Making sense of Ryoshiron (Quantum theory): Introduction of quantum mechanics into Japan, 1920--1940 (Yoshio Nishina)

This work studies what “quantum mechanics” meant in Japan from the 1920s to the early 1940s, when quantum mechanics was introduced there. By studying various scientific cultures during this period, this work shows how Japanese scientists replicated the scientific practices of quantum mechanics within their scientific cultures. This work shows what the transmission of scientific knowledge involves, analogizing it to “resonance.” Similar (but not the same) scientific practices in different places occur when certain cultural and other conditions meet, and when certain partial intermediaries (human or non-human) that tie the two places trigger a resonance of scientific practices. This does not necessarily require personal contact, the implant of “scientific spirits,” or the transporting of a totality of practices.; I distinguish three phases of the introduction of quantum mechanics into Japan. The first phase is the period before the introduction of quantum mechanics, the next is the late 1920s, when young scientists began learning quantum mechanics, and the third is the period after Nishina's return to Japan when quantum mechanical research was conducted there. After methodological discussions in Chapter 1, Chapter 2 focuses on the first phase and shows that a scientific culture that emphasized advanced mathematics and meticulous calculation dominated theoretical physics. Chapter 3 examines the second phase and reveals how young physicists' efforts to learn quantum mechanics were tied to the rebellious youth culture of the 1920s. Chapters 4 through 7 illuminate various aspects of the third phase. Chapter 4 explores the educational background of Nishina Yoshio, who played a pivotal role in the third phase, comparing his electrical engineering training and theoretical work in quantum mechanics. Chapter 5 compares practices in Niels Bohr's group in Copenhagen and Nishina's group in Japan, discussing how scientific practices were replicated. Chapter 6 explores Nishina's family background and ties the familial and local cultures of the Nishina clan to Nishina's research style in science. Chapter 7 widens the scope and discusses how philosophical issues of quantum mechanics, in particular Bohr's complementarity, were discussed among Japanese intellectuals, illustrating how differently intellectuals from different cultural backgrounds interpreted these problems.