When Johann and Daniel Bernoulli founded fluid dynamics they encountered several problems. To go beyond the vision of Newtonian particles, a new set of images was needed in order to deal with the spatial extensibility and lack of form of fluids. I point to evidence that analogy was an essential abductive strategy in the creation of this imagery. But its heuristic behavior is complex: analogy can provide an initial model or proto-model that establishes the starting point of a theoretical process, (...) but it can play other roles as well. The historical genesis analyzed here shows that the participation of analogy in physicists’ creativity is not so restricted and that its richness opens up the field for very different roles and strategies in model-based discovery processes. Analogies can crop up intermittently in the evolution of a theory; and they can cooperate with images, extreme case reasoning and thought experiments, and even activate these processes at origin. Although it may seem that the contributions of analogy are generative in the sense of helping to discover new aspects of reality, we must stress the evaluative function that sometimes is performed by analogical reasoning in order to gain confidence. The study of the Bernoulli’s genesis of the foundations of fluid dynamics generates interesting hypotheses about the multiple roles that analogy can play in scientific model-based reasoning. (shrink)

The fact that the same equations or mathematical models reappear in the descriptions of what are otherwise disparate physical systems can be seen as yet another manifestation of Wigner's “unreasonable effectiveness of mathematics.” James Clerk Maxwell famously exploited such formal similarities in what he called the “method of physical analogy.” Both Maxwell and Hermann von Helmholtz appealed to the physical analogies between electromagnetism and hydrodynamics in their development of these theories. I argue that a closer historical examination of the different (...) ways in which Maxwell and Helmholtz each deployed this analogy gives further insight into debates about the representational and explanatory power of mathematical models. (shrink)

Key words: rationality, communication, maxwellian revolution, Ampere-Weber research programme, synthesis, Kantian epistemology.. Why did Maxwell’s programme supersede the Ampere-Weber one? – To answer the question one has to consider the intertheoretic context of maxwellian electrodynamics genesis and development. It is demonstrated that maxwellian electrodynamics was created as a result of the old pre-maxwellian programmes reconciliation: the electrodynamics of Ampere-Weber, the wave theory of Young-Fresnel and Faraday’s programme. The programmes’ meeting led to construction of the hybrid theory at first with an (...) irregular set of theoretical schemes. However, step by step, on revealing and gradual eliminating the contradictions between the programmes involved, the hybrid set is “put into order”.A hierarchy of theoretical schemes starting from the crossbreeds and up to usual hybrids is set up. And after the displacement current construction the interpenetration of the pre-maxwellian programmes begins that markes the commencement of theoretical schemes of optics and electromagnetism real unification. Maxwell’s programme did supersede the Ampere-Weber one because it did assimilate the ideas of the Ampere-Weber programme, as well as the presuppositions of the programmes of Young-Fresnel and Faraday properly co-ordinating them with each other. But the opposite proposition is not true. Ampere-Weber programme did not assimilate the propositions of the Maxwellian programme. Maxwell’s victory became possible because the core of Maxwell’s unification strategy was formed by Kantian epistemology looked through the prism of William Whewell and such representatives of Scottish Enlightenment as Thomas Reid and William Hamilton. Maxwell did put forward as a basic synthetic principle the idea that radically differed from that of Ampere-Weber approach by its open, flexible and contra-ontological, strictly epistemological, Kantian character. For Maxwell, ether was not the last building block of physical reality, from which all the charges and fields should be constructed. “Action at a distance”, “incompressible fluid”, “molecular vortices” were contrived analogies for Maxwell, capable only to direct the researcher at the “right” mathematical relations. Namely the application of Kantian epistemology enabled Hermann von Helmholtz and his pupil Heinrich Hertz to arrive at such a version of Maxwell’s theory that served a heuristical basis for the radio waves discovery. (shrink)

It is contended that one of the promising directions for brooding over the problem of incommensurability of paradigms, coined by T. Kuhn and P. Feyerabend, may be associated with the trend of neo-Kantian epistemology, embodied by the writings of Ernst Cassirer. According to Cassirer, the statements fixing connections and relationships between mathematical ideal constructs render a reliable ‘neutral language’ that can serve as a firm ground for comparing the ‘old’ and ‘new’ paradigms. The aim of the paper is to offer (...) Maxwell’s work as a test case against the incommensurability thesis. A case study of the genesis and functioning of a neutral mathematical language related to the Maxwellian solid synthesis of optics and electromagnetism is provided. It is elicited that its basis is constituted by stodgy language of continuum mechanics. The main function of the neutral language was to project the consequences of all the unified partial theoretical schemes (‘old’ rival paradigms) of Ampѐre, Faraday, Biot, Savar et al. onto the grand mathematical model, ‘rewrite’ all known laws in this pervasive mathematical language, compare their conclusions with each other to eliminate contradictions. Eventually the stuff was generalized in a self-consistent system of Maxwell’s equations. (shrink)

It is demonstrated that Maxwellian electrodynamics was created as a result of the old pre-Maxwellian programmes’s reconciliation: the electrodynamics of Ampère–Weber, the wave theory of Young–Fresnel and Faraday’s programme. Maxwell’s programme finally superseded the Ampère–Weber one because it assimilated the ideas of the Ampère–Weber programme, as well as the presuppositions of the programmes of Young–Fresnel and Faraday. Maxwell’s victory became possible because the core of Maxwell’s unification strategy was formed by Kantian epistemology. Maxwell put forward as a basic synthetic principle (...) an idea that radically differed from that of rival approaches by its open, flexible and contra-ontological character. “Action at a distance”, “incompressible fluid”, “molecular vortices” were contrived analogies for Maxwell, capable only of directing the researcher to the “right” mathematical relations Kantian epistemology subsequently enabled Helmholtz and Hertz to arrive at a version of Maxwell’s theory that served as a heuristical basis for the discovery of radio waves. Finally, though neither of Einstein’s relativistic ideas came directly from Kant, they were made possible by the Kantian worldview that had permeated Einstein’s thinking. The Maxwellian revolution can be described in terms of Habermas’s communicative rationality encouraging the establishment of mutual understanding between the various scientific communities. Maxwell’s programme constituted a progressive step in respect to its rivals because it constituted a basis of communication and interpenetration between the main paradigms of 19th century physics. (shrink)

This paper distinguishes in Maxwell’s thought between “atomic molecules” and “ultimate atoms,” and arrives at a set of properties that characterize each type of atom. It concludes that Maxwell is a mathematical atomist, an approach that entails the notion that although it is impossible to observe the ultimate atoms as free particles, we can nevertheless study them as mathematical observables, on the caveat that mathematical formalism remains tied to phenomenalism and to theoretical interpretations of such phenomena as, for example, mass (...) and force variations, gravitational pull, gas diffusion and viscosity, and heat conduction. (shrink)

Computer simulations are involved in numerous branches of modern science, and science would not be the same without them. Yet the question of how they can explain real-world processes remains an issue of considerable debate. In this context, a range of authors have highlighted the inferences back to the world that computer simulations allow us to draw. I will first characterize the precise relation between computer and target of a simulation that allows us to draw such inferences. I then argue (...) that in a range of scientifically interesting cases they are particular abductions and defend this claim by appeal to two case studies. (shrink)