Faraday is often described as an experimentalist, but his work is a dialectical interplay of concrete objects, visual images, abstract, theoretically-informed visual models and metaphysical precepts. From phenomena described in terms of patterns formed by lines of force he created a general explanation of space-ªlling systems of force which obey both empirical laws and principles of conservation and economy. I argue that Faraday’s articulation of situated experience via visual models into a theory capable of verbal expression owed much to his strategy of moving—via conjectural visual models—between the phenomenology of particulars (often displayed as patterns) and the general features of dynamical phenomena which he depicted as structures. Everyday human reasoning combines visual, auditory and other sensory experience with non-sensory information and of course, with verbal and symbolic modes of expression. Scientiªc reasoning is no different. Scientists use a variety of images that visualize phenomena, visual representations of theories about phenomena and models that display structure and connectivity. Such objects always combine visual and non-visual elements because scientiªc work requires representations that are hybrid (that combine verbal or symbolic expressions with visual and other sensory modalities) and plastic, enabling the meaning of an image, word or symbol to be negotiated and ªxed (Gooding 2004a, 2004b). A diagrammatic rendering of a photograph of a fossil, X-ray, fMRI scan or bubble chamber track moves the eye and the mind from a barely interpreted visual source to a meaningful construct. This ‘move ’ is motivated by the desire to under-This work has been supported by grants from the Royal Society, London and by a Leverhulme Research Fellowship. I thank Frank James and Ryan Tweney for many stimulating discussions, and staff of the Royal Institution and the Institution of Electrical Engineers for help with archive material and apparatus.

Science is a social process that functions through social networks of researchers that form invisible colleges. Analysis of these social networks provides a means for examining the structure of relations among researchers. The Industrial Marketing and Purchasing (IMP) group, “an informal international group of scholars concerned with developing concepts and knowledge in the field of business-to-business marketing and purchasing, ” is used as a case study of a network of researchers because it has been responsible for considerable research over the last decades in the area of business-to-business marketing, yet its structure remains hidden because of its informal network characteristics. The results of a social network analysis of the IMP group is described based on the pattern of co-authorship at annual IMP conferences. The results reveal a power law distribution of paper co-authorship and a small

ABSTRACT This paper describes and analyses the history of the fundamental equation of modern financial economics: the Black-Scholes (or Black-Scholes-Merton) option pricing equation. In that history, several themes of potentially general importance are revealed. First, the key mathematical work was not rule-following but bricolage, creative tinkering. Second, it was, however, bricolage guided by the goal of finding a solution to the problem of option pricing analogous to existing exemplary solutions, notably the Capital Asset Pricing Model, which had successfully been applied to stock prices. Third, the central strands of work on option pricing, although all recognizably ‘orthodox ’ economics, were not unitary. There was significant theoretical disagreement amongst the pioneers of option pricing theory; this disagreement, paradoxically, turns out to be a strength of the theory. Fourth, option pricing theory has been performative. Rather than simply describing a preexisting empirical state of affairs, it altered the world, in general in a way that made itself more true.

This article analyzes the role played in the credit crisis of the processes by which different groups of market participants produce knowledge about financial instruments. Employing documentary sources and a set of 76 predominantly oralhistory interviews, the article presents a historical sociology of the clusters of evaluation practices surrounding ABSs (asset-backed securities) and CDOs (collateralized debt obligations). Despite the close structural similarity between ABSs and CDOs, these practices came to differ substantially, and became the province (e.g. in the rating agencies) of organizationally separate groups. In consequence, when ABS CDOs (CDOs in which the underlying assets are ABSs) emerged, they were evaluated in two separate stages. This created a fatally attractive arbitrage opportunity, large-scale exploitation of which sidelined a previously important set of gate keepers (risk-sensitive investors in the lower tranches of ABSs) and eventually magnified and concentrated the banking system’s calamitous mortgage-related losses. 2