Decorative Initial S ome historians of science have pointed out that the nature and aims of physical experimentation can differ according to national and even local traditions and preferences. One of these scholars, David Gooding, has used historical case studies of the work of Michael Faraday on lines (curves) of electromagnetic magnetic force, in order to demonstrate that the relation of experiment and theory can be very close — that scientific change does not occur solely as a result of new experimental techniques and equipment, nor as a result of the development of better mathematical and conceptual descriptions of the observed world.

Gooding's work opposes that of philosophers and historians of science who insist on the essentially theoretical nature of all experimentation, leading them to conclude that the success of an experiment relies wholly upon the presence of a coherent argument, rather than on demonstration or some other experimental or laboratory-based activity. Gooding claims that such a view "bifurcates the scientist's world into an empirical world of pre-articulate experience and know-how, and another world of thought, talk, and argument."

Gooding's view of the relation of theory (roughly, a set of often only barely articulated assumptions about the structure and workings of the material world, assumptions that are often but not always mathematical) and practical experiment in scientific change is more synthetic. Specifically, in his discussion of the role of visual representation in the development of Faraday's work, Gooding finds a qualitative difference between French and English physics of electricity and magnetism during early to mid-nineteenth century. He argues that this difference reflects different individual, local, and national dispositions toward the relation of laboratory practice (in this case, demonstration) to mathematics.

For example, when representing the distribution of electric charge as analogous to what happens when iron filings are scattered in the vicinity of a bar magnet, British physicist Michael Faraday and his colleague, Peter Barlow, displayed change as continuous variation in the form of curves; that is, the position of the filings was observed to change in a regular manner according to their position relative to the poles of a magnet. Similarly, because a magnetic pole tends to move in a circle around a current-carrying wire, Faraday argued that both electricity and magnetism occurred as a result of movements in a medium, rather than as a result of changes in currents and magnets. Using this subtle distinction, Faraday displaced the efficient cause of electromagnetic force from currents and magnets to the medium between them, from which followed the insight that currents take time to propagate through a medium. These insights were not lost on his followers. In his Treatise on Electricity and Magnetism (1861), James Clerk Maxwell wrote that Faraday

saw lines of force traversing all space where the mathematicians saw centers of force acting at a distance. Faraday saw a medium where they saw nothing but distance: Faraday sought the seat of the phenomena in real actions going on in the medium, they were satisfied that they had found it in a power of action at a distance impressed on the electric fluids.

By contrast, Gooding argues, the French were uninterested in representation or modeling as explanation of physical processes, and were content to rely upon implicit notions of immediate action at a distance (between, for example, currents and magnets). In England, however, the visual representation — as a way to "illustrate experimentally" — functioned to place this style of experimentation at the forefront of physical research, as a template for a national scientific style or experimental aesthetic. Whereas neither Biot nor Ampère was interested in interpreting continuous processes directly (for them, mathematical reduction came first), physicists in England deployed a more descriptive, rather than quantitative, style that relied upon imaging techniques and other ways to visually and concretely represent how electricity and magnetism worked.

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Main text last modified 1998; links last added 14 August 2013