Recent work in quantum information science has produced a revolution in our understanding of quantum entanglement. Scientists now view entanglement as a physical resource with many important applications. These range from quantum computers, which would be able to compute exponentially faster than classical computers, to quantum cryptographic techniques, which could provide unbreakable codes for the transfer of secret information over public channels. These important advances in the study of quantum entanglement and information touch on deep (...) foundational issues in both physics and philosophy. This interdisciplinary volume brings together fourteen of the world's leading physicists and philosophers of physics to address the most important developments and debates in this exciting area of research. It offers a broad spectrum of approaches to resolving deep foundational challenges - philosophical, mathematical, and physical - raised by quantum information, quantum processing, and entanglement. This book is ideal for historians, philosophers of science and physicists"--Provided by publisher. (shrink)

From the philosopher’s perspective, the interest in quantum computation stems primarily from the way that it combines fundamental concepts from two distinct sciences: Physics, in particular Quantum Mechanics, and Computer Science, each long a subject of philosophical speculation and analysis in its own right. Quantum computing combines both of these more traditional areas of inquiry into one wholly new, if not quite independent, science. Over the course of this chapter we will be discussing some of the most (...) important philosophical questions that arise from this merger and philosophical lessons to be learned. (shrink)

The present monograph is devoted to the principal problems of quantum mechanics and is based on the conception first stated in my course on 'Fundamentals of Quantum Mechanics'. The scope and purpose of the above course did not allow some principal questions to be brought out as fully as they deserved, and besides, some important points were only very recently developed to a sufficient extent. This refers especially to the analysis of the action of the measuring instrument, whose (...) dual role as an analyser of a quantum ensemble and as a detector of individual events was insufficiently elucidated. The reader will find that the present monograph is concerned more with theoretical physics than with philosophy. However, I have never separated Weltanschauung from science (and particularly theoretical physics) so that the philosophical implications are also discussed, justi fying publication in the philosophical series. In conclusion, I should like to thank the publisher and the translator, whose initiative and effort have made it possible for the book to reach the English-speaking reader. (shrink)

This is one of the most important books on quantum mechanics to have appeared in recent years. It offers a dramatically new interpretation that resolves puzzles and paradoxes associated with the measurement problem and the behavior of coupled systems. A crucial feature of this interpretation is that a quantum mechanical measurement can be certain to have a particular outcome even when the observed system fails to have the property corresponding to that outcome just prior to the measurement interaction.

If we divide our physical theories into theories of matter and theories of spacetime, quantum field theory is our most fundamental empirically successful theory of matter. As such, it has attracted increasing attention from philosophers over the past two decades, beginning to eclipse its predecessor theory of quantum mechanics in the philosophical literature. Here I survey some central philosophical puzzles about the theory's foundations.

This book provides a thorough and up-to-date introduction to the philosophy of quantum physics. Although quantum theory is renowned for its spectacular empirical successes, controversial discussion about how it should be understood continue to rage today. In this volume, the authors provide an overview of its numerous philosophical challenges: Do quantum objects violate the principle of causality? Are particles of the same type indistinguishable and therefore not individual entities? Do quantum objects retain their identity over (...) time? How does a compound quantum system relate to its parts? These questions are answered here within different interpretational approaches to quantum theory. Finally, moving to Quantum Field Theory, we find that the problem of non-locality is exacerbated. Philosophy of quantum physics is aimed at philosophers with an interest in physics, while also serving to familiarize physicists with many of the essential philosophical questions of their subject. (shrink)

An astonishing thesis in the philosophy of quantum gravity is that spacetime ”disappears” at the fundamental level of reality, and that the geometrical notions of ”length” and ”duration” are derived from the dynamics of the basic non–geometrical building blocks of the theory. Unveiling here the analysis of the concepts of spacetime, measure, and magnitude, given by the philosopher Nicolai Hartmann, I argue that the ”disappearance” thesis is too strong. The fundamental geometrical notions are, on the contrary, primitive and (...) cannot be derived from the fundamental building blocks; they must be presupposed ab initio not only for epistemological, but also for methodological reasons. (shrink)

A sophisticated and original introduction to the philosophy of quantum mechanics from one of the world’s leading philosophers of physics In this book, Tim Maudlin, one of the world’s leading philosophers of physics, offers a sophisticated, original introduction to the philosophy of quantum mechanics. The briefest, clearest, and most refined account of his influential approach to the subject, the book will be invaluable to all students of philosophy and physics. Quantum mechanics holds a unique (...) place in the history of physics. It has produced the most accurate predictions of any scientific theory, but, more astonishing, there has never been any agreement about what the theory implies about physical reality. Maudlin argues that the very term “quantum theory” is a misnomer. A proper physical theory should clearly describe what is there and what it does—yet standard textbooks present quantum mechanics as a predictive recipe in search of a physical theory. In contrast, Maudlin explores three proper theories that recover the quantum predictions: the indeterministic wavefunction collapse theory of Ghirardi, Rimini, and Weber; the deterministic particle theory of deBroglie and Bohm; and the conceptually challenging Many Worlds theory of Everett. Each offers a radically different proposal for the nature of physical reality, but Maudlin shows that none of them are what they are generally taken to be. (shrink)

The University of Western Ontario hosted a lively and stimulating workshop in the spring of 2009 that brought together many of the philosophers actively working on QFT. This issue collects some of the papers presented at the workshop, along with one (Earman's) that was intended for the workshop but not presented there. These papers approach the foundational problems of QFT from a variety of different technical and philosophical perspectives.

Patrick Aidan Heelan’s The Observable offers the reader a completely articulated development of his 1965 philosophy of quantum physics, Quantum Mechanics and Objectivity. In this previously unpublished study dating back more than a half a century, Heelan brings his background as both a physicist and a philosopher to his reflections on Werner Heisenberg’s physical philosophy. Including considerably broader connections to the contributions of Niels Bohr, Wolfgang Pauli, and Albert Einstein, this study also reflects Heelan’s experience in (...) Eugene Wigner’s laboratory at Princeton along with his reflections on working with Erwin Schrödinger dating from Heelan’s years at the Institute for Advanced Cosmology in Dublin. A contribution to continental philosophy of science, the phenomenological and hermeneutic resources applied in this book to the physical and ontological paradoxes of quantum physics, especially in connection with laboratory science and measurement, theory and model making, will enrich students of the history of science as well as those interested in different approaches to the historiography of science. University courses in the philosophy of physics will find this book indispensable as a resource and invaluable for courses in the history of science. (shrink)

The use of probability theory is widespread in our daily life as well as in scientific theories. In virtually all cases, calculations can be carried out within the framework of classical probability theory. A special exception is given by quantum mechanics, which gives rise to a new probability theory: quantum probability theory. This dissertation deals with the question of how this formalism can be understood from a philosophical and physical perspective. The dissertation is divided into three parts. In (...) the first part, the formalism of quantum probability theory and its relation to quantum mechanics is presented. The second part considers the possibility of reformulating quantum probability theory to embed it within classical probability. Mathematically, this possibility overlaps with the possibility of the existence of hidden variables theories of quantum mechanics: theories that attempt to solve fundamental problems in quantum mechanics by introducing additional physical properties of systems. The conclusion of this part is that, although classical reformulations of quantum probability theory are formally possible, they offer little insight into the formalism of quantum probability theory itself. The third part regards a more direct investigation of quantum probability theory. A reformulation of quantum probability theory is obtained by constructing a quantum logic on the basis of empirical non-probabilistic predictions of quantum mechanics. In this reformulation quantum probability functions are conditional probability functions on an algebra of propositions about measurements and measurement outcomes. (shrink)

This book is the final outcome of two projects. My first project was to publish a set of texts written by Schrodinger at the beginning of the 1950's for his seminars and lectures at the Dublin Institute for Advanced Studies. These almost completely forgotten texts contained important insights into the interpretation of quantum mechanics, and they provided several ideas which were missing or elusively expressed in SchrOdinger's published papers and books of the same period. However, they were likely to (...) be misinterpreted out of their context. The problem was that current scholarship could not help very much the reader of these writings to figure out their significance. The few available studies about SchrOdinger's interpretation of quantum mechanics are generally excellent, but almost entirely restricted to the initial period 1925-1927. Very little work has been done on Schrodinger's late views on the theory he contributed to create and develop. The generally accepted view is that he never really recovered from his interpretative failure of 1926-1927, and that his late reflections are little more than an expression of his rising nostalgia for the lost ideal of picturing the world, not to say for some favourite traditional picture. But the content and style of Schrodinger's texts of the 1950's do not agree at all with this melancholic appraisal; they rather set the stage for a thorough renewal of accepted representations. In order to elucidate this paradox, I adopted several strategies. (shrink)

In the area of the foundations of quantum mechanics a true industry appears to have developed in the last decades, with the aim of proving as many results as possible concerning what there cannot be in the quantum realm. In principle, the significance of proving ‘no-go’ results should consist in clarifying the fundamental structure of the theory, by pointing out a class of basic constraints that the theory itself is supposed to satisfy. In the present paper I will (...) discuss some more recent no-go claims and I will argue against the deep significance of these results, with a two-fold strategy. First, I will consider three results concerning respectively local realism, quantum covariance and predictive power in quantum mechanics, and I will try to show how controversial the main conditions of the negative theorem turn out to be—something that strongly undermines the general relevance of these theorems. Second, I will try to discuss what I take to be a common feature of these theoretical enterprises, namely that of aiming at establishing negative results for quantum mechanics in absence of a deeper understanding of the overall ontological content and structure of the theory. I will argue that the only way toward such an understanding may be to cast in advance the problems in a clear and well-defined interpretational framework—which in my view means primarily to specify the ontology that quantum theory is supposed to be about—and after to wonder whether problems that seemed worth pursuing still are so in the framework. (shrink)

This book discusses the philosophical work of Décio Krause. Non-individuality, as a new metaphysical category, was thought to be strongly supported by quantum mechanics. No one did more to promote this idea than the Brazilian philosopher Décio Krause, whose works on the metaphysics and logic of non-individuality are now widely regarded as part of the consolidated literature on the subject. This volume brings together chapters elaborating on the ideas put forward and defended by Krause, developing them in many different (...) directions, commenting on aspects not completely developed so far, and, more importantly, critically addressing their current formulations and defenses by Krause himself. Given that Krause’s ideas do connect directly and indirectly with a wide array of subjects, such as the philosophy of quantum mechanics, more broadly understood, the philosophy of logic and logical philosophy, non-classical logics, metaphysics, and ontology, this volume contains important material for the research on logic and foundations of science, broadly understood. All the invited contributors have already worked with the ideas developed by Décio (some of them still work with them), being also distinct authors and extremely relevant in their areas of expertise. The volume is aimed at philosophers, including those of physics and quantum mechanics. (shrink)

Aiming to unravel the mystery of quantum mechanics, this book is concerned with questions about action-at-a-distance, holism, and whether quantum mechanics gives a complete account of microphysical reality. With rigorous arguments and clear thinking, the author provides an introduction to the philosophy of physics.

Steen Brock paints a cross-disciplinary picture of the philosophical and scientific background for the rise of the quantum theory. He accounts for the unity of Kantian metaphysics of Nature, the Helmholtzian principles, and the Hamiltonian methods of modern pre-quantum physics. Brock shows how Planck's vision of a generalization of classical physics implies that the original quantum mechanics of Heisenberg can be regarded as a successful attempt to maintain this modern unity of physics.However, for Niels Bohr, the unity (...) of science and metaphysics did not end in the world of physics. The development of quantum physics had general implications both for other sciences and for various philosophical issues. Brock discusses these matters with respect to recent topics within the philosophy of science and major interpretations of Bohr's ideas. The author invites the reader to follow a long andwinding route of thought which, in the end, culminates in Bohr's ideas of complementarity, culture and Spirit. (shrink)

Quantum mechanics involves a generalized form of information, that of quantum information. It is the transfinite generalization of information and re-presentable by transfinite ordinals. The physical world being in the current of time shares the quality of “choice”. Thus quantum information can be seen as the universal substance of the world serving to describe uniformly future, past, and thus the present as the frontier of time. Future is represented as a coherent whole, present as a choice among (...) infinitely many alternatives, and past as a well-ordering obtained as a result of a series of choices. The concept of quantum information describes the frontier of time, that “now”, which transforms future into past. Quantum information generalizes information from finite to infinite series or collections. The concept of quantum information allows of any physical entity to be interpreted as some nonzero quantity of quantum information. The fundament of quantum information is the concept of ‘quantum bit’, “qubit”. A qubit is a choice among an infinite set of alternatives. It generalizes the unit of classical information, a bit, which refer to a finite set of alternatives. The qubit is also isomorphic to a ball in Euclidean space, in which two points are chosen. (shrink)

This book concentrates on research done during the last twenty years on the philosophy of quantum mechanics. In particular, the author focuses on three major issues: whether quantum mechanics is an incomplete theory, whether it is non-local, and whether it can be interpreted realistically. Much of the book is concerned with distinguishing various senses in which these questions can be taken, and assessing the bewildering variety of answers philosophers and physicists have given up to now. The book (...) is self-contained in that it presents the necessary parts of the mathematical formalism of quantum mechanics and also covers other interpretative topics, such as the problem of measurement and the uncertainty relations. A considerable portion of the book is based on original arguments presented by the author in lectures and research papers over the past ten years. However, this material is integrated with a broad coverage of most of the recent research in the field, so as to provide a balanced introduction to the whole subject. (shrink)

A systematic effort is here made to express some of the general results of quantum mechanics in a conceptual form closer to ordinary language than is the case with most modern physics. Many of the implications of the theory appear much more clearly thereby, in particular the fact that the laws of quantum mechanics are only statistical propositions about classes, not referring to individual objects. Conversely, the microscopic structure of an object cannot be precisely defined in quantum (...) mechanical terms. To say that an object has a definite microscopic structure is an operationally meaningless statement; it is on the same level as saying in relativity that a selected coordinate system is “at rest.” This raises the need for a “theory of matching”: What is the best statement about the structure of an object, given that the tools of description are only statistical? A technique is known for this: the theory of inductive probabilities. There is no longer one true description but a manifold of statistical descriptions, some of which have a greater likelihood of being satisfactory than others. The main concrete application of this type of conceptual reasoning lies in its power to clean out the speculative underbrush which so far has prevented the transition from theoretical physics to theoretical biology. (shrink)

This paper is intended to be an introductory survey of subjects related to the problems dealt with in the three other papers in this symposium on quantum field theory. A brief history of quantum electrodynamics is given and some of the objections to it are stated. A brief history of quantum field theories from the 1970's to the present is then provided. Finally, a sketch of some of the philosophical work that has been done on quantum (...) field theories is presented. The object of the paper is to explain why philosophers of physics have tended to neglect quantum field theories and to point out several of the conceptual issues raised by quantum field theories that call out for further analysis. (shrink)

The philosophical problems discussed by the author of this scientifically erudite work concern the usual and much debated questions of the role of causality in microphysics and the "completeness" and "indeterminism" of statistical theories in natural science. Blokhintsev, the author of a highly-regarded Russian text on quantum theory, advocates the direct opposite of the Einsteinian thesis; and furthermore, he seems to interpret the alleged irreducibly statistical nature of physical theory in a quite literal ontological sense. "We must now accept," (...) he says, "that we cannot ignore the element of games of chance in the behavior of the universe." The materials adduced in support of this thesis consist almost entirely of various essays in theoretical physics, which, while undoubtedly relevant to the question at issue, will be accessible in their details and content only to those philosophers with better than average mathematical acumen, particularly in classical analysis. Unfortunately, as so often happens in discussions of this type, the author's scientific expertise is not matched by his degree of philosophical rigor and awareness of important conceptual distinctions. Thus, although the concept of measurement in quantum mechanics and the differences between "direct" and "derived" measurement play a central role in his argument, the author seems unaware of the important logical differences which are brought out by rigorous postulational treatments of measurement theory. Moreover, when the author argues, convincingly enough, that even classical Newtonian mechanics is not a fit candidate for the label of "deterministic theory" if such factors as random fluctuations in the initial conditions and lack of isolation of actual physical systems are taken into account, he seems to forget that this is not the basis on which deterministic status is properly assigned to classical physical theory in the first place. It is physical theory as applied to suitably idealized physical systems which is held to be deterministic, and the same sort of idealizations are commonly assumed when quantum mechanics is said to be indeterministic.--H. P. K. (shrink)

Niels Bohr, founding father of modern atomic physics and quantum theory, was as original a philosopher as he was a physicist. This study explores several dimensions of Bohr's vision: the formulation of quantum theory and the problems associated with its interpretation, the notions of complementarity and correspondence, the debates with Einstein about objectivity and realism, and his sense of the infinite harmony of nature. Honner focuses on Bohr's epistemological lesson, the conviction that all our description of nature is (...) dependent on the words we use and the ways we can unambiguously use them. (shrink)

Authored by an acclaimed teacher of quantum physics and philosophy, this textbook pays special attention to the aspects that many courses sweep under the carpet. Traditional courses in quantum mechanics teach students how to use the quantum formalism to make calculations. But even the best students - indeed, especially the best students - emerge rather confused about what, exactly, the theory says is going on, physically, in microscopic systems. This supplementary textbook is designed to help such (...) students understand that they are not alone in their confusions (luminaries such as Albert Einstein, Erwin Schroedinger, and John Stewart Bell having shared them), to sharpen their understanding of the most important difficulties associated with interpreting quantum theory in a realistic manner, and to introduce them to the most promising attempts to formulate the theory in a way that is physically clear and coherent. The text is accessible to students with at least one semester of prior exposure to quantum (or "modern") physics and includes over a hundred engaging end-of-chapter "Projects" that make the book suitable for either a traditional classroom or for self-study. (shrink)

Since Rescher's earliest publication of the middle 1950's in this field, the philosophy of science has constituted one focus of his interest and preoccupation. Some dozen of Rescher's contributions to the field are published in the present volume, and they combine to convey his favored way of blending empirical data with philosophical theorizing.

A review of *Niels Bohr’s Philosophy of Quantum Physics in the Light of the Helmholtzian Tradition of Theoretical Physics *.