This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book considers the challenge to traditional Aristotelian metaphysics posed by the 'block universe' of special relativity, as modeled by Minkowski spacetime. It focuses on quantum physics and the modern (Oxford) version of the Everett or many-worlds interpretation of quantum mechanics. The book offers a formal development of the Traveling Forms interpretation (TF) and defends it from various objections. It utilizes quantum physics to launch an attack on neo-Humean metaphysics, a contemporary Humean account of the nature of causal powers. The book also considers the threat to localized causal powers posed by quantum holism. It proposes a special kind of power possessed by certain composite entities—namely, a dynamic structural power, by which the entity sustains itself in existence over time. The book seeks to rehabilitate the idea of animals as agents.
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book considers the challenge to traditional Aristotelian metaphysics posed by the 'block universe' of special relativity, as modeled by Minkowski spacetime. It focuses on quantum physics and the modern (Oxford) version of the Everett or many-worlds interpretation of quantum mechanics. The book offers a formal development of the Traveling Forms interpretation (TF) and defends it from various objections. It utilizes quantum physics to launch an attack on neo-Humean metaphysics, a contemporary Humean account of the nature of causal powers. The book also considers the threat to localized causal powers posed by quantum holism. It proposes a special kind of power possessed by certain composite entities—namely, a dynamic structural power, by which the entity sustains itself in existence over time. The book seeks to rehabilitate the idea of animals as agents.
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book reviews classical physical and quantum theories for nonspecialists, building on the basics to introduce recent advances. A definition of physical is included for specialists also to consider. The book analyzes quantum theory interpretations, revealing a developmental progression from the standard, many-worlds, decoherence/consistent histories, quantum probability, quantum information field, and transactional interpretations to neorealism. It outlines a new holistic interpretation of quantum theory; of major significance is the subtle concept of levels of spacetime. The book considers loop quantum gravity, string, inflationary big bang, and unified field theories. The diverse interpretations are in large part due to focusing on the observed as the only reality: the process of observing and the observer were practically ignored.
I am very grateful to the Master and Fellows of Trinity College for inviting me to give the Tarner Lectures. What I want to do in this book, stated boldly and baldly, is to consider the relevance of developments in modern theoretical physics to metaphysical questions about the ultimate nature of reality. By metaphysical questions I mean the very general sorts of questions that arise out of a critical examination of the principles, concepts and fundamental presuppositions that lie behind modern physics. How should we interpret the claims that physicists seem to be making about the world? Are they intended to be understood as literally true, for example, and exactly what are those claims, given that the pages of theoretical physics monographs are largely filled with abstract mathematical formalism? In the first chapter, I shall be looking at a range of philosophical points of view in the framework of which such questions can be addressed, and attempt the difficult task of adjudicating between the different approaches. At the end of the day I shall be arguing for a pretty straightforward metaphysical realism, that the external world exists independently of our knowledge of it. In the second chapter I shall look at arguments from various branches of modern physics that are sometimes claimed to bring in an essential role for subjectivity in physics, bringing the observer into a central role, creating his own reality.
The aim of this volume is to develop and evaluate the suggestion that if one adopts the interpretation of quantum mechanics initially proposed by Hugh Everett, today frequently referred to as the “many-worlds interpretation,” then one can avoid the kind of nonlocality that is often thought to be a consequence of quantum entanglement according to other approaches, and thus permit the compatibility of these two pillars of modern physics: quantum mechanics and special relativity. Although this is an idea that seems to have been recognized by Everett and is sometimes touted as a reason to prefer his approach to interpreting quantum mechanics over others, the precise way in which Everett’s interpretation achieves this locality, indeed whether it even does achieve locality, has been debated, including among the interpretation’s proponents. The aim of this introductory chapter is to provide readers with a background of this debate concerning the locality of Everettian quantum mechanics. We begin with a brief historical introduction to Everett’s proposed interpretation of quantum mechanics and its later development into the many-worlds interpretation. The following section discusses how the by now well-established phenomenon of quantum entanglement seems to imply what Albert Einstein, in a 1947 letter to Max Born, called “spooky action at a distance,” and a tension with special relativity. We then discuss why one might think that the many-worlds interpretation allows one to avoid nonlocality in this sense. The next sections bring the reader up to date with how the locality of Everettian quantum mechanics has been debated both by critics and proponents of the interpretation. As we will see, the desire to understand Everettian quantum mechanics as an interpretation that avoids nonlocality has opened up some interesting debates concerning both what it means to say an interpretation of quantum mechanics is local and over the metaphysical and mathematical interpretation of Everettian quantum mechanics itself. This introductory chapter concludes with a summary of the contributions to the present volume in the context of this ongoing debate.
Abstract Metaphysicians should pay attention to quantum mechanics, but not because it provides definitive answers to many metaphysical questions. The theory itself is remarkably silent on the nature of the physical world, and the various interpretations of the theory on offer present conflicting ontological pictures. Rather, quantum mechanics is essential to the metaphysician because it reshapes standard metaphysical debates and opens up unforeseen new metaphysical possibilities. Even if quantum mechanics provides few clear answers, there are good reasons to think that any adequate understanding of the quantum world will result in a radical reshaping of our classical worldview in some way or other. Whatever the world is like at the atomic scale, it is almost certainly not the swarm of particles pushed around by forces that is often presupposed. This book guides readers through the theory of quantum mechanics and its implications for metaphysics in a clear and accessible way. The theory and its various interpretations are presented with a minimum of technicality. The consequences of these interpretations for metaphysical debates concerning realism, indeterminacy, causation, determinism, holism, and individuality (among other topics) are explored in detail, stressing the novel form that the debates take given the empirical facts in the quantum domain. While quantum mechanics may not deliver unconditional pronouncements on these issues, the range of possibilities consistent with our knowledge of the empirical world is relatively small—and each possibility is metaphysically revisionary in some way.
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book explores the minimalist ontology of matter points and their dynamics in general philosophical as well as mathematical terms, independently of any particular physical theory. It shows how this ontology fits both classical mechanics of gravitation and quantum mechanics, as long as the latter includes a primitive ontology of matter distributed in ordinary space, as in Bohmian mechanics. The book points out the similarities between these two theories as well as their differences. It explains how in both cases one gets from an ontology and a dynamics defined for the universe as a whole to a description of subsystems of the universe and a dynamics for them. The book shows how an ontology of persisting particles that move according to a deterministic law can explain the characteristic phenomena of quantum field theory and ground its empirical predictions.
This chapter sets the informal stage for the subject matter of the book. Section 1.1 presents in concise form what is typically taught as the basics in quantum physics courses around the world. Section 1.2 gives a short overview of the most important interpretations of these basic rules that were spawned by a century-long lack of clarity of the meaning of quantum mechanics. Section 1.3 gives an account of the deplorable tradition of quantum magic that resulted from this lack of clarity. Section 1.4, the final section, gives a preview of the coherent quantum physics proposed in this book as a solution to the problems of interpreting quantum physics.