I offer an account of how the quantumtheory we have helps us explain so much. The account depends on a pragmatist interpretation of the theory: This takes a quantum state to serve solely as a source of sound advice to physically situated agents on the content and appropriate degree of belief about matters concerning which they are currently inevitably ignorant. The general account of how to use quantum states and probabilities to explain otherwise puzzling (...) regularities is then illustrated by showing how we can explain single particle interference phenomena, the stability of matter, and interference of Bose-Einstein condensates. Finally I note some open problems and relate this account to alternative approaches to explanation that emphasize the importance of causation, of unification, and of structure. (shrink)
The measurement problem of quantumtheory is discussed, and the difficulty of trying to solve it within the confines of a local, Lorentz-invariant physics is emphasised. This leads to the obvious suggestion to seek a solution beyond physics, in particular, by introducing the concept of consciousness. The resulting dualistic model, in the natural form suggested by quantumtheory, is shown to differ in several respects from the classical model of Descartes, and to suggest solutions to some (...) of the long-standing problems concerning the relation of consciousness to the physical world. (shrink)
The Everett interpretation of quantumtheory requires either the existence of an infinite number of conscious minds associated with each brain or the existence of one universal consciousness. Reasons are given, and the two ideas are compared.
It is usually taken for granted that orthodox quantumtheory poses a serious problem for scientific realism, in that the theory is empirically extraordinarily successful, and yet has instrumentalism built into it. This paper stand this view on its head. I argue that orthodox quantumtheory suffers from a number of serious (if not always noticed) defects precisely because of its inbuilt instrumentalism. This defective character of orthdoox quantumtheory thus undermines instrumentalism, and (...) supports scientific realism. I go on to consider whether there is here the basis of a general argument against instrumentalism. (shrink)
In this new edition, Arthur Fine looks at Einstein's philosophy of science and develops his own views on realism. A new Afterword discusses the reaction to Fine's own theory. "What really led Einstein . . . to renounce the new quantum order? For those interested in this question, this book is compulsory reading."--Harvey R. Brown, American Journal of Physics "Fine has successfully combined a historical account of Einstein's philosophical views on quantum mechanics and a discussion of some (...) of the philosophical problems associated with the interpretation of quantumtheory with a discussion of some of the contemporary questions concerning realism and antirealism. . . . Clear, thoughtful, [and] well-written."--Allan Franklin, Annals of Science "Attempts, from Einstein's published works and unpublished correspondence, to piece together a coherent picture of 'Einstein realism.' Especially illuminating are the letters between Einstein and fellow realist Schrodinger, as the latter was composing his famous 'Schrodinger-Cat' paper."--Nick Herbert, New Scientist "Beautifully clear. . . . Fine's analysis is penetrating, his own results original and important. . . . The book is a splendid combination of new ways to think about quantum mechanics, about realism, and about Einstein's views of both."--Nancy Cartwright, Isis. (shrink)
QuantumTheory and the Flight from Realism is a critical introduction to the long-standing debate concerning the conceptual foundations of quantum mechanics, and the problems it has posed for physicists and philosophers from Einstein to the present. Quantumtheory has been a major influence on postmodernism, and presents significant challenges for realists. Clarifying these debates for the non-specialist, Christopher Norris examines the premises of orthodox quantumtheory and its impact on various philosophical developments. (...) He subjects a wide range of opponents and supporters of realism to a high and equal level of scrutiny. Combining rigor and intellectual generosity, he draws out the merits and weaknesses from opposing arguments. (shrink)
Quantumtheory is one the most important and successful theories of modern physical science. It has been estimated that its principles form the basis for about 30 per cent of the world's manufacturing economy. This is all the more remarkable because quantumtheory is a theory that nobody understands. The meaning of QuantumTheory introduces science students to the theory's fundamental conceptual and philosophical problems, and the basis of its non-understandability. It does (...) this with the barest minimum of jargon and very little mathematics in the main text. Readers wishing to delve more deeply into the theory's mathematical subtleties can do so in an extended series of appendices. The book brings the reader up to date with the results of new experimental tests of quantum weirdness and reviews the latest thinking on alternative interpretations, the frontiers of quantum cosmology, quantum gravity and potential application of this weirdness in computing, cryptography and teleportation. (shrink)
Because it fails to solve the wave-particle problem, orthodox quantumtheory is obliged to be about observables and not quantum beables. As a result the theory is imprecise, ambiguous, ad hoc, lacking in explanatory power, restricted in scope and resistant to unification. A new version of quantumtheory is needed that is about quantum beables.
In the Critique of Pure Reason Kant argues that the empirical knowledge of the world depends on a priori conditions of human sensibility and understanding, i. e., our capacities of sense experience and concept formation. The objective knowledge presupposes, on one hand, space and time as a priori conditions of sensibility and, on another hand, a priori judgments, like the principle of causality, as constitutive conditions of understanding. The problem is that in the XX century the physical science completely changed (...) how we conceive our knowledge of the world. Face to this new situation, what was changed in our classical reason? However, if the transcendental point of view is adopted, in the specific case of quantum mechanics, we have to wonder about the general conditions of this theory that make possible such knowledge, which predictive value is much more accurate than the classical physics. The aim of this work is firstly to show the Kantian implications on Bohr’s interpretation of quantum phenomena and secondly to provide an overview of the key elements for understanding the transcendental locus of ordinary language in the quantum mechanics context, in order to give support to a transcendental pragmatic position in the analysis of science. (shrink)
The basic theme of Popper's philosophy--that something can come from nothing--is related to the present situation in physical theory. Popper carries his investigation right to the center of current debate in quantum physics. He proposes an interpretation of physics--and indeed an entire cosmology--which is realist, conjectural, deductivist and objectivist, anti-positivist, and anti-instrumentalist. He stresses understanding, reminding us that our ignorance grows faster than our conjectural knowledge.
Work on the central problems of the philosophy of science has led the author to attempt to create an intelligible version of quantumtheory. The basic idea is that probabilistic transitions occur when new stationary or particle states arise as a result of inelastic collisions.
This conference was devoted to the 80 years of the Copenhagen Interpretation, and to the question of the relevance of the Copenhagen interpretation for the present understanding of quantum mechanics. It is in this framework that fundamental questions raised by quantum mechanics, especially in information theory, were discussed throughout the conference. As has become customary in our series of conference in Växjö, we were glad to welcome a fruitful assembly of theoretical physicists, experimentalists, mathematicians and even philosophers (...) interested in the foundations of probability and physics. The nature of quantum fluctuations---in the form of Stochastic Electrodynamics or in other approaches to stochastic quantum mechanics---was also a central topic discussed during the conference, especially during debates. We should also mention talks on the completeness or incompleteness of quantum mechanics; on macroscopic quantum systems; on Bell's inequality, entanglement and experiments on quantum nonlocality (and locality); on Bohmian mechanics; on the connection between quantum mechanics and general relativity; on quantum probability; on quantum computing, quantum teleportation and quantum cryptography technologies; and more generally on the mathematical formalism of quantum mechanics and on the philosophical problems raised by its interpretations. (shrink)
This Växjö conference was devoted to the reconsideration of quantum foundations. Due to increasing research in quantum information theory, especially on quantum computing and cryptography, many questions regarding the foundations of quantum mechanics, which have long been considered to be exclusively of philosophical interest, nowadays play an important role in theoretical and experimental quantum physics.
In this paper I put forward a new micro realistic, fundamentally probabilistic, propensiton version of quantumtheory. According to this theory, the entities of the quantum domain - electrons, photons, atoms - are neither particles nor fields, but a new kind of fundamentally probabilistic entity, the propensiton - entities which interact with one another probabilistically. This version of quantumtheory leaves the Schroedinger equation unchanged, but reinterprets it to specify how propensitons evolve when no (...) probabilistic transitions occur. Probabilisitic transitions occur when new "particles" are created as a result of inelastic interactions. All measurements are just special cases of this. This propensiton version of quantumtheory, I argue, solves the wave/particle dilemma, is free of conceptual problems that plague orthodox quantumtheory, recovers all the empirical success of orthodox quantumtheory, and at the same time yields as yet untested predictions that differ from those of orthodox quantumtheory. (shrink)
A fully micro realistic, propensity version of quantumtheory is proposed, according to which fundamental physical entities - neither particles nor fields - have physical characteristics which determine probabilistically how they interact with one another (rather than with measuring instruments). The version of quantum "smearon" theory proposed here does not modify the equations of orthodox quantumtheory: rather, it gives a radically new interpretation to these equations. It is argued that (i) there are strong (...) general reasons for preferring quantum "smearon" theory to orthodox quantumtheory; (ii) the proposed change in physical interpretation leads quantum "smearon" theory to make experimental predictions subtly different from those of orthodox quantumtheory. Some possible crucial experiments are considered. (shrink)
Decoherence and entanglement : new concepts and perspectives -- Quantum-like models in cognitive science and economics -- Invited presentations -- Contributed presentations -- Post-conference papers.
As previous Växjö conferences on quantum foundations, QTRF-5 was notable not only for the contributions of the papers presented there but also for its exciting debates. These debates offered a great diversity of opinions on foundations of quantum mechanics (QM) and its future developments: from those defined by the view of those who adhere to the orthodox Copenhagen interpretation (which rejected realism and causality), at one end of the spectrum, to those who subscribed to realist views of the (...) type advocated by Einstein, at the other end, with a number of views in between. (shrink)
While for the majority of physicists the problem of the deciphering of the brain code, the intelligence code, is a matter for future generations, the author boldly and forcefully disagrees. Breaking with the dogma of classical logic he develops in the form of the conversion postulate a concrete working hypothesis for the actual thought mechanism. The reader is invited on a fascinating mathematical journey to the very edges of modern scientific knowledge. From lepton and quark to mind, from cognition to (...) a logic analogue of the Schrodinger equation, from Fibonacci numbers to logic quantum numbers, from imaginary logic to a quantum computer, from coding theory to atomic physics - the breadth and scope of this work is overwhelming. Combining quantum physics, fundamental logic and coding theory this unique work sets the stage for future physics and is bound to titillate and challenge the imagination of physicists, biophysicists and computer designers. Growing from the author's matrix operator formalization of logic, this work pursues a synthesis of physics and logic methods, leading to the development of the concept of infophysics. The experimental verification of the proposed quantum hypothesis of the brain is presently in preparation in cooperation with the Cavendish Laboratory, Cambridge, UK, and, if proved positive, would have major theoretical implications. Even more significant should be the practical applications in such fields as molecular electronics and computer science, biophysics and neuroscience, medicine and education. The new possiblities that could be opened up by quantum level computing could be truly revolutionary. The book aims at researchers and engineers in technical sciences as well as in biophysics and biosciences in general. It should have great appeal for physicists, mathematicians, logicians and for philosophers with a mathematical bent. (shrink)
Quantum field theory (QFT) combines quantum mechanics with Einstein's special theory of relativity and underlies elementary particle physics. This book presents a philosophical analysis of QFT. It is the first treatise in which the philosophies of space-time, quantum phenomena, and particle interactions are encompassed in a unified framework. Describing the physics in nontechnical terms, and schematically illustrating complex ideas, the book also serves as an introduction to fundamental physical theories. The philosophical interpretation both upholds the (...) reality of the quantum world and acknowledges the irreducible cognitive elements in its representation. The interpretation is based on an analysis of our ways of thinking as the are embedded in the logical structure of QFT. The author argues that philosophical categories are significant only if they play active and essential roles in our knowledge and hence constitute part of the theories in actual use. Thus she regards physical theories as primary, extracts their categorical structure, and uses it to rethink key philosophical questions. Among the questions this book tries to answer are: What are the quantum properties independent of measurements? How do we refer to individual things in a continuous field? How do theories relate to objects? What are the general conditions of the world and of our ways of thinking that make possible our knowledge of the microscopic realm, which is so intangible and counterintuitive? As a penetrating analysis of vital themes in contemporary science, the book will engage the interest of students and professionals in physics and philosophy alike. (shrink)
In the paper we will employ set theory to study the formal aspects of quantum mechanics without explicitly making use of space-time. It is demonstrated that von Neuman and Zermelo numeral sets, previously efectively used in the explanation of Hardy’s paradox, follow a Heisenberg quantum form. Here monadic union plays the role of time derivative. The logical counterpart of monadic union plays the part of the Hamiltonian in the commutator. The use of numerals and monadic union in (...) the classical probability resolution of Hardy’s paradox [1] is supported with the present derivation of a commutator for sets. (shrink)
Quantum field theory, one of the most rapidly developing areas of contemporary physics, is full of problems of great theoretical and philosophical interest. This collection of essays is the first systematic exploration of the nature and implications of quantum field theory. The contributors discuss quantum field theory from a wide variety of standpoints, exploring in detail its mathematical structure and metaphysical and methodological implications.
Methods developed in a previous paper are employed to define an exact correspondence between the states of a deterministic cellular automaton in 1+1 dimensions and those of a bosonic quantum field theory. The result may be used to argue that quantum field theories may be much closer related to deterministic automata than what is usually thought possible.
I argue that algebraic quantum field theory (AQFT) permits an undisturbed view of the right ontology for fundamental physics, whereas standard (or Lagrangian) QFT offers different mutually incompatible ontologies.My claim does not depend on the mathematical inconsistency of standard QFT but on the fact that AQFT has the same concerns as ontology, namely categorical parsimony and a clearly structured hierarchy of entities.
Acclaimed mathematical physicist and natural philosopher Luciano Boi expounds the quantum vacuum, exploring the meaning of nothingness and its relationship with ...
Abstract: This paper assesses the Everettian approach to the measurement problem, especially the version of that approach advocated by Simon Saunders and David Wallace. I emphasise conceptual, indeed metaphysical, aspects rather than technical ones; but I include an introductory exposition of decoherence. In particular, I discuss whether---as these authors maintain---it is acceptable to have no precise definition of 'branch' (in the Everettian kind of sense). (A version of this paper will appear in a CTNS/Vatican Observatory volume on Quantum (...) class='Hi'>Theory and Divine Action, ed. Robert Russell et al.). (shrink)
When I look at the scale of the apparatus I know what it reads. Those absurdly delicate, hopelessly inaccessible, global correlations obviously vanish when they connect up with me. Whether this is because consciousness is beyond the range of phenomena that quantum mechanics is capable of dealing with, or because it has infinitely many degrees of freedom or special super selection rules of its own, I would not presume to guess. But this is a puzzle about consciousness that should (...) not get mixed up with efforts to understand quantum mechanics as a theory of subsystem correlations in the nonconscious world. ( David Mermin 1998). (shrink)
It is widely accepted that consciousness or, in other words, mental activity is in some way correlated to the behavior of the brain or, in other words, material brain activity. Since quantumtheory is the most fundamental theory of matter that is currently available, it is a legitimate question to ask whether quantumtheory can help us to understand consciousness. Several approaches answering this question a?rmatively, proposed in recent decades, will be surveyed. It will be (...) pointed out that they make di?erent epistemological assumptions, refer to di?erent neurophysiological levels of description, and adopt quantumtheory in di?erent ways. For each of the approaches discussed, these imply both.. (shrink)
The relationship between quantum collapse and consciousness is reconsidered under the assumption that quantum collapse is an objective dynamical process. We argue that the conscious observer can have a distinct role from the physical measuring device during the process of quantum collapse owing to the intrinsic nature of consciousness; the conscious observer can know whether he is in a definite state or a quantum superposition of definite states, while the physical measuring device cannot “know”. As a (...) result, the consciousness observer can distinguish the definite states and their quantum superposition, while the physical measuring device without consciousness cannot do. This provides a possible quantum physical method to distinguish man and machine. The new result also implies that consciousness has causal efficacies in the physical world when considering the existence of quantum collapse. Accordingly consciousness is not reducible or emergent, but a new fundamental property of matter. This may establish a quantum basis for panpsychism, and make it be a promising solution to the hard problem of consciousness. Furthermore, it is suggested that a unified theory of matter and consciousness includes two parts: one is the psychophysical principle or corresponding principle between conscious content and matter state, and the other is the complete quantum evolution of matter state, which includes the definite nonlinear evolution element introduced by consciousness and relating to conscious content. Lastly, some experimental schemes are presented to test the proposed quantumtheory of consciousness. (shrink)
Hugh Everett III died of a heart attack in July 1982 at the age of 51. Almost 26 years later, a New York Times obituary for his PhD advisor, John Wheeler, mentioned him and Richard Feynman as Wheeler’s most prominent students. Everett’s PhD thesis on the relative state formulation of quantum mechanics, later known as the “Many Worlds Interpretation”, was published (in its edited form) in 1957, and later (in its original, unedited form) in 1973, and since then has (...) given rise to one of the most radical schools of thought in the foundations of quantumtheory. Several years ago two conferences held in Oxford and in the Perimeter Institute celebrated the occasion of 50 years to the first publication of Everett’s thesis. The book Many worlds? grew out from contributions to these conferences, but, as its editors emphasize, it is more than mere conference proceedings. Instead, an attempt was made to assemble an impressive collection of papers which together illustrate the promise of the many worlds interpretation and the obstacles it faces. 23 papers divided into six sections follow an introduction by Simon Saunders, one of Oxford’s fiercest Everettians. The first four sections cover two thorny issues that have been flagged by contemporary opponents to the many worlds interpretation, namely, the problem of ontology and the problem of probability, while the fifth discusses alternatives to Everett such as Bohmian mechanics and information–theoretic approaches to quantumtheory. The sixth section seems to be a wild card, hosting several papers unrelated to each other, including one of the most interesting contributions to this volume on the history of Everett’s thesis and his (some may say all too) short academic career. Each section concludes with transcripts of the discussion session that took place after the talks, thus giving an additional emphasis to the points of contention. Apart from general comments on the volume, in what follows I would like to concentrate on few papers I found especially illuminating. Start with ontology.. (shrink)
The concepts of complementarity and entanglement are considered with respect to their significance in and beyond physics. A formally generalized, weak version of quantumtheory, more general than ordinary quantumtheory of physical systems, is outlined and tentatively applied to two examples.
We put forward a possible new interpretation and explanatory framework for quantumtheory. The basic hypothesis underlying this new framework is that quantum particles are conceptual entities. More concretely, we propose that quantum particles interact with ordinary matter, nuclei, atoms, molecules, macroscopic material entities, measuring apparatuses, in a similar way to how human concepts interact with memory structures, human minds or artificial memories. We analyze the most characteristic aspects of quantumtheory, i.e. entanglement and (...) non-locality, interference and superposition, identity and individuality in the light of this new interpretation, and we put forward a specific explanation and understanding of these aspects. The basic hypothesis of our framework gives rise in a natural way to a Heisenberg uncertainty principle which introduces an understanding of the general situation of ‘the one and the many’ in quantum physics. A specific view on macro and micro different from the common one follows from the basic hypothesis and leads to an analysis of Schrödinger’s Cat paradox and the measurement problem different from the existing ones. We reflect about the influence of this new quantum interpretation and explanatory framework on the global nature and evolutionary aspects of the world and human worldviews, and point out potential explanations for specific situations, such as the generation problem in particle physics, the confinement of quarks and the existence of dark matter. (shrink)
While its applications have made quantumtheory arguably the most successful theory in physics, its interpretation continues to be the subject of lively debate within the community of physicists and philosophers concerned with conceptual foundations. This situation poses a problem for a pragmatist for whom meaning derives from use. While disputes about how to use quantumtheory have arisen from time to time, they have typically been quickly resolved, and consensus reached, within the relevant scientific (...) sub-community. Yet rival accounts of the meaning of quantumtheory continue to proliferate . In this article I offer a diagnosis of this situation and outline a pragmatist solution to the problem it poses, leaving further details for subsequent articles. (shrink)
Review of "The Collected Works of Eugene Paul Wigner", Volume I, III, and VI. Excerpt from the Conclusions: Many of Wigner’s papers on mathematical physics are great classics. Most famous is his work on group representations which is of lasting value for a proper mathematical foundation of quantumtheory. The modern development of quantumtheory (which is not reflected in Wigner’s work) is in an essential way a representation theory (e.g. representations of kinematical groups, or (...) representations of C*-algebras). This view owes very much to Wigner’s seminal papers on the unitary representations of compact and noncompact groups. Wigner showed much courage in relating the then unresolved questions of the measurement problem to the much deeper problem of consciousness. In view of this very unorthodox proposal it is astonishing that Wigner was very reactionary with respect of the dogmas of orthodox quantum mechanics. In contrast to von Neumann himself, he took the old von-Neumann codification of quantum mechanics as authoritative and not to be questioned. Much of the efforts to interpret the meaning of this codification and to prove no-go theorems, such as the insolubility of the measurement problem or the impossibility of a quantumtheory of individual objects, are physically irrelevant since they are based on a codification of quantum mechanics that is valid only for strictly closed systems with finitely many degrees of freedom. However, in nature there are no such systems. Every material system is coupled to the gravitational and to the electromagnetic field – systems which require in a Hamiltonian description infinitely many degrees of freedom. A deeper insight into the conceptual problems of quantumtheory is possible only if the modern development of a quantumtheory of infinite systems is taken into account. (shrink)
It has been suggested, on the one hand, that quantum states are just states of knowledge; and, on the other, that quantumtheory is merely a theory of correlations. These suggestions are confronted with problems about the nature of psycho-physical parallelism and about how we could define probabilities for our individual future observations given our individual present and previous observations. The complexity of the problems is underlined by arguments that unpredictability in ordinary everyday neural functioning, ultimately (...) stemming from small-scale uncertainties in molecular motions, may overwhelm, by many orders of magnitude, many conventionally recognized sources of observed ``quantum'' uncertainty. Some possible ways of avoiding the problems are considered but found wanting. It is proposed that a complete understanding of the relationship between subjective experience and its physical correlates requires the introduction of mathematical definitions and indeed of new physical laws. (shrink)
This is a philosophical paper in favor of the many-worlds interpretation (MWI) of quantumtheory. The necessity of introducing many worlds is explained by analyzing a neutron interference experiment. The concept of the “measure of existence of a world” is introduced and some difficulties with the issue of probability in the framework of the MWI are resolved.
[Abstract: Anti-realism – the denial that reality exists apart from our conceptions of it – is rampant, not just among Postmodernists and other literati, but also among many of the leading spokesmen of orthodox quantumtheory – from Born, Bohr, and Heisenberg to Wheeler and Wigner. Undoubtedly they've done good physics. Why, then, do they indulge in bad metaphysics? This paper offers some answers.].
Science is always presupposing some basic concepts that are held to be useful. These absolute presuppositions (Collingwood) are rarely debated and form the framework for what has been termed paradigm by Kuhn. Our currently accepted scientific model is predicated on a set of presuppositions that have difficulty accommodating holistic structures and relationships and are not geared towards incorporating non-local correlations. Since the theoretical models we hold also determine what we perceive and take as scientifically viable, it is important to look (...) for an alternative model that can deal with holistic relationships. One approach is to generalise algebraic quantumtheory, which is an inherently holistic framework, into a generic model. Relaxing some restrictions and definitions from quantumtheory proper yields an axiomatic framework that can be applied to any type of system. Most importantly, it keeps the core of the quantum theoretical formalism. It is capable of handling complementary observables, i.e. descriptors which are non-commuting, incompatible and yet collectively required to fully describe certain situations. It also predicts a generalised form of non-local correlations that in quantumtheory are known as entanglement. This generalised version is not quantum entanglement but an analogue form of holistic, non-local connectedness of elements within systems, predicted to occur whenever elements within systems are described by observables which are complementary to the description of the whole system. While a considerable body of circumstantial evidence supports the plausibility of the model, we are not yet in a position to use it for clear cut predictions that could be experimentally falsified. The series of papers offered in this special issue are the beginning of what we hope will become a rich scientific debate. (shrink)
Quantumtheory is a tremendously successful physical theory, but nevertheless suffers from two serious problems: the measurement problem and the problem of interpretational underdetermination. The latter, however, is largely overlooked as a genuine problem of its own. Both problems concern the doctrine of realism, but pull, quite curiously, into opposite directions. The measurement problem can be captured such that due to scientific realism about quantumtheory common sense anti-realism follows, while theory underdetermination usually counts (...) as an argument against scientific realism. I will also consider the more refined distinctions of ontic and epistemic realism and demonstrate that quantumtheory in its most viable interpretations conflicts with at least one of the various realism claims. A way out of the conundrum is to come to the bold conclusion that quantumtheory is, possibly, wrong (in the realist sense). (shrink)
Schrödinger’s first proposal for the interpretation of quantum mechanics was based on a postulate relating the wave function on configuration space to charge density in physical space. Schrödinger apparently later thought that his proposal was empirically wrong. We argue here that this is not the case, at least for a very similar proposal with charge density replaced by mass density. We argue that when analyzed carefully, this theory is seen to be an empirically adequate many-worlds theory and (...) not an empirically inadequate theory describing a single world. Moreover, this formulation—Schrödinger’s first quantumtheory—can be regarded as a formulation of the many-worlds view of quantum mechanics that is ontologically clearer than Everett’s. (shrink)
Confused ideas about the weirdness of quantum mechanics have sometimes been blamed for the spread of anti-realist positions in philosophy. In this seminar, I shall re-examine the relation between realism and quantumtheory. My goal is to argue that one can remain a realist in a reasonably familiar sense, while adopting a theory which amounts to a form of idealism. After sketching the abstract mathematical structure of quantumtheory, I will introduce realism and consider (...) some of its problems and some counter-arguments. Next I will look at why quantumtheory needs an interpretation and at some of the features common to many proposed interpretations. Then I will discuss some of the gaps in decoherence theory, when it is considered as an interpretation of quantumtheory, and I will end with a sketch of my own realist version of idealism in which the fundamental entities are structures which define minds, and the fundamental laws govern the stochastic developments of those structures. (shrink)
What belongs to quantumtheory is no more than what is needed for its derivation. Keeping to this maxim, we record a paradigmatic shift in the foundations of quantum mechanics, where the focus has recently from interpreting to reconstructing quantumtheory. Several historic and contemporary reconstructions are analyzed, including works of Hardy, Rovelli, and Clifton, Bub and Halvorson. We conclude by discussing the importance of a novel concept of intentionally incomplete reconstruction.
Orthodox Copenhagen quantumtheory renounces the quest to understand the reality in which we are imbedded, and settles for practical rules that describe connections between our observations. Many physicist have believed that this renunciation of the attempt describe nature herself was premature, and John von Neumann, in a major work, reformulated quantumtheory as a theory of the evolving objective universe. In the course of his work he converted to a benefit what had appeared to (...) be a severe deficiency of the Copenhagen interpretation, namely its introduction into physical theory of the human observers. He used this subjective element of quantumtheory to achieve a significant advance on the main problem in philosophy, which is to understand the relationship between mind and matter. That problem had been tied closely to physical theory by the works of Newton and Descartes. The present work examines the major problems that have appeared to block the development of von Neumann’s theory into a fully satisfactory theory of Nature, and proposes solutions to these problems. (shrink)
Both physicists and philosophers claim that quantum mechanics reduces to classical mechanics as 0, that classical mechanics is a limiting case of quantum mechanics. If so, several formal and non-formal conditions must be satisfied. These conditions are satisfied in a reduction using the Wigner transformation to map quantum mechanics onto the classical phase plane. This reduction does not, however, assist in providing an adequate metaphysical interpretation of quantumtheory.
The main formal structures of generalized quantumtheory are summarized. Recent progress has sharpened some of the concepts, in particular the notion of an observable, the action of an observable on states (putting more emphasis on the role of proposition observables), and the concept of generalized entanglement. Furthermore, the active role of the observer in the structure of observables and the partitioning of systems is emphasized.
These are notes designed to bring the beginning student of the philosophy of quantum mechanics 'up to scratch' on the mathematical background needed to understand elementary finite-dimensional quantumtheory. There are just three chapters: Ch. 1 'Vector Spaces'; Ch. 2 'Inner Product Spaces'; and Ch. 3 'Operators on Finite-Dimensional Complex Inner Product Spaces'. The notes are entirely self-contained and presuppose knowledge of only high school level algebra.
A remarkable theorem by Clifton, Bub and Halvorson (2003) (CBH) characterizes quantumtheory in terms of information--theoretic principles. According to Bub (2004, 2005) the philosophical significance of the theorem is that quantumtheory should be regarded as a ``principle'' theory about (quantum) information rather than a ``constructive'' theory about the dynamics of quantum systems. Here we criticize Bub's principle approach arguing that if the mathematical formalism of quantum mechanics remains intact then (...) there is no escape route from solving the measurement problem by constructive theories. We further propose a (Wigner--type) thought experiment that we argue demonstrates that quantum mechanics on the information--theoretic approach is incomplete. (shrink)
Although quantumtheory is applicable, in principle, to both the microscopic and macroscopic realms, the strategy of practically applying quantumtheory only at the microscopic level while retaining a classical conception of the macroscopic world (through the correspondence principle) has had tremendous success. This has nevertheless rendered the task of interpretation daunting. We argue the need for recognizing and solving the 'observation problem', namely constructing a 'quantum-compatible' view of the properties and states of macroscopic objects (...) in everyday thinking to realistically interpret quantumtheory consistently at both the microscopic and macroscopic levels. Toward a solution to this problem, we point out a category of properties called 'relational properties' that we regularly associate with everyday objects. We see them as being potentially quantum-compatible. Some possible physical implications are discussed. We conclude by touching upon the nexus between the relational property view within quantum physics and some neurobiological issues underlying cognition. (shrink)
Although many physicists have little interest in philosophical arguments about their subject, an analysis of debates about the paradoxes of quantum mechanics shows that their disagreements often depend upon assumptions about the relationship between theories and the real world. Some consider that physics is about building mathematical models which necessarily have limited domains of applicability, while others are searching for a final theory of everything, to which their favourite theory is supposed to be an approximation. We discuss (...) some particular recent debates about quantumtheory in which the underlying assumptions are not fully articulated. Introduction Setting the scene The Ghirardi, Rimini and Weber theoryQuantum marbles Radioactive decay and isomerism The limits of quantumtheory. (shrink)
In a series of papers, a many-minds interpretation of quantumtheory has been developed. The aim in these papers is to present an explicit mathematical formalism which constitutes a complete theory compatible with relativistic quantum field theory. In this paper, which could also serve as an introduction to the earlier papers, three issues are discussed. First, a significant, but fairly straightforward, revision in some of the technical details is proposed. This is used as an opportunity (...) to introduce the formalism. Then the probabilistic structure of the theory is revised, and it is proposed that the experience of an individual observer can be modelled as the experience of observing a particular, identified, discrete stochastic process. Finally, it is argued that the formalism can be modified to give a physics in which no constants are required. Instead, “constants” have to be determined by observation, and are fixed only to the extent to which they have been observed. (shrink)
According to a common conception of causality the truth of a state ment that refers only to phenomena con ned to an earlier time cannot depend upon which measurement an experimenter will freely choose to perform at a later time According to a common idea of the theory of relativity this causality condition should be valid in all Lorentz frames It is shown here that this concept of relativistic causality is incompatible with some simple predictions of quantum (...) class='Hi'>theory.. (shrink)
The central and most recalcitrant problem for environmental ethics is the problem of constructing an adequate theory of intrinsic value for nonhuman natural entities and for nature as a whole. In part one, I retrospectively survey the problem, review certain classical approaches to it, and recommend one as an adequate, albeit only partial, solution. In part two, I show that the classical theory of inherent value for nonhuman entities and nature as a whole outlined in part one is (...) inconsistent with a contemporary scientific world view because it assumes the validity of the classical Cartesian partition between subject and object which has been overturned by quantumtheory. Based upon the minimalistic Copenhagen Interpretation of quantumtheory, I then develop a theory of inherent value which does not repose upon the obsolete subject/object and ancillary fact/value dichotomies. In part three, I suggest that a more speculative metaphysical interpretation of quantumtheory--one involving the notion ofreal internal relations anda holistic picture of nature-permits a principle of “axiological complementary,” a theory of “intrinsic”-as opposed to “inherent”-value in nature as a simple extension of ego. (shrink)
In the May 15, 1935 issue of Physical Review Albert Einstein co-authored a paper with his two postdoctoral research associates at the Institute for Advanced Study, Boris Podolsky and Nathan Rosen. The article was entitled “Can Quantum Mechanical Description of Physical Reality Be Considered Complete?” (Einstein et al. 1935). Generally referred to as “EPR”, this paper quickly became a centerpiece in the debate over the interpretation of the quantumtheory, a debate that continues today. The paper features (...) a striking case where two quantum systems interact in such a way as to link both their spatial coordinates in a certain direction and also their linear momenta (in the same direction). As a result of this “entanglement”, determining either position or momentum for one system would fix (respectively) the position or the momentum of the other. EPR use this case to argue that one cannot maintain both an intuitive condition of local action and the completeness of the quantum description by means of the wave function. This entry describes the argument of that 1935 paper, considers several different versions and reactions, and explores the ongoing significance of the issues they raise. (shrink)
A paradigmatic shift in the foundations of quantum mechanics is recorded, from interpreting to reconstructing quantumtheory. Examples of reconstruction are analyzed, and conceptual foundations of the information-theoretic reconstruction developed. A concept of intentionally incomplete reconstruction is introduced to mark the novel content of research in the foundation of quantumtheory. ‡Many thanks to Lucien Hardy, Jeff Bub and Bill Demopoulos for their comments. This research was supported through the ANR grant ANR-06-BLAN-0348-01. Part of this (...) research was held at the Perimeter Institute for Theoretical Physics. Research at Perimeter Institute for Theoretical Physics is supported in part by the Government of Canada through NSERC and by the Province of Ontario through MRI. †To contact the author, please write to: CEA-Saclay, 91191 Gif-sur-Yvette, France; e-mail: alexei.grinbaum@cea.fr. (shrink)
In this paper (which is, at best, a work in progress), I discuss different modes of scientific explanation identified by philosophers (Hempel, Salmon, Kitcher, Friedman, Hughes) and examine how well or badly they capture the "explanations" of phenomena that modern quantumtheory provides. I tentatively conclude that quantum explanation is best seen as "structural explanation", and spell out in detail how this works in the case of explaining vacuum correlations. Problems and prospects for structural explanation in (...) class='Hi'>quantumtheory are also discussed. (shrink)
Quantumtheory has been formulated in several different ways. The original version was ‘Copenhagen’ quantumtheory, which was formulated as a practical set of rules for making predictions about what we human observers would observe under certain well-defined sets of conditions. However, the human observers themselves were excluded from the system, in much the same way that Descartes excluded human beings from the part of the world governed by the natural physical laws. This exclusion of human (...) beings from the world governed by the physical laws is an awkward feature of Copenhagen quantumtheory that is fixed by “Orthodox” quantumtheory, which is the form devised by von Neumann and Wigner. This orthodox form treats the entire world as a quantum system, including the brains and bodies of human beings. Some more recent formulation of quantumtheory seek to exclude from the theory all reference to the experiences of human observers, but I do not consider them, both because of their technical deficiencies, and because they are constitutionally unequipped to deal adequately with the causal efficacy of our conscious thoughts.1 The observer plays a central role in both Copenhagen and Orthodox quantumtheory. In this connection, Bohr, describing the 1927 Solvay conference, noted that: “…an interesting discussion arose about how to speak of the appearance of phenomena for which only statistical predictions can be made. The question was whether, as to the occurrence of such individual events, we should adopt the.. (shrink)
Synchronistic or psi phenomena are interpreted as entanglement correlations in a generalized quantumtheory. From the principle that entanglement correlations cannot be used for transmitting information, we can deduce the decline effect, frequently observed in psi experiments, and we propose strategies for suppressing it and improving the visibility of psi effects. Some illustrative examples are discussed.
Uncertainty relations and complementarity of canonically conjugate position and momentum observables in quantumtheory are discussed with respect to some general coupling properties of a function and its Fourier transform. The question of joint localization of a particle on bounded position and momentum value sets and the relevance of this question to the interpretation of position-momentum uncertainty relations is surveyed. In particular, it is argued that the Heisenberg interpretation of the uncertainty relations can consistently be carried through in (...) a natural extension of the usual Hilbert space frame of the quantumtheory. (shrink)
We present a scenario describing how time emerges in the framework of weak quantumtheory. In a process similar to the emergence of time in quantum cosmology, time arises after an epistemic split of an undivided unus mundus as a quality of the individual conscious mind. Synchronization with matter and other mental systems is achieved by entanglement correlations. In the course of its operationalization, time loses its original quality and the time of physics as measured by clocks (...) appears. avoided/explicated. (shrink)
Two successes of old quantumtheory are particularly notable: Bohr’s prediction of the spectral lines of ionised helium, and Sommerfeld’s prediction of the fine-structure of the hydrogen spectral lines. Many scientific realists would like to be able to explain these successes in terms of the truth or approximate truth of the assumptions which fuelled the relevant derivations. In this paper I argue that this will be difficult for the ionised helium success, and is almost certainly impossible for the (...) fine-structure success. Thus I submit that the case against the realist’s thesis that success is indicative of truth is marginally strengthened. (shrink)
The paper compares ontic structural realism in quantum physics with ontic structural realism about space–time. We contend that both quantumtheory and general relativity theory support a common, contentful metaphysics of ontic structural realism. After recalling the main claim of ontic structural realism and its physical support, we point out that both in the domain of quantumtheory and in the domain of general relativity theory, there are objects whose essential ways of being (...) are certain relations so that these objects do not possess an intrinsic identity. Nonetheless, the qualitative, physical nature of these relations is in the quantum case (entanglement) fundamentally different from the classical, metrical relations treated in general relativity theory. (shrink)
Measures and theories of information abound, but there are few formalised methods for treating the contextuality that can manifest in different information systems. Quantumtheory provides one possible formalism for treating information in context. This paper introduces a quantum inspired model of the human mental lexicon. This model is currently being experimentally investigated and we present a preliminary set of pilot data suggesting that concept combinations can indeed behave non-separably.
The aim of this paper is to present and discuss a probabilistic framework that is adequate for the formulation of quantumtheory and faithful to its applications. Contrary to claims, which are examined and rebutted, that quantumtheory employs a nonclassical probability theory based on a nonclassical "logic," the probabilistic framework set out here is entirely classical and the "logic" used is Boolean. The framework consists of a set of states and a set of quantities (...) that are interrelated in a specified manner. Each state induces a classical probability space on the values of each quantity. The quantities, so considered, become statistical variables (not random variables). Such variables need not have a "joint distribution." For the quantum theoretic application, there is a uniform procedure that defines and determines the existence of such "joint distributions" for statistical variables. A general rule is provided and it is shown to lead to the usual compatibility-commutivity requirements of quantumtheory. The paper concludes with a brief discussion of interference and the misunderstandings that are involved in the false move from interference to nonclassical probability. (shrink)
After a brief account of theway quantumtheory deals with naturalprocesses, the crucial problem that such atheory meets, the measurement or, better, themacro-objectification problem is discussed.The embarrassing aspects of the occurrence ofentangled states involving macroscopic systemsare analyzed in details. The famous example ofSchroedinger's cat is presented and it ispointed out how the combined interplay of thesuperposition principle and the ensuingentanglement raises some serious difficultiesin working out a satisfactory quantum worldview, agreeing with our definiteperceptions. The orthodox solution to (...) themacro-objectification problem, i.e. thepostulate of wave packet reduction, isanalyzed and is proved to be inconsistent withthe assumption that the theory governes alsothe measurement process. After these premises,the rest of the paper is devoted to discuss arecent proposal of overcoming the difficultiesof the standard formalism by acceptingnonlinear and stochastic modifications of thequantum dynamics. The proposed theory is shownto agree with all known predictions of thestandard theory concerning microscopic systemsand to account, on the basis of a universaldynamics which is assumed to govern allnatural processes, for wave packet reductionin measurement processes and, more important,to eliminate all the difficulties concerningmacroscopic situations. Actually, the proposedtheory allows one to take consistently amacrorealistic position about natural processes and about our definite perceptions. (shrink)
The basic purpose of this essay, the first of an intended pair, is to interpret standard von Neumann quantumtheory in a framework of iterated measure algebraic truth for mathematical (and thus mathematical-physical) assertions — a framework, that is, in which the truth-values for such assertions are elements of iterated boolean measure-algebras (cf. Sections 2.2.9, 5.2.1–5.2.6 and 5.3 below).The essay itself employs constructions of Takeuti's boolean-valued analysis (whose origins lay in work of Scott, Solovay, Krauss and others) to (...) provide a metamathematical interpretation of ideas sometimes considered disparate, heuristic, or simply ill-defined: the collapse of the wave function, for example; Everett's many worlds'-construal of quantum measurement; and a natural product space of contextual (nonlocal) hidden variables. (shrink)
There is already in quantumtheory the huge *fact* of the apparent nonlocal (faster than light) connections: if one rejects the many worlds notion that all things happen [and I believe that that idea must be rejected for technical reasons --but that is a whole long argument itself] then there is an absolute need for some sort of FTL transfer of information. There simply must be a strong interconnectedness of the universe: FTL influence is unavoidable in quantum (...)theory, if many worlds is rejected. (shrink)
Weak QuantumTheory (WQT) and the Model of Pragmatic Information (MPI) are two psychophysical concepts developed on the basis of quantum physics. The present study contributes to their empirical examination. The issue of the study is whether WQT and MPI can not only explain ‘psi’-phenomena theoretically but also prove to be consistent with the empirical phenomenology of extrasensory perception (ESP). From the main statements of both models, 33 deductions for psychic readings are derived. Psychic readings are defined (...) as settings, in which psychics support or counsel clients by using information not mediated through the five senses. A qualitative approach is chosen to explore how the psychics experience extrasensory perceptions. Eight psychics are interviewed with a half-structured method. The reports are examined regarding deductive and inductive aspects, using a multi-level structured content analysis. The vast majority of deductions is clearly confirmed by the reports. Even though the study has to be seen as an explorative attempt with many aspects to be specified, WQT and MPI prove to be coherent and helpful concepts to explain ESP in psychic readings. (shrink)
Physicists and philosophers argue whether quantumtheory has spiritual implications. The vast majority of opinions are at two extremes: Some contend that quantumtheory has absolutely no spiritual implications whatsoever, whereas others assert that it forms the very basis of a modern spirituality and can be directly applied to the human condition. It is this article's contention that neither extreme is correct. Quantumtheory does have spiritual implications - a fact that its founders intuited (...) and its enemies, Einstein preeminent among them, considered prima facie evidence of its as yet undiscovered flaws. Quantumtheory has proven itself against all challenges more successfully than any other scientific theory, but its spiritual implications are extremely subtle. It provides a boundary to the materialistic, deterministic worldview and shows that there must be more to reality than that, but is inherently incapable of providing evidence as to the nature of what lies beyond that boundary. (shrink)
Interpretations, or generalizations, of quantumtheory that are applicable to cosmology are of interest because they must display and resolve the "paradoxes" directly. The Everett interpretation is reexamined and compared with two alternatives. Its "metaphysical" connotations can be removed, after which it is found to be more acceptable than a theory which incorporates collapse, while retaining some unsatisfactory features.
In 1912, Henri Poincaré published an argument which apparently shows that the hypothesis of quanta is both necessary and sufficient for the truth of Planck''s experimentally corroborated law describing the spectral distribution of radiant energy in a black body. In a recent paper, John Norton has reaffirmed the authority of Poincarés argument, setting it up as a paradigm case in which empirical data can be used to definitively rule out theoretical competitors to a given theoretical hypothesis. My goal is (...) to dispute Norton''s claim that there is no theoretical underdetermination problem arising between classical physics and early quantumtheory. The strategy I use in defending my view is to adopt a suggestion made by Jarrett Leplin and Larry Laudan on how to assess the relative merits of competing theoretical alternatives, where each alternative has an equal capacity to save the phenomena. In the course of the paper, I distinguish between two branches of classical physics: classical mechanics and classical electromagnetism. The former is claimed by Norton and Poincaré to be determinately ruled out by the black body evidence; and it is the former that I argue is compatible with this evidence. (shrink)
Quantum Mechanics can be viewed as a linear dynamical theory having a familiar mathematical framework but a mysterious probabilistic interpretation, or as a probabilistic theory having a familiar interpretation but a mysterious formal framework. These points of view are usually taken to be somewhat in tension with one another. The first has generated a vast literature aiming at a ``realistic" and ``collapse-free" interpretation of quantum mechanics that will account for its statistical predictions. The second has generated (...) an at least equally large literature aiming to derive, or at any rate motivate, the formal structure of quantumtheory in probabilistically intelligible terms. In this paper I explore, in a preliminary way, the possibility that these two programs have something to offer one another. In particular, I show that a version of the measurement problem occurs in essentially any non-classical probabilistic theory, and ask to what extent various interpretations of quantum mechanics continue to make sense in such a general setting. I make a start on answering this question in the case of a simplified version of the Everett interpretation. (shrink)
We consider probability theories in general. In the first part of the paper, various constraints are imposed and classical probability and quantumtheory are recovered as special cases. Quantumtheory follows from a set of five reasonable axioms. The key axiom which gives us quantumtheory rather than classical probability theory is the continuity axiom, which demands that there exists a continuous reversible transformation between any pair of pure states. In the second part (...) of this paper, we consider in detail how the measurement process works in both the classical and the quantum case. The key differences and similarities are elucidated. It is shown how measurement in the classical case can be given a simple ontological interpretation which is not open to us in the quantum case. On the other hand, it is shown that the measurement process can be treated mathematically in the same way in both theories even to the extent that the equations governing the state update after measurement are identical. The difference between the two cases is seen to be due not to something intrinsic to the measurement process itself but, rather, to the nature of the set of allowed states and, therefore, ultimately to the continuity axiom. (shrink)
Recent authors have raised objections to the counterfactual interpretation of the Aharonov-Bergmann-Lebowitz (ABL) rule of time-symmetrised quantumtheory (TSQT). I distinguish between two different readings of the ABL rule, counterfactual and non-counterfactual, and confirm that TSQT advocate L. Vaidman is employing the counterfactual reading to which these authors object. Vaidman has responded to the objections by proposing a new kind of time-symmetrised counterfactual, which he has defined in two different ways. It is argued that neither definition succeeds in (...) overcoming the objections, except in a limited special case previously noted by Cohen and Hiley. In addition, a connection is made between TSQT and Price's concept of 'advanced action', which further supports the special case discussed. (shrink)
