Particle Physics

In this paper, we review a general technique for converting the standard Lagrangian description of a classical system into a formulation that puts time on an equal footing with the system's degrees of freedom. We show how the resulting framework anticipates key features of special relativity, including the signature of the Minkowski metric tensor and the special role played by theories that are invariant under a generalized notion of Lorentz transformations. We then use this technique to revisit a classification of (...) classical particle-types that mirrors Wigner's classification of quantum particle-types in terms of irreducible representations of the Poincaré group, including the cases of massive particles, massless particles, and tachyons. Along the way, we see gauge invariance naturally emerge in the context of classical massless particles with nonzero spin, as well as study the massless limit of a massive particle and derive a classical-particle version of the Higgs mechanism. (shrink)

The physics literature contains many claims that elementary particles have been observed: such observational claims are, of course, important for the development of existential knowledge. Regarding claimed observations of short-lived unstable particles in particular, the use of the word 'observation' is based on the convention in physics that the observation of a short-lived unstable particle can be claimed when its predicted decay products have been observed with a significance of 5 sigma. This paper, however, shows that this 5 sigma convention (...) is inconsistent with existing concepts of observation by showing that unstable particles with a lifetime of less than 0.01 attosecond are fundamentally unobservable both from the perspective of Fox's recent concepts of direct and indirect observation, and from the perspective of Van Fraassen's notion of observability. This cognitive inaccessibility of parts of the subatomic world has far-reaching implications for physics, not the least of which is that the aforementioned convention is untenable: claims that such short-lived unstable particles have been observed will thus have to be retracted. The main implications are two incompleteness theorems for physics, respectively stating (i) that experiments cannot prove completeness of a physical theory predicting short-lived unstable particles, and (ii) that experiments cannot prove correctness of such a theory|one can at most test its empirical adequacy. On a general note, the conclusion is that the importance of philosophical arguments for particle physics is herewith demonstrated: it is, thus, a widespread misconception that philosophical arguments can be completely avoided. (shrink)

From time involved in pair production process, in the photon-photon collision, we consider energy and then mass uncertainty. Taking the latter as the mass of a particle, we repeat pair production process obtaining another mass uncertainty, then another particle mass, and so on. Starting with the heaviest charged elementary particle that is possible using Planck length for electromagnetic mass, we obtain a mass value close to electron mass. It is supposed exactly electron mass, considering the presence of uncertainties in the (...) process. Then plausible neutrino mass and other particles masses are obtained. (shrink)

This paper is a critical suvery on the philosophy and the Interpretations of Quantum Mechanics.

In this paper, we will introduce a brief history of Quantum Entanglement (QE) with reference to important works: 1) Jaeger (Jaeger 2010) and 2) Emerson (Emerson, 2009).

In this brief paper, we argue about some epistemological positions about quantum non-locality.

The debate between Fraser and Wallace over the foundations of quantum field theory has spawned increased focus on both the axiomatic and conventional formalisms. The debate has set the tone for future foundational analysis, and has forced philosophers to “pick a side”. The two are seen as competing research programs, and the major divide between the two manifests in how each handles renormalization. In this paper I argue that the terms set by the Fraser-Wallace debate are misleading. AQFT and CQFT (...) should be viewed as complementary formalisms that start from the same physical basis. Further, the focus on cutoffs as demarcating the two approaches is also highly misleading. Though their methods differ, both axiomatic and conventional QFT seek to use the same physical principles to explain the same domain of phenomena. (shrink)

Following the 26th General Conference on Weights and Measures are fixed the numerical values of the 4 physical constants ($h, c, e, k_B$). This is premised on the independence of these constants. This article discusses a model of a mathematical electron from which can be defined the Planck units as geometrical objects (mass M=1, time T=2$\pi$ ...). In this model these objects are interrelated via this electron geometry such that once we have assigned values to 2 Planck units then we (...) have fixed the values for all Planck units. As all constants can then be defined using geometrical forms (in terms of 2 fixed mathematical constants, 2 unit-specific scalars and a defined relationship between the units $kg, m, s, A$), the least precise CODATA 2014 constants ($G, h, e, m_e, k_B$...) can then be solved via the most precise ($c, \mu_0, \alpha, R_\infty$), with numerical precision limited by the precision of the fine structure constant $\alpha$. In terms of this model we now for example have 2 separate values for elementary charge, calculated from ($c, \alpha, R_\infty$) and the 2017 revision. (shrink)

Metaphysicians as well as philosophers of science often turn to particle physics for a description of the most fundamental entities in our universe. The common assumption is that physics readily provides a clear account of both what those fundamental building blocks are and how they come together to form more complicated objects, and, conversely, how compound objects can be seen as being composed of those fundamental entities. I argue that this picture contains a major difficulty because quantum theories allow for (...) more than one metaphysically meaningful procedure to decompose a system into parts, fundamental or otherwise. I will identify and interpret two such procedures, mathematically given by the direct sum and the tensor product, and show that they lead to different results for what the parts of a quantum system are. This shows that there are conventional choices involved in finding the fundamental parts of an object which have not yet been widely recognised by either metaphysicians or philosophers of science. I take my findings to provide a sense in which, as a result, particle physics on its own is not enough to determine the fundamental ontology of the world. (shrink)

This paper presents a novel unified field theory based on the complex Hopf fibration S^1 → S^9 → CP^4, a 9-dimensional spacetime that elegantly unifies gravity, electromagnetism, and the strong and weak nuclear forces through topological principles. The Standard Model gauge groups SU(3)_C × SU(2)_L × U(1)_Y are derived from the fibration’s geometry and topology, with gravity formulated as a topological field theory in a 4D reduction. The base CP^4 encodes complex time and space dynamics, distinguishing between inertial and accelerated (...) states. The theory is consistent with current experimental data and yields first-principles predictions of boson and fermion masses, including neutrino masses and quark masses, which is an unprecedented achievement. The topology further accounts for the muon and electron g-2 wobbles, with predictions matching experimental data in divergence from the standard model. The theory offers a falsifiable, topologically grounded theory of everything, predicting phase shifts testable via contemporary interferometry. The theory provides a new paradigm for understanding fundamental interactions and spacetime structure. (shrink)

Gravity remains the most elusive field. Its relationship with the electromagnetic field is poorly understood. Relativity and quantum mechanics describe the aforementioned fields, respectively. Bosons and fermions are often credited with responsibility for the interactions of force and matter. It is shown here that fermions factually determine the gravitational structure of the universe, while bosons are responsible for the three established and described forces. Underlying the relationships of the gravitational and electromagnetic fields is a symmetrical probability distribution of fermions and (...) bosons. Werner Heisenberg's assertion that the Schr\'f6dinger wave function and Heisenberg matrices do not describe one thing is confirmed. It is asserted that the conscious observation of Schr\'f6dinger's wave function never causes its collapse, but invariably produces the classical space described by the Heisenberg picture. As a result, the Heisenberg picture can be explained and substantiated only in terms of conscious observation of the Schr\'f6dinger wave function. Schr\'f6dinger\'92s picture is defined as information space, while Heisenberg\'92s picture is defined as classical space. B-theory postulates that although the Schr\'f6dinger picture and the Heisenberg picture are mathematically connected, the former is eternal while the latter is discrete, existing only as the sequence of discrete conscious moments. Inferences related to information-based congruence between physical and mental phenomena have long been discussed in the literature. Moreover, John Wheeler suggested that information is fundamental to the physics of the universe. However, there is a great deal of uncertainty about how the physical and the mental complement each other. Bishop Berkeley and Ernst Mach, to name two who have addressed the subject, simply reject the concept of the material world altogether. Professor Hardy defined physical reality as 'dubious and elusive'. It is proposed in this paper that physical reality, or physical instantiation in the classical space as described by Heisenberg picture is one thing with the consciousness. (shrink)

It is standardly believed that the generally time-reversal symmetric fundamental laws of physics themselves cannot explain the apparent asymmetry of time. In particular, it is believed that CP violation is of no help. In this paper, I want to push back against a quick dismissal of CP violation as a potential source for the arrow of time and argue that it should be taken more seriously for conceptualising time in physics. I first recall that CP violation is a key feature (...) of our best physical theory which also has large-scale explanatory import regarding the matter-antimatter asymmetry of the universe. I then investigate how CP violation may help to explain the directionality of time. I argue that accounts à la Maudlin that posit an intrinsic fundamental direction of time are not convincing and instead propose to utilise recent results from work on the dynamical approach to relativity theory. (shrink)

Fundamental physics contains an important link between properties of elementary particles and continuous symmetries of particle systems. For example, properties such as mass and spin are said to be 'associated' with specific continuous symmetries. -/- These 'associations' have played a key role in the discovery of various new particle kinds, but more importantly: they are thought to provide a deep insight into the nature of physical reality. The link between properties and symmetries has been said to call for a radical (...) revision of perceived metaphysical orthodoxy. However, if we are to use claims about an 'association' between properties and symmetries in the articulation of metaphysical views, we first need to develop a sufficiently precise understanding of the content of these claims. The goal of this paper is to do just that. (shrink)

I propose a gentle reconciliation of Quantum Theory and General Relativity. It is possible to add small, but unshackling constraints to the quantum fields, making them compatible with General Relativity. Not all solutions of the Schrodinger's equation are needed. I show that the continuous and spatially separable solutions are sufficient for the nonlocal manifestations associated with entanglement and wavefunction collapse. After extending this idea to quantum fields, I show that Quantum Field Theory can be defined in terms of partitioned classical (...) fields. One key element is the idea of integral interactions, which also helps clarifying the quantum measurement and classical level problems. The unity of Quantum Theory and General Relativity can now be gained with the help of the partitioned fields' energy-momentum. A brief image of a General Relativistic Quantum Standard Model is outlined. (shrink)

In a recent paper I proposed a novel relativity theory termed Information Relativity (IR). Unlike Einstein's relativity which dictates as force majeure that relativity is a true state of nature, Information Relativity assumes that relativity results from difference in information about nature between observers who are in motion relative to each other. The theory is based on two axioms: 1. the laws of physics are the same in all inertial frames of reference (Special relativity's first axiom); 2. All translations of (...) information from one frame of reference to another are carried by light or by another carrier with equal velocity (information-carrier axiom). For the case of constant relative velocities, I showed in the aforementioned paper that IR accounts successfully for the results of a class of relativistic time results, including the Michelson-Morley's "null" result, the Sagnac effect, and the neutrino velocities reported by OPERA and other collaborations. Here I apply the theory, with no alteration, to cosmology. I show that the theory is successful in accounting for several cosmological findings, including the pattern of recession velocity predicted by inflationary theories, the GZK energy suppression phenomenon at redshift z ̴ 1.6, and the amounts of matter and dark energy reported in recent ΛCDM cosmologies. (shrink)

Four initial postulates are presented (with two more added later), which state that construction of the physical universe proceeds from a sequence of discrete steps or "projections" --- a process that yields a sequence of discrete levels (labeled 0, 1, 2, 3, 4). At or above level 2 the model yields a (3+1)-dimensional structure, which is interpreted as ordinary space and time. As a result, time does not exist below level 2 of the system, and thus the quantum of action, (...) h, which depends on time (since its unit is time•energy), also does not exist below level 2. This implies that the quantum of action is not fundamental, and thus e.g. that the physical universe cannot have originated from a quantum fluctuation. When the gravitational interaction for the model is developed, it is seen that the basic ingredient for gravity is already operating at level 1 of the system, which implies that gravity, too, is not fundamentally quantum mechanical (since, as stated, h only kicks in at level 2) --- perhaps obviating the need for a quantum theory of gravity. Further arguments along this line lead to the conclusion that quantum fluctuations cannot be a source of gravity, and thus cannot contribute to the cosmological constant --- thereby averting the cosmological constant problem. Along the way, the model also provides explanations for dark energy, the beginning and ending of inflation, quark confinement, and more. Although the model dethrones the quantum, it nevertheless elevates an idea in physics that was engendered by quantum mechanics: the necessary role of "observers" in constructing the world. (shrink)

In this note I examine some implications of stochastic interpretations of quantum mechanics for the concept of "charge without charge" presented by Wheeler and Misner. I argue that if a stochastic interpretation of quantum mechanics were correct, then certain shortcomings of the "charge without charge" concept could be overcome.

In this paper, we pursue three general aims: (I) We will define a notion of fundamental opacity and ask whether it can be found in High Energy Physics (HEP), given the involvement of machine learning (ML) and computer simulations (CS) therein. (II) We identify two kinds of non-fundamental, contingent opacity associated with CS and ML in HEP respectively, and ask whether, and if so how, they may be overcome. (III) We address the question of whether any kind of opacity, contingent (...) or fundamental, is unique to ML or CS, or whether they stand in continuity to kinds of opacity associated with other scientific research. (shrink)

The cosmological constant problem stems from treating quantum field theory and general relativity as an effective field theory. We argue that the problem is a reductio ad absurdum, and that one should reject the assumption that general relativity can generically be treated as an EFT. This marks a failure of naturalness, and an internal signal that EFT methods do not apply in all spacetime domains. We then take an external view, showing that the assumptions for using EFTs are violated in (...) general relativistic domains where Λ is relevant. We highlight some ways forward that do not depend on naturalness. (shrink)

Philosophers of physics have spent much effort unpacking the structure of gauge theories. But surprisingly, little attention has been devoted to the question of why we should require our best theories to be locally gauge invariant in the first place. Drawing on Steven Weinberg's works in the mid-1960s, I argue that the principle of local gauge invariance follows from Lorentz invariance and other natural assumptions in the context of perturbative relativistic quantum field theory. On this view, gauge freedom is a (...) mere accidental feature of an already highly constrained set of quantities; the distinctive structure of our best gauge theories, in turn, traces back to the peculiar space-time transformation properties of particles like photons, gluons, and gravitons. I conclude by drawing a few interpretative lessons for the philosophy of gauge theories. (shrink)

Scientific principles can undergo various developments. While philosophers of science have acknowledged that such changes occur, there is no systematic account of the development of scientific principles. Here we propose a template for analyzing the development of scientific principles called the ‘life cycle’ of principles. It includes a series of processes that principles can go through: prehistory, elevation, formalization, generalization, and challenge. The life cycle, we argue, is a useful heuristic for the analysis of the development of scientific principles. We (...) illustrate this by discussing examples from foundational physics including Lorentz invariance, Mach’s principle, the naturalness principle, and the perfect cosmological principle. We also explore two applications of the template. First, we propose that the template can be employed to diagnose the quality of scientific principles. Second, we discuss the ramifications of the life cycle’s processes for the empirical testability of principles. (shrink)

How do scientists navigate between the need to capitalize on their prior knowledge through specialization, and the urge to adapt to evolving research opportunities? Drawing from diverse perspectives on adaptation, this paper proposes an unsupervised Bayesian approach motivated by Optimal Transport of the evolution of scientists' research portfolios in response to transformations in their field. The model relies on $186,162$ scientific abstracts and authorship data to evaluate the influence of intellectual, social, and institutional resources on scientists' trajectories within a cohort (...) of $2\,108$ high-energy physicists between 2000 and 2019. Using Inverse Optimal Transport, the reallocation of research efforts is shown to be shaped by learning costs, thus enhancing the utility of the scientific capital disseminated among scientists. Two dimensions of social capital, namely ``diversity'' and ``power'', have opposite associations with the magnitude of change in scientists' research interests: while ``diversity'' is associated with greater change and expansion of research portfolios, ``power'' is associated with more stable research agendas. Social capital plays a more crucial role in shifts between cognitively distant research areas. More generally, this work suggests new approaches for understanding, measuring and modeling collective adaptation using Optimal Transport. (shrink)

This is a revised and expanded second edition of Why Machines Will Never Rule the World. Its core argument remains the same: that an artificial intelligence (AI) that could equal or exceed human intelligence – sometimes called ‘artificial general intelligence’ (AGI) – is for mathematical reasons impossible. It offers two specific reasons for this claim: -/- - Human intelligence is a capability of the human brain and central nervous system, which is a complex dynamic system -/- - Systems of this (...) sort cannot be modelled mathematically in a way that allows them to operate inside a computer -/- In supporting their claim, the authors, Jobst Landgrebe and Barry Smith, marshal evidence from mathematics, physics, computer science, philosophy, linguistics, biology, and anthropology, setting up their book around three central questions: What are the essential marks of human intelligence? What is it that researchers try to do when they attempt to achieve ‘Artificial Intelligence’ (AI)? And why, after more than 50 years, are our interactions with AI, for example when on the telephone with our bank’s computers, still so unsatisfactory? (shrink)

The view that our best current physics deals with effective systems has gained philosophical traction in the last two decades. A similar view about open systems has also been picking up steam in recent years. Yet little has been said about how the concepts of effective and open systems relate to each other despite their apparent kinship—both indeed seem at first sight to presuppose that the system in question is somehow incomplete. In this paper, I distinguish between two concepts of (...) effectiveness and openness in quantum field theory, which provides a remarkably well-developed theoretical framework to make a first stab at the matter, and argue that on both counts, every realistic effective system in this context is also open. I conclude by highlighting how the discussion opens novel avenues for thinking of systems as open across scales. (shrink)

Computer simulations are nowadays often directly involved in the generation of experimental results. Given this dependency of experiments on computer simulations, that of simulations on models, and that of the models on free parameters, how do researchers establish trust in their experimental results? Using high-energy physics (HEP) as a case study, I will identify three different types of robustness that I call conceptual, methodological, and parametric robustness, and show how they can sanction this trust. However, as I will also show, (...) simulation models in HEP themselves fail to exhibit a type of robustness I call inverse parametric robustness. This combination of robustness and failures thereof is best understood by distinguishing different epistemic capacities of simulations and different senses of trust: Trusting simulations in their capacity to facilitate credible experimental results can mean accepting them as means for generating belief in these results, while this need not imply believing the models themselves in their capacity to represent an underlying reality. (shrink)

Supersymmetry (SUSY) has long been considered an exceptionally promising theory. A central role for the promise has been played by naturalness arguments. Yet, given the absence of experimental findings it is questionable whether the promise will ever be fulfilled. Here, I provide an analysis of the promises associated with SUSY, employing a concept of pursuitworthiness. A research program like SUSY is pursuitworthy if (1) it has the plausible potential to provide high epistemic gain and (2) that gain can be achieved (...) with manageable research efforts. Naturalness arguments have been employed to support both conditions (1) and (2). First, SUSY has been motivated by way of analogy: the proposed symmetry between fermions and bosons is supposed to 'protect' the small Higgs mass from large quantum corrections just as the electron mass is protected through the chiral symmetry. Thus, SUSY held the promise of solving a major problem of the Standard Model of particle physics. Second, naturalness arguments have been employed to indicate that such gain is achievable at relatively low cost: SUSY discoveries seemed to be well in reach of upcoming high-energy experiments. While the first part of the naturalness argument may have the right form to facilitate considerations of pursuitworthiness, the second part of the argument has been problematically overstated. (shrink)

The early history of string theory is marked by a shift from strong interaction physics to quantum gravity. The first string models and associated theoretical framework were formulated in the late 1960s and early 1970s in the context of the S-matrix program for the strong interactions. In the mid-1970s, the models were reinterpreted as a potential theory unifying the four fundamental forces. This paper provides a historical analysis of how string theory was developed out of S-matrix physics, aiming to clarify (...) how modern string theory, as a theory detached from experimental data, grew out of an S-matrix program that was strongly dependent upon observable quantities. Surprisingly, the theoretical practice of physicists already turned away from experiment before string theory was recast as a potential unified quantum gravity theory. With the formulation of dual resonance models (the “hadronic string theory”), physicists were able to determine almost all of the models' parameters on the basis of theoretical reasoning. It was this commitment to “non-arbitrariness”, i.e., a lack of free parameters in the theory, that initially drove string theorists away from experimental input, and not the practical inaccessibility of experimental data in the context of quantum gravity physics. This is an important observation when assessing the role of experimental data in string theory. (shrink)

Gauge symmetries play a central role, both in the mathematical foundations as well as the conceptual construction of modern (particle) physics theories. However, it is yet unclear whether they form a necessary component of theories, or whether they can be eliminated. It is also unclear whether they are merely an auxiliary tool to simplify (and possibly localize) calculations or whether they contain independent information. Therefore their status, both in physics and philosophy of physics, remains to be fully clarified. In this (...) overview we review the current state of affairs on both the philosophy and the physics side. In particular, we focus on the circumstances in which the restriction of gauge theories to gauge invariant information on an observable level is warranted, using the Brout-Englert-Higgs theory as an example of particular current importance. Finally, we determine a set of yet to be answered questions to clarify the status of gauge symmetries. (shrink)

It has been suggested that particle physics has reached the "dawn of the post-naturalness era." I provide an explanation of the current shift in particle physicists' attitude towards naturalness. I argue that the naturalness principle was perceived to be supported by the theories it has inspired. The potential coherence between major beyond the Standard Model (BSM) proposals and the naturalness principle led to an increasing degree of credibility of the principle among particle physicists. The absence of new physics at the (...) Large Hadron Collider (LHC) has undermined the potential coherence and has led to the principle's loss of significance. (shrink)

According to Peter Galison, the coordination of different “subcultures” within a scientific field happens through local exchanges within “trading zones.” In his view, the workability of such trading zones is not guaranteed, and science is not necessarily driven towards further integration. In this paper, we develop and apply quantitative methods (using semantic, authorship, and citation data from scientific literature), inspired by Galison’s framework, to the case of the disunity of high-energy physics. We give prominence to supersymmetry, a concept that has (...) given rise to several major but distinct research programs in the field, such as the formulation of a consistent theory of quantum gravity or the search for new particles. We show that “theory” and “phenomenology” in high-energy physics should be regarded as distinct theoretical subcultures, between which supersymmetry has helped sustain scientific “trades.” However, as we demonstrate using a topic model, the phenomenological component of supersymmetry research has lost traction and the ability of supersymmetry to tie these subcultures together is now compromised. Our work supports that even fields with an initially strong sentiment of unity may eventually generate diverging research programs and demonstrates the fruitfulness of the notion of trading zones for informing quantitative approaches to scientific pluralism. (shrink)

This paper proposes a way to understand the meaning of reality (in science) on the basis of the concepts of persistence and resistance. It first supports the ontological view that reality consists of persistent potentialities, which resist being excluded from existence. A study of the cases of the Higgs boson and the hypothetical Ϝ-particle helps to illustrate how real entities persist and resist. The paper then suggests that, perceptually speaking, the results of ordinary perception or observational processes persistently appear under (...) appropriate conditions, and they resist disappearance even when the appropriate conditions are not completely prepared. Finally, it argues that, epistemologically speaking, a truthful theory resists being falsified and persists across replicable observations and experiments. (shrink)

Can an ugly experiment be a good experiment? Philosophers have identified many beautiful experiments and explored ways in which their beauty might be connected to their epistemic value. In contrast, the present chapter seeks out (and celebrates) ugly experiments. Among the ugliest are those being designed by AI algorithms. Interestingly, in the contexts where such experiments tend to be deployed, low aesthetic value correlates with high epistemic value. In other words, ugly experiments can be good. Given this, we should conclude (...) that beauty is not generally necessary or sufficient for epistemic value, and increasing beauty will not generally tend to increase epistemic value. (shrink)

Experiments in particle physics have hitherto failed to produce any significant evidence for the many explicit models of physics beyond the Standard Model (BSM) that had been proposed over the past decades. As a result, physicists have increasingly turned to model-independent strategies as tools in searching for a wide range of possible BSM effects. In this paper, we describe the Standard Model Effective Field Theory (SM-EFT) and analyse it in the context of the philosophical discussions about models, theories, and (bottom-up) (...) effective field theories. We find that while the SM-EFT is a quantum field theory, assisting experimentalists in searching for deviations from the SM, in its general form it lacks some of the characteristic features of models. Those features only come into play if put in by hand or prompted by empirical evidence for deviations. Employing different philosophical approaches to models, we argue that the case study suggests not to take a view on models that is overly permissive because it blurs the lines between the different stages of the SM-EFT research strategies and glosses over particle physicists' motivations for undertaking this bottom-up approach in the first place. Looking at EFTs from the perspective of modelling does not require taking a stance on some specific brand of realism or taking sides in the debate between reduction and emergence into which EFTs have recently been embedded. (shrink)

I reply to Henk de Regt's "Can Scientific Understanding be Reduced to Knowledge?," which appears in the same volume.

The aim of this article is to provide an overview of various discourses relevant to developing a construct of collective _phronesis_, from a (neo)-Aristotelian perspective, with implications for professional practice in general and business practice and business ethics education in particular. Despite the proliferation of interest in practical wisdom within business ethics and more general areas of both psychology and philosophy, the focus has remained mostly on the construct at the level of individual decision-making, as in Aristotle’s _Nicomachean Ethics_. However, (...) he also made intriguing remarks about _phronesis_ at the collective level in his _Politics_: remarks that have mostly eluded elaboration. The aim of this article is practical and revisionary, rather than exegetical and deferential, with respect to Aristotle. Nevertheless, just as most of the literature on individual _phronesis_ draws on Aristotle’s exposition in the _Nicomachean Ethics_, the obvious first port of call for an analysis of collective _phronesis_ is to explore the resources handed down to us by Aristotle himself. The lion’s share of this article is, therefore, devoted to making sense of Aristotle’s somewhat unsystematic remarks and the lessons we can draw from them about collective managerial _phronesis_ and business ethics education. (shrink)

Particle physics intertwines theory and experiments, and this text demonstrates and develops the interplay between the two, following the author's detailed and original approach. This complete and comprehensive treatise, written for a two-semester Master's or graduate course, covers all aspects of modern particle physics. Richly illustrated with more than 450 figures, this text guides students through all the intricacies of quantum mechanics and quantum field theory in an intuitive manner that few books achieve. Featuring rigorous step-by-step derivations and more than (...) 100 end-of-chapter problems for additional practice, it ensures that students will not only understand the material but also be able to apply their knowledge. Containing up-to-date experimental material, including the discovery of the Higgs boson at CERN and of neutrino oscillations, this monumental volume also serves as a one-stop reference for particle physics researchers of all levels and specialties. (shrink)

The Nothing from Infinity paradox arises when the combination of two infinitudes of point particles meet in a supertask and disappear. Corral-Villate claims that my arguments for disappearance fail and concedes that this failure also produces an extreme kind of indeterminism, which I have called plenitudinous. So my supertask at least poses a dilemma of extreme indeterminism within Newtonian point particle mechanics. Plenitudinous indeterminism might be trivial, although easy attempts to prove it so seem to fail in the face of (...) plausible continuity principles. However, the question of its triviality is here moot, since I show that, except in one case, Corral-Villate’s disproofs fail, and with a correction, the original arguments are unrefuted. Consequently, of the two contenders for the outcome of my supertask, the Nothing from Infinity paradox has won out. (shrink)

Hans Reichenbach’s posthumous book The Direction of Time ends somewhere between Socratic aporia and historical irony. Prompted by Feynman’s diagrammatic formulation of quantum electrodynamics, Reichenbach eventually abandoned the delicate balancing between the macroscopic foundation of the direction of time and microscopic descriptions of time order undertaken throughout the previous chapters in favor of an exclusively macroscopic theory that he had vehemently rejected in the 1920s. I analyze Reichenbach’s reasoning against the backdrop of the history of Feynman diagrams and the current (...) practice of particle physics. Building upon the debates about processes and conserved quantities between Wesley Salmon and Phil Dowe in the 1990s, and the exchange between Reichenbach and the gestalt theorist Kurt Lewin during the 1920s about topology and genidentity, I investigate whether the aporia about local time order could be avoided by following a strategy that Reichenbach adopted elsewhere in the book and develop a notion of functional genidentity that captures the practice of present-day elementary particle physics and the fact that Feynman diagrams have to be understood in the context of a complex mathematical description of scattering processes. (shrink)

This is an introduction to renormalization group methods in quantum field theory aimed at philosophers of science. review path integral methods, the relationship between early renormalization theory and renormalization group methods, and conceptual shifts in thinking about quantum field theory spurred by the development of renormalization group methods.

Many decades ago Patrick Suppes argued rather convincingly that theoretical hypotheses are not confronted with the direct, raw results of an experiment, rather, they are typically compared with models of data. What exactly is a data model however? And how do the interactions of particles at the subatomic scale give rise to the huge volumes of data that are then moulded into a polished data model? The aim of this paper is to answer these questions by presenting a detailed case (...) study of the construction of data models at the LHCb for testing Lepton Flavour Universality in rare decays of B-mesons. The close examination of the scientific practice at the LHCb leads to the following four main conclusions: raw data in their pure form are practically useless for the comparison of experimental results with theory, and processed data are in some cases epistemically more reliable, real and simulated data are involved in the co-production of the final data model and cannot be easily distinguished, theory-ladenness emerges at three different levels depending on the scope and the purpose for which background theory guides the overall experimental process and the overall process of acquiring and analysing data in high energy physics is too complicated to be fully captured by a generic methodological description of the experimental practice. (shrink)

Wigner's quantum-mechanical classification of particle-types in terms of irreducible representations of the Poincaré group has a classical analogue, which we extend in this paper. We study the compactness properties of the resulting phase spaces at fixed energy, and show that in order for a classical massless particle to be physically sensible, its phase space must feature a classical-particle counterpart of electromagnetic gauge invariance. By examining the connection between massless and massive particles in the massless limit, we also derive a classical-particle (...) version of the Higgs mechanism. (shrink)

This paper criticizes the traditional philosophical account of the quantization of gauge theories and offers an alternative. On the received view, gauge theories resist quantization because they feature distinct mathematical representatives of the same physical state of affairs. This resistance is overcome by a sequence of ad hoc modifications, justified in part by reference to semiclassical electrodynamics. Among other things, these modifications introduce "ghosts": particles with unphysical properties which do not appear in asymptotic states and which are said to be (...) purely a notational convenience. I argue that this sequence of modifications is unjustified and inadequate, making it a poor basis for the interpretation of ghosts. I then argue that gauge theories can be quantized by the same method as any other theory. On this account, ghosts are not purely notation: they are coordinates on the classical configuration space of the theory—specifically, on its gauge structure. This interpretation does not fall prey to the standard philosophical arguments against the significance of ghosts, due to Weingard. Weingard’s argumentative strategy, properly applied, in fact tells in favor of ghosts’ physical significance. (shrink)

In the paper it is demonstrated that Bell’s theorem is an unprovable theorem. The unprovable characteristic has, on the chemical side, repercussions for e.g. spin chemistry and the related magneto-reception studies. We claim that the unprovability of this basic mathematics cannot be ignored by the physics and chemical research community. The demonstrated mathematical multivaluedness could be an overlooked aspect of nature.

The cosmological constant problem is widely viewed as an important barrier and hint to merging quantum field theory and general relativity. It is a barrier insofar as it remains unsolved, and a solution may hint at a fuller theory of quantum gravity. I critically examine the arguments used to pose the cosmological constant problem, and find many of the steps poorly justified. In particular, there is little reason to accept an absolute zero point energy scale in quantum field theory, and (...) standard calculations are badly divergent. It is also unclear exactly how a semiclassical treatment of gravity would include a vacuum energy contribution to the total stress-energy. Large classes of solution strategies are also found to be conceptually wanting. I conclude that one should not accept the cosmological constant problem as standardly stated. (shrink)

Most cosmologists say dark matter must exist. So far, it’s nowhere to be found. A widely scorned rival theory explains why.

I discuss the relevance of the current predicament in cosmology to the debate over scientific realism. I argue that the existence of two, empirically successful but ontologically inconsistent cosmological theories presents difficulties for the realist position.

Reeves and Sinnicks present Theodor Adorno as a philosopher with a sombre message to business ethics. Capitalist markets distort our needs and work in business organisations stultifies our moral capacities. Thus, the discipline's self-understanding must be revised, and supplemented with reflections on what would be good work: free creative activity. After raising some questions about their interpretation of Adorno's writings on human needs, I argue that the paper does not contain all the necessary resources to support its ferociously critical claims. (...) Once such resources are made available, however, the appeal to a notion of good work is no longer viable. (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)