It is argued that Minkowski space-time cannot serve as the deep structure within a ``constructive'' version of the special theory of relativity, contrary to widespread opinion in the philosophical community.
The implications for the substantivalist–relationalist controversy of Barbour and Bertotti's successful implementation of a Machian approach to dynamics are investigated. It is argued that in the context of Newtonian mechanics, the Machian framework provides a genuinely relational interpretation of dynamics and that it is more explanatory than the conventional, substantival interpretation. In a companion paper (Pooley [2002a]), the viability of the Machian framework as an interpretation of relativistic physics is explored. 1 Introduction 2 Newton versus Leibniz 3 Absolute space versus (...) an affine connection 4 Anti-relationalist arguments 5 Rehabilitating relationalism 6 Dynamics on the relative configuration space 7 Intrinsic particle dynamics 8 Conclusion. (shrink)
In a recent paper in this journal, Kosso () discussed the observational status of continuous symmetries of physics. While we are in broad agreement with his approach, we disagree with his analysis. In the discussion of the status of gauge symmetry, a set of examples offered by 't Hooft () has influenced several philosophers, including Kosso; in all cases the interpretation of the examples is mistaken. In this paper, we present our preferred approach to the empirical significance of symmetries, re-analysing (...) the cases of gauge symmetry and general covariance. Direct and indirect empirical significance Global and local continuous symmetries Gauge symmetry 3.1 Local gauge symmetry 3.1.1 Discussion of the first claim 3.1.2 Discussion of the second claim 3.2 Global gauge symmetry Space-time symmetries Direct and indirect empirical significance again Conclusion. (shrink)
Abstract The historical evolution of the principle of relativity from Galileo to Einstein is briefly traced, and purported difficulties with Einstein's formulation of the principle are examined and dismissed. This formulation is then compared to a precise version formulated recently in the geometrical language of spacetime theories. We claim that the recent version is both logically puzzling and fails to capture a crucial physical insight contained in the earlier formulations. The implications of this claim for the modern treatment of general (...) dynamical symmetries are discussed. (shrink)
The purpose of this paper is to evaluate the `Lorentzian Pedagogy' defended by J.S. Bell in his essay ``How to teach special relativity'', and to explore its consistency with Einstein's thinking from 1905 to 1952. Some remarks are also made in this context on Weyl's philosophy of relativity and his 1918 gauge theory. Finally, it is argued that the Lorentzian pedagogy---which stresses the important connection between kinematics and dynamics---clarifies the role of rods and clocks in general relativity.
Einstein regarded as one of the triumphs of his 1915 theory of gravity - the general theory of relativity - that it vindicated the action-reaction principle, while Newtonian mechanics as well as his 1905 special theory of relativity supposedly violated it. In this paper we examine why Einstein came to emphasise this position several years after the development of general relativity. Several key considerations are relevant to the story: the connection Einstein originally saw between Mach's analysis of inertia and both (...) the equivalence principle and the principle of general covariance, the waning of Mach's influence owing to de Sitter's 1917 results, and Einstein's detailed correspondence with Moritz Schlick in 1920. (shrink)
The action-reaction principle (AR) is examined in three contexts: (1) the inertial-gravitational interaction between a particle and space-time geometry, (2) protective observation of an extended wave function of a single particle, and (3) the causal-stochastic or Bohm interpretation of quantum mechanics. A new criterion of reality is formulated using the AR principle. This criterion implies that the wave function of a single particle is real and justifies in the Bohm interpretation the dual ontology of the particle and its associated wave (...) function. But it is concluded that the Bohm theory is not dynamically complete because the particle and its associated wave function do not satisfy the AR principle. (shrink)
This paper examines the debate that has arisen in connection with J. L. Schellenberg's work on divine hiddenness. It singles out as especially deserving of attention Paul Moser's proposal that the debate distinguish more clearly between classical theism and Hebraic theisms. This worthwhile proposal, I argue, will be unlikely to exert its full potential influence upon the debate unless certain features of Christian incarnation belief are recognized and addressed in connection with it.
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.
It is argued that awareness of the distinction between dynamical and variational symmetries is crucial to understanding the significance of Noether's 1918 work. Specific attention is paid, by way of a number of striking examples, to Noether's first theorem, which establishes a correlation between dynamical symmetries and conservation principles.
We discuss what we take to be three possible misconceptions in the foundations of general relativity, relating to: the interpretation of the weak equivalence principle and the relationship between gravity and inertia; the connection between gravitational redshift results and spacetime curvature; and the Einstein equivalence principle and the ability to ``transform away" gravity in local inertial coordinate systems.
This book develops an explanation for the roles of observation and theory in scientific endeavor that occupies the middle ground between empiricism and rationalism, and captures the strengths of both approaches. Brown argues that philosophical theories have the same epistemological status as scientific theories and constructs an epistemological theory that provides an account of the role that theory and instruments play in scientific observation. His theory of perception yields a new analysis of objectivity that combines the traditional view of observation (...) as the foundation of scientific objectivity with the contemporary recognition that observation is theory-dependent. (shrink)
The existence of a definite tangent space structure (metric with Lorentzian signature) in the general theory of relativity is the consequence of a fundamental assumption concerning the local validity of special relativity. There is then at the heart of Einstein's theory of gravity an absolute element which depends essentially on a common feature of all the non-gravitational interactions in the world, and which has nothing to do with space-time curvature. Tentative implications of this point for the significance of the vacuum (...) solutions in general relativity, and for the issue of quantising gravity, are briefly examined. (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)
The quantum theory of de Broglie and Bohm solves the measurement problem, but the hypothetical corpuscles play no role in the argument. The solution ﬁnds a more natural home in the Everett interpretation.
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.
In his later writings Kuhn reconsidered his earlier account of incommensurability, clarifying some aspects, modifying others, and explicitly rejecting some of his earlier claims. In Kuhn’s new account incommensurability does not pose a problem for the rational evaluation of competing scientific theories, but does pose a problem for certain forms of realism. Kuhn maintains that, because of incommensurability, the notion that science might seek to learn the nature of things as they are in themselves is incoherent. I develop Kuhn’s new (...) account of incommensurability, respond to his anti-realist argument, and sketch a form of realism in which the realist aim is a pursuable goal.Keywords: Incommensurability; Thomas Kuhn; Rationality; Skill; Theory choice; Translation. (shrink)
The kinematical principle of Equal Passage Times (EPT) was introduced by Winnie in his 1970 derivation of the relativistic coordinate transformations compatible with arbitrary synchrony conventions in one-dimensional space. In this paper, the claim by Winnie and later Giannoni that EPT is a direct consequence of the relativity principle is questioned. It is shown that EPT, given Einstein's 1905 postulates, is equivalent to the relativistic (synchrony independent) clock retardation principle, and that for standard synchrony it reduces to an isotropy condition (...) for contraction (and dilation) effects. (shrink)
A major theme of recent philosophy of science has been the rejection of the empiricist thesis that, with the exception of terms which play a purely formal role, the language of science derives its meaning from some, possibly quite indirect, correlation with experience. The alternative that has been proposed is that meaning is internal to each conceptual system, that terms derive their meaning from the role they play in a language, and that something akin to "meaning" flows from conceptual framework (...) to experience. Much contemporary debate on the nature of conceptual change is a direct outgrowth of this holistic view of concepts, and much of the inconclusiveness of that debate derives from the lack of any clear understanding of what a conceptual system is, or of how conceptual systems confer meaning on their terms. (shrink)
A number of philosophers have argued that a naturalized epistemology cannot be normative, and thus that the norms that govern science cannot themselves be established empirically. Three arguments for this conclusion are here developed and then responded to on behalf of naturalized epistemology. The response is developed in three stages. First, if we view human knowers as part of the natural world, then the attempt to establish epistemic norms that are immune to scientific evaluation faces difficulties that are at least (...) as severe as the purported difficulties for naturalized epistemology. Second, some examples of the ways in which norms are proposed and evaluated in the course of scientific research are considered and it is concluded that science has no need for trans?scientific norms. Finally, the three arguments introduced at the outset have no force when they are viewed in the light of the preceding discussion. (shrink)
One of the widespread confusions concerning the history of the 1887 Michelson-Morley experiment has to do with the initial explanation of this celebrated null result due independently to FitzGerald and Lorentz. In neither case was a strict, longitudinal length contraction hypothesis invoked, as is commonly supposed. Lorentz postulated, particularly in 1895, any one of a certain family of possible deformation effects for rigid bodies in motion, including purely transverse alteration, and expansion as well as contraction; FitzGerald may well have had (...) the same family in mind. A careful analysis of the Michelson-Morley experiment (which reveals a number of serious inadequacies in many text-book treatments) indeed shows that strict contraction is not required. (shrink)
This paper argues that when used judiciously Bayes's law has a role to play in the evaluation of scientific hypotheses. Several examples are presented in which a rational response to evidence requires a judgement whether to apply Bayes's law or whether, for example, to redistribute prior probabilities. The paper concludes that reflection on Bayes's law illustrates how an adequate account of the rational evaluation of hypotheses requires an account of judgement--a point which several philosophers have noted despite few attempts to (...) develop an adequate theory of judgement. (shrink)
It is argued that an unheralded moment marking the beginnings of relativity theory occurred in 1889, when G. F. FitzGerald, no doubt with the puzzling 1887 Michelson-Morley experiment fresh in mind, wrote to Heaviside about the possible effects of motion on inter-molecular forces in bodies. Emphasis is placed on the difference between FitzGerald's and Lorentz's independent justifications of the shape distortion effect involved. Finally, the importance of the their `constructive' approach to kinematics---stripped of any commitment to the physicality of the (...) ether--- will be defended, in the spirit of Pauli, Swann and Bell. (shrink)
J. S. Bell's classic 1966 review paper on the foundations of quantum mechanics led directly to the Bell nonlocality theorem. It is not widely appreciated that the review paper contained the basic ingredients needed for a nonlocality result which holds in certain situations where the Bell inequality is not violated. We present in this paper a systematic formulation and evaluation of an argument due to Stairs in 1983, which establishes a nonlocality result based on the Bell-Kochen-Specker “paradox” in quantum mechanics.
The thesis that certain competing scientific theories are incommensurable was introduced by Kuhn and Feyerabend in 1962 and has been a subject of widespread critique. Critics have generally taken incommensurable theories to be theories which cannot be compared in a rational manner, but both Kuhn and Feyerabend have explicitly rejected this interpretation, and Feyerabend has discussed ways in which such comparisons can be made in a number of his writings. This paper attempts to clarify the incommensurability thesis through the examination (...) of a number of examples, both scientific and nonscientific, of cases in which incommensurable points of view compete. There follows a discussion of Kuhn's analogy between paradigm change and gestalt shifts, the ways in which incommensurable theories can be compared, and one key reason why the incommensurability thesis has been so often misinterpreted by its critics. (shrink)
This paper considers psychotic symptoms in terms of false inferences or beliefs. It is based on the notion that the brain is an organ of inference that actively constructs hypotheses to explain or predict its sensations. This perspective provides a normative account of action and perception that emphasises probabilistic representations; in particular, the confidence or precision of beliefs about the world. We consider sensory attenuation deficits, catatonia and delusions as various expressions of the same core pathology: namely, an aberrant encoding (...) of precision in a predictive coding hierarchy. In predictive coding, precision is thought to be encoded by the postsynaptic gain of neurons reporting prediction error. This suggests that both pervasive trait abnormalities and florid failures of inference in the psychotic state can be linked to factors controlling postsynaptic gain—such as NMDA receptor function and neuromodulation. We illustrate these points using a biologically plausible simulation of attribution of agency—showing how a reduction in the precision of prior beliefs, relative to sensory evidence, can lead to false inference. (shrink)
Between 1964 and 1990, the notion of nonlocality in Bell's papers underwent a profound change as his nonlocality theorem gradually became detached from quantum mechanics, and referred to wider probabilistic theories involving correlations between separated beables. The proposition that standard quantum mechanics is itself nonlocal became divorced from the Bell theorem per se from 1976 on, although this important point is widely overlooked in the literature. In 1990, the year of his death, Bell would express serious misgivings about the mathematical (...) form of the local causality condition, and leave ill-defined the issue of the consistency between special relativity and violation of the Bell-type inequality. In our view, the significance of the Bell theorem, both in its deterministic and stochastic forms, can only be fully understood by taking into account the fact that a fully Lorentz-covariant version of quantum theory, free of action-at-a-distance, can be articulated in the Everett interpretation. (shrink)
The limitations of rational models of ethical decision making and the importance of nurses’ human involvement as moral agents is increasingly being emphasized in the nursing literature. However, little is known about how nurses involve themselves in ethical decision making and action or about educational processes that support such practice. A recent study that examined the meaning and enactment of ethical nursing practice for three groups of nurses (nurses in direct care positions, student nurses, and nurses in advanced practice positions) (...) highlighted that humanly involved ethical nursing practice is also simultaneously a personal process and a socially mediated one. Of particular significance was the way in which differing role expectations and contexts shaped the nurses’ ethical practice. The study findings pointed to types of educative experiences that may help nurses to develop the knowledge and ability to live in and navigate their way through the complex, ambiguous and shifting terrain of ethical nursing practice. (shrink)
It is still perhaps not widely appreciated that in 1905 Einstein used his postulate concerning the ‘constancy’ of the light-speed in the ‘resting’ frame, in conjunction with the principle of relativity, to derive numerical light-speed invariance. Now a ‘weak’ version of the relativity principle (or, alternatively, appeal to the Michelson—Morley experiment) leads from Einstein's light postulate to a condition that we call universal light-speed constancy. which is weaker than light-speed invariance. It follows from earlier independent investigations (Robertson ; Steigler ; (...) Tzanakis and Kyritsis ) that this condition is none the less sufficient to derive the Lorentz transformations up to a scale factor, given the well-known kinematic principle of ‘reciprocity’. In this paper, we follow Robertson and explore the kinematics consistent with universal light-speed constancy without imposing reciprocity, and we recover the Lorentz transformations by further appeal only to the weak relativity principle and spatial isotropy. (shrink)
We highlight and resolve what we take to be three common misconceptions in general relativity, relating to the interpretation of the weak equivalence principle and the relationship between gravity and inertia; the connection between gravitational redshift results and spacetime curvature; and the strong equivalence principle and the local recovery of special relativity in curved, dynamical spacetime.
Fine has recently proved the surprising result that satisfaction of the Bell inequality in a Clauser-Horne experiment implies the existence of joint probabilities for pairs of noncommuting observables in the experiment. In this paper we show that if probabilities are interpreted in the von Mises-Church sense of relative frequencies on random sequences, a proof of the Bell inequality is nonetheless possible in which such joint probabilities are assumed not to exist. We also argue that Fine's theorem and related results do (...) not impugn the common view that local realists are committed to the Bell inequality. (shrink)