Interpretation of Quantum Mechanics

Calculus is seen as describing continuous functions through the act of breaking them down to the smallest possible parts, suggesting that the whole is only an aggregation of its parts. But modern science has demanded the creation of new kinds of measurements, where the deterministic rules of classical physics cease to exist and we can no longer see the individual member parts as sole explanations towards the continuity of the whole. There is a duality between states of dis/continuous being, and (...) we seem to be doomed to only see the measured discontinuous version grounded in our own objectivity. But can the knowledge of this duality maybe help us better understand the social consequences of our world’s massively intraconnected social order? With the infrastructure of modern trade, seemingly instant communication possibilities, and newly created tribes numbering beyond what we thought possible; we have created a world that seem to defy our preconceptions of what social groups and responsibility means. Using agential realism and its groundbreaking insights into quantum philosophy with the idea of complementarity, I think we can start to understand these new states of being, and with it bring about a better grasp of the ethics that are an intrinsic part of all. Setting a foundation for how we can understand the duality of groups and individuals across all areas of our world, seeing complementarity as the grounding state of un/certain objectivity. (shrink)

In Everettian quantum mechanics, justifications for the Born rule appeal to self-locating uncertainty or decision theory. Such justifications have focused exclusively on a pure-state Everettian multiverse, represented by a wave function. Recent works in quantum foundations suggest that it is viable to consider a mixed-state Everettian multiverse, represented by a (mixed-state) density matrix. Here, we develop the conceptual foundations for decoherence and branching in a mixed-state multiverse, and extend arguments for the Born rule to this setting. This extended framework provides (...) a unification of 'classical' and 'quantum' probabilities, and additional theoretical benefits, for the Everettian picture. (shrink)

The mathematical formulation of theories is a key driver of modern physics' successes, and reflects a foundational principle. Physicists are guided by this principle, and in doing so are granted all the benefits afforded by a hard science. Herein, I argue that this principle has even more to offer. For physicists to make sense of each other's mathematically formulated theories (MFTs) they must share a universal understanding on how to interpret them. In terms of model theory, there must be a (...) set of (basic but) universally accepted interpretations that relate the language of MFTs to meaningful elements. Because these interpretations apply to all MFTs, a model of (just) these interpretations would be a submodel of all models of MFTs. These universally accepted interpretations were, effectively, the bases for Max Tegmark’s mathematical universe hypothesis (MUH). This allowed Tegmark to relate many aspects of quantum and relativistic physics back to his hypothesis. However, Tegmark's goal of accounting for spacetime and quantum phenomena requires a model beyond universally accepted interpretations. I show that as a result, the model described by Tegmark's MUH is not a submodel of all existing models of MFTs. In contrast, I derive a novel model of just these universally accepted interpretations such that all models of all potential MFTs are, effectively, extensions to this novel model. Therefore, this novel model can enhance our understanding of every MFT, and facilitate collaboration and the unification of models across the branches of modern physics. (shrink)

Dinner tonight may be 6 hours later than lunch today. Also, lunch and dinner go from being in our future to being in our present (consecutively) and then our past (consecutively). How do quantum mechanics and relativity account for this?

Dinner today is 6 hours later than lunch. Also they are in our future and then (consecutively) in our present and then (consecutively) in our past. How do both quantum mechanics and relativity account for this?

The centered Everett interpretation solves a problem that various approaches to quantum theory face. In this paper, I continue developing the theory underlying that solution. In particular, I defend the centered Everett interpretation against a few objections, and I provide additional motivation for some of its key features.

The mistake of quantum physics relying on classical physics with its concept of reality confined to mas and space. The mistake of viewing the photon as a particle. The mistake of ignoring the latent identities of entities.

Everettian quantum mechanics tells us that the fundamental dynamics of the universe are deterministic. So what are the `probabilities' that the Born rule describes? One popular answer has been to treat these probabilities as rational credences. A recent alternative, Isaac Wilhelm's centered Everett Interpretation (CEI), takes the Born probabilities to be centered chances: the objective chances that some centered propositions are true. Thus, the CEI challenges the `orthodox assumption’ that fundamental physical laws concern only uncentered facts. I provide three arguments (...) against the centered Everett Interpretation. First, I argue that the CEI is in apparent tension with a significant motivation for adopting Everettian quantum mechanics: rejecting the attribution of special significance to observers or agents in fundamental physics. I suggest the CEI can avoid this tension, but only at the cost of sacrificing its central claim that there are objective chances in an Everettian multiverse. My second argument concerns the CEI’s claim that the centered Born rule is a fundamental physical law. I provide two plausible notions of fundamentality for physical laws, and I argue that the centered Born rule satisfies neither. My final argument is that the CEI’s branch-relative laws cannot explain or constrain an agent’s rational credences in the way that the CEI claims. (shrink)

Quantum physics is believed to be the fundamental theory underlying our understanding of the physical universe. However, it is based on concepts and principles that have always been difficult to understand and controversial in their interpretation. This book aims to explain these issues using a minimum of technical language and mathematics. After a brief introduction to the ideas of quantum physics, the problems of interpretation are identified and explained. The rest of the book surveys, describes and criticises a range of (...) suggestions that have been made with the aim of resolving these problems; these include the traditional, or 'Copenhagen' interpretation, the possible role of the conscious mind in measurement, and the postulate of parallel universes. This new edition has been revised throughout to take into account developments in this field over the past fifteen years, including the idea of 'consistent histories' to which a completely new chapter is devoted. (shrink)

We propose the Prototime Interpretation of quantum mechanics, which claims that quantum entanglement occurs in a "prototemporal" realm which underlies spacetime. Our paper is tentative and exploratory. The argument form is inference to the best explanation. We claim that the Prototime Interpretation (PI) is worthy of further consideration as a superior explanation for perplexing quantum phenomena such as delayed choice, superposition, the wave-particle duality and nonlocality. In Section One, we introduce the Prototime Interpretation. Section Two identifies its advantages. Section Three (...) discusses several implications of the view, such as its deterministic nature and relation to the simulation hypothesis. (shrink)

Physik und Biologie der Erkenntnis. Die Natur- und Wissenschaftsphilosophie von Carl Friedrich von Weizsäcker und Rupert Riedl, 2017 (M.A.-Abschlussarbeit, Wiener Rupert-Riedl-Preis 2019) -/- Schon Erwin Schrödinger hat sich mit der Frage der Gesetzlichkeit der Natur auseinandergesetzt, wie ein endlicher menschlicher Geist zu einer Formulierung von Gesetzen der Natur gelangen kann, worin der konstruktive Beitrag der menschlichen Subjektivität zu unserem objektiven Bild von der Natur besteht, worin die Relationen zwischen Erkenntnissubjekt und Naturobjekten bestehen, welche uns eine Wirklichkeitserschließung möglich machen. Es fragt (...) sich, wie das Bild von der Natur im Denken des menschlichen Ichs überhaupt entstehen kann und wie die Welt durch die Betrachtung des menschlichen Geistes Bedeutung erlangen kann. -/- Es lässt sich außerdem mit Erwin Schrödinger fragen, wie natürliche Außenwelt und Bewusstsein aufeinander bezogen sind und in welchem Verhältnis sie aus der Perspektive des menschlichen Denkens und Vorstellens zueinander stehen. Bei der Reflexion dessen lässt sich die Annahme von Moritz Schlick stark machen, dass das philosophisch Geistige in der naturwissenschaftlichen Erkenntnis selbst zu suchen ist. Ebenso kann man sich bei der Reflexion solcher Fragen der Annahme von Karl Raimund Popper anschließen, dass es sich bei den von uns vorgestellten Gesetzen der Natur um vom menschlichen Geist erschaffene Idealisierungen der Welt handelt, welche wir als Fangnetze auswerfen, um den Kosmos einzufangen, wodurch wir versuchen analog zu einem Musikstück die Natur in den Rhythmen ihrer Strukturen zu erfassen. -/- Ähnlich ließe sich mit Werner Heisenberg vermuten, dass etwa die Quantentheorie sich als bedeutsam für ein umfassendes Weltverständnis erweist, indem sie auf die für diese Welt grundlegenden Strukturen und platonischen Ideen hinweist. Damit muss auch das Verhältnis von Geist und Materie neu bestimmt werden, wobei jemand wie Carl Friedrich von Weizsäcker diesbezüglich auf das durch die moderne Physik gewandelte Bild vom Ganzen dieser Wirklichkeit eingegangen ist, indem er versucht hat die Einheit der Natur zu rekonstruieren auf der Grundlage der Auffassung, dass die Quantentheorie als fundamentale Theorie für unsere Naturerkenntnis in der Gegenwart anzusehen ist und damit auch eine Theorie des menschlichen Wissens über die Welt insgesamt darstellt. -/- Damit stellt Weizsäcker schließlich die Frage nach dem Verhältnis von Sein und Wissen überhaupt, wobei die Zeit als Horizont menschlichen Wissens auftrete und die Quantentheorie als eine Logik der Zeitlichkeit die Bedingungen für die Möglichkeit von Wissen angebe und eben dadurch das Sein in seiner naturgesetzlichen Einheit bestimme. Die verschiedenen Erscheinungen der Welt stellen sich dann nach Weizsäcker als zeitliche Erscheinungen des Seienden im Bewusstsein dar. Die Wissenschaft untersuche die Realität in ihrer Vielfalt als Gegenstand des Wissens, welches menschlichen Subjekten zukommt und sich zeitlich entwickelt, wobei die Natur selber eine geschichtliche Bedingung für die Möglichkeit von wissenden Subjekten darstellt und ein philosophisches Bewusstsein die Zeitlichkeit allen Wissens zu bedenken hat. -/- Jene Geschichtlichkeit der Natur zeigt sich seit jeher im Bereich des Organischen, in welchem die der natürlichen Auslese entspringende evolutionäre Variation und die Unvorhersagbarkeit zukünftiger Phänomene als besonders kennzeichnend in das Blickfeld rücken, wobei sich offenbart, um mit Ernst Mayr zu sprechen, dass das Lebewesen Mensch als sehr unwahrscheinlich erscheinen muss und dennoch dem Planeten Erde mehr oder weniger bloß „passiert“ ist. Jener Mensch untersteht dabei, wie auch Jacques Monod ausgeführt hat, genauso wie alle anderen Lebewesen in der Evolution der Zusammenwirkung von Zufallsereignissen auf der mikroskopischen Ebene und Selektionsbedingungen auf der makroskopischen Ebene. -/- Somit lässt sich dann auch mit Konrad Lorenz der konsequente Schluss ziehen, dass auch der menschliche Erkenntnisapparat als ein Objekt der Realität mit seinen Denkformen und Anschauungsweisen aus der Auseinandersetzung mit der Umwelt und der Anpassung an ihre Bedingungen hervorgegangen ist. Damit lässt sich auch etwa mit Adolf Portmann der Glaube, dass die Natur den Menschen „entlassen“ haben, durchaus bezweifeln. -/- So hat dann Rupert Riedl jene „Strategien“ der Evolution aufgedeckt, welche bei der Entwicklung der Komplexität dieser Realität von der materiellen und der organischen Ebene bis hin zur geistigen und soziokulturellen Ebene maßgeblich sind und durch welche sich das Leben organisiert. Dabei zeigt sich nach Riedl, dass der geschichtlichen Ordnung der Natur und der in ihr waltenden Auslese auch die Ordnung des menschlichen Denkens entspringt, wodurch die organische Evolution zur Ausdifferenzierung eines bestimmten Hypothesensystems in uns geführt hat. So zeigt also Riedl, wie sich entlang materieller Gesetzlichkeiten der menschliche Geist entwickelt und differenziert hat und durch die Stammesgeschichte auch das menschliche Vorstellen in seinem Vermögen ausgeformt worden ist. -/- Nach Weizsäcker zeichnet sich Materie durch die Eigenschaft aus, dass sie möglicher Gegenstand des menschlichen Denkens sein kann. Weizsäcker zufolge hat die moderne Physik philosophisch gesehen das Verdienst, erkannt und wieder der Aufmerksamkeit zugeführt zu haben, dass bezüglich des Seins „überhaupt eine Frage zu stellen“ ist, weshalb das Problem der modernen Physik ein solches der Ontologie wäre. Die Quantenphysik könnte sich nach Weizsäcker als jene „Theorie des überhaupt begrifflich Erkennbaren“ und „allgemeine Wissenschaft des Verstandes“ herausstellen. Die Quantenphysik als „Logik objektivierbarer Erfahrung“ bietet nach Weizsäcker eine neue Herangehensweise an „das Seiende zu verstehen“. -/- Riedl sieht in der Evolutionsbiologie die Möglichkeit einer objektiven Betrachtung des „Werdens der Vernunft“ im Sinne eines kosmischen Prozesses, indem sie es ermögliche den „stammesgeschichtlichen Grundlagen“ der menschlichen Vernunft nachzugehen, um zu erfahren, für die Bewältigung welcher Art von Lebensaufgaben die menschlichen Anschauungsformen von der Selektion ausgewählt worden sind. So hätten sich nach Riedl auch im Menschen bestimmte „ratiomorphe Anlagen“ ausgebildet, durch welche die Grundstrukturen der Welt gespiegelt werden, wodurch der Erkenntnismechanismus des menschlichen Bewusstseins auf einem angeborenen Lehrmeister beruht. So wendet sich Riedl in seiner „evolutionären Theorie der Erkenntnis“ einer objektiven Beschreibung der „naturgesetzlichen Evolution des Bewusstseins“ zu, wobei die individuell „angeborenen Anschauungsformen“ des menschlichen „Weltbildapparates“ als aposteriorische „Selektionsprodukte“ des genetischen Lernens beschrieben werden. -/- Weizsäcker empfiehlt ausgehend von der mathematischen Physik der Gegenwart eine Rückbesinnung auf den Kantianismus und den Platonismus und sieht durch das gewandelte Denken der modernen Naturwissenschaft eine idealistische Erkenntnistheorie als bekräftigt an. Riedl sieht ausgehend von der Evolutionsbiologie und durch die Möglichkeit der natürlichen Erklärung menschlichen Denkens eine idealistische Erkenntnistheorie sowie platonistische und kantianische Ansätze als überholt an. -/- Weizsäcker und Riedl versuchen in ihrem Blick auf die logisch-empiristische Erkenntnis- und Wissenschaftstheorie eines Carnap und eines Popper bei der Besprechung von Fragen nach der Möglichkeit menschlicher und wissenschaftlicher Erkenntnis alternative Wege zu gehen, indem Weizsäcker gegenüber den analytisch-empiristischen Zugängen der konventionellen Wissenschaftstheorie einen mehr transzendentalen und holistischen Zugang vorzieht und Riedl im Kontrast zu den „logizistischen“ Zugängen der etablierten Wissenschaftstheorie für einen evolutionären und mehr dynamisch-systemischen Zugang zur philosophischen Diskussion menschlichen und wissenschaftlichen Wissens plädiert. (shrink)

Super-Humeans argue that the most parsimonious ontology of the natural world compatible with our best physical theories consists exclusively of particles and the distance relations between them. This paper argues by contrast that Super-Humean reduction goes insufficiently far, by showing there to be a more parsimonious ontology compatible with physics: Ultimate-Humeanism. This novel view posits an ontology consisting solely of the particles and distance relations required for the existence of a single brain. Super-Humeans impose conditions on what counts as an (...) ontology of the natural world to avoid their view slipping into this kind of ontology, but these conditions are arbitrarily imposed and once this is exposed, Super-Humeans face a dilemma. Either they can embrace Ultimate-Humeanism as the minimal ontology of the natural world compatible with physics, or (more likely) they can rethink the methodology that got them there. Overall, this paper argues that Super-Humeanism currently lacks principled motivation, outlines a framework for naturalistic ontological reductions, and exposes the consequences of unchecked adherence to a simplicity-driven methodology. (shrink)

The ontology behind quantum mechanics has been the subject of endless debate since the theory was formulated some 100 years ago. It has been suggested, at one time or another, that the objects described by the theory may be individual particles, waves, fields, ensembles of particles, observers, and minds, among many other possibilities. I maintain that these disagreements are due in part to a lack of precision in the use of the theory’s various semantic designators. In particular, there is some (...) confusion about the role of representation, reference, and denotation in the theory. In this article, I first analyze the role of the semantic apparatus in physical theories in general and then discuss the corresponding ontological implications for quantum mechanics. Subsequently, I consider the extension of the theory to quantum fields and then analyze the semantic changes of the designators with their ontological consequences. In addition to the classical arguments to rule out a particle ontology in the case of non-relativistic quantum field theory, I show how the existence of black holes makes the proposal of a particle ontology in general spacetimes unfeasible. I conclude by proposing a provisional pluralistic ontology of fields and spacetime and discussing some prospects for possible future ontological economies. (shrink)

In this article, we discuss some of the challenges related to formulating and adopting a realist position regarding non-relativistic quantum mechanics. In a standard approach to ontology, the ontological commitments of scientific theories can be extracted from them. Scientific realism is the standpoint that our best scientific theories are approximately true, and thus, their ontological commitments, roughly speaking, correspond to reality. Quantum mechanics complicates this view by introducing an interpretational requirement that links a particular conception of how reality should be (...) to the theory. This generates comprehensive difficulties: when we separate theory and interpretation, we have a clear conception of theory but not of interpretation and how to extract its ontology. On the other hand, if we somehow identify theory and interpretation, we have a reasonably clear conception of the desired ontology but lose our best characterizations of theory, rendering our methods for extracting ontology ineffective. Our aim is to map out the challenges for future rigorous realist approaches to quantum mechanics. (shrink)

What's wrong with Copenhagen, GRW, Superdeterminism, QBism, Many-worlds, Bohmianism, and Retrocausality, and how theses differ from Presentist Fragmentalism.

It is impossible to have a noun without a verb (an entity without a process) (the arithmetic number ‘one’ without the arithmetic number ‘two’). This is why and how humans are amiss, currently, about ‘quantum’ circuits… (the entity and process humans identify as 'mind').

Einstein thought that quantum mechanics was incomplete because it was nonlocal. In this paper I argue instead that quantum theory is incomplete, even if it is nonlocal, and that relativity is incomplete because its minimal spatiotemporal structure cannot naturally accommodate such nonlocality. So, I show that relativistic pilot-wave theories are the rational completion of quantum mechanics as well as relativity: they provide a spatiotemporal ontology of particles, as well as a spatiotemporal structure able to explain quantum correlations.

For scientific realists, quantum mechanics is unsatisfactory because it suffers from the measurement problem. However, there are at least three promising solutions: the pilot-wave theory, the many-worlds theory, and the theory of spontaneous collapse. In this paper I argue that the measurement problem is a false problem for the realist: it was proposed as the last resort to convince the positivists that the theory is not empirically adequate. Instead realists should focus on preserving the reductive explanatory schema that had worked (...) so well in physics before, which requires a theory to have a three-dimensional ontology. Incompleteness argument to this effect have been proposed in the 1920s, but effectively ignored due to the positivistic climate, other unscientific reasons, and theorems which claimed that this project was impossible. When realists re-examined quantum mechanics in the 1950s and later, they happened to focus on the measurement problem. In this paper I speculate on what would have happened if realists instead focused on finding a three-dimensional ontology to complete quantum theory. I show that most paradoxes, puzzles and mysteries connected with quantum mechanics would have never emerge, and that many of what are now considered possible ontological interpretations of the theory would have hardly been taken as viable options. (shrink)

The first purpose of this series of articles is to introduce case studies on how current AI models can be used in the development of a possible theory of quantum gravity, their limitations, and the role the researcher has in steering the development in the right direction, even highlighting the errors, weaknesses and strengths of the whole process. -/- The second is to introduce the new Presentist Fragmentalist ontology as a framework and use it for developing theories of quantum gravity (...) and speculate on achieving a TOE. We emphasize it is necessary for the researcher to check everything in these articles for themselves. While there are many good ideas in this series of papers, the AI is known to make even arithmetic and algebraic mistakes. -/- To select just five apparently good ideas, there is a causal interaction tensor Cαβγδ(F1, F2) that encodes the causal relationship and the strength of the (possibly non-local) interaction between two fragments of reality (formed by each quantum system). There is a quantitative prediction for a testable table-top experiment. There is an explanation of how spacetime emerges from the fragments and their interactions. There is an explicit account of the double-slit experiment. And there is an explanation how this theory accommodates dark matter and dark energy simultaneously. -/- We explore ideas, equations they lead to, concrete calculations, and give corrections along the way. While these are generally morally right within this framework they must be checked by the researcher. Given this caveat, we believe we have made significant progress with the PF interpretation in developing a theory of quantum gravity and pointing out a possible path to a TOE. (shrink)

The first purpose of this series of articles is to introduce case studies on how current AI models can be used in the development of a possible theory of quantum gravity, their limitations, and the role the researcher has in steering the development in the right direction, even highlighting the errors, weaknesses and strengths of the whole process. The second is to introduce the new Presentist Fragmentalist ontology as a framework and use it for developing theories of quantum gravity and (...) speculate on achieving a TOE. We emphasize it is necessary for the researcher to check everything in these articles for themselves. While there are many good ideas in this series of papers, the AI is known to make even arithmetic and algebraic mistakes. To select just five apparently good ideas, there is a causal interaction tensor Cαβγδ(F1, F2) that encodes the causal relationship and the strength of the (possibly non-local) interaction between two fragments of reality (formed by each quantum system). There is a quantitative prediction for a testable table-top experiment. There is an explanation of how spacetime emerges from the fragments and their interactions. There is an explicit account of the double-slit experiment. And there is an explanation how this theory accommodates dark matter and dark energy simultaneously. We explore ideas, equations they lead to, concrete calculations, and give corrections along the way. While these are generally morally right within this framework they must be checked by the researcher. Given this caveat, we believe we have made significant progress with the PF interpretation in developing a theory of quantum gravity and pointing out a possible path to a TOE. (shrink)

This paper continues and extensive exploration of the QG and TOE resulting from the PF interpretation of QM. Some highlights are an exploration of symmetries of the Standard Model, outlines of testable predictions of implications for QG, that this theory can simultaneously give an account of dark matter and dark energy, probabilities and statevector collapse vs. gravity, applications of the causal interaction tensor Cαβγδ(Fi, Fj). Note the first section mentions qualia but this is not a psychological theory this is an (...) ontic theory. (shrink)

This paper give the first foray into the development of a Theory of Everything that is consistent with the PF interpretation of quantum mechanics.

"This self-consistent evolution of the fragments, their causal relationships, and their quantum properties is at the heart of the FCQG-SM framework, providing a unified description of quantum mechanics, general relativity, and the Standard Model.".

This is an introduction to wave function realism for a compendium on the philosophy of quantum mechanics that will be edited and translated into Portuguese by Raoni Arroyo, entitled Compêndio de Filosofia da Física Quântica. This essay presents the history of wave function realism, its various interpretations, the main arguments that are given for the position, and the main objections that have been raised to it.

In this commentary, I ask six questions concerning the implications of Philipp Berghofer’s experience-first approach for the epistemology of science, in general, and that of quantum mechanics, in particular. His responses will deepen my comprehension of his ideas. I also anticipate that these questions will aid him in further refining and strengthening his arguments.

This paper investigates the formation and propagation of wavefunction `branches' through the process of entanglement with the environment. While this process is a consequence of unitary dynamics, and hence significant to many if not all approaches to quantum theory, it plays a central role in many recent articulations of the Everett or `many worlds' interpretation. A highly idealized model of a locally interacting system and environment is described, and investigated in several situations in which branching occurs, including those involving Bell (...) inequality violating correlations; we illustrate how any non-locality is compatible with the locality of the dynamics. Although branching is particularly important for many worlds quantum theory, we take a neutral stance here, simply tracing out the consequences of a unitary dynamics. The overall goals are to provide a simple concrete realization of the quantum physics of branch formation, and especially to emphasise the compatibility of branching with relativity; the paper is intended to illuminate matters both for foundational work, and for the application of quantum theory to non-isolated systems. (shrink)

In this contribution I will retrace the main stages of my research on the objectification problem in quantum mechanics by highlighting some personal memories of my supervisor, the theoretical physicist Giovanni Morchio. The central aim of my MSc thesis was to ask whether the hypothesis of objectification, which is currently added to the formalism, is not, at least in one case, deducible from it and in particular from the dynamics of the temporal evolution. The case study we were looking for (...) had to: 1) represent a situation similar to that in which a macroscopic system such as a measurement apparatus, following interaction with a system, assumes a well-defined state (which or for example represents the fact that the result of a measurement is a particular value), i.e becomes objective 2) represent a fact in nature in which it is not clear whether its explanation can be derived from the formalism of quantum mechanics or whether a hypothesis of objectification is necessary for its explanation. Proving that such a fact can be deduced from the time evolution of quantum mechanics allowed us to conclude that there are cases in which the hypothesis of objectification is superfluous or, in other words, obtainable from the formalism. (shrink)

Three accounts of effective realism (ER) have been advanced to solve three problems for scientific realism: Fraser and Vickers (forthcoming) develop a version of ER about non-relativistic quantum mechanics that they argue is compatible with all the main realist versions (‘interpretations’) of quantum mechanics avoiding the problem of underdetermination among them; Williams (2019) and Fraser (2020b) propose ER about quantum field theory as a response to the problems facing realist interpretations; Robertson and Wilson (forthcoming) propose ER to deal with the (...) dubious ontological status of the entities belonging to superseded theories. This paper argues for the unification of these proposals based on realism about modal structure and the idea of scale relativity of ontology developed by ontic structural realists. This solves problems some or all the accounts of ER face, especially that of making explicit in what way they are realist. Furthermore, we respond to a recent critique that has been raised against the ontic structural realist account of quantum mechanics that we employ. (shrink)

This volume brings together philosophers and physicists to explore the parallels between Quantum Bayesianism, or QBism, and the phenomenological tradition. It is the first book exclusively devoted to phenomenology and quantum mechanics. By emphasizing the role of the subject's experiences and expectations, and by explicitly rejecting the idea that the notion of physical reality could ever be reduced to a purely third-personal perspective, QBism exhibits several interesting parallels with phenomenology. The central message of QBism is that quantum probabilities must be (...) interpreted as the experiencing agent's personal Bayesian degrees of belief--degrees of belief for the consequences of their actions on a quantum system. The chapters in this volume elaborate whether and specify how phenomenology could serve as the philosophical foundation of QBism. This objective is pursued from the perspective of QBists engaging with phenomenology as well as the perspective of phenomenologists engaging with QBism. These approaches enable us to realize a better understanding of quantum mechanics and the world we live in, achieve a better understanding of QBsim, and introduce the phenomenological foundations of quantum mechanics. Phenomenology and QBism is an essential resource for researchers and graduate students working in philosophy of physics, philosophy of science, quantum mechanics, and phenomenology. (shrink)

Wave function realism is an interpretative framework for quantum theories which recommends taking the central ontology of these theories to consist of the quantum wave function, understood as a field on a high-dimensional space. This paper presents and evaluates three standard arguments for wave function realism, and clarifies the sort of ontological framework these arguments support.

The interpretation of quantum mechanics has been controversial since the introduction of quantum theory in the 1920s. Although the Copenhagen interpretation is commonly accepted, its usual formulation suffers from some serious drawbacks. Based mainly on Bohr's concepts, the formulation assumes an independent and essential validity of classical concepts running in parallel with quantum ones, and leaves open the possibility of their ultimate conflict. In this book, Roland Omnès examines a number of recent advances, which, combined, lead to a consistent revision (...) of the Copenhagen interpretation. His aim is to show how this interpretation can fit all present experiments, to weed out unnecessary or questionable assumptions, and to assess the domain of validity where the older statements apply. Drawing on the new contributions, The Interpretation of Quantum Mechanics offers a complete and self-contained treatment of interpretation (in nonrelativistic physics) in a manner accessible to both physicists and students. Although some "hard" results are included, the concepts and mathematical developments are maintained at an undergraduate level. This book enables readers to check every step, apply the techniques to new problems, and make sure that no paradox or obscurity can arise in the theory. In the conclusion, the author discusses various philosophical implications pertinent to the study of quantum mechanics. (shrink)

This is a textbook on quantum mechanics. It is addressed to graduates and advanced undergraduates. The book presents quantum theory as a logically coherent system, placing stronger emphasis on the theory' s probabilistic structure and on the role of symmetries. It makes students aware of foundational problems from the very beginning, but at the same time, it urges them to adopt a pragmatic attitude towards the quantum formalism. The book consists of five parts. Part I is a review of classical (...) physics, including probability theory, and a historical introduction to quantum theory. Part II presents quantum theory in terms of six fundamental principles. The principles are presented together with the necessary mathematical background and with applications to simple systems. Part III analyses the properties of quantum particles. It starts with the description of symmetries, continues to non-relativistic particles, the introduction of spin, and particle statistics. It concludes with a symmetries-based introduction to relativistic quantum systems and with the first steps towards relativistic quantum field theory. Part IV presents techniques adapted to specific problems: the structure and spectra of composite systems, decays and transitions, particle scattering, and open quantum systems. Finally, Part V revisits quantum foundations: quantum measurement theory, the major interpretations of quantum theory, and the frontiers of quantum theory in contemporary research. (shrink)

This paper presents and critically discusses the “logos approach to quantum mechanics” from the point of view of the current debates concerning the relation between metaphysics and science. Due to its alleged direct connection with quantum formalism, the logos approach presents itself as a better alternative for understanding quantum mechanics than other available views. However, we present metaphysical and methodological difficulties that seem to clearly point to a different conclusion: the logos approach is on an epistemic equal footing among alternative (...) realist approaches to quantum mechanics. (shrink)

It is well-known that developments of quantum mechanical states according to the Schrödinger equation during a measurement seem to prevent measurements from having definite results. For, the usually assumed (idealized) Schrödinger development of the measured object and the measuring apparatus during a measurement typically results in a state of the entire system which is a superposition of the eigenstates of the measured observable and measuring observable. And the most common interpretations of quantum mechanics state that an observable does not have (...) a definite value if the quantum mechanical state is a superposition of the eigenstates of the observable. Many ways out of this problem have been suggested. I want to discuss an interpretation suggested by S. Kochen (Kochen 1985), and suggest similar interpretations, each of which accept the universal validity of the Schrödinger equation, and yet yield definite results for measurements. (shrink)

Bohm’s interpretation of quantum mechanics has generally been received as an attempt to restore the determinism of classical physics. However, although this interpretation, as Bohm initially proposed it in 1952, does indeed have the feature of being deterministic, for Bohm this was never the main point. In fact, in other publications and in correspondence from this period, he argued that the assumption that nature is deterministic is unjustified and should be abandoned. Whereas it has been argued before that Bohm’s commitment (...) to determinism was connected to his interest in Marxism, I argue for the opposite: Bohm found resources in Marxist philosophy for developing a nondeterministic notion of causality, which is based on the idea of infinite complexity and an infinite number of levels of nature. From ca. 1954 onwards, Bohm’s conception of causality further weakened, as he developed the idea of a dialectical relation between causality and chance. (shrink)

In the controversy on the philosophical foundations of quantum mechanics Whitehead's philosophy of organism has an essential place. But its realistic position invalidates any attempt to relate it to the School of Copenhagen's “orthodox interpretation”. Unlike, the Eurhythmic Physics developed by the Lisbon School has notable theoretical tunings with Whitehead's philosophy. In both, the notion of passive matter disappears; entities are understood as ecstatic process of becoming arising from a continuum of potentialities; and they achieve physical persistence grace to a (...) set of synergistic interactions among their own regimes of rhythmical activity. The principle of Eurhythmy proposed by Prof. Croca then appears as the hypothesis, in contemporary theoretical physics, corresponding to the organicist vision of a universe in a developmental process of realization of the abstract potentiality of all possible worlds: a universe that, as a living organism, should be described as guided by an immanent teleological principle. (shrink)

The mathematical formalism of quantum theory has been established for nearly a century, yet its physical foundations remain elusive. In recent decades, connections between quantum theory and information theory have garnered increasing attention. This study presents a physical derivation of the mathematical formalism quantum theory based on information-theoretic considerations in physical systems. We postulate that quantum systems are characterized by single independent adjustable variables. Utilizing this physical postulate along with the conservation of total probability, we derive the standard Hilbert space (...) formalism of quantum theory, including the Born probability rule. This comprehensive derivation of quantum theory offers a clear and concise physical foundation for the mathematical formalism of quantum mechanics. (shrink)

It is generally believed that two rival non-relativistic quantum theories, the realist interpretation of quantum mechanics and Bohmian mechanics, are empirically equivalent. In this paper, I use these two quantum theories to show that it is possible to offer a solution to underdetermination in some local cases, by specifying what counts as relevant empirical evidence in empirical equivalence and underdetermination. I argue for a _domain-sensitive_ approach to underdetermination. Domain sensitivity on theories’ predictions plays a role in determining whether two or (...) more theories are empirically equivalent and underdetermined. To support my argument for the denial of the empirical equivalence between Bohmian mechanics and the realist interpretation of quantum mechanics, I argue that they are not empirically equivalent when we consider their predictions for domains outside their application, using the relativistic domain as an example. (shrink)

في الرابع من أكتوبر (2022)، أعلنت الأكاديمية الملكية السويدية للعلوم في ستوكهولم منح جائزة نوبل في الفيزياء لثلاثة فيزيائيين من جنسيات مختلفة؛ هم: الفرنسي «آلان أسبيه»، والأمريكي «جون فرانسيس كلاوزر»، والنمسوي «أنطون تسايلينغر»، تقديرًا لتجاربهم الرائدة في ميدان ميكانيكا الكم، وبصفة خاصة على صعيد ما يُعرف بالفوتونات المتشابكة، ما يُمهد الطريق لتقنيات جديدة في الحوسبة الكمومية والاتصالات فائقة الأمان. لفهم ما يعنيه هذا، ولماذا اكتسب عملهم هذه الأهمية، نحتاج إلى فهم كيف حسمت هذه التجارب نقاشًا طويل الأمد بين علماء الفيزياء. (...) وكان اللاعب الرئيس في هذا النقاش عالم فيزياء من آيرلندا الشمالية يُدعى «جون ستيورات بل»، نجح في الستينات من القرن العشرين في تبيان كيفية ترجمة سؤال فلسفي ميتافيزيقي حول طبيعة الواقع إلى سؤال فيزيائي يمكن أن يجيب عنه العلم تجريبيًا، وكسر التمييز بين ما نعرفه عن العالم وما يمكن أن يكون عليه العالم حقًا. (shrink)

The paper discusses this year’s Nobel Prize in physics for experiments of entanglement “establishing the violation of Bell inequalities and pioneering quantum information science” in a much wider, including philosophical context legitimizing by the authority of the Nobel Prize a new scientific area out of “classical” quantum mechanics relevant to Pauli’s “particle” paradigm of energy conservation and thus to the Standard model obeying it. One justifies the eventual future theory of quantum gravitation as belonging to the newly established quantum information (...) science. Entanglement, involving non-Hermitian operators for its rigorous description, non-unitarity as well as nonlocal and superluminal physical signals “spookily” (by Einstein’s flowery epithet) synchronizing and transferring some nonzero action at a distance, can be considered to be quantum gravity so that its local counterpart to be Einstein’s gravitation according to general relativity therefore pioneering an alternative pathway to quantum gravitation different from the “secondary quantization” of the Standard model. So, the experiments of entanglement once they have been awarded by the Nobel Prize launch particularly the relevant theory of quantum gravitation grounded on “quantum information science” thus granted to be nonclassical quantum mechanics in the shared framework of the generalized quantum mechanics obeying rather quantum-information conservation than only energy conservation. The concept of “dark phase” of the universe naturally linked to the very well confirmed “dark matter” and “dark energy” and opposed to its “light phase” inherent to classical quantum mechanics and the Standard model obeys quantum-information conservation, after which reversible causality or the mutual transformation of energy and information are valid. The mythical Big Bang after which energy conservation holds universally is to be replaced by an omnipresent and omnitemporal medium of decoherence of the dark and nonlocal phase into the light and local phase. The former is only an integral image of the latter and borrowed in fact rather from religion than from science. Physical, methodological and proper philosophical conclusions follow from that paradigm shift heralded by this year’s Nobel Prize in physics. For example, the scientific theory of thinking should originate from the dark phase of the universe, as well: probably only approximately modeled by neural networks physically belonging to the light phase thoroughly. A few crucial philosophical sequences follow from the break of Pauli’s paradigm: (1) the establishment of the “dark” phase of the universe as opposed to its “light” phase, only to which the Cartesian dichotomy of “body” and “mind” is valid; (2) quantum information conservation as relevant to the dark phase, furthermore generalizing energy conservation as to its light phase, productively allowing for physical entities to appear “ex nihilo”, i.e., from the dark phase, in which energy and time are yet inseparable from each other; (3) reversible causality as inherent to the dark phase; (4) the interpretation of gravitation only mathematically: as an interpretation of the incompleteness of finiteness to infinity, for example, following the Gödel dichotomy (“either contradiction or incompleteness”) about the relation of arithmetic to set theory; (5) the restriction of the concept of hierarchy only to the light phase; (6) the commensurability of both physical extremes of a quantum and the universe as a whole in the dark phase obeying quantum information conservation and akin to Nicholas of Cusa’s philosophical and theological worldview. (shrink)

The quantum symmetrization procedure that is used to handle systems of identical quantum particles brings into question whether the elementary constituents of matter, such as electrons, have the fundamental characteristics of persistence and reidentifiability that are attributed to classical particles. However, we presently lack a coherent conception of matter composed of entities that do not possess one or both of these fundamental characteristics. We also lack a clear a priori understanding of why systems of identical particles (as opposed to non-identical (...) particles) require special mathematical treatment, and this only in the quantum mechanical (as opposed to classical mechanical) setting. -/- Here, on the basis of a conceptual analysis of a recent mathematical reconstruction of the quantum symmetrization procedure, we argue that the need for the symmetrization procedure originates in the confluence of identicality and the active nature of the quantum measurement process. We propose a conception in which detection-events are ontologically primary, while the notion of individually persistent object is relegated to merely one way of bringing order to these events. On this basis, we outline a new interpretation of the symmetrization procedure which gives a new physical interpretation to the indices in symmetrized states and to non-symmetric measurement operators. (shrink)

This paper concerns metaphysical indeterminacy and, in particular, the issue of whether quantum mechanics gives motivation for thinking the world contains it. In a previous paper (Darby G, Pickup M. Synthese 198:1685–1710, 2021), we have offered one way to think about metaphysical indeterminacy which we take to avoid some issues arising from certain features of quantum mechanics (such as the Kochen-Specker theorem). This approach has recently been criticised by Corti (Synthese, forthcoming), and we take this opportunity to respond. Our paper (...) will therefore reply to Corti’s argument, but we also take it as a case study in ‘naturalistic metaphysics’ and hence to contribute to a more general discussion of the relationship between philosophy of science and analytic metaphysics. (shrink)

Max Jammer claimed that, "There can be no doubt that the Danish precursor of modern existentialism and neo-orthodox theology, Soren Kierkegaard, through his influence on Bohr, affected also the course of modern physics to some extent." Despite Jammer's failure to supply sufficient evidence for this claim, I argue that it is not completely off base. In particular, I argue that Kierkegaard and Bohr belong to a common philosophical tradition, and I begin to investigate some of the themes that characterize this (...) tradition. (shrink)

How should we account for the extraordinary regularity in the world? Humeans and Non-Humeans sharply disagree. According to Non-Humeans, the world behaves in an extraordinarily regular way because of certain necessary connections in nature. However, Humeans have thought that Non-Humean views are metaphysically objectionable. In particular, there are two general metaphysical principles that Humeans have found attractive that are incompatible with all existing versions of Non-Humeanism. My goal in this paper is to develop a novel version of Non-Humeanism that is (...) consistent with (and even entails) both of these general metaphysical principles. By endorsing such a view, one can have the explanatory benefits of Non-Humeanism while at the same time avoiding two of the major metaphysical objections towards Non-Humeanism. (shrink)

Within the interdisciplinary field of new materialism Karen Barad’s theory of agential realism deconstructs our current euro-western metaphysical perception of the world and our existence within it, to then re-build an understanding based on relatively new findings within quantum physics. In this thesis I try to recreate Barad’s theory to see what ethical consequences might come from it. Together with practical examples within the discourse of today’s social world and our global connectedness I hope to create a better understanding of (...) the impact of our actions and being on our culture and what we call the natural world. Removing the unique agency given to human culture and language to instead, with the help of post-humanistic ideas, add agency as a universal enactment rather than an attribute, we should start to see ourselves as active and real parts of the world-building that is our home. One main question that I see arise in the end is: what does responsibility entail when we all are one and the same? (shrink)

Throughout these last few decades, phenomenology and modern physics have slowly started to approach each other in order to bridge the gap between subjective and objective. In this thesis I aim to show an approach done with the help of Karen Barad's agential realism; a quantum interpretation enabling us to better understand and analyse our complex world, as well as our perception of it. Taking inspiration from new materialism, phenomenology, and physics, I see a need to properly leave discrete dualism (...) behind, in order to be able to describe cultural and material structures as continuous manifolds. Instead of endlessly searching for their binary and changeless parts. (shrink)