The author considers the empirical component of physical theories. He studies the origin and development of the theory of physical experiment, the structure and gnoseological hypotheses of the measuring process, as well as the relativity principle concerning the measuring equipment. Examples of modern physical theories are used in order to demonstrate the influence of experimental facts on the formation and development, verification and accepting of these theories in the structure of scientific systems. The role of accidental (...) experimental facts in this process is also the subject. (shrink)
New perspectives on Pierre Duhem’s The aim and structure of physicaltheory Content Type Journal Article DOI 10.1007/s11016-010-9467-3 Authors Anastasios Brenner, Department of Philosophy, Paul Valéry University-Montpellier III, Route De Mende, 34199 Montpellier cedex 5, France Paul Needham, Department of Philosophy, University of Stockholm, 10691 Stockholm, Sweden David J. Stump, Department of Philosophy, University of San Francisco, 2130 Fulton Street, San Francisco, CA 94117, USA Robert Deltete, Department of Philosophy, Seattle University, 901 12th Avenue, Seattle, WA 98122-1090, USA (...) Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796 Journal Volume Volume 20 Journal Issue Volume 20, Number 1. (shrink)
This paper addresses the extent to which both Julian Barbour‘s Machian formulation of general relativity and his interpretation of canonical quantum gravity can be called timeless. We differentiate two types of timelessness in Barbour‘s (1994a, 1994b and 1999c). We argue that Barbour‘s metaphysical contention that ours is a timeless world is crucially lacking an account of the essential features of time—an account of what features our world would need to have if it were to count as being one in which (...) there is time. We attempt to provide such an account through considerations of both the representation of time in physicaltheory and in orthodox metaphysical analyses. We subsequently argue that Barbour‘s claim of timelessness is dubious with respect to his Machian formulation of general relativity but warranted with respect to his interpretation of canonical quantum gravity. We conclude by discussing the extent to which we should be concerned by the implications of Barbour‘s view. (shrink)
: The Hellenistic reception of Babylonian horoscopic astrology gave rise to the question of what the planets really do and whether astrology is a science. This question in turn became one of defining the Greco-Latin science of astronomy, a project that took Aristotle's views as a starting-point. Thus, I concentrate on one aspect of the various definitions of astronomy proposed in Hellenistic times, their demarcation of astronomy and physicaltheory. I explicate the account offered by Geminus and its (...) subordination of astronomy to arguments made in physicaltheory about what really is the case. I then show how Ptolemy treats the same topic but maintains that this science is sufficient on its own to determine the realia it studies. In this way, I identify two moments in an obvious process of intellectual change that had profound consequences for the history of astronomy and cosmology over the next 1500 years. My hope is that this will advance our understanding of the reception of horoscopic astrology in Hellenistic times and also serve to locate Ptolemy more fully in his intellectual context. (shrink)
Abstract This paper examines a fundamental, though relatively understudied, aspect of the physicaltheory of the physician Asclepiades of Bithynia, namely his doctrine of pores. My principal thesis is that this doctrine is dependent on a conception of void taken directly from Epicurean physics. The paper falls into two parts: the first half addresses the evidence for the presence of void in Asclepiades' theory, and concludes that his conception of void was basically that of Epicurus; the second (...) half focuses on the precise nature of Asclepiadean pores, and seeks to show that they represent void interstices between the primary particles of matter which are the constituents of the human body, and are thus exactly analogous to the void interstices between atoms within solid objects in Epicurus' theory. (shrink)
One can (for the most part) formulate a model of a classical system in either the Lagrangian or the Hamiltonian framework. Though it is often thought that those two formulations are equivalent in all important ways, this is not true: the underlying geometrical structures one uses to formulate each theory are not isomorphic. This raises the question whether one of the two is a more natural framework for the representation of classical systems. In the event, the answer is yes: (...) I state and prove two technical results, inspired by simple physical arguments about the generic properties of classical systems, to the effect that, in a precise sense, classical systems evince exactly the geometric structure Lagrangian mechanics provides for the representation of systems, and none that Hamiltonian mechanics does. The argument not only clarifies the conceptual structure of the two systems of mechanics, their relations to each other, and their respective mechanisms for representing physical systems. It also provides a decisive counter-example to the semantical view of physical theories, and one, moreover, that shows its crucial deficiency: a theory must be, or at least be founded on, more than its collection of models (in the sense of Tarski), for a complete semantics requires that one take account of global structures defined by relations among the individual models. The example also shows why naively structural accounts of theory cannot work: simple isomorphism of theoretical and empirical structures is not rich enough a relation to ground a semantics. (shrink)
We want to consider anew the question, which is recurrent along the history of philosophy, of the relationship between rationality and mathematics, by inquiring to which extent the structuration of rationality, which ensures the unity of its function under a variety of forms (and even according to an evolution of these forms), could be considered as homeomorphic with that of mathematical thought, taken in its movement and made concrete in its theories. This idea, which is as old as philosophy itself, (...) although it has not been dominant, has still been present to some degree in the thought of modern science, in Descartes as well as in Kant, Poincaré or Einstein (and a few other scientists and philosophers). It has been often harshly questioned, notably in the contemporaneous period, due to the failure of the logistic programme, as well as to the variety of “empirical” knowledges, and, in a general way, to the character of knowledges that show them as transitory, evolutive and mind-built. However, the analysis of scientific thought through its inventive and creative processes leads to characterize this thought as a type of rational form whose configurations can be detailed rather precisely. In this work we shall propose, first, a quick sketch of some philosophical requirements for such a research programme, among which the need for an harmonization, and even a conciliation, between the notions of rational (or rationality), of intuitive grasp and of creative thought. Then we shall examine some processes of creative scientific thought bearing on the knowledge and the understanding of the world, distinct from mathematics although keeping tight relations with them. Contemporary physical theories are privileged witnesses in this respect, for in them the rational thought of phenomena makes an intrinsic use of mathematical thought, which contributes to the structuration of the formers and to the expression of their concepts (which entails the physical contents of the latter). The General Theory of Relativity and the Quantum Theory are exemplar to this, as they directly reveal what can be called the “drag of physical thought par the mathematical form”, which makes possible to overcome the limitations of the physical knowledge previously adquired. This process is tightly related to the modalities and to the stucture of the rational thought underlying it. This is what we would like to show. DOI:10.5007/1808-1711.2011v15n2p303. (shrink)
It is common in the literature on electrodynamics and relativity theory that the transformation rules for the basic electrodynamical quantities are derived from the hypothesis that the relativity principle (RP) applies for Maxwell's electrodynamics. As it will turn out from our analysis, these derivations raise several problems, and certain steps are logically questionable. This is, however, not our main concern in this paper. Even if these derivations were completely correct, they leave open the following questions: (1) Is (RP) a (...) true law of nature for electrodynamical phenomena? (2) Are, at least, the transformation rules of the fundamental electrodynamical quantities, derived from (RP), true? (3) Is (RP) consistent with the laws of electrodynamics in one single inertial frame of reference? (4) Are, at least, the derived transformation rules consistent with the laws of electrodynamics in one single frame of reference? Obviously, (1) and (2) are empirical questions. In this paper, we will investigate problems (3) and (4). First we will give a general mathematical formulation of (RP). In the second part, we will deal with the operational definitions of the fundamental electrodynamical quantities. As we will see, these semantic issues are not as trivial as one might think. In the third part of the paper, applying what J. S. Bell calls “Lorentzian pedagogy”---according to which the laws of physics in any one reference frame account for all physical phenomena---we will show that the transformation rules of the electrodynamical quantities are identical with the ones obtained by presuming the covariance of the coupled Maxwell--Lorentz equations, and that the covariance is indeed satisfied. As to problem (3), the situation is much more complex. As we will see, the relativity principle is actually not a matter of the covariance of the physical equations, but it is a matter of the details of the solutions of the equations, which describe the behavior of moving objects. This raises conceptual problems concerning the meaning of the notion “the same system in a collective motion”. In case of electrodynamics, there seems no satisfactory solution to this conceptual problem; thus, contrary to the widespread views, the question we asked in the title has no obvious answer. (shrink)
Orthodox quantum mechanics is technically built around an element that von Neumann called Process 1. In its basic form it consists of an action that reduces the prior state of a physical system to a sum of two parts, which can be regarded as the parts corresponding to the answers ‘Yes’ and ‘No’ to a specific question that this action poses, or ‘puts to nature’. Nature returns one answer or the other, in accordance with statistical weightings specified by the (...)theory. Thus the standard statistical element in quantum theory enters only after the Process-1 choice is made, while the known deterministic element in quantum theory governs the dynamics that prevails between the reduction events, but not the process that determines which of the continuum of allowed Process-1 probing actions will actually occur. The rules governing that selection process are not fixed by the theory in its present form. This freedom can be used to resolve in a natural way an apparent problem of the orthodox theory, its biocentrism. That resolution produces a rationally coherent realization of the theory that preserves the basic orthodox structure but allows naturally.. (shrink)
The measurement problem of quantum theory 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 quantum theory, 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)
It is demonstrated that the reduction of a physicaltheory S to another one, T, in the sense that S can be derived from T holds in general only for the mathematical framework. The interpretation of S and the associated central terms cannot all be derived from those of T because of the qualitative differences between the cognitive levels of S and T. Their cognitively autonomous status leads to an epistemic as well as an ontological pluralism. This pluralism (...) is consistent with the unity of nature in the sense of a substantive monism. (shrink)
This article addresses the question of the mechanisms of the emergence of structure and meaning in the biological and physical sciences. It proceeds from an examination of the concept of intentionality and proposes a model of intentional behavior on the basis of results of computer simulations of structural and functional self-organization. Current attempts to endow intuitive aspects of meaningful complexity with operational content are analyzed and the metaphor of DNA as a computer program (the `genetic program') is critically examined (...) in relation to an alternative metaphor of DNA as data. It is argued that relatively simple networks of boolean automata can classify and recognize patterns of binary strings on the basis of non-programmed, self-generated criteria, but lack a capacity for self-observation and interpretation. To overcome this problem it is necessary to clarify the relationships between the goals and underlying mechanisms of a process and between a system and its environment. It will be shown that memory devices that record the histories of interactions are essential for models of conscious and unconscious intentional behavior and that the possibility of infinitely sophisticated - and therefore unprogrammable - machines cannot be avoided. It will be argued that the notion of infinite sophistication allows the ideas of self-organization and physical determinism to be reconciled. These models will be used to suggest how the voluntary aspect of decision-making in general can emerge out of functional self-organizing processes. The conclusion will introduce the notion of `underdetermination' of theories, which imposes an intrinsic limitation on models of complex natural systems - a limitation that, at the same time, may be precisely what makes possible mutual understanding and intersubjectivity. (shrink)
Considerable work within the modern 'space-time theory' approach to relativity physics has been devoted to clarifying the role and meaning of the principle of relativity. Two recent discussions of the principle within this approach, due to Arntzenius (1990) and Friedman (1983), are found to contain difficulties.
Several authors have recently attempted to provide a physicalist analysis of causation by appealing to terms from physics that characterise causal processes. Accounts based on forces, energy/momentum transfer and fundamental interactions have been suggested in the literature. In this paper, I wish to show that the former two are untenable when the effect of enclosed electromagnetic fluxes in quantum theory is considered (i.e. the Aharonov-Bohm effect). Furthermore, I suggest that even in the classical and non-relativistic limits, a (...) class='Hi'>theory of fundamental interactions should not be reduced to either a theory of forces or of energy/momentum transfer, but should be understood as a classical account of mutual interactions. Causal links are therefore correctly characterised by generalised potentials. This leads to some speculation regarding the fundamental ontology of interactions and, in particular, the role of the quantum mechanical phase. (shrink)
This classic work in the philosophy of physical science is an incisive and readable account of the scientific method. Pierre Duhem was one of the great figures in French science, a devoted teacher, and a distinguished scholar of the history and philosophy of science. This book represents his most mature thought on a wide range of topics.
The empirical validity of the locality (LOC) principle of relativity is used to argue in favour of a local hidden variable theory (HVT) for individual quantum processes. It is shown that such a HVT may reproduce the statistical predictions of quantum mechanics (QM), provided the reproducibility of initial hidden variable states is limited. This means that in a HVT limits should be set to the validity of the notion of counterfactual definiteness (CFD). This is supported by the empirical evidence (...) that past, present, and future are basically distinct. Our argumentation is contrasted with a recent one by Stapp resulting in the opposite conclusion, i.e. nonlocality or the existence of faster-than-light influences. We argue that Stapp’s argumentation still depends in an implicit, but crucial, way on both the notions of hidden variables and of CFD. In addition, some implications of our results for the debate between Bohr and Einstein, Podolsky and Rosen are discussed. (shrink)
It is shown that both covariant harmonic oscillator formalism and quantum field theory are based on common physical principles which include Poincaré covariance, Heisenberg's space-momentum uncertainty relation, and Dirac's “C-number” time-energy uncertainty relation. It is shown in particular that the oscillator wave functions are derivable from the physical principles which are used in the derivation of the Klein-Nishina formula.
The time-dependent Schrödinger equation has been derived from three assumptions within the domain of classical and stochastic mechanics. The continuity equation isnot used in deriving the basic equations of the stochastic theory as in the literature. They are obtained by representing Newton's second law in a time-inversion consistent equation. Integrating the latter, we obtain the stochastic Hamilton-Jacobi equation. The Schrödinger equation is a result of a transformation of the Hamilton-Jacobi equation and linearization by assigning the arbitrary constant ħ=2mD. An (...) experiment is proposed to determine ħ and to test a hypothesis of the theory directly. A mathematical apparatus is formulated from the Jacobian formalism to derive physical parameters from ψ(x, t) and to obtain operators for the boundary cases of the theory. The operator formalisms are compared by means of a well-known solution in the quantum theory. (shrink)
The connection of the structure of statistical selection procedures with measure theory is investigated. The methods of measure theory are applied in order to analyze a mathematical description of preparation and registration of physical systems that is used by G. Ludwig for a foundation of quantum mechanics.
I reject the widely held view that Duhem's 1906 book La Théorie physique is a statement of instrumentalistic conventionalism, motivated by the scientific crisis at the end of the nineteenth century. By considering Duhem's historical context I show that his epistemological views were already formed before the crisis occured; that he consistently supported general thermodynamics against the new atomism; and that he rejected the epistemological views of the latter's philosophical supporters. In particular I show that Duhem rejected Poincaré's account of (...) scientific language, Le Roy's view that laws are definitions, and the conventionalist's use of simplicity as the criterion of theory choice. Duhem regarded most theory choices as decidable on empirical grounds, but made historical context the main determining factor in scientific change. (shrink)
Discussions of the metaphysical status of spacetime assume that a spacetime theory offers a causal explanation of phenomena of relative motion, and that the fundamental philosophical question is whether the inference to that explanation is warranted. I argue that those assumptions are mistaken, because they ignore the essential character of spacetime theory as a kind of physical geometry. As such, a spacetime theory does notcausally explain phenomena of motion, but uses them to construct physicaldefinitions of basic (...) geometrical structures by coordinating them with dynamical laws. I suggest that this view of spacetime theories leads to a clearer view of the philosophical foundations of general relativity and its place in the historical evolution of spacetime theory. I also argue that this view provides a much clearer and more defensible account of what is entailed by realism concerning spacetime. (shrink)
An objective and relational theory of local time is expounded and its philosophical implications are discussed in Sect. 2. In Sect. 3 certain physical and metaphysical questions concerning time are taken up in the light of that theory. The basic concepts of the theory are those of event, reference frame, chronometric scale, and time function. These are subject to four axioms: existence of events, frames and scales; time is a real valued function; the set of events (...) is compact; and any duration can be subdivided into two contiguous durations. Several theorems are derived, among them the one of the asymmetry of time. And a number of concepts are defined, such as those of time order, instant, and time coordinate. It is argued that the theory, though untestable, belongs to the background of a number of scientific theories. It is also shown that it includes all relational theories of time. The usual confusion between the asymmetry of time and the direction of irreversible processes is clarified. Time reversal is interpreted either as a purely formal operation or as a convenient way of describing motion reversed processes. Time orders are shown to be both relative and objective, apart from the choice of the positive direction, which is conventional. The various attempts to define the direction of time in terms of irreversible processes are shown to be logically untenable and methodologically undesirable. A number of metaphysical questions, such as the one of the reality and the fundamental character of time, are tackled. Finally the occasion is seized to extoll the advantages of systematization over both ordinary language discussions and open context analyses. (shrink)
Consciousness and the mind are prescientific concepts that begin with Greek theorizing. They suppose human rationality and reasoning placed in the human head by God, who structured the universe he created with the same kind of underlying characteristics. Descartes’ development of the model included scientific objectivity by placing the mind outside the physical universe. In its failure under evidential scrutiny and without physical explanation, this model is destined for terminal decline. Instead, a genuine biological and physical function (...) for the brain phenomenon can be developed. This is the theory of brain-sign. It accepts the causality of the brain as its physical characteristics, already under scientific scrutiny. What is needed is a new neurophysiological language that specifies the relation of the structure and operation of the brain to organismic action in the world. Still what is lacking is an account of how neurophysiologies in different organisms communicate on unpredictable dynamic tasks. It is this evolved capacity that has emerged as brain-sign. Thus rather than mentality being an inner epistemological parallel world suddenly appearing in the head, brain-sign, as the neural sign of the causal status of the brain capable of being held adequately in common, facilitates the communicative medium of otherwise isolated organisms. The biogenesis of the phenomenon thus emerges directly from the account of the physical brain, and functions as a monistic feature of organisms in the physical world. This new paradigm offers disciplinary compatibility, and genuine development in behavioral and brain sciences. (shrink)
Earlier, we have studied computations possible by physical systems and by algorithms combined with physical systems. In particular, we have analysed the idea of using an experiment as an oracle to an abstract computational device, such as the Turing machine. The theory of composite machines of this kind can be used to understand (a) a Turing machine receiving extra computational power from a physical process, or (b) an experimenter modelled as a Turing machine performing a test (...) of a known physicaltheory T. Our earlier work was based upon experiments in Newtonian mechanics. Here we extend the scope of the theory of experimental oracles beyond Newtonian mechanics to electrical theory. First, we specify an experiment that measures resistance using a Wheatstone bridge and start to classify the computational power of this experimental oracle using non-uniform complexity classes. Secondly, we show that modelling an experimenter and experimental procedure algorithmically imposes a limit on our ability to measure resistance by the Wheatstone bridge. The connection between the algorithm and physical test is mediated by a protocol controlling each query, especially the physical time taken by the experimenter. In our studies we find that physical experiments have an exponential time protocol, this we formulate as a general conjecture. Our theory proposes that measurability in Physics is subject to laws which are co-lateral effects of the limits of computability and computational complexity. (shrink)
This paper discusses Husserl’s views on physical theories in the first volume of his Logical Investigations , and compares them with those of his contemporaries Pierre Duhem and Henri Poincaré. Poincaré’s views serve as a bridge to a discussion of Husserl’s almost unknown views on physical geometry from about 1890 on, which in comparison even with Poincaré’s—not to say Frege’s—or almost any other philosopher of his time, represented a rupture with the philosophical tradition and were much more in (...) tune with the physical geometry underlying the Einstein-Hilbert general theory of relativity developed more than two decades later. (shrink)
The formal methods of the representational theory of measurement (RTM) are applied to the extensive scales of physical science, with some modifications of interpretation and of formalism. The interpretative modification is in the direction of theoretical realism rather than the narrow empiricism which is characteristic of RTM. The formal issues concern the formal representational conditions which extensive scales should be assumed to satisfy; I argue in the physical case for conditions related to weak rather than strong extensive (...) measurement, in the sense of Holman 1969 and Colonius 1978. The problem of justifying representational conditions is addressed in more detail than is customary in the RTM literature; this continues the study of the foundations of RTM begun in an earlier paper. The most important formal consequence of the present interpretation of physical extensive scales is that the basic existence and uniqueness properties of scales (representation theorem) may be derived without appeal to an Archimedean axiom; this parallels a conclusion drawn by Narens for representations of qualitative probability. It is concluded that there is no physical basis for postulation of an Archimedean axiom. (shrink)
The purpose of this paper is to present a bio-physical basis of mathematics. The essence of the theory is that function in the nervous system is mathematical. The mathematics arises as a result of the interaction of energy (a wave with a precise curvature in space and time) and matter (a molecular or ionic structure with a precise form in space and time). In this interaction, both energy and matter play an active role. That is, the interaction results (...) in a change in form of both energy and matter. There are at least six mathematical operations in a simple synaptic region. It is believed the form of both energy and matter are specific, and their interaction is specific, that is, function in most of the nervous system is stereotyped. It is suggested that mathematics be taken out of the mind and placed where it belongs — in nature and the synaptic regions of the nervous system; it results in both places from a precise interaction between energy (in a precise form) and matter (in a precise structure). (shrink)
This paper discusses Husserl’s views on physical theories in the first volume of his Logical Investigations, and compares them with those of his contemporaries Pierre Duhem and Henri Poincaré. Poincaré’s views serve as a bridge to a discussion of Husserl’s almost unknown views on physical geometry from about 1890 on, which in comparison even with Poincaré’s—not to say Frege’s—or almost any other philosopher of his time, represented a rupture with the philosophical tradition and were much more in tune (...) with the physical geometry underlying the Einstein-Hilbert general theory of relativity developed more than two decades later. (shrink)
The questions of observational error and ambiguity of interpretation that have been raised in connection with the reported observation of a magnetic monopole have precipitated a situation calling for some further insight into the pairing principles of nature. A basic distinction relates to whether or not a pair is “ordered” (e.g., sexual pair) or without a priori order (e.g., mirror pair). It is shown that the polarity of electric charge is to be regarded as an example of pairing without an (...) intrinsic a priori order. It then follows that “action” also exhibits a pairing without a priori order. The relation ofPC andTC to unordered and ordered pairing is discussed, with neutral kaon pairing as a striking example of ordered pairing. The pairing of magnetic charge, if it exists, becomes an ordered pairing! (shrink)
The basic theme of Popper's philosophy--that something can come from nothing--is related to the present situation in physicaltheory. 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.
I discuss donald davidson's argument for the psycho-Physical identity theory and contend that it fails: it relies on an implausible account of mental and physical events. Davidson proposes a linguistic test for determining whether a given event is mental or physical. I argue that the assumptions that are necessary for employing such a criterion of the mental are either false or presuppose the truth of the identity theory.