This article revisits the debate between Leibniz and Clarke to explore conceptual shifts in the use of the term medium. A basic tenet of physics since antiquity says that every act of communication ‐ that is, every transmission of a force from the place of its cause to that of its effect ‐ requires a medium to ensure its interaction. In the context of the Early Modern Period, media were regarded as mediating instances that enabled communication. If these instances were (...) not immediately connected but rather spatially separated from one another ‐ as in the case of gravitation, magnetism or electricity ‐ then there had to be a medium to ensure both the transmission of the force and the causal connection. Although the mediation of the medium took place in an inexplicable way, it seemed to explain one process or another by its mere introduction. The epistemological foundations of communicability ‐ those with which Leibniz, Clarke and Newton were attempting to come to terms ‐ remain relevant to the descriptive language with which we depict our present and its technological condition. Without duration there is no mediation but rather immediacy and simultaneity. Immediacy means that the necessary separation between the two events, the abyss of communication, is negated. Immediacies, like instantaneous actions at a distance, presuppose the difference they are deemed to eradicate. (shrink)

The historical background of the 19th century electromagnetic theory is revisited from the standpoint of the opposition between alternative approaches in respect to the problem of interactions. The 19th century electrodynamics became the battle-field of a paramount importance to test existing conceptions of interactions. Hertz’s experiments were designed to bring a solid experimental evidence in favor of one of them. The modern scientific method applied to analyze Hertz’s experimental approach as well as the analysis of his laboratory notes, dairy and (...) private letters show that Hertz’s ‘‘crucial’’ experiments cannot be considered as conclusive at many points as it is generally implied. We found that alternative Helmholtz’s electrodynamics did not contradict any of Hertz’s experimental observations of transverse components as Maxwell’s theory predicted. Moreover, as we now know from recently published Hertz’s dairy and private notes, his first experimental results indicated clearly on infinite rate of propagation. Nevertheless, Hertz’s experiments provided no further explicit information on non-local longitudinal components which were such an essential feature of Helmholtz’s theory. Necessary and sufficient conditions for a decisive choice on the adequate account of electromagnetic interactions are discussed from the position of modern scientific method. (shrink)

The standard mathematical apparatus of classical electromagnetic theory in Minkowski space-time allows an interpretation in terms of retarded distant action, as well as the standard field interpretation. This interpretation is here presented and defended as a scientifically significant alternative to the field theory, casting doubt upon the common view that classical electromagnetic theory provides scientific support for the physical existence of fields as fundamental entities. The various types of consideration normally thought to provide evidence for the existence of the electromagnetic (...) field are surveyed and analyzed in retarded distant action terms, from both a contemporary viewpoint and with regard to the late 19th century context within which the field theory was first generally accepted. It is concluded that acceptance of the field as real is not evidentially justified in either context, and that the customary historical explanation of the triumph of field theory as due to its empirical superiority is inadequate. An alternative explanation is suggested but not developed, appealing to non-empirical factors associated with the research program based on the conservation of energy. (shrink)