Dissertation Proposal

Submitted to the Department of the History of Science, Harvard University, on November 30, 1999

This project concerns what "quantum mechanics" meant in the Japanese context from the 1920s to the early 1940s. It is about how physicists and other intellectuals in Japan reacted to the development of a new theory of physics abroad, how they introduced this theory from Europe into Japan, and how they made (or failed to make) sense of it. People from different cultural backgrounds understood quantum mechanics differently, and the ways they imposed meanings on quantum mechanics reflected their cultures. My goal is to explore ways of understanding the processes by which scientists make sense of a new theory, or more generally, how one gives meaning to terms or notions that did not originally belong to his/her own culture.

In particular, I examine the meanings of quantum mechanics within various cultural traditions of Japanese scientists and intellectuals. Chapters 1, 2, and 4 deal with the cultures specific to physicists, and roughly correspond to the three stages through which quantum mechanics was introduced to Japan. Chapter 3 examines how quantum mechanics could be understood and conducted in the engineering tradition, focusing on Nishina Yoshio, a physicist, who played a central role in the introduction of quantum mechanics. In Chapter 5, the focus is on the political culture in which Japanese scientists, such as Nishina, operated. In the final chapter I discuss how various philosophical traditions in modern Japan, particularly Marxism and the Kyoto School philosophy, reacted to quantum mechanics and its interpretations.

In this dissertation, I aim to explore two interrelated issues in science studies by asking what quantum mechanics meant in Japan. One is the issue of relations, or rather entanglements, between knowledge, meaning, practice, and culture; the other is the issue of transmission of these four. These are not separate issues. Rather, by examining the latter, one can make a breakthrough in the former problem. Here I am going to outline this problem-complex regarding knowledge, meaning, practice, culture, and their transmission, to how complicated is the question of what quantum mechanics meant in Japan.

When I ask about the "meanings" of quantum mechanics, I mean not only the denotation but also the connotations of quantum mechanics. To account for science as a human activity, it is essential to take the feelings and nuance of scientific notions into account. Describing the bare bones of science does not give the whole story. Moreover, what makes the bare bones of a scientific theory or how to make the distinction of denotation and connotation is not obvious. I claim that these depend on historical contexts.

In the film "The Gods Must Be Crazy (1980)" Bushmen in the Kalahari Desert encounter an unfamiliar technological object, a coke bottle. The Bushmen perceived totally different meanings in the coke bottle than the one familiar to us. They used it as a tool, a musical instrument, and even as a weapon. In this instance, the coke bottle stopped functioning as a "coke bottle" as we know it. Even if the material substance did not change, the function of an object could change completely. Similar things can happen in science. In the early 18^th century Japanese "mathematicians" obtained some mathematical results, which had counterparts in western mathematics, such as the calculation of p , the integration of the circle, ellipse, and sphere, and the theory of determinants. Yet, the meaning of mathematics was completely different in Japan. Japanese "mathematicians" perceived their work as a hobby, a kind of art, similar to chess or poetry. Even if these two theories were mathematically almost equivalent, they had totally different meanings.

In these examples, there are things (the coke bottle and mathematics) which had different meanings in different cultural contexts. Both of them kept their identities, even if they had different meanings. In the case of the coke bottle, it was a material identity. We see something with the same form and substance, and therefore identify it as a coke bottle. Yet, it is us, who identity it as a coke bottle, not the Kalahari bushmen. And there is no reason that the identity should be based on the material constitution. Take a round tray, as an example. It can easily change its identity into a Frisbee. In that case, the identity is based on function. In the case of Japanese mathematics, the identity can been seen as mathematical equivalence, and this was established later by Japanese mathematicians and historians. But there is no reason that we have to regard Japanese mathematics as mathematics at all. People usually don’t regard a chess master as a specialist of game theory. It is just contingent that we think of "Japanese mathematics" as mathematics.

In these cases, identities are contingent, but not arbitrary. For us, even when used as a weapon, a coke bottle is still a coke bottle, because we don’t have a name for a coke-bottle-used-as-a-weapon. If a round tray becomes a Frisbee, that is when we want to use it as a Frisbee. It is because of us. Japanese mathematics is mathematics, because Japanese mathematicians and historians of mathematics after the Meiji Restoration, who knew western mathematics, perceived Japanese mathematics as mathematics. It is because of an act of interpretation by someone that things keep or lose their identities. In either case, it is not that there are certain essential meanings of a coke bottle or mathematics that go through different cultures.

This consideration is in accordance with the view to see transmission of knowledge as appropriation. Traditionally, a study of transmission of knowledge is often regarded as a question of "reception." When a scientific idea is transmitted, it is not necessarily simply "received;" it can be actively transformed, distorted, or appropriated. Even when a historian uses the term "reception," it does not necessarily mean simple relocation of knowledge. For example, Loren Graham in a paper entitled "The reception of Einstein’s ideas" described how Vladimir Fock and Arthur Eddington gave different meanings to relativity theory, and how their understandings were embedded in the political or religious cultures (dialectical materialism and Quakerism) in which they lived. A more appropriate term than "reception" is "appropriation" as used by Andrew Warwick. He shows how the meaning of relativity changed when British scientists incorporated it into their own practice, by reinterpreting it. These studies suggest a way to understand "reception" in terms of cultures and practices that historical actors possessed. It is a question of what "relativity theory" meant to those who had specific sets of practices.

Davidsonian semantics gives us an insight into the relation between practice and meaning. As Joseph Rouse suggested, Davidsonian considerations of notions of science are quite relevant to the program of cultural studies of science. According to Davidsonians, a word is not a representation; its meaning appears only in relation to its use in the actual world. Samuel Wheeler writes:

Without a magic language whose terms carry meanings by their very nature, the determination of what sentences mean and what is true, that is, what the facts are, rests on a single kind of data, what people say when. Thus, there is no separating learning a language from learning about the world.

Along with Davidsonians, I claim that these notions or terms that are used diachronically or transculturally cannot have well-defined meaning without being situated in a context, and here context consists of practices, including, among others, utterance of the term and various activities attached to it.

An essentialist definition of quantum mechanics might be the following: "quantum mechanics is a physical theory, which describes systems by state vectors in a Hilbert space, stipulating an equation of motion for the state vectors, commutation relations for canonical variables, and a procedure for converting state vectors to observable probabilities."

From my viewpoint the definition of quantum mechanics as it was understood in Europe during the late 1920s requires at least a paragraph: "quantum mechanics is a term coined by Max Born in 1924 to designate a theory for atomic phenomena, in contrast to classical mechanics which deals with macroscopic phenomena. The content of the theory itself was non-existent when this term was coined. Werner Heisenberg’s 1925 paper filled this gap, and Pascual Jordan and Max Born further developed Heisenberg’s theory, which constitutes what one now calls matrix mechanics, although Heisenberg continued calling it quantum mechanics. On the other hand, Erwin Schrödinger proposed a new theory that applied to the same kind of problems as matrix mechanics. This theory is what we now call wave mechanics. Schrödinger himself and Paul A. M. Dirac showed that these two theories gave the same results for the same problems; physicists then began to regard these as different formulations of one theory, quantum mechanics."

An essentialist definition cannot help being a historical fiction. The more clearly one formulates quantum mechanics, the more distant it becomes from the way people actually understood it. The fact that Heisenberg continued calling his "matrix mechanics" "quantum mechanics" pinpoints another difficulty. No one can claim that Heisenberg’s use of the term was incorrect, an accusation unavoidable if one adopts an essentialist stance. From my viewpoint, the totality of activities of historical actors in which utterance of the term "quantum mechanics" occurred shapes the multiple meanings of "quantum mechanics."

From the practices of historical actors we interpret how they understood and gave meanings to quantum mechanics. On one hand, we cannot talk solely about meanings, because the meanings of quantum mechanics were dependent on the practices of its practitioners. On the other, a study solely concerned with practices will lead to a behaviorist account, which does not help us to understand practices. Studies on practices and meanings are complementary, and the Davidsonian semantics suggests a way to unite them.

I have already tacitly introduced the notion of culture into some of the discussions above. In parallel to the relation between meaning and practice, culture can be seen in two ways. Culture can be the matrix that generates practices. For example, one can see culture as something like Pierre Bourdieu’s "habitus." Culture can also be the set of interpretive frameworks, through which we attach meanings to things. For example one may use "culture" in a Geertzian way: The culture is a historically transmitted pattern of meanings, or a system of inherited conceptions expressed in symbolic forms by means of which men communicate and develop their knowledge about and attitudes toward life.

By adding knowledge to this meaning-practice-culture entanglement, we now see the four-body problem I promised to show at the beginning of this section. Again, consideration of transmission illuminates the point. The transmission of quantum mechanics across cultures involved more than importing writings on quantum mechanics. Japanese physicists had to interpret the formal theory using available interpretative resources, which differed from those available to the European physicists who codified the theory of quantum mechanics. In order to start working on quantum mechanics, they had to recreate the practices of quantum theory, which were not easily transferred. The question is how practice can be transferred, when knowledge can be conceived as practice.

Thus, transmission of knowledge involves transmission of practices. This is not a novel point. Simon Schaffer, for example, would claim that the multiplication of contexts enables transfer of knowledge, and for Schaffer the multiplication of contexts is nothing other than transfer of practices. Similarly, when Bruno Latour stresses "the dependency of facts and machines on networks to travel back from the centers to the periphery," he seems to have essentially the same model in mind.

Although I agree that practices constitute the contexts in which knowledge is transmitted, these models are, however, not quite satisfactory in two respects. First, if one applies Schaffer’s idea of "multiplication of contexts," the original contexts where quantum theory was practiced should be imposed on the physicists in Japan, in the case of transmission of quantum mechanics, for example. Such a view would, however, underrate the differences of the context that persist. Since in reality it is usually impossible to replicate the whole relevant contexts, the multiplication of contexts is always partial and often selective. Second, Schaffer’s and Latour’s models are predicated on transfer of practices, which is not accounted for. As I already stated above, the question is how practices transfer, and this is not an easy question.

Peter Galison’s idea of the "trading zone" gives us an alternative viewpoint. He stresses the two aspects of the knowledge transfer that Schaffer and Latour failed to address, namely, the activity of interpretation that takes place upon "receiving" and the locality of the shared elements. Galison’s view fits in perfectly with the ideas I have developed here so far. The activity of interpretation is absolutely essential in my conception of transmission of knowledge, as illustrated by the question of what quantum mechanics meant in Japan. The issue of locality is implied in my discussion of identity. Things can keep their identities, even in different cultural contexts. Then, parts of these things are shared, other parts not.

Adapting Galison’s ideas, I describe the case in Japan in a slightly different form. Instead of talking about "transfer," I regard what happened as a "resonance," which occurred through various kinds of mediation. Introducing the practice of quantum physics needed human mediation, for example. This model implies three things. First, it incorporates a mediator. In the case I study here, where the geographical and cultural distance is vast, it seems more reasonable to set up a mediator between two parts. Second, the process of translation across cultures transformed the practice, incorporating the new into the old. Practice (and therefore knowledge) is not a stable entity that one can carry around. It is rather a process, and transmission of quantum mechanics from Europe to Japan was a resonance of two events, mediated on multiple levels, including formal mathematical theories, cultural values, skills, techniques, and meanings. Third, in accordance with Galison’s ideas, mediation does not have to take place on all the levels, and the mediation does not imply a global or a total relocation of contexts. Tuning forks do not need to be identical for them to resonate.

To analyze this resonance, I tentatively identify three distinct dimensions. First and most obvious, there is the dimension of scientific culture. How was physics practiced in Japan? What kind of cultural values were attached to physics? What was its disciplinary identity, in relation to other disciplines, especially mathematics and engineering, and how did expertise in these adjacent disciplines affect physicists’ understanding and skills in quantum mechanics?

Second, this scientific culture should be understandable in the broader context in which it is situated. How did the political culture in this newly modernized nation affect the way physicists conducted and conceived the new physics? How did the perceived role of intellectuals in the society define the meaning and practice of physics? How could modern physics be compatible with Japanese nationalism, whose core was the mythical emperor ideology?

Third, there is also the dimension of philosophical ideas. Similar to political thought, prewar Japan had an interesting amalgam of western and modern philosophical thoughts. How did Japanese physicists and other intellectuals react to the philosophical and interpretative issues of quantum mechanics?

In each aspect, I can add questions concerning similarities and differences. How were Japanese physicists, the contexts in which they lived, and the physics they did different from and similar to European (or American) counterparts?

Asking what quantum mechanics meant in Japan addresses all of these questions. By answering them this project will be more than a regional study of physics.

Chapter 1: Culture of Calculating or Theory and Practice of Theoretical Physics

This chapter tries to ascertain what "theoretical physics" meant in Japan from the late 1910s to early 1920s, during the time just before quantum mechanics began to be introduced there. The aim of this chapter is not simply to set up the stage for the chapters to come, but to explore a way to grasp multiplicity of the meaning. This is a paradigmatic example of how meaning, culture, and practice interact.

I explore how various meanings of "theory" and "theoretical physics" emerged in dictionaries, popular writings, institutional organizations, and the texts physicists produced and how these normative texts prescribed (or in them physicists projected) what "theoretical physics" should be like. Then I turn to what "theoretical physicists" actually did or produced and examine how their works constituted the meaning of "theoretical physics." I point out a gap between the prescribed meaning and the practiced meaning: in principle, "theoretical physics" was supposed to be a "pursuit of the deepest principles," while in practice, it was mathematical elaboration of known physical principles.

Behind this was the domination of the "culture of calculating," where mathematical skills were highly regarded, and theoretical physics was conceived as mathematical elaboration of known physical principles. Japanese physicists developed this culture of calculating under social, institutional, pedagogical, and intellectual constraints. First, physics in Japan was in a close contact with mathematics, which was more advanced than physics institutionally and pedagogically. Japanese physicists shared the same academic society with mathematicians; they were in close contact at the universities, where physics students were intensively trained in higher mathematics. Second, social demands shaped the nature of "theoretical physics" in Japan. Engineering often required theoretical physicists to work out lengthy calculations. Such demands from industry, military, and engineering encouraged the calculation-oriented approach of Japanese "theoretical physicists." Third, the specialization of theory and experiment along with the inflexible organizational structure of the Japanese university did not encourage theorists to go beyond the domain of mathematics and to pursue physical meanings of physics. The unique kôza (chair) system of the Japanese university produced a kind of theoretical physics, which was different from a theoretical physics, for example, in Germany, which had a different institutional background.

This gap between theory and the practice of "theoretical physics" poses a problem when one asks what "theoretical physics" meant in Japan in the early 1920s. Was "theoretical physics" what theoretical physicists understood as "theoretical physics", that is, a pursuit of truth behind experimental phenomena by means of mathematics? Or was "theoretical physics" what theoretical physicists mostly did, that is, application of known physical laws, lengthy calculation with arcane mathematics such as elliptic functions or group theory, and derivation of specific results of practical use?

It is meaningless and counterproductive to say that only one of them is correct. It simply reflects the fact that the meaning of "theoretical physics" in Japan in the early 1920s had a complex structure. The meaning does not only depend on contexts; it depends on the mode of the person who uses the term.

In the second stage, from 1925 to 28, the younger generation challenged their elders and began learning new physics as a way of asserting their independence. The activities of these young dissidents in physics reflected the culture of rebellion among students in the ‘20s and ‘30s. They tried to absorb quantum mechanics through papers in journals and books from 1927 to 1928, but their efforts did not immediately lead to fruitful results.

What I do in this chapter is a species of cultural history of science. It is a story of how a particular culture generated meanings and practices of theoretical physics.

I start with a description of the social and cultural milieu in which these young rebels grew up. In the early 1920s, physical, industrial, political, educational, and scientific landscapes in Japan changed, or were changing dramatically. In 1923, the Kantô Earthquake destroyed many buildings in Tokyo (including the library at Tokyo Imperial University), which created both a sense of insecurity in people’s minds, and a more modernized Tokyo following reconstruction. The First World War had triggered a vast change in the industrial landscape, which was moving toward heavy industry. The democratization of imperial Japan, the so-called "Taisho Democracy" was reaching its high-point in the 1920s. It was also a time when higher education was being popularized, along with the inception of several new higher schools and the expansion of private universities. The development of heavy and chemical industry led to the founding of several new scientific research institutes, such as the Institute of Physical and Chemical Research (Riken) and Osaka Imperial University.

A more direct impact on Japanese physics came in 1922. On November 11, Albert Einstein visited Japan. Einstein stayed in Japan for 43 days, and gave numerous lectures in several cities. His impact on Japanese society and culture was great, and even greater on physicists and would-be physicists. Many popular physics magazines were founded to answer the sudden rise of interest in relativity theory. The name of Einstein, articles and books on relativity theory by Ishiwara Jun and other authors caught the imagination of young students, including ones who later became physicists, such as Tomonaga Shin’ichirô.

The social and cultural upheaval of this period produced radicals both of the left and of the right. Student radicalism was a dominant feature of university and high school life, where the younger generation challenged old values and old thoughts. Many students were involved in social movements, and joined organizations such as Shinjinkai, a leftist organization which, seeking social reforms, later became radicalized.

Within the academic setting, the younger generation, frustrated by the stagnancy of the universities, began their movement. Although science students were relatively less political than others, they had their way of rebellion: they formed independent study groups. Having experienced the "Einstein Shock" in their youth, young physicists in the late 1920s were not satisfied by what the universities had to offer.

In particular, the younger generations of physicists took the initiative of digesting the original papers of quantum mechanics at the earliest stages. For them, quantum mechanics was a harbinger of a new age, if not of a revolution.

In 1927 young physicists in Tokyo formed a study group, "Butsurigaku Rinkôkai" (Physics Reading Seminar). They were mostly physicists working at the Institute of Physical and Chemical Research or at local higher schools, having just graduated from Tokyo Imperial University. The physics department of Tokyo Imperial University had a weekly physics colloquium, but it appeared to these eager younger physicists that it had degenerated into a mere formality. Discussions lacked physical content, and with the presence of senior physicists, young physicists could not speak freely. Frustrated, they decided to form an independent study group, choosing only those people who were committed to the freer atmosphere. Originally they did not intend to focus on quantum mechanics, but with such a motivation their attention was directed to something totally new, and something unknown to senior physicists. By 1927 major foundational works of quantum mechanics had appeared. This splinter group read and translated these works into Japanese, and published them in 1927 and 1928. By examining these translations, one can evaluate their understanding of quantum mechanics. These physicists freely changed details and sometimes even the structure of the papers, correcting at the same time mistakes in the originals. This means that they did not simply linguistically translate those papers, but they understood them, at least in terms of mathematics. But their "understanding" or the meaning they attached to quantum mechanics was different from those of European physicists. For European physicists, quantum mechanics was scientifically revolutionary. For those young Japanese physicists, learning quantum mechanics was an act of defiance, a revolt against the academic establishment, which included their own old professor.

Around the same time in Kyoto four undergraduates interested in quantum mechanics began studying it by themselves. They were students of Professor Tamaki Kajûrô, a theoretical physicist who specialized in fluid dynamics, but who had little knowledge of quantum theory. Two of them were to become prominent physicists: Yukawa Hideki and Tomonaga Shin’ichirô.

Chapter 3: Alternating Current and Relativistic Electrons: Nishina Yoshio in 1918 and 1928.

The "student rebellion" phase ended around 1929, giving way to what we might call the third stage of Japanese quantum mechanics, the "Copenhagen" stage. Nishina Yoshio played a central role during this stage as an organizer of the newly emerging group of physicists working on atomic physics. Although slightly older than the rebellious young physicists, politically conservative, and unaffected by the upheaval of the 1920s since he had left Japan in 1921 just before Einstein visited Japan, he could nonetheless tame these young rebels, and nurtured many of them to become full-fledged physicists.

In this chapter, I examine how Nishina’s engineering background affected his understanding and practice of theoretical physics. My focus in this chapter lies on how Nishina could transfer the conceptual framework, skills, and values that he acquired in his work on alternating current theory.

In his later years, Nishina remembered four books that inspired him during his undergraduate years: The Mathematical Theory of Electricity and Magnetism by James Jeans, Theory and Calculation of Alternating Current Phenomena by Charles Proteus Steinmetz; Wechselstromtechnik by Engelbert Arnold; Kôryûriron (Alternating Current Theory) by Hô Hidetarô. Relying on these works, Nishina wrote his B. A. thesis, "Effects of Unbalanced Single-Phase Loads on Poly-Phase Machinery and Phase Balancing."

Electrical engineering at that time was not simply an application of electromagnetism, nor just a collection of practical knowledge and rules of thumb. It was what Edwin Layton called an "engineering science," an autonomous body of knowledge and skill based on experience and the Maxwellian theory of electromagnetism and organized in a similar way as science. The tension between physics and electrical engineering is well represented by Charles Proteus Steinmetz, who himself made the transition from mathematics to electrical engineering. His theory on alternating current has typical features of an "engineering science." While physicists used differential equations, Steinmetz used more intuitive graphical representations. A physicist would use the Maxwellian theory as the surest basis for alternating current theory, whereas Steinmetz, although he applied the Maxwellian theory, developed a theory applicable to certain machines, such as dynamos and motors, a theory less universal but far more practical. Engineers valued theories, not because they were universal, but because they were practical and could help them to conceive a new design of machines.

Steinmetz had one influential follower in Japan: Hô Hidetarô. Hô was a professor in the department of electrical engineering of Tokyo Imperial University, who was specialized in alternating current theory, and became known among electrical engineers for the Hô-Thevenin theorem. Besides his position as a professor at Tokyo Imperial University, Hô exerted his influence through his well-read textbooks. One of those textbooks was Alternating Current Theory, the one Nishina read, which Hô regarded as an "introduction" to Steinmetz’s book.

Nishina as an undergraduate student was inculcated in Hô’s tradition of theoretical electrical engineering. Steinmetz’s Alternating Current Phenomena is the work most often cited in his thesis. Hô was the leading figure in the department of the electrical engineering and Nishina was deeply impressed by Hô’s lectures and books, from which he learned "how to grasp the physical meanings of things."

Nishina’s B. A. thesis is a theoretical work on the effect of unbalanced loads on three-phase system addressed in Steinmetz and Hô’s tradition. It is a highly mathematical work; supplemented with a few experiments he conducted to corroborate the theory. He started with definitions of concepts, such as "symmetrical/unsymmetrical system" or "balanced/unbalanced system." He then moved to examine the effect of unbalanced loads on machines of alternating current systems, such as an alternator, a motor, or a rotary transformer, identifying unfavorable effects of unbalanced loads for each machine. Finally, he discussed the behavior of "balancers," to remove these unwanted effects.

It is easy to see how the education and the work in his undergraduate years prepared him for what was to come. The relative ease with which he made transitions from experimental physics to theoretical physics, and from theoretical physics to cyclotron physics can be understood in terms of the electrical engineering he had learned, which was both highly theoretical and closely connected to actual machines. The nature of his work in theoretical physics, which was basically concerned with the derivation of experimentally verifiable results, is similar to what he did in his B. A. thesis. Also, one might say how Nishina’s practical mind made him immune to Bohr’s overly philosophical tendency. One can also talk about the affinity of engineering’s rule-oriented approach to that of the correspondence principle, on which Nishina and Klein’s derivation of their famous formula was based.

In addition, one might want to explore more direct connections between Nishina’s engineering work and his physics. In the history of physics, we have seen several examples of such connections. Julian Schwinger writes that his wartime engineering work on microwave-band radar helped him to conceive the idea of renormalization. Peter Galison tells us how Richard Feynman took over certain skills and a culture of engineering with which he became familiar through his wartime work into his postwar work on theoretical physics. There is, however, a limit to what one can say about Nishina’s style in theoretical physics. Nishina has only one single-authored paper on theoretical physics, which is a continuation of the work done in collaboration with Oskar Klein. It is difficult to see in Nishina’s papers a distinct style such as Feynman’s.

What I attempt in this chapter is to infer how electrical engineering formed an interpretative framework for Nishina when he struggled to understand quantum mechanics. For example, Hô, in his Alternating Current Theory, introduced the "Principle of Superposition," which was essential in his derivation of his own Hô-Thevenin’s theorem. In his analysis of the unsymmetrically loaded polyphase system, with which Nishina must have been quite familiar, Hô applied the principle of superposition and discussed the resulting higher harmonics in the polyphase system. These concepts, the principle of superposition and harmonics, are essential in understanding the technical aspects of quantum mechanics. Indeed, P. A. M. Dirac, who also had an electrical engineering background, started his textbook with the principle of superposition.

The third subculture of physics issued from direct contact with the Copenhagen school, and this one was launched in no small measure by Nishina Yoshio’s return to Japan after an extended stay in Copenhagen with Bohr. Only after his return to Japan in December 1928 did Japanese physicists begin forming a research school and producing theoretical and experimental work in atomic physics on a regular basis. Working with European physicists, Nishina had learned quantum mechanics and how to conduct research with it. What Nishina brought back to Japan was not simply the formal theory of quantum mechanics. One could learn that in Japan through journals and books, as several young Japanese physicists did. Nishina took back something more elusive. Contemporary Japanese physicists, such as Hori Takeo, recognized it, and called it the "Copenhagen Spirit." I will argue that it was a subtle style or culture of research that students of quantum mechanics gained with Nishina’s return to Japan. Yet this culture was not exactly the same as in Copenhagen, taking on, for example, a more calculation-intensive, pragmatic, and less philosophical character. By closely examining Nishina’s intellectual trajectory and his role in the introduction of quantum mechanics into Japan, I depict how Nishina re-created in Riken a culture of conducting physics research based on, but not identical to, his experience in Copenhagen.

As a junior researcher of the Institute of Physical and Chemical Research, Nishina stayed in Europe from1921 to 1928, first in Cambridge, then in Göttingen, but mostly in Copenhagen, under the direction of Niels Bohr. Since he had turned from electrical engineering to physics he had been conducting experimental research. That changed in 1927 when with I. I. Rabi he moved to Hamburg, apparently following Bohr’s suggestion, to study theory under Wolfgang Pauli’s guidance. There he conducted a theoretical work with Rabi, and when he returned to Copenhagen, he worked with Oskar Klein on a theoretical subject, an application of Dirac’s theory of the electron. Two years after his return to Japan, he became one of the chief researchers at the Institute of the Physical and Chemical Research and began forming a group of atomic physicists, including Tomonaga Shin’ichirô, Sakai Shôichi, and Tamaki Hidehiko. Some physicists attributed the success of Nishina’s group to the "Copenhagen spirit" that Nishina supposedly brought back from Bohr’s institute in Copenhagen, a mentality that created a friendly atmosphere and free-flowing discussion in to his division at the Institute of Physical and Chemical Research.

The Institute of Physical and Chemical Research provided a unique research environment. In his later years, Tomonaga called it a "scientists’ paradise." When scientists received hardly any research funding from an imperial university, at Riken the chief scientists enjoyed virtually limitless budget, which Riken earned from its own burgeoning industrial combine. Unlike imperial universities, which were restricted by imperial orders and regulations, Riken’s organizational structure was extremely flexible. Each research chief managed his group with maximum autonomy, with no supervisor except the director of the Institute, Ôkôchi Masatoshi who was usually extremely supportive of scientists. Riken, with its ample resources and flexible organization, was always the foremost scientific research center in Japan from its foundation in 1917 until the end of the Second World War. Nishina’s success was to a great extent due to the research environment at Riken. Unlike university professors, Nishina was free from undergraduate teaching obligations and administrative chores. He could concentrate on his work and collaboration with his handpicked disciples, such as Tomonaga Shin’ichirô and Sakata Shôichi. An environment that could accommodate the "Copenhagen spirit" was already there before Nishina’s return.

Moreover Nishina’s "Copenhagen spirit" was not identical to Bohr’s. In the early 1930s, Nishina tried to lecture on foundational issues of quantum mechanics to his young disciples, but they, Tomonaga included, could hardly keep themselves awake. Nishina’s understanding of complementarity came from Wolfgang Pauli, whose seminar Nishina had attended, more than from Niels Bohr himself. Nishina’s philosophical attitude was definitely different from Bohr’s. When Bohr visited Japan in 1937, he made a cynical remark to Yukawa about his meson theory: "Do you like new particles?" It is understandable that Bohr did not like to introduce naively a new physical entity. Such a philosophical nicety, however, did not concern Nishina, who encouraged Yukawa. Being trained as an engineer, Nishina had a much more practical mind than Bohr and never indulged in a philosophical problem for its own sake, whereas for Bohr philosophical issues, including problems concerning life and consciousness, were always central. Nishina selectively absorbed Bohr’s ideas, transforming them into a workable methodology, rather than philosophical dogma.

My task is to analyze what exactly was the "Copenhagen spirit" that was brought into Japan by Nishina. I will argue that Nishina transmitted a style of conducting physics that was inseparably attached to quantum mechanics. If such conduct of physics is essential to the knowledge of quantum mechanics, it is more appropriate to regard "knowledge" of quantum mechanics as an activity or an event rather than a static entity. Yet this does not mean that such a transmission of knowledge requires transmission of the whole set of values. As we see in Nishina’s case, the values on which scientific practice in his group was based were not identical to those in Bohr’s institute in Copenhagen.

Nishina’s role in establishing physics in Japan can be fully understood only when on takes into account the political context of the country. In this chapter, I show how the native political and ideological culture of the prewar Japan gives meanings to Nishina’s activity for us who reflect on his role in Japanese physics. In addition, this chapter shows how Nishina’s activity was embedded in the native Japanese context. Nishina had two faces. While he introduced European practices of atomic physics, his activities followed the pattern of the Meiji elite. It shows how the life and practices of this Japanese physicist was multi-layered, and how his transfer of scientific practices was partial, not global.

Nishina’s role in Japan was that of an organizer. After he came back to Japan, Nishina poured his energy into forming a research tradition, rather than into his own research. His papers in Japan were all written in collaboration with his disciples. His principal role in Japan was not that of a researcher, but of a teacher and an organizer. His efforts were directed toward building a respectable physics community, a group of trained physicists, and an infrastructure in which physics could flourish. I argue that one can interpret Nishina’s effort to build a modern scientific community as a scientific analog of the construction of the modern state in the Meiji era, the era when Nishina grew up. There was a structural parallelism between Nishina and the Meiji elite, which Nishina himself was not necessarily aware of. This also implies that Nishina was not simply trained and shaped in the West. In one aspect, Nishina was deeply rooted in the native Japanese culture; and this very aspect enabled him to play a unique and positive role in physics.

Nishina was born in 1889 in Satoshô Village, Okayama Prefecture, as the 8^th child of a rich farmer’s family. The Nishinas are a clan deeply rooted and well respected in this small rural village, with many relatives in this area. However, the Nishina family’s fortune declined after the Meiji Restoration. To rebuild the family was the wish of the Nishinas. In this environment, I argue, Nishina developed an exceptional sense of mission to be successful and to rebuild the Nishina clan: To be rich and successful in order to rebuild the Nishina clan was his primary motive in his youth.

By closely studying Nishina’s correspondence with his mother and brothers, I show how Nishina chose his life path driven by this sense of mission to rebuild the family’s fortune. At the same time, however, his correspondence reveals Nishina’s other objective: to serve the nation as a scholar, a task widely shared by the Japanese elite. When he graduated college and entered the Institute of Physical and Chemical Research, his oldest brother Teisaku wrote Nishina: "Your calling is not to make money but to master the profoundest truth of arts and sciences and to serve the nation. You are certainly suited for that." Yet even during his stay in Europe, Nishina remained ambivalent between science as a vocation and a real job. The balance between these two goals was finally broken by his mother’s death in October 1921. In his diary, Nishina wrote: "Half of my wishes in my life are gone." He later told his sons that "After your grandmother died, I changed my mind. I began to think there was no need to go back to Japan in a hurry." Having abandoned one of the two objectives of his life, he began to seek the other: to serve the nation by promoting science. He shifted his interest from rebuilding the house to rebuilding the physics community in Japan.

His career was analogous to that of the early Meiji elite. After the restoration, with the collapse of hereditary system, lower samurai and upper commoners had a chance to succeed by climbing academic ladders. Young people read ardently books like Smiles’ Self-Help or Fukuzawa’s An Encouragement of Learning. Many ambitious young men pursued higher education in order to achieve their goals. Many of those "self-made men," especially those who went abroad and were struck by what they perceived as Japan’s backwardness, sought to help build the new Japan. Nishina’s activity of building a physics community can been interpreted as a scientific analogy of the modern state building in the Meiji era. And one sees how deeply Nishina’s whole activity was embedded in the context of the modern Japan.

Chapter 6: Complementarity in the ‘Far East’: Philosophy of Quantum Mechanics and Japanese Intellectuals in the 1930s

Lastly, I turn to the broader spectrum of Japanese intellectuals. I discuss diverse intellectual cultures in the 1930s in which scientists, scientific journalists, and philosophers discussed foundational problems of quantum mechanics, especially Niels Bohr’s idea of how to interpret quantum mechanics, namely complementarity. I examine various meanings of complementarity within the contexts of these various cultural traditions.

Bohr’s complementarity, first published at a conference in Como in 1927, epitomizes various aspects of quantum mechanics. First of all, it was supposed to be an essential part of the Copenhagen interpretation, allegedly the orthodox interpretation of quantum mechanics. Moreover it is the core of the philosophy of Niels Bohr, a fatherly figure to many quantum physicists. Discussing complementarity and related issues was not uncharacteristic of the physicists around Bohr. By looking at how people from different backgrounds perceived and treated complementarity, one can reveal the place physics occupied in Japanese scholastic and cultural spheres at that time, the relation between physics and philosophy, and the role of journalism in science.

The introduction of complementarity in Japan began in 1928. Nishina and Sakai Takuzô, a physics teacher, were responsible for it. These early attempts to introduce complementarity into Japan did not reach a wide audience. Even in Nishina’s and Sakai’s community, the foundational issues of quantum mechanics seems to have captured little attention.

The situation changed around the time when Niels Bohr visited Japan in 1937. Bohr’s visit attracted a wide range of Japanese intellectuals, if not as much as Einstein’s visit in 1922. Here scientific journalism played an important role to facilitate discussion of complementarity in Japan. . From the late 1910s to the early 1930s, the number of popular science magazines had been steadily increasing. Some physicists had close ties with publishing companies. After his retirement Ishiwara Jun became the scientific journalist par excellence and published numerous articles on modern physics. He was the editor in chief of Kagaku, a scientific journal published by Iwanami Publishers. For scientific journalists, the philosophical issues of quantum mechanics were attractive subjects, along with Niels Bohr’s visit to Japan in 1937. Journalism tracked what Bohr did in Japan and published his lectures. They also invited renowned scholars and intellectuals to write about complementarity. The most striking example is a special issue of Kagaku Chishiki (Scientific knowledge) probably organized by Nishina, which dealt with "complementarity in physiology," "complementarity and philosophy," "complementarity in theology," and "complementarity in art."

Another strong tie between science and publishing companies was what I call scientist-literati, scientists who at the same time engaged in literary activities. Terada Torahiko and his followers represent this tradition. It was not uncommon among Japanese scientists to publish literary works. Some scientists were more than amateurs. For example, Ishiwara was a famous waka poet. Terada was the first disciple of Natsume Sôseki, one of the greatest novelists in the prewar Japan, known for his works such as I am a Cat. Terada started his literary career by writing haiku under Natsume’s guidance. Yet, Terada’s uniqueness lay in the amalgam of science and literature that he accomplished in his scientific essays. Young physicists, who became familiar with Japanese literature in their higher school years, admired Terada, and some of them, emulating Terada, wrote scientific essays with various degree of success. For these writer-scientists, philosophical discussion of complementarity appeared attractive, since they could write literary essays on it. For example, Fujioka Yoshio wrote an essay entitled "Yôki" (Evil presence) in an attempt to apply complementarity to his personal experiences.

However, some of the younger Japanese physicists, who had learned quantum mechanics as a mathematical formalism from the beginning, found the philosophical considerations of Bohr superfluous. For example, in 1937, when Bohr came to Japan, Tomiyama Kotarô, opposing Bohr’s claim about the inevitability of classical concepts, argued that quantum mechanics is a self-sufficient theory, and that physical concepts in quantum mechanics did not require a resort to classical concepts; therefore there was no need for complementarity.

Two groups dominated the intellectual landscape of philosophical thoughts in the prewar Japan. One was the so-called Kyoto School, represented by Nishida Kitarô and Tanabe Hajime. The other was the group of Marxist philosophers, such as Tosaka Jun, Nagai Kazuo, and Taketani Mitsuo. These opposing groups, one conservative, the other revolutionary, waged battles in all the academic disciplines where the issues related to science and technology were of central importance. Both paid close attention to the recent development in science, especially physics, and Bohr’s visit to Japan provided them a good opportunity to challenge the opponent.

The Kyoto School philosophy is a unique amalgam of western philosophy, especially the Southwest German School of Neo-Kantianism, and Japanese traditional thoughts, such as Buddhist philosophy. They were politically conservative, and generally anti-West, in a similar way that the German Mandarins were. One of their goals was to overcome the problems of modernity, by criticizing the tradition of the western philosophical thoughts. Kyoto school philosophers found Bohr’s complementarity and other philosophical reflections on quantum mechanics intriguing, because these considerations fit into their own philosophical agenda to overcome the dichotomy of subject and object, a problem they regarded as fundamental in the western intellectual tradition.

In the 1930s Marxism was probably the only intellectual movement that could compete with the Kyoto School. Marxist philosophers of science, represented by Nagai Kazuo and Taketani Mitsuo, attacked what they perceived as the subjectivism of the Kyoto School philosophers. For them, Bohr’s idea was a "Machian idealist bourgeois" philosophy, and hence to be rejected. They were, however, put in a difficult position; Marxism advertised itself as scientific, and for Marxist thinkers it was difficult to downgrade an authoritative figure in science such as Niels Bohr. Taketani, in particular, had to praise Niels Bohr when he translated and commented on Bohr’s response to Einstein, Podolsky, and Rosen’s attack on the Copenhagen interpretation.

I conclude the dissertation by discussing the transmission of scientific ideas across cultures and the formation of their meanings among the recipients. Meanings of quantum mechanics to Japanese physicists and other intellectuals were inseparably connected to their everyday practice. The meaning of "quantum mechanics" is dependent on the culture of its practitioners in a broad sense. If the practice of "quantum mechanics" including talking, writing, calculating, experimenting and philosophizing defines what quantum mechanics is, quantum mechanics in Japan had different meanings, while keeping its identity through its lineage to the European origin. What European and Japanese physicists after Nishina shared was not only the rigid mathematical core of quantum mechanics. Rather, they came to have a similar way of practicing physics, whi, in the sense that they could produce such works as Yukawa’s meson theory, or Tomonaga’s renormalization theory, which could be shared by European physicists. Yet, the way they perceived quantum mechanics and the meanings physicists and the society attached to it did not remain the same when quantum mechanics was introduced. Even within Japan, they were not homogeneous.

Historiography of physics in Japan, or of science in the modern Japan in general, is still scant and has left much to be studied. Some subjects are relatively well studied by Japanese historians, but even in these cases, there is usually no attempt to related empirical historical studies with theoretical issues. As for Nagaoka, there is a definitive biography by Itakura and others. Yukawa’s work in 1935 and the development of meson theory in Japan are the subject well studied both by western and Japanese historians, especially by Laurie Brown.

Chapter 1. Koizumi Ken’ichirô’s works in English make good background literature for the history of physics in the Meiji Japan. In his works, he stresses the uniqueness of the Japanese context into which western physics was introduced. He sees, however, the whole process as a matter of importation, and gives no discussion of what was actually introduced. Itakura, Kimura, and Yagi’s biography of Nagaoka is an informative source not only for Nagaoka’s work and life, but also for the general situation of physics in his time. Kim Dong-Won in his work "The Emergence of Theoretical Physics in Japan" stresses the dominance of experimental physics (and relative paucity of theoretical physics) in Japan. He sees that "the Japanese physics community did not respond effectively to the rapidly changing milieu of world physics community during the 1920s and even early 1930s." Beside the ambiguity of "world physics community," Kim does not give any account about what he sees as "theoretical physics" in Japan, which is the point that I explore in this chapter.

Chapter 2. It was Tomonaga Shin’ichirô who originally found the activities of Butsurigaku Rinkôkai and made it known. Katsuki Atsushi clarified its historical significance and has been working on it by interviewing its participants, as a part of his study on the history of solid state physics in Japan. As for the cultural context of science in the 1920s, Kaneko Tsutomu’s work on Einstein’s visit to Japan in 1923 is the best work. My work is an attempt to contextualize the activity of those young physicists that Katsuki found in the cultural context of the Taishô and Early Showa Japan.

Chapter 3. Nothing is written on this subject so far. To my surprise, no one has ever seriously studied Nishina’s B. A. thesis. In terms of methodology, as I mentioned in the summary, Galison’s works on Schwinger and Feynman are the most relevant.

Chapter 4. As I mentioned in the summary, to see Nishina as the person who introduced the "Copenhagen spirit" or a new way of doing physics, into Japan is written in physicists’ accounts such as Tomonaga or Hori’s reminiscences. These accounts are, however, seen as reflection of physicists’ perceptions of Nishina. Departing from physicists’ accounts, I try to address a theoretical problem concerning transmission of knowledge using this material, which has never been done before.

Chapter 5. Nishina as an organizer is a point stressed by Ezawa Hiroshi and Tsuji Tetsuo. The idea to contextualize his life in the political culture of the Meiji Japan was partly inspired by tries to account Nishina as a "scientist of Meiji." Yet, nobody has ever seriously engaged Nishina’s upbringing from this perspective.

Chapter 6. Here again there is nothing on this subject before me. As for the "reception" of the interpretation of quantum mechanics, Heilbron’s study on the dissemination of complementarity is the most relevant. There is a study on Taketani’s view on quantum mechanics, which discusses Taketani’s view totally out of historical context. There is a vast literature on the Kyoto school in Japanese, English, and German. However, nothing written about its connection to the philosophy of quantum mechanics.

Generally speaking, archives in Japan are ill-organized and not ready for the use of scholars. There is no Japanese word for "archivist," and no institution to train archivists. For a still unestablished field like the history of science, the situation is even worse than for Japanese history proper. There are places where archival documents are preserved, but there is not necessarily an explicit procedure to access them. Personal connections, authority of affiliate institutions, and titles are essential to approach these sources.

Most of archival materials relevant to my work are deposited in places that are meant to commemorate well-known scientists. For the central figure of this dissertation, Nishina Yoshio, there are two such places. One is the Nishina Memorial Room, located in the Institute of Physical and Chemical Research, in Wakô City, Saitama, Japan. It has Nishina’s notes during his stay in Europe, his reading notes, some of his letters, and manuscripts. The other place one finds Nishina’s archival material is the Nishina Memorial Hall in Satoshô, Okayama, which houses Nishina’s personal belongings in his youth and his letters to his family and relatives. While the papers in Riken are of a scientific and administrative nature, documents deposited here will be important for exploring explore personal aspects of Nishina.

The National Science Museum in Tokyo has the archival materials of several scientists, including extensive amount of correspondence, manuscripts, and lecture notes left by Nagaoka Hantaro and Takamine Toshio.

The Yukawa Hall in Kyoto, a research institution built to commemorate Yukawa, possesses Yukawa’s manuscripts, including his reading and research notes from the early 1930s.

The Tomonaga Memorial Room at the University of Tsukuba houses and displays Tomonaga’s manuscripts, lecture notes, books and his personal belongings, including the notes he took at the lectures by Dirac and Heisenberg during their visit to Japan in 1929.

Outside Japan, the most important archive for my project is the Niels Bohr Archive in Copenhagen, which has correspondence by Nishina and other Japanese physicists, such as Takamine Toshio. There are also documents related to Bohr’s stay in Japan in 1937, including several letters sent to Bohr from various people, and Hans Bohr’s extensive journal during this trip, as well as Niels Bohr’s film that he made in Japan. I also found Bohr’s letters of recommendation for Nishina.

The Library of Congress possesses collections of papers, which include a few of letters by Japanese physicists.

The United States National Archive possesses intelligence reports on Japanese science during World War II; some of them are relevant to Japanese physicists’ wartime work, such as the development of atomic bomb (although the development of the atomic bomb is not the main focus of this project).

Some archival materials are published. A collection of microfilms entitled Archives for the History of Quantum Physics contains papers by major quantum physicists, including correspondence by Japanese scientists, such as Nishina, Takamine, and Nagaoka, as well as an interview of Yukawa Hideki. The Nishina Memorial Foundation published extensive amount of Nishina’s scientific correspondence in European languages. The Nishina Memorial Hall in Okayama edited and published a part of his correspondence in Japanese.

The University of Tokyo as well as the University of Kyoto possesses sources relevant to this project, including administrative documents as well as B. A. theses of the graduates.

I have physics background including quantum mechanics and electromagnetism, enough to understand physics by the 1930s and alternating current theory. I am proficient in Japanese, English, and German, and can read French and Danish. These five languages cover all the relevant materials.

To date, the main body of Chapter 3 "Transplanting Spirit," is finished. It is based on the final paper for the History of Science 200 (by Everett Mendelsohn and Mario Biagioli) in Fall 1996. Similarly, the essential part of Chapter 6 "Complementarity in the ‘Far East’" was submitted as the final paper for the Japanese History 2852 Seminar, with Andrew Gordon, Albert Craig, and Harold Bolitho in Fall 1998.

So far, I have conducted archival research at the Niels Bohr Archive in Copenhagen, the Nishina Memorial Room in the Institute of Physical and Chemical Research in Waco City, the National Science Museum in Tokyo, the Yukawa Memorial Hall in Kyoto, the Tomonaga Memorial Room in Tsukuba, and the Nishina Memorial Hall in Okayama.

The first draft for Chapter 1 "Culture of Calculating" will be finished in January 2000. This will be submitted as the paper for the History of Science 221: "Theory" Seminar, by Peter Galison.

By June 2000, the first draft for Chapter 2 "Student ‘Dissidents’ in Physics" will be finished. From June to August 2000, I will conduct additional archival work in Japan. The main locations will be the Nishina Memorial Room in Institute of the Physical, Chemical Research, in Wako City, Saitama, the Nishina Memorial Hall in Okayama, and Yukawa Memorial Hall in Kyoto.

By September 2000, the first draft for Chapter 5 "Rebuilding the House and the Nation and Rebuilding Physics" will be finished.

By December 2000, the first draft for Chapter 3, "A. C. Theory to Electron," will be finished.