Many areas of frontier physics are confronted with the crisis of a lack of accessible, direct evidence. As a result, direct model building has failed to lead to any new empirical discoveries. In this paper I argue that these areas of frontier physics have developed common methods for turning precision measurements of known quantities into potential evidence for anomalies hinting at new physics. This method of framework generalization has arisen as a sort of model-independent method for generalizing beyond known physics (...) and organizing experimental searches. I argue that this method is well-justified given the current epistemic landscape, and that theory construction in general is much broader than simply building new dynamical models. (shrink)

In this article, we offer a detailed study of two important episodes in the early history of high-energy physics, namely the development of the Chew and the Nambu-Jona-Lasinio models. Our study reveals that both models resulted from the combination of an old Hamiltonian, which had been introduced by earlier researchers, and two new approximation methods developed by Chew and by Nambu and Jona-Lasinio. These new approximation methods, furthermore, were the key component behind the models’ success. We take this historical investigation (...) to support two philosophical theses about the manner in which scientific modelling operates in high-energy physics. Both of these theses run counter to a view that is commonly accepted among philosophers of science: the view that all approximations can be embedded within an equivalent idealized system, and that whatever role the former might play in scientific modelling is therefore parasitic on the much more substantial work performed by the latter. Our first thesis, which we call “Distinctness,” states that approximation methods constitute an independent category of theoretical output from idealized systems. We thus believe that approximations and idealized systems constitute two independent types of objects, both of which are essential to the practice of modelling. Our second, more radical thesis is called “Content Determination.” Our claim here is that approximation methods can in fact be essential to assigning determinate physical content to the idealized systems with which they jointly operate. As we show, this is due to the fact that quantum field theory allows for a very thin characterization of idealized systems only, making the use of approximations necessary to supply additional content. We conclude the paper with a few reflections about the manner in which our two theses can be used to articulate David Kaiser’s views on the “vanishing of scientific theory” in physics after WWII. (shrink)

This article traces the origins of Kenneth Wilson's conception of effective field theories (EFTs) in the 1960s. I argue that what really made the difference in Wilson's path to his first prototype of EFT are his long-standing pragmatic aspirations and methodological commitments. Wilson's primary interest was to work on mathematically interesting physical problems and he thought that progress could be made by treating them as if they could be analyzed in principle by a sufficiently powerful computer. The first point explains (...) why he had no qualms about twisting the structure of field theories; the second why he divided the state-space of a toy model field theory into continuous slices by following a standard divide-and-conquer algorithmic strategy instead of working directly with a fully discretized and finite theory. I also show how Wilson's prototype bears the mark of these aspirations and commitments and clear up a few striking ironies along the way. (shrink)

Science is a process, through which theoretical frameworks are developed, new phenomena defined and discovered, and properties of entities tested. The goal of this dissertation is to illustrate how high-energy physics exemplified the process of theory construction from the 1950s to 1970s, and the promising ways in which it can continue to do so today. The lessons learned from the case studies examined here can inform future physics, and may provide methodological clues as to the best way forward today. I (...) examine the discovery of parity nonconservation in weak interactions, the emergence of Yang-Mills theories as the foundation of the standard model, and contemporary precision testing of quantum electrodynamics. In each of these cases, I examine the details of the physicists’ practice to draw conclusions regarding the epistemology behind successful episodes of theory construction. I reconstruct the methodology of each episode in order to find generalizable lessons to apply to contemporary issues at the frontiers of the search for a theory of quantum gravity. In order to understand the many moving parts in each case study, I introduce a new terminology to distinguish the “parts” of a scientific discipline, inspired by the literature on scientific modelling. These terms—theoretical framework, dynamical model, phenomenological model, experiment, and mathematical tools—are meant to aid in investigating other quantitative scientific disciplines beyond high-energy physics. Ultimately, high-energy physics is at its best when various avenues of theoretical ideas are being pursued, spurring the development of new mathematical techniques to use as tools, and new ideas are quickly and vigorously tested experimentally. Proliferation of new ideas in response to theoretical developments is characteristic of the era of construction of the standard model, and is still ongoing in precision testing of quantum electrodynamics today. (shrink)