This paper aims to give a substantive account of how Feynman used diagrams in the first lectures in which he explained his new approach to quantum electrodynamics. By critically examining unpublished lecture notes, Feynman’s use and interpretation of both "Feynman diagrams" and other visual representations will be illuminated. This paper discusses how the morphology of Feynman’s early diagrams were determined by both highly contextual issues, which molded his images to local needs and particular physical characterizations, and an overarching common diagrammatic (...) style, which facilitated Feynman’s movement between different diagrams despite their divergent forms and significance. (shrink)

This paper examines the meanings of the daguerreotype for the astronomer and physicist who introduced it to the world, François Arago. The regime of knowledge production which held sway at the birth of photography implied an alternative view of the moral and political implications of machines from that usually suggested by discussions of ‘mechanization’. Instead of celebrating detachment, instantaneity, transparency and abstraction, Arago understood instruments and human citizens as dynamic mediators which necessarily modify the forces they transmit. His moral economy (...) of instruments also implied specific aesthetic and political commitments. Arago’s republican convictions and expressive personal style, as well as his identification with revolutionary scientist–statesmen including Lazare Carnot and Condorcet, present a strong contrast with the imperial science of Laplace and the image of disengaged, impersonal ‘mechanism’ often associated with the physical science of this time.Keywords: Daguerreotype; Photography; François Arago; Romanticism; Mechanism; Pierre-Simon. (shrink)

In the early nineteenth century, Henry Brougham endeavored to improve the moral character of England through the publication of educational texts. Soon after, Brougham helped form the Society for the Diffusion of Useful Knowledge to carry his plan of moral improvement to the people. Despite its goal of improving the nation’s moral character, the Society refused to publish any treatises on explicitly moral or religious topics. Brougham instead turned to a mathematician, Augustus De Morgan, to promote mathematics as a rational (...) subject that could provide the link between the secular and religious worlds. Using specific examples gleaned from the treatises of the Society, this article explores both how mathematics was intended to promote the development of reason and morality and how mathematical content was shaped to fit this particular view of the usefulness of mathematics. In the course of these treatises De Morgan proposed a fundamentally new pedagogical approach, one which focused on the student and the role mathematics could play in moral education.Keywords: Mathematics; Education; Henry Brougham; Augustus De Morgan; Nineteenth-century England. (shrink)

Once one of the main protagonists of history of science, the historiography on quantum theory has recently gone through a process of reconfiguration of methods, research questions and epistemological framework. In this paper, I review the recent developments and propose some reflections on its future evolution.