Physical Relativity explores the nature of the distinction at the heart of Einstein's 1905 formulation of his special theory of relativity: that between kinematics and dynamics. Einstein himself became increasingly uncomfortable with this distinction, and with the limitations of what he called the 'principle theory' approach inspired by the logic of thermodynamics. A handful of physicists and philosophers have over the last century likewise expressed doubts about Einstein's treatment of the relativistic behaviour of rigid bodies and clocks in motion in (...) the kinematical part of his great paper, and suggested that the dynamical understanding of length contraction and time dilation intimated by the immediate precursors of Einstein is more fundamental. Harvey Brown both examines and extends these arguments, after giving a careful analysis of key features of the pre-history of relativity theory. He argues furthermore that the geometrization of the theory by Minkowski in 1908 brought illumination, but not a causal explanation of relativistic effects. Finally, Brown tries to show that the dynamical interpretation of special relativity defended in the book is consistent with the role this theory must play as a limiting case of Einstein's 1915 theory of gravity: the general theory of relativity.Appearing in the centennial year of Einstein's celebrated paper on special relativity, Physical Relativity is an unusual, critical examination of the way Einstein formulated his theory. It also examines in detail certain specific historical and conceptual issues that have long given rise to debate in both special and general relativity theory, such as the conventionality of simultaneity, the principle of general covariance, and the consistency or otherwise of the special theory with quantum mechanics. Harvey Brown' s new interpretation of relativity theory will interest anyone working on these central topics in modern physics. (shrink)

Modern insolubility proofs of the measurement problem in quantum mechanics not only differ in their complexity and degree of generality, but also reveal a lack of agreement concerning the fundamental question of what constitutes such a proof. A systematic reworking of the (incomplete) 1970 Fine theorem is presented, which is intended to go some way toward clarifying the issue.

Quantum mechanics has raised in an acute form three problems which go to the heart of man's relationship with nature through experimental science: (r) the public objectivity of science, that is, its value as a universal science for all investigators; (2) the empirical objectivity of scientific objects, that is, man's ability to construct a precise or causal spatio-temporal model of microscopic systems; and finally (3), the formal objectivity of science, that is, its value as an expression of what (...) nature is independently of its being an object of human knowledge. These are three aspects of what is generally called the "crisis of objec tivity" or the "crisis of realism" in modern physics. This crisis is. studied in the light of Werner Heisenberg's work. Heisenberg was one of the architects of quantum mechanics, and we have chosen his writings as the principal source-material for this study. Among physicists of the microscopic domain, no one except perhaps Bohr has expressed himself so abundantly and so profoundly on the philosophy of science as Heisenberg. His writings, both technical and non-technical, show an awareness of the mysterious element in scientific knowledge, far from the facile positivism of Bohr and others of his contemporaries. The mystery of human knowledge and human SUbjectivity is for him an abiding source of wonder. (shrink)

The purpose of the paper is to explore different aspects of the covariance of non-relativistic quantum mechanics. First, doubts are expressed concerning the claim that gauge fields can be 'generated' by way of imposition of gauge covariance of the single-particle wave equation. Then a brief review is given of Galilean covariance in the general case of external fields, and the connection between Galilean boosts and gauge transformations. Under time-dependent translations the geometric phase associated with Schrödinger evolution is (...) non-invariant, and the significance of this result is briefly analysed. The covariance properties of Schrödinger dynamics are then brought to bear on certain versions of the modal interpretation of quantum mechanics. The conclusion that it is only relational properties that can be considered coordinate- or gauge-independent elements of reality is reinforced by appeal to the theory of quantum reference frames due to Aharonov and Kauffher. , Cambridge University Press ; pp. 45-70.). (shrink)

Heisenberg'sgendanken experiments in quantum mechanics have given rise to a widespread belief that the indeterminacy relations holding for the variables of a quantal system can be explained quasiclassically in terms of a disturbance suffered by the system in interaction with a quantal measurement, or state preparation, agent. There are a number of criticisms of this doctrine in the literature, which are critically examined in this article and found to be ininconclusive, the chief error being the conflation of this (...) disturbance with the projection postulate. We present a critique of the disturbance theory based on the fact that the required disturbance will in general depend on the interaction time of the system and state-preparer. This point is exploited in the construction of a spin-interaction model which acts as a counterexample to the disturbance doctrine, while remaining faithful to the spirit of Heisenberg'sgedanken experiments. Several consequences of this result are discussed. (shrink)

It was shown by de Broglie and Bohm that the concept of a deterministic particle trajectory is compatible with quantum mechanics. It is demonstrated by explicit construction that there exists another more general deterministic trajectory interpretation. The method exploits an internal angular degree of freedom that is implicit in the Schrödinger equation, in addition to the particle position. The de Broglie-Bohm model is recovered when the new theory is averaged over the internal freedom. The model exhibits a (...) strong form of entanglement which implies a primary role for the wavefunction of the Universe. The conditions of autonomy are examined, and the viability of the theory is established by application to the measurement problem. (shrink)

A relativistic one-particle, quantum theory for spin-zero particles is constructed uponL 2(x, ct), resulting in a positive definite spacetime probability density. A generalized Schrödinger equation having a Hermitian HamiltonianH onL 2(x, ct) for an arbitrary four-vector potential is derived. In this formalism the rest mass is an observable and a scalar particle is described by a wave packet that is a superposition of mass states. The requirements of macroscopic causality are shown to be satisfied by the most probable trajectory (...) of a free tardyon and a nontrivial framework for charged and neutral particles is provided. The Klein paradox is resolved and a link to the free particle field operators of quantum field theory is established. A charged particle interacting with a static magnetic field is discussed as an example of the formalism. (shrink)

This paper presents a minimal formulation of nonrelativistic quantum mechanics, by which is meant a formulation which describes the theory in a succinct, self-contained, clear, unambiguous and of course correct manner. The bulk of the presentation is the so-called “microscopic theory”, applicable to any closed system S of arbitrary size N, using concepts referring to S alone, without resort to external apparatus or external agents. An example of a similar minimal microscopic theory is the standard formulation of classical (...) mechanics, which serves as the template for a minimal quantum theory. The only substantive assumption required is the replacement of the classical Euclidean phase space by Hilbert space in the quantum case, with the attendant all-important phenomenon of quantum incompatibility. Two fundamental theorems of Hilbert space, the Kochen–Specker–Bell theorem and Gleason’s theorem, then lead inevitably to the well-known Born probability rule. For both classical and quantum mechanics, questions of physical implementation and experimental verification of the predictions of the theories are the domain of the macroscopic theory, which is argued to be a special case or application of the more general microscopic theory. (shrink)

Textbooks in quantum mechanics frequently claim that quantum mechanics explains the success of classical mechanics because “the mean values [of quantum mechanical observables] follow the classical equations of motion to a good approximation,” while “the dimensions of the wave packet be small with respect to the characteristic dimensions of the problem.” The equations in question are Ehrenfest’s famous equations. We examine this case for the one-dimensional motion of a particle in a box, and extend (...) the idea deriving a special case of the ideal gas law in terms of the mean value of a generalized force, which has been used in statistical mechanics to define ‘pressure’. The example may be an important test case for recent philosophical theories about the relationship between micro-theories and macro-theories in science. (shrink)

A new approach to developing formulisms of physics based solely on laws of mathematics is presented. From simple, classical statistical definitions for the observed space-time position and proper velocity of a particle having a discrete spectrum of internal states we derive u generalized Schrödinger equation on the space-time manifold. This governs the evolution of an N component wave function with each component square integrable over this manifold and is structured like that for a charged particle in an electromagnetic field but (...) also includes SU(N) gauge field couplings. This construction reveals a new hasis for gauge invariance and new insight into the appearance of spin and other such properties in relativistic quantum mechanics and suggests a new charged particle model. (shrink)

The orthodox presentation of quantum theory often includes statements on state preparation and measurements without mentioning how these processes can be achieved. The often quoted projection postulate is regarded by many as problematical. This paper presents a systematic framework for state preparation and measurement. Within the existing Hilbert space formulation of quantum mechanics for spinless particles we show that it is possible (1)to prepare an arbitrary state and (2)to reduce all quantum measurements to local position measurements (...) in an asymptotic way by unitary evolution processes without recourse to the projection postulate. A generalization to spin-1/2particles is also given. The theory presented provides a general mathematical and theoretical foundation for many practical schemes for state preparation and measurement. (shrink)

In the present paper we give a precise definition of a hidden-variable theory for quantum mechanics, whereby we adopt the weakest possible definition of a hidden-variable theory, which is compatible with the assumption that the bounded observables of a quantum mechanical system are represented by the elements of the real part Ar of a W*-algebra A (of the most general type) and the states are represented by the “normal states” (in the mathematical sense) of A. We (...) then go on to show that an example put forward by Bell in 1966 satisfies our definition (Sec. 2). Finally we make use of Bell's famous theorem to show that for a sufficiently non-commutative W*-algebra A no hidden-variable theory in our sense exists (Theorem 3.3 and its corollaries). (shrink)

One of the key episodes of history of modern physics – Paul Dirac’s startling contrivance of the relativistic theory of the electron – is elicited in the context of lucid epistemological model of mature theory change. The peculiar character of Dirac’s synthesis of special relativity and quantum mechanics is revealed by comparison with Einstein’s sophisticated methodology of the General Relativity contrivance. The subtle structure of Dirac’s scientific research program and first and foremost the odd principles that (...) put up its powerful heuristics is scrutinized with special emphasis on the highly controversial tenet of “mathematical beauty.” It is contended that despite the relentless Dirac’s remarks denigrating the controversial role of philosophy one can trace its indirect influence through Arthur Eddington’s and Hermann Weyl’s whimsical mathematical models. Accordingly, the milestones of Dirac’s research programme realization in the distinctive context of the applied epistemological doctrine are indicated. (shrink)

R.I.G Hughes offers the first detailed and accessible analysis of the Hilbert-space models used in quantum theory and explains why they are so successful.

In this paper we study in details a system of two weakly coupled harmonic oscillators from the point of view of Bohm’s interpretation of quantum mechanics. This system may be viewed as a simple model for the interaction between a photon and a photodetector. We obtain exact solutions for the general case. We then compute approximate solutions for the case where one oscillator is initially in its first excited state (a single photon) reaching the other oscillator in (...) its ground state (the photodetector). The approximate solutions represent the state of both oscillators after the interaction, which is not an eigenstate of the individual hamiltonians for each oscillator, and therefore the energies for each oscillator do not exist in the Copenhagen interpretation of Quantum Mechanics. We use the approximate solutions that we obtained to compute Bohmian trajectories and to study the energy transfer between the oscillators. We conclude that, even using the Bohmian view, the energy of each individual oscillator is not well defined, as the nonlocal quantum potential is not negligible even after the coupling is turned off. (shrink)

A theory of the extended classical charged particle is presented. The theory assumes extension along the forward light cone of the particle instead of the usual now-plane. Solutions are given for many of the traditional problems including 4/3, instability, infinite self-energy, and runaway velocity. The Lorentz and Lorentz-Dirac equations are derived from a more general equation of motion.

When David Bohm published his alternative theory of quantum mechanics in 1952, it was not received well; a recurring criticism was that it formed a reactionary attempt to return to classical physics. In response, Bohm emphasized the progressiveness of his approach, and even turned the accusation of classicality around by arguing that he wanted to move beyond classical elements still inherent in orthodox quantum mechanics. In later years, he moved more and more towards speculative and mystical (...) directions. This paper aims to explain this discrepancy between the ways in which Bohm’s work on quantum mechanics has been received and the way in which Bohm himself presented it. I reject the idea that Bohm’s early work can be described as mechanist, determinist, and realist, in contrast to his later writings, and argue that there is in fact a strong continuity between his work on quantum mechanics from the early 1950s and his later, more speculative writings. In particular, I argue that Bohm was never strongly committed to determinism and was a realist in some ways but not in others. A closer look at Bohm’s philosophical commitments highlights the ways in which his theory of quantum mechanics is non-classical and does not offer a way to avoid all ‘quantum weirdness’. (shrink)

Medieval interpretations of hylomorphism, in which substances are conceived as metaphysical composites of prime matter and substantial form, are receiving attention in contemporary philosophy. It has even been suggested that a recovery of Aquinas's conception of prime matter as a ‘pure potentiality’, lacking any actuality apart from substantial form, may be expedient in hylomorphic interpretations of quantum mechanics. In this paper, we consider a recent hylomorphic interpretation of non-relativistic quantum mechanics, the theory of Cosmic Hylomorphism, which (...) does not explicitly invoke any notion of prime matter in its original formulation. We argue that prime matter does in fact play a role in constituting and individuating particles in this theory. However, we demonstrate that the notion of prime matter which features in the extended version of Cosmic Hylomorphism that we propose here is distinct from Aquinas's conception of prime matter, inasmuch as it has discrete metaphysical parts. (shrink)

Quite rightly, philosophers of physics examine the theories of physics, theories like Quantum Mechanics, Quantum Field Theory, the Special and General Theories of Relativity, and Statistical Mechanics. Far fewer, however, examine how these theories are put to use; that is to say, little attention is paid to the practices of theoretical physicists. In the early 1950s David Bohm and David Pines published a sequence of four papers, collectively entitled, ‘A Collective Description (...) of Electron Interaction.’ This essay uses that quartet as a case study in theoretical practice. In Part One of the essay, each of the Bohm-Pines papers is summarized, and within each summary an overview is given, framing a more detailed account. In Part Two theoretical practice is broken into six elements: (a) the use of models, (b) the use of theory, (c) modes of description and narrative, (d) the use of approximations, (e) experiment and theory, (f) the varied steps employed in a deduction. The last element is the largest, drawing as it does from the earlier ones. Part Three enlarges on the concept of ‘theoretical practice,’ and briefly outlines the subsequent theoretical advances which rendered the practices of Bohm and Pines obsolete, if still respected. (shrink)

Laws of mechanics, quantum mechanics, electromagnetism, gravitation and relativity are derived as “related mathematical identities” based solely on the existence of a joint probability distribution for the position and velocity of a particle moving on a Riemannian manifold. This probability formalism is necessary because continuous variables are not precisely observable. These demonstrations explain why these laws must have the forms previously discovered through experiment and empirical deduction. Indeed, the very existence of electric, magnetic and gravitational fields is (...) predicted by these purely mathematical constructions. Furthermore these constructions incorporate gravitation into special relativity theory and provide corrected definitions for coordinate time and proper time. These constructions then provide new insight into the relationship between manifold geometry and gravitation and present an alternative to Einstein’s general relativity theory. (shrink)

This work, which first appeared in 1936, offers in addition to an historical treatment displaying Cassirer's characteristic insight, an analysis of quantum mechanics largely unaffected by subsequent development in the field. The author argues, on the basis of epistemological considerations, that quantum mechanics necessitates no major revisions in our basic understanding of causality. The new laws simply refer to "definite collectives" rather than things or events and are no less determinate than the old. In the final (...) part the author stresses the independence of causality and continuity in nature and closes by sensibly warning the reader against attempting to establish ethical freedom within the gaps of physical law. Henry Margenau has expanded the bibliography and added a helpful preface which, in part, reports Cassirer's thoughts up to 1945.--R. P. (shrink)

PHILOSOPHY OF SCIENCE, vol. 52, number 1, pp.44-63. R.M. Nugayev, Kazan State |University, USSR. -/- THE HISTORY OF QUANTUM THEORY AS A DECISIVE ARGUMENT FAVORING EINSTEIN OVER LJRENTZ. -/- Abstract. Einstein’s papers on relativity, quantum theory and statistical mechanics were all part of a single research programme ; the aim was to unify mechanics and electrodynamics. It was this broader program – which eventually split into relativistic physics and quantummmechanics – that superseded Lorentz’s theory. The argument (...) of this paper is partly historical and partly methodological. A notion of “crossbred objects” – theoretical objects with contradictory properties which are part of the domain of application of two different research programs – is developed that explains the dynamics of revolutionary theory change. (shrink)

In this basically expository paper we discuss the role of logic and mathematics in researches concerning the ontology of scientific theories, and we consider the particular case of quantum mechanics. We argue that systems of logic in general, and classical logic in particular, may contribute substantially with the ontology of any theory that has this logic in its base. In the case of quantum mechanics, however, from the point of view of philosophical discussions concerning (...) identity and individuality, those contributions may not be welcome for a specific interpretation, and an alternative system of logic perhaps could be used instead of a classical system. In this sense, we argue that the logic and ontology of a scientific theory may be seen as mutually influencing each other. On the one hand, logic contributes to shape the general features of the ontology of a theory; on the other hand, the theory also puts constraints on the possible understanding of ontology and, respectively, on possible systems of logic that may be the underlying logic of the theory. (shrink)

The axiomatic approaches of quantum mechanics and relativity theory are compared with approaches in which the theories are thought to describe readings of certain measurement operations. The usual axioms are shown to correspond with classes of ideal measurements. The necessity is discussed of generalizing the formalisms of both quantum mechanics and relativity theory so as to encompass more realistic nonideal measurements. It is argued that this generalization favours an empiricist interpretation of the mathematical formalisms over (...) a realist one. (shrink)

Why does one theory "succeed" while another, possibly clearer interpretation, fails? By exploring two observationally equivalent yet conceptually incompatible views of quantum mechanics, James T. Cushing shows how historical contingency can be crucial to determining a theory's construction and its position among competing views. Since the late 1920s, the theory formulated by Niels Bohr and his colleagues at Copenhagen has been the dominant interpretation of quantum mechanics. Yet an alternative interpretation, rooted in the work of Louis (...) de Broglie in the early 1920s and reformulated and extended by David Bohm in the 1950s, equally well explains the observational data. Through a detailed historical and sociological study of the physicists who developed different theories of quantum mechanics, the debates within and between opposing camps, and the receptions given to each theory, Cushing shows that despite the preeminence of the Copenhagen view, the Bohm interpretation cannot be ignored. Cushing contends that the Copenhagen interpretation became widely accepted not because it is a better explanation of subatomic phenomena than is Bohm's, but because it happened to appear first. Focusing on the philosophical, social, and cultural forces that shaped one of the most important developments in modern physics, this provocative book examines the role that timing can play in the establishment of theory and explanation. (shrink)

Alberto Cortes, in [1], attempts to show that Leibniz's Principle of The Identity of Indiscernibles is a principle restricted to individuals, and that photons appear to violate L. L is stated by Leibniz as “no two substances are completely similar, or differ solo numero.” In second-order quantification theory with identity L becomes.

It is put forward that modern elementary particle physics cannot be completely unified with the laws of gravity and general relativity without addressing the question of the ontological interpretation of quantum mechanics itself. The position of superstring theory in this general question is emphasized: superstrings may well form exactly the right mathematical system that can explain how quantum mechanics can be linked to a deterministic picture of our world. Deterministic interpretations of quantum (...) mechanics are usually categorically rejected, because of Bell’s powerful observations, and indeed these apply here also, but we do emphasize that the models we arrive at are super-deterministic, which is exactly the case where Bell expressed his doubts. Strong correlations at space-like separations could explain the apparent contradictions. (shrink)

The first part of this long two-part work is a history of the development of the modern theory of the atom from Dalton to the present. The second part offers philosophical reflections on this history beginning with a discussion of epistemological implications and following that with an account of ontological implications. The author deals with familiar questions about the reality of micro-particles, complementarity, indeterminism, the role of the observer and other topics. But he also discusses topics like holism, atomic (...) order, the intelligibility of matter and others which are less commonly discussed by philosophers in connection with modern physical theories. The author, who is trained in physics as well as philosophy, has a flair for metaphysical speculation as well as wide knowledge of contemporary physical theory. He stresses the novelties of the quantum conception of matter, argues against its critics like Bohm, and sees it as presenting a radically new conception of atomic order despite its commitment to indeterminism. The views of Werner Heisenberg, who encouraged the author to write the book and who read it in manuscript, have clearly influenced the author, although they do not dominate his thinking.--R. H. K. (shrink)

This is the first comprehensive study of Schrödinger's scientific and philosophical writings. The task requires a person trained thoroughly in physical science and yet capable of appreciating the sometimes puzzling philosophical ideas Schrödinger put forward. Professor Scott, a physicist, is remarkably successful at communicating both the physical and the philosophical ideas. After a brief summary of Schrödinger's diverse writings, he divides the writings into four groups which are treated in separate chapters. The first group, including very early papers, deals with (...) Schrödinger's work on Statistical Mechanics, and statistical theories in general. The second covers the crucial development of Wave Mechanics. The third concerns Schrödinger's interpretation of quantum mechanics and the important departures from the prevailing views of the Copenhagen school. Finally the fourth group contains Schrödinger's views on life and the self. The author shows that Schrödinger was led to his doctrine of identity by reflecting on the paradox of freedom and determinism. His study "What is Life?" convinced him that living systems are governed by the law of causality but he also believed that men were free. The doctrine of identity was his solution to the paradox. Scott is critical of this solution and a number of other doctrines of Schrödinger. The book is clearly written throughout and is a good introduction to Schrödinger's thought.--R. H. K. (shrink)

The operator form of the generalized canonical momenta in quantum mechanics is derived by a new, instructive method and the uniqueness of the operator form is proven. If one wishes to find the correct representation of the generalized momentum operator, he finds the Hermitian part of the operator —iħ ∂/∂q, whereq q is the generalized coordinate. There are interesting philosophical implications involved in this: It is like saying that a physical structure is composed of two parts, one which (...) is real (the measurable quantity) and one which is pure imaginary. However, in order to understand the theoretical generation of the physical structure, one must look at the imaginary part as well as the real part since the sum of these two parts gives the simplified physical theory. That is why we can choose the total generalized momentum operator as simply —iħ ∂/∂q, but in order to arrive at the “measurable” momentum operator, we must choose the real (Hermitian) part, the other part being anti-Hermitian (corresponding to pure imaginary eigenvalues). We also discuss the operator form of the generalized Hamiltonian and show that the primary focus in developing fundamental concepts and prescriptions in quantum mechanics should be on the generalized momenta rather than on the Hamiltonian. (shrink)

This is the first comprehensive study of Schrödinger's scientific and philosophical writings. The task requires a person trained thoroughly in physical science and yet capable of appreciating the sometimes puzzling philosophical ideas Schrödinger put forward. Professor Scott, a physicist, is remarkably successful at communicating both the physical and the philosophical ideas. After a brief summary of Schrödinger's diverse writings, he divides the writings into four groups which are treated in separate chapters. The first group, including very early papers, deals with (...) Schrödinger's work on Statistical Mechanics, and statistical theories in general. The second covers the crucial development of Wave Mechanics. The third concerns Schrödinger's interpretation of quantum mechanics and the important departures from the prevailing views of the Copenhagen school. Finally the fourth group contains Schrödinger's views on life and the self. The author shows that Schrödinger was led to his doctrine of identity by reflecting on the paradox of freedom and determinism. His study "What is Life?" convinced him that living systems are governed by the law of causality but he also believed that men were free. The doctrine of identity was his solution to the paradox. Scott is critical of this solution and a number of other doctrines of Schrödinger. The book is clearly written throughout and is a good introduction to Schrödinger's thought.--R. H. K. (shrink)

This collection contains twenty-three papers published by Suppes over the last eighteen years. For the most part they are foundational studies ranging over a wide variety of topics in the philosophy of science. The first two of four parts contain papers on methodological issues like models, measurement, probability and utility. There are two papers on models, an axiomatic treatment of extensive quantity and two papers on measurement. The six papers in Part II deal with probability theory and decision theory with (...) reference to theories of behavior, economics, and other topics. Part III contains studies in the axiomatic foundations of physics, one on relativistic kinematics and three on probability in quantum mechanics. The final and longest section contains eight papers on the foundations of psychology. Several of these deal with the psychological or behavioral bases of mathematics. Others deal with unpredictability in human behavior, finite automata, cognition and other topics. The book is nicely printed and those who have learned from Suppes work in the past will be grateful for this collection of his most important papers.--R. H. K. (shrink)

In a comparison of the principles of special relativity and of quantum mechanics, the former theory is marked by its relative economy and apparent explanatory simplicity. A number of theorists have thus been led to search for a small number of postulates - essentially information theoretic in nature - that would play the role in quantum mechanics that the relativity principle and the light postulate jointly play in Einstein's 1905 special relativity theory. The purpose of the (...) present paper is to resist this idea, at least in so far as it is supposed to reveal the fundamental form of the theory. It is argued that the methodology of Einstein's 1905 theory represents a victory of pragmatism over explanatory depth; and that its adoption only made sense in the context of the chaotic state state of physics at the start of the 20th century - as Einstein well knew. (shrink)

The historical development of the electronic configuration model is traced and the status of the model with respect to quantum mechanics is examined. The successes and problems raised by the model are explored, particularly in chemical ab initio calculations. The relevance of these issues to whether chemistry has been reduced to quantum mechanics is discussed, as are some general notions on reduction.

Molecular vibrations and quantum tunneling may link ligand binding to the function of pharmacological receptors. The well‐established lock‐and‐key model explains a ligand's binding and recognition by a receptor; however, a general mechanism by which receptors translate binding into activation, inactivation, or modulation remains elusive. The Vibration Theory of Olfaction was proposed in the 1930s to explain this subset of receptor‐mediated phenomena by correlating odorant molecular vibrations to smell, but a mechanism was lacking. In the 1990s, inelastic electron tunneling (...) was proposed as a plausible mechanism for translating molecular vibration to odorant physiology. More recently, studies of ligands’ vibrational spectra and the use of deuterated ligand analogs have provided helpful information to study this admittedly controversial hypothesis in metabotropic receptors other than olfactory receptors. In the present work, based in part on published experiments from our laboratory using planarians as an experimental organism, I will present a rationale and possible experimental approach for extending this idea to ligand‐gated ion channels. (shrink)

Foundations research in physics, according to Bunge, has lagged behind its sister discipline, the foundations of mathematics. His book is an attempt to partially remedy this situation by analyzing the form and content of some basic ideas in physics and presenting some of the fundamental theories of physics in an axiomatic fashion. The heart of the book consists of axiomatizations of Classical Mechanics, Classical Field Theories, and Quantum Mechanics. Bunge does not claim to be working (...) without predecessors. While the idea of a separate discipline in the foundations of physics is rather new, the existence of material that clearly belongs to foundations research is not. This is attested to by the substantial bibliography at the end of the book. But he is ideally suited to the task of bringing this difficult material together and welding it in his own fashion into a coherent whole. His grasp of physical theory is wide-ranging and he writes with clarity and wit. In the first chapter he states his views on a number of issues in the philosophy of science: explanation, prediction, operationalism, laws, and other topics. The arguments are usually summarized very briefly, or reference is made to other books. Thus those who disagree with his philosophical presuppositions will not be convinced; but friends or foes will miss a great deal of informative material if they do not push on to the axiomatizations which follow and which are the main concern of the book. This book will undoubtedly be a source-book for future foundations research in the physical sciences.--R. H. K. (shrink)

This paper is a comment on both Bunamano and Rovelli (Bridging the neuroscience and physics of time arXiv:2110.01976. (2022)) and Gruber et al. (in Front. Psychol. Hypothesis Theory, 2022) and which discuss the relation between physical time and human time. I claim here, contrary to many views discussed there, that there is no foundational conflict between the way physics views the passage of time and the way the mind/brain perceives it. The problem rather resides in a number of misconceptions leading (...) either to the representation of spacetime as a timeless Block Universe, or at least that physically relevant universe models cannot have preferred spatial sections. The physical expanding universe can be claimed to be an Evolving Block Universe with a time-dependent future boundary, representing the dynamic nature of the way spacetime develops as matter curves spacetime and spacetime tells matter how to move. This context establishes a global direction of time that determines the various local arrows of time. Furthermore time passes when quantum wave function collapse takes place to an eigenstate; during this process, information is lost. The mind/brain acts as an imperfect clock, which coarse-grains the physical passage of time along a world line to determine the experienced passage of time, because neural processes take time to occur. This happens in a contextual way, so experienced time is not linearly related to physical time in general. Finally I point out that the Universe is never infinitely old: its future endpoint always lies infinitely faraway in the future. (shrink)

One problem with assessing quantum logic is that there are considerable differences between its practitioners. In particular they offer different versions of the set of sentences which the logic governs. On some accounts the sentences involved describe events, on others they are ascriptions of properties. In this paper a framework is offered within which to discuss different quantum logical interpretations of quantum theory, and then the works of Jauch, Putnam, van Fraassen and Kochen are located within it.

Quantum mechanics is currently being tried to be used as a probe to unravel the mysteries of consciousness. Present paper deals with this probe, quantum mechanics and its usefulness in getting an insight of working of human consciousness. The formation of quantum mechanics based on certain axioms, its development to study the dynamical behavior and motions of fundamental particles and quantum energy particles moving with the velocity of light, its insistence on wave functions, (...) its probability approach, its dependence on uncertainty principles will all be critically discussed. The result of this discussion will be presented. Its limitations in unraveling the form, function and biological nature of consciousness will be presented. The alternative probe available and being used – the translation of Upanishadic insight and Advaita philosophy into cognitive science elements in delineating the definition, form and function of Consciousness will be given. The usefulness of this modeling and analysis in understanding the consciousness, mind and its functions in cognitive science and theory of human language acquisition and communication will also be presented. The physic-chemical nature of ideas, senses, thoughts, feelings, utterances will be grossly dealt with. The functions of consciousness and mind, in knowledge and language acquisition and communication will be dealt with. (shrink)

The contemporary view of the fundamental role of time in physics generally ignores its most obvious characteric, namely its flow. Studies in the foundations of relativistic mechanics during the past decade have shown that the dynamical evolution of a system can be treated in a manifestly covariant way, in terms of the solution of a system of canonical Hamilton type equations, by considering the space-time coordinates and momenta ofevents as its fundamental description. The evolution of the events, as functions (...) of a universal invariant world, or historical, time, traces out the world lines that represent the phenomena (e.g., particles) which are observed in the laboratory. The positions in time of each of the events, i.e., the time of their potential detection, are, in this framework, controlled by this universal parameter τ, the time at which they are generated (and may proceed in the positive or negative sense). We find that the notion of thestate of a system requires generalization; at any given τ, it involves information about the system at timest(τ) ≠ τ. The correlation of what may be measured att(τ) with what is generated at τ is necessarily quite rigid, and is related covariantly to the spacelike correlations found in interference experiments. We find, furthermore, that interaction with Maxwell electromagnetism leads back to a static picture of the world, with no real evolution. As a consequence of this result, and the requirement of gauge invariance for the quantum mechanical evolution equation, we conclude that electromagnetism is described by a pre-Maxwell field, whose τ-integral (or asymptotic behavior as τ → ∞) may be identified with the Maxwell field. We therefore consider the world of events in space time, interacting through τ-dependent pre-Maxwell fields, as far as electrodynamics is concerned, as the objective dynamical reality. Our perception of the world, through laboratory detectors and our eyes, are based onintegration over τ over intervals sufficiently large to obtain an aposteriori description of the phenomena which coincides with the Maxwell theory. Fundamental notions, such as the conservation of charge, rest on this construction. The decomposition of the common notion of time into two essentially different aspects, one associated with an unvarying flow, and the second with direct observation subject to dynamical modification, has profound philosophical consequences, of which we are able to explore here only a few. (shrink)

INTERNATIONAL STUDIES IN THE PHILOSOPHY OF SCIENCE Vol. 2, number 1, Autumn 1987, pp. 84-104. R.M. Nugayev. The genesis and structure of models in the modern theory of gravity. Abstract. The analysis of theory-choice problem in modern theory of gravity necessitates consideration of the genesis and the structure of the systems of gravitational abstract objects. My approach to physical theory structure uses and develops the ideas of V.S.Stepin. The basic equations of general relativity - Einstein’s equations – (...) are shown to describe the relations between the abstract objects of the basic model only. The whole theory of gravity chain consists of general relativity, nonmetric theories of gravitation, Newton’s theory of gravitation and special theory of relativity. All these theories describe the relations between the abstract objects of partial ideal models subordinated to the basic one. (shrink)

The first part of this long two-part work is a history of the development of the modern theory of the atom from Dalton to the present. The second part offers philosophical reflections on this history beginning with a discussion of epistemological implications and following that with an account of ontological implications. The author deals with familiar questions about the reality of micro-particles, complementarity, indeterminism, the role of the observer and other topics. But he also discusses topics like holism, atomic (...) order, the intelligibility of matter and others which are less commonly discussed by philosophers in connection with modern physical theories. The author, who is trained in physics as well as philosophy, has a flair for metaphysical speculation as well as wide knowledge of contemporary physical theory. He stresses the novelties of the quantum conception of matter, argues against its critics like Bohm, and sees it as presenting a radically new conception of atomic order despite its commitment to indeterminism. The views of Werner Heisenberg, who encouraged the author to write the book and who read it in manuscript, have clearly influenced the author, although they do not dominate his thinking.--R. H. K. (shrink)

The inherently subjective nature of consciousness severely limits our ability to make progress on the problem of consciousness. The inability to acquire objective, publicly available data on the phenomenal aspect of consciousness makes evaluating alternative theories very difficult, if not impossible. However, the anomalous nature of subjective states with respect to our conventional theories of the physical world suggests the possibility of considering other anomalous data around consciousness that happen to be objective. For such purposes, I propose that (...) we examine the psi data gathered under laboratory conditions, which generally receive little attention. I wish to consider whether we have theories or frameworks of consciousness that attempt to account for subjective qualia but also fit the psi data. I argue that Russellian monism can be combined with an argument regarding quantum holism to arrive at a version of cosmopsychism that fits very well with the psi data. While I do not argue that such a framework exhausts the theoretical possibilities, I do suggest we can move forward with a framework that has attractive theoretical features and is also consistent with objective data currently on the table. (shrink)

Robin Hendry has presented an account of two equally valid ways of understanding the nature of chemical bonding, consisting of what the terms the structural and the energetic views respectively. In response, Weisberg has issued a “challenge to the structural view”, thus implying that the energetic view is the more correct of the two conceptions. In doing so Weisberg identifies the delocalization of electrons as the one robust feature that underlies the increasingly accurate quantum mechanical calculations starting with the (...) Heitler-London method and moving on to such approaches as the valence bond and molecular orbital theories of chemical bonding. The present article provides a critical evaluation of Weisberg’s article and concludes that he fails to characterize the nature of chemical bonding in several respects. I claim that Hendry’s structural and energetic views remain as equally viable ways of understanding chemical bonding. Whereas the structural view is more appropriate for chemists, the energetic view is preferable to physicists. Neither view is more correct unless one subscribes to the naively reductionist view of considering that the more physical energetic view is the more correct one. (shrink)

The centerpiece of Jeffrey Bub's book Interpreting the Quantum World is a theorem (Bub and Clifton 1996) which correlates each member of a large class of no-collapse interpretations with some 'privileged observable'. In particular, the Bub-Clifton theorem determines the unique maximal sublattice L(R,e) of propositions such that (a) elements of L(R,e) can be simultaneously determinate in state e, (b) L(R,e) contains the spectral projections of the privileged observable R, and (c) L(R,e) is picked out by R and e alone. (...) In this paper, we explore the issue of maximal determinate sets of observables using the tools provided by the algebraic approach to quantum theory; and we call the resulting algebras of determinate observables, "maximal *beable* subalgebras". The capstone of our exploration is a generalized version of Bub and Clifton's theorem that applies to arbitrary (i.e., both mixed and pure) quantum states, to Hilbert spaces of arbitrary (i.e., both finite and infinite) dimension, and to arbitrary observables (including those with a continuous spectrum). Moreover, in the special case covered by the original Bub-Clifton theorem, our theorem reproduces their result under strictly weaker assumptions. This added level of generality permits us to treat several topics that were beyond the reach of the original Bub-Clifton result. In particular: (a) We show explicitly that a (non-dynamical) version of the Bohm theory can be obtained by granting privileged status to the position observable. (b) We show that Clifton's (1995) characterization of the Kochen-Dieks modal interpretation is a corollary of our theorem in the special case when the density operator is taken as the privileged observable. (c) We show that the 'uniqueness' demonstrated by Bub and Clifton is only guaranteed in certain special cases -- viz., when the quantum state is pure, or if the privileged observable is compatible with the density operator. We also use our results to articulate a solid mathematical foundation for certain tenets of the orthodox Copenhagen interpretation of quantum theory. For example, the uncertainty principle asserts that there are strict limits on the precision with which we can know, simultaneously, the position and momentum of a quantum-mechanical particle. However, the Copenhagen interpretation of this fact is not simply that a precision momentum measurement necessarily and uncontrollably disturbs the value of position, and vice-versa; but that position and momentum can never in reality be thought of as simultaneously determinate. We provide warrant for this stronger 'indeterminacy principle' by showing that there is no quantum state that assigns a sharp value to both position and momentum; and, a fortiori, that it is mathematically impossible to construct a beable algebra that contains both the position observable and the momentum observable. We also prove a generalized version of the Bub-Clifton theorem that applies to "singular" states (i.e., states that arise from non-countably-additive probability measures, such as Dirac delta functions). This result allows us to provide a mathematically rigorous reconstruction of Bohr's response to the original EPR argument -- which makes use of a singular state. In particular, we show that if the position of the first particle is privileged (e.g., as Bohr would do in a position measuring context), the position of the second particle acquires a definite value by virtue of lying in the corresponding maximal beable subalgebra. But then (by the indeterminacy principle) the momentum of the second particle is not a beable; and EPR's argument for the simultaneous reality of both position and momentum is undercut. (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)

Saunders' recent arguments in favour of the weak discernibility of (certain) quantum particles seem to be grounded in the 'generalist' view that science only provides general descriptions of the worlIn this paper, I introduce the ‘generalist’ perspective and consider its possible justification and philosophical basis; and then look at the notion of weak discernibility. I expand on the criticisms formulated by Hawley (2006) and Dieks and Veerstegh (2008) and explain what I take to be the basic problem: that (...) the properties invoked by Saunders cannot be pointed to as ‘individuators’ of otherwise indiscernible (and thus numerically identical) entities because their ontological status remains underdetermined by the evidence and the established interpretation of the theory. In addition to to this, I suggest that Saunders does not deal adequately with bosons, and cannot do so exactly because he subscribes to PII and the generalist picture. The last part of the paper contains a critical examination of the claim (or at least implicit assumption) that the generalist picture should be regarded as obviously compelling by the modern-day empiricist. (shrink)