mostly a list of names of physicists who have helped spread the fame of Japanese physics. I cannot close without mentioning a very great physicist and kind personality, the late Ryogo Kubo. My wife and I had the great pleasure to live in his house in Tokyo for several months in 1984, and to come to know him and his family, when I was working on the Japan-USA project in Yokohama with Michiji Konuma. Kubo-san was a worthy global representative of all that is best in Japan, and a teacher and scholar who has helped to insure a great future for Japanese physics.