Since 1939, when Wigner published his proposal to define particles via symmetries expressed as algebraic groups, we have seen a long stream of attempts to formulate an ontology of matter based on mathematics. It has become apparent that such attempts must fail, and more particularly that we cannot derive an ontology of matter from the Standard Model on the basis of quantum field theory. We briefly recapitulate the reasons for this and demonstrate how the philosophy of physics has become scholasticised through a series of vain attempts to obtain a coherent ontology of matter. Here we propose an alternative approach in the form of an ontology of the science of physics. It draws on a framework developed by Husserl which admits not only real material entities but also the idealities which physicists make use of in their thinking. We specify the upper level of this ontology, which addresses the way in which physicists use mathematics when conducting their enquiries. This ontology provides a new perspective concerning the dilemmas of modern physics, including the measurement problem.
Since 1939, when Wigner published his proposal to define particles via symmetries expressed as algebraic groups, we have seen a long stream of attempts to formulate an ontology of matter based on mathematics. It has become apparent that such attempts must fail, and more particularly that we cannot derive an ontology of matter from the Standard Model on the basis of quantum field theory. We briefly recapitulate the reasons for this and demonstrate how the philosophy of physics has become scholasticised through a series of vain attempts to obtain a coherent ontology of matter. Here we propose an alternative approach in the form of an ontology of the science of physics. It draws on a framework developed by Husserl which admits not only real material entities but also the idealities which physicists make use of in their thinking. We specify the upper level of this ontology, which addresses the way in which physicists use mathematics when conducting their enquiries. This ontology provides a new perspective concerning the dilemmas of modern physics, including the measurement problem.
In glaring contrast to its indisputable century-old experimental success, the ultimate objects and meaning of quantum physics remain a matter of vigorous debate among physicists and philosophers of science. This article attempts to shed new light on the debate. It relies upon two comments by Albert Einstein on his general approach to physical theories. I draw their consequences for the definition of a physical theory's ontology, and next for the ontology of quantum physics - i.e. what it may ultimately be about. The quantum ontology thus derived appears to be strictly limited to evolving experimental contexts and instantaneous measurement outcomes, which are to be understood, respectively, as mere potential measurement outcomes and actual ones. The notions of material body in particular and physical system in general are absent from this ontology, hence the vanishing of Schroedinger's cat and EPR paradoxes, as well as of the quantum measurement problem. Apart from its ability to clear up well-known conundrums, this ontology reveals what quantum physics may fundamentally be - i.e. its possible ultimate meaning - namely a theory of general relativity of experimental context. On this basis, I conclude with a new conception of objectivity in the sciences of nature.
One of the foundational challenges in both Quantum Field Theory and the philosophy of physics lies in the traditional binary classification of entities as either real or unreal. The classical view posits that material entities are real, while mental constructs or theoretical entities are unreal. However, quantum phenomena such as virtual particles challenge this simplistic dichotomy. These unobservable entities, by influencing measurable phenomena, raise profound questions about the nature and modes of existence. To address this, we propose a four-level ontological hierarchy that spans from the quantum vacuum and the virtual level to the quantum level and phenomenal reality, providing a coherent continuum from potentiality to actualization. This framework not only clarifies the interpretation of quantum theory but also offers a unified perspective linking the unobservable with the observable. In QFT, virtual particles play a crucial role in mediating forces and in correcting the measurable properties of real particles. They arise within the mathematical structure of Feynman diagrams and, despite being unobservable, produce real, measurable effects such as the Lamb shift and the Casimir effect. Philosophically, this raises deep ontological questions: if unobservable entities affect measurable phenomena, can they truly be dismissed as unreal? Conversely, if they are real, what mode of existence do they possess? The traditional dichotomy of real versus unreal is thus insufficient for interpreting the ontological implications of quantum processes. To overcome these limitations, we propose a four-level ontological hierarchy.
This work proposes a minimal ontological framework aimed at systematically resolving key conceptual paradoxes of contemporary physics. The central claim is that many foundational difficulties of twentieth- and twenty-first-century physics arise not from empirical anomalies or mathematical inconsistencies, but from a conflation of mathematical formalism with ontological interpretation. On the basis of a small set of minimal ontological axioms, the work addresses and resolves ten fundamental paradoxes, including wave–particle duality, the measurement problem and collapse, the arrow of time, irreversibility, quantization, the nature of gravity, cosmological origin, the finiteness of the Universe, the status of singularities, and the information paradox. The proposed framework introduces no new physical entities and does not modify existing physical equations. Instead, it imposes strict ontological constraints from which these phenomena follow as necessary consequences. The work does not present an alternative physical theory, but rather an ontological foundation explaining why modern physical theories are successful and why they encounter inherent explanatory limits.
A common learning goal for modern physics instructors is for students to recognize a difference between the experimental uncertainty of classical physics and the fundamental uncertainty of quantum mechanics. Our studies suggest this notoriously difficult task may be frustrated by the intuitively realist perspectives of introductory students, and a lack of ontological flexibility in their conceptions of light and matter. We have developed a framework for understanding and characterizing student perspectives on the physical interpretation of quantum mechanics, and demonstrate the differential impact on student thinking of the myriad ways instructors approach interpretive themes in their introductory courses. Like expert physicists, students interpret quantum phenomena differently, and these interpretations are significantly influenced by their overall stances on questions central to the so-called measurement problem: Is the wave function physically real, or simply a mathematical tool? Is the collapse of the wave function an ad hoc rule, or a physical transition not described by any equation? Does an electron, being a form of matter, exist as a localized particle at all times? These questions, which are of personal and academic interest to our students, are largely only superficially addressed in our introductory courses, often for fear of opening a Pandora's Box of student questions, none of which have easy answers. We show how a transformed modern physics curriculum (recently implemented at the University of Colorado) may positively impact student perspectives on indeterminacy and wave-particle duality, by making questions of classical and quantum reality a central theme of our course, but also by making the beliefs of our students, and not just those of scientists, an explicit topic of discussion.
All men by nature desire to know, states Aristotle in the famous first sentence of his Metaphysics. Knowledge about fundamental particles and interactions, that is, knowledge about the deepest aspects of matter, is certainly high if not top on the priority list, not only for physicists and philosophers. The goal of the present book is to contribute to this knowledge by going beyond the usual presentations of quantum field theory in physics textbooks, both in mathematical approach and by critical reflections inspired by epistemology, that is, by the branch of philosophy also referred to as the theory of knowledge. Hopefully, the present book motivates physicists to appreciate philosophical ideas. Epistemology and the philosophy of the evolution of science often seem to lag behind science and to describe the developments a posteriori. As philosophy here has a profound influence on the actual shaping of an image of fundamental particles and their interactions, our development should stimulate the curiosity and imagination of physicists. This book can be used as a textbook on quantum field theory for students of physics or as a monograph for philosophers and physicists interested in the epistemological foundations of particle physics. The benefits of an approach resting on philosophical foundations is twofold: the reader is stimulated to critical thinking and the entire story flows very naturally, thus removing all the mysteries from quantum field theory.
Scientific realism has traditionally maintained that our best scientific theories can be regarded as more or less true and as representing the world as it is (more or less). However, one of our very best current theories—quantum mechanics—has famously resisted such a realist construal, threatening to undermine the realist stance altogether. The chapters in this volume carefully examine this tension and the reasons behind it, including the underdetermination generated by the multiplicity of formulations and interpretations of quantum physics, each presenting a different way the world could be. Authors in this volume offer a range of alternative ways forward: some suggest new articulations of realism, limiting our commitments in one way or another; others attempt to articulate a ‘third way’ between traditional forms of realism and antirealism, or are critical of such attempts. Still others argue that quantum theory itself should be reconceptualised, or at least alternative formulations should be considered in the hope of evading the problems faced by realism. And some examine the nature of these issues when moving beyond quantum mechanics to quantum field theory. Taken together they offer an exciting new set of perspectives on one of the most fundamental questions in the philosophy of modern physics: how can one be a realist about quantum theory, and what does this realism amount to?