Spreading the tools of theory: Feynman diagrams in the USA, Japan, and the Soviet Union

Historians and sociologists have highlighted the importance of skills, local practices and material culture in their studies of experimental sciences. This paper argues that the acquisition and transfer of skills in theoretical sciences should be understood in similar terms. Using the example of Feynman diagrams - first introduced by the US theoretical physicist Richard Feynman in 1948 as an aid for making certain kinds of calculations - we study how physicists in the USA, Japan, and the Soviet Union learned how to use the new tools and put them to work. Something about the diagrammatic tools could be learned from written instructions alone, at a distance from those physicists already 'in the know', although this type of transfer proved to be very difficult, slow, and rare. The rate at which new physicists began to use the diagrams in various settings, and the types of uses to which the diagrams were put, reveal the interplay between geopolitics, personal communication, and pedagogical infrastructures in shaping how paper tools spread.