Knowledge of residual perturbations in Uranus's orbit led to Neptune's discovery in 1846 rather than the refutation of Newton's law of gravitation. Karl Popper asserts that this case is untypical of science and that the law was at least prima facie falsified. I argue that these assertions are the product of a false, a priori methodological position, 'Weak Popperian Falsificationism' (WPF), and that on the evidence the law was not, and was not considered, prima facie false. Many of Popper's (...) commentators presuppose WPF and their views on this case and its implications for scientific rationality and method are similarly unwarranted or defective. (shrink)
In this essay, I attempt to assess Henk de Regt and Dennis Dieks recent pragmatic and contextual account of scientific understanding on the basis of an important historical case-study: understanding in Newton’s theory of universal gravitation and Huygens’ reception of universal gravitation. It will be shown that de Regt and Dieks’ Criterion for the Intelligibility of a Theory (CIT), which stipulates that the appropriate combination of scientists’ skills and intelligibility-enhancing theoretical virtues is a condition for scientific understanding, is (...) too strong. On the basis of this case-study, it will be shown that scientists can understand each others’ positions qualitatively and quantitatively, despite their endorsement of different worldviews and despite their convictions as what counts as a proper explanation. (shrink)
Several variant "Newtonian" theories of inertia and gravitation are described, and their scientific usefulness discussed. An examination of these theories is used to throw light on traditional epistemological and metaphysical questions about space and time. Finally these results are examined in the light of the changes induced by the transition from "Newtonian" to general relativistic spacetime.
Kant's views on the epistemological status of physical science provide an important example of how a philosophical system can be applied to understand the foundation of scientific theories. Michael Friedman has made considerable progress towards elucidating Kant's philosophy of science; in particular, he has argued that Kant viewed Newton's law of universal gravitation as necessary for the possibility of experiencing what Kant called true motion, which is more than the mere relative motion of appearances but is different from Newton's (...) concept of absolute motion. In this context, Friedman has provided an account of how Kant must have viewed Newton's supposed derivation of universal gravitation from Kepler's laws, based on, among other things, Kant's claim that Newton really needed to make extra assumptions in order to derive universal gravitation. In this paper, I argue that Friedman's account is incomplete for three reasons. First, Friedman has overlooked an important aspect of how Newton's third law is applied in the relevant sections of the Principia; as a result, Friedman's account partially misconstrues the relation between the planetary phenomena and the theory of universal gravitation. Second, his account fails to account for Kant's apparent belief that Kepler's laws are only empirically-based rules, even though they seem to be necessary for the derivation of universal gravitation and hence also necessary for Kant's own definition of true motion. Third, Friedman has overlooked some remarks by Kant that indicate that Kant thought the crucial properties of universal gravitation could be known without reference to the empirically determined motions of the planets and hence seemingly without any help from Newton. (shrink)
In his book Philosophie der Raum-Zeit-Lehre (1928) Reichenbach introduced the concept of universal force. Reichenbach's use of this concept was later severely criticized by Grünbaum. In this article it is argued that although Grünbaum's criticism is correct in an important respect, it misses part of Reichenbach's intentions. An attempt is made to clarify and defend Reichenbach's position, and to show that universal force is a useful notion in the physically important case of gravitation.
In this paper an analysis of Newton’s argument for universal gravitation is provided. In the past, the complexity of the argument has not been fully appreciated. Recent authors like George E. Smith and William L. Harper have done a far better job. Nevertheless, a thorough account of the argument is still lacking. Both authors seem to stress the importance of only one methodological component. Smith stresses the procedure of approximative deductions backed-up by the laws of motion. Harper stresses “systematic (...) dependencies” between theoretical parameters and phenomena. I will argue that Newton used a variety of different inferential strategies: causal parsimony considerations, deductions, demonstrative inductions, abductions and thought-experiments. Each of these strategies is part of Newton’s famous argument. (shrink)
The advent of the special theory of relativity in 1905 brought many problems for the physics community. One, it seemed, would not be a great source of trouble. It was the problem of reconciling Newtonian gravitation theory with the new theory of space and time. Indeed it seemed that Newtonian theory could be rendered compatible with special relativity by any number of small modiﬁcations, each of which would be unlikely to lead to any signiﬁcant deviations from the empirically (...) testable conse- 1 quences of Newtonian theory. Einstein’s response to this problem is now legend. He decided almost immediately to abandon the search for a Lorentz covariant gravitation theory, for he had failed to construct such a theory that was compatible with the equality of inertial and gravitational mass. Positing what he later called the principle of equivalence, he decided that gravitation theory held the key to repairing what he perceived as the defect of the special theory of relativity—its relativity principle.. (shrink)
This paper seeks to provide a historically well-informed analysis of an important post-Newtonian area of research in experimental physics between 1798 and 1898, namely the determination of the mean density of the earth and, by the end of the nineteenth century, the gravitational constant. Traditionally, research on these matters is seen as a case of ‘puzzle solving.’ In this paper, I show that such focus does not do justice to the evidential significance of eighteenth- and nineteenth-century experimental research on the (...) mean density of the earth and the gravitational constant. As Newton’s theory of universal gravitation was mainly based on astronomical observation, it remained to be shown that Newton’s law of universal gravitation did not break down at terrestrial distances. In this context, Cavendish’ experiment and related nineteenth-century experiments played a decisive role, for they provided converging and increasingly stronger evidence for the universality of Newton’s theory of gravitation. More precisely, I shall argue that, as the accuracy and precision of the experimental apparatuses and the procedures to eliminate external disturbances involved increasingly improved, the empirical support for the universality of Newton’s theory of gravitation improved correspondingly. (shrink)
Until the present, the Newtonian theory of gravitation has only been studied in any detail through the usual, presupposed ontology of point particles. This paper shows that changing our ontology into one which makes use of continuous bodies (non-point particles) allows us to obtain in a simple way two important results relevant to the theory: (a) The Newtonian theory of gravitation is indeterministic in a way apparently unparalleled when non-point particle models of it are used. (b) In the (...) Newtonian theory of gravitation it is possible to find non-collision singularities qualitatively different from the ones presented in point particle models. (shrink)
The paper shows a new example of nonuniqueness of the solutionto Newtonian equations of motion for infinite gravitational systems. Unlike otherexamples, the gravitational field presents no singularity, nor are the non-gravitational forcesintroduced in the model singular (in particular, there are no collisions). The result is also ofinterest because it points to an interesting limitation of the elementary (Newtonian) formulationof classical mechanics.
Newtonian cosmology is logically inconsistent. I show its inconsistency in a rigorous but simple and qualitative demonstration. "Logic driven" and "content driven" methods of controlling logical anarchy are distinguished.
We argue that Isaac Newton really is best understood as being in the tradition of the Mechanical Philosophy and, further, that Newton saw himself as being in this tradition. But the tradition as Newton understands it is not that of Robert Boyle and many others, for whom the Mechanical Philosophy was defined by contact action and a corpuscularean theory of matter. Instead, as we argue in this paper, Newton interpreted and extended the Mechanical Philosophy's slogan “matter and motion” in reference (...) to the long and distinguished tradition of mixed mathematics and the study of simple machines. (shrink)
Newton's methodology emphasized propositions "inferred from phenomena." These rest on systematic dependencies that make phenomena measure theoretical parameters. We consider the inferences supporting Newton's inductive argument that gravitation is proportional to inertial mass. We argue that the support provided by these systematic dependencies is much stronger than that provided by bootstrap confirmation; this kind of support thus avoids some of the major objections against bootstrapping. Finally we examine how contemporary testing of equivalence principles exemplifies this Newtonian methodological theme.
: This paper first discusses the current historical and philosophical framework forged during the last century to account for both the history and the epistemic status of Newton's theory of general gravitation. It then examines the conflict surrounding this theory at the close of the seventeenth century and the first steps towards the revolutionary shift in rational mechanics in the eighteenth century. From a historical point of view, it shows the crucial contribution of the Cartesian mechanistic philosophy and Leibnizian (...) analytic methods to the emergence of so-called Newtonian mechanics which can also be fairly characterized as a synthetic theory of attraction. From a philosophical standpoint, the paper suggests that the reworking of Newton's theory in the 18th century is better understood in a theoretical framework that reconciles Kuhn's notion of "invisible revolution" rather than his notion of "normal science" with Whewell's ascription of the completion of dynamical studies to the post Newtonian period. (shrink)
I criticise the view that the relativity and equivalence principles are consequences of the small-scale structure of the metric in general relativity, by arguing that these principles also apply to systems with non-trivial self-gravitation and hence non-trivial spacetime curvature (such as black holes). I provide an alternative account, incorporating aspects of the criticised view, which allows both principles to apply to systems with self-gravity.
A quantum measurement-like event can produce any of a number of macroscopically distinct results, with corresponding macroscopically distinct gravitational fields, from the same initial state. Hence the probabilistically evolving large-scale structure of space-time is not precisely or even always approximately described by the deterministic Einstein equations.Since the standard treatment of gravitational wave propagation assumes the validity of the Einstein equations, it is questionable whether we should expect all its predictions to be empirically verified. In particular, one might expect the stochasticity (...) of amplified quantum indeterminacy to cause coherent gravitational wave signals to decay faster than standard predictions suggest. This need not imply that the radiated energy flux from gravitational wave sources differs from standard theoretical predictions. An underappreciated bonus of gravitational wave astronomy is that either detecting or failing to detect predicted gravitational wave signals would constrain the form of the semi-classical theory of gravity that we presently lack. (shrink)
How can we make informed decisions about whom to trust given expert disagreement? Can experts on both sides be reasonable in holding conflicting views? Epistemologists have engaged the issue of reasonable expert disagreement generally; here I consider a particular expert dispute in physics, given conflicting accounts from Harry Collins and Allan Franklin, over Joseph Weber’s alleged detection of gravitational waves. Finding common ground between Collins and Franklin, I offer a characterization of the gravity wave dispute as both social and evidential. (...) While experimental evidence alone may not have forced resolution of the dispute, there were also credibility‐based reasons warranting epistemic trust and distrust. Thus we see how social factors can have evidential significance and how expert disagreement can be reasonable. †To contact the author, please write to: Philosophy Dept., Communication Arts Division, College of Lake County, 19351 W. Washington St., Grayslake, IL 60030; e‐mail: email@example.com. (shrink)
A four dimensional approach to Newtonian physics is used to distinguish between a number of different structures for Newtonian space-time and a number of different formulations of Newtonian gravitational theory. This in turn makes possible an in-depth study of the meaning and status of Newton's Law of Inertia and a detailed comparison of the Newtonian and Einsteinian versions of the Law of Inertia and the Newtonian and Einsteinian treatments of gravitational forces. Various claims about the status of Newton's Law of (...) Inertia are critically examined including these: the Law of Inertia is not an empirical law but a definition; it is not a law simpliciter but a family of schemata; it is a convention and gravitational forces exist only by convention; it is (or is not) redundant; the concepts it embodies can be dispensed with in favor of operationally defined entities; it is unique for a given theory. More generally, the paper demonstrates the importance of space-time structure for the philosophy of space and time and provides support for a realist interpretation of space-time theories. (shrink)
We present a logically detailed case-study of explanation and prediction in Newtonian mechanics. The case in question is that of a planet’s elliptical orbit in the Sun’s gravitational field. Care is taken to distinguish the respective contributions of the mathematics that is being applied, and of the empirical hypotheses that receive a mathematical formulation. This enables one to appreciate how in this case the overall logical structure of scientific explanation and prediction is exactly in accordance with the hypotheticodeductive model.
Based on an analysis of what it may mean for one tensor to depend in the proper way on another, I prove that, under certain natural conditions, there can be no tensor whose interpretation could be that it represents gravitational stress-energy in general relativity. It follows that gravitational energy, such as it is in general relativity, is necessarily non-local. Along the way, I prove a result of some interest in own right about the structure of the associated jet bundles of (...) the bundle of Lorentz metrics over spacetime. (shrink)
Classical and quantum field theory provide not only realistic examples of extant notions of empirical equivalence, but also new notions of empirical equivalence, both modal and occurrent. A simple but modern gravitational case goes back to the 1890s, but there has been apparently total neglect of the simplest relativistic analog, with the result that an erroneous claim has taken root that Special Relativity could not have accommodated gravity even if there were no bending of light. The fairly recent acceptance of (...) nonzero neutrino masses shows that widely neglected possibilities for nonzero particle masses have sometimes been vindicated. In the electromagnetic case, there is permanent underdetermination at the classical and quantum levels between Maxwell's theory and the one-parameter family of Proca's electromagnetisms with massive photons, which approximate Maxwell's theory in the limit of zero photon mass. While Yang–Mills theories display similar approximate equivalence classically, quantization typically breaks this equivalence. A possible exception, including unified electroweak theory, might permit a mass term for the photons but not the Yang–Mills vector bosons. Underdetermination between massive and massless (Einstein) gravity even at the classical level is subject to contemporary controversy. (shrink)
In Extragalactic Reality: The Case of Gravitational Lensing Hacking resumes the discussion of scientific realism from the last chapter of Representing and Intervening. Since the criterion of manipulability cannot be applied to astronomical objects, experimental entity realism seems to be restricted to terrestrial entities. In fact, Hacking explicitly argues against astronomical realism. The case at issue is the existence of gravitational lenses. In this paper, I question Hacking's chief witness for astronomical antirealism: the gravitational lens system “0957+ (...) 561”. It will be shown that Hacking's argumentation is misleading. Discussing astronomical realism as theory realism, Hacking focuses on the question of how to infer the existence of gravitational lenses from the truth of gravitational lens theory. But neither the reconstruction of gravitational lensing in terms of inference to the best explanation (IBE) nor the argument of underdetermination are tenable under closer inspection. My thesis is that a realist account of gravitational lensing can be given by relying on observation, causal capacities and home truths. (shrink)
Four empirically equivalent versions of general relativity, namely standard GR, Lorentz-invariant gravitational theory,and the gravitational gauge theories of the Lorentz and translation groups, are investigated in the form of a case study for theory underdetermination. The various ontological indeterminacies (both underdetermination and inscrutability of reference) inherent in gravitational theories are analyzed in a detailed comparative study. The concept of practical underdetermination is proposed, followed by a discussion of its adequacy to describe scientific progress.
This paper deals with a number of technical achievements that are instrumental for a dis-solution of the so-called "Hole Argument" in general relativity. Such achievements include: 1) the analysis of the "Hole" phenomenology in strict connection with the Hamiltonian treatment of the initial value problem. The work is carried through in metric gravity for the class of Christoudoulou-Klainermann space-times, in which the temporal evolution is ruled by the "weak" ADM energy; 2) a re-interpretation of "active" diffeomorphisms as "passive and metric-dependent" (...) dynamical symmetries of Einstein's equations, a re-interpretation which enables to disclose their (up to now unknown) connection to gauge transformations on-shell; understanding such connection also enlightens the real content of the Hole Argument or, better, dis-solves it together with its alleged "indeterminism"; 3) the utilization of the Bergmann-Komar "intrinsic pseudo-coordinates", defined as suitable functionals of the Weyl curvature scalars, as tools for a peculiar gauge-fixing to the super-hamiltonian and super-momentum constraints; 4) the consequent construction of a "physical atlas" of 4-coordinate systems for the 4-dimensional "mathematical" manifold, in terms of the highly non-local degrees of freedom of the gravitational field (its four independent "Dirac observables"). Such construction embodies the "physical individuation" of the points of space-time as "point-events", independently of the presence of matter, and associates a "non-commutative structure" to each gauge fixing or four-dimensional coordinate system; 5) a clarification of the multiple definition given by Peter Bergmann of the concept of "(Bergmann) observable" in general relativity. This clarification leads to the proposal of a "main conjecture" asserting the existence of i) special Dirac's observables which are also Bergmann's observables, ii) gauge variables that are coordinate independent (namely they behave like the tetradic scalar fields of the Newman-Penrose formalism). A by-product of this achievements is the falsification of a recently advanced argument asserting the absence of (any kind of) "change" in the observable quantities of general relativity. 6) a clarification of the physical role of Dirac and gauge variables as their being related to "tidal-like" and "inertial-like" effects, respectively. This clarification is mainly due to the fact that, unlike the standard formulations of the equivalence principle, the Hamiltonian formalism allows to define notion of "force" in general relativity in a natural way; 7) a proposal showing how the physical individuation of point-events could in principle be implemented as an experimental setup and protocol leading to a "standard of space-time" more or less like atomic clocks define standards of time. We conclude that, besides being operationally essential for building measuring apparatuses for the gravitational field, the role of matter in the non-vacuum gravitational case is also that of "participating directly" in the individuation process, being involved in the determination of the Dirac observables. This circumstance leads naturally to a peculiar new kind of "structuralist" view of the general-relativistic concept of space-time, a view that embodies some elements of both the traditional "absolutist" and "relational" conceptions. In the end, space-time point-events maintain a "peculiar sort of objectivity". Some hints following from our approach for the quantum gravity programme are also given. (shrink)
Using a model quantum clock, I evaluate an expression for the time of a nonrelativistic quantum particle to transit a piecewise geodesic path in a background gravitational ﬁeld with small spacetime curvature (gravity gradient), in the case that the apparatus is in free fall. This calculation complements and extends an earlier one (Davies 2004) in which the apparatus is ﬁxed to the surface of the Earth. The result conﬁrms that, for particle velocities not too low, the quantum and classical transit (...) times coincide, in conformity with the principle of equivalence. I also calculate the quantum corrections to the transit time when the de Broglie wavelengths are long enough to probe the spacetime curvature. The results are compared with the calculation of Chiao and Speliotopoulos (2003), who propose an experiment to measure the foregoing effects. (shrink)
The problem of finding a covariant expression for the distribution and conservation of gravitational energy-momentum dates to the 1910s. A suitably covariant infinite-component localization is displayed, reflecting Bergmann's realization that there are infinitely many gravitational energy-momenta. Initially use is made of a flat background metric (or rather, all of them) or connection, because the desired gauge invariance properties are obvious. Partial gauge-fixing then yields an appropriate covariant quantity without any background metric or connection; one version is the collection of pseudotensors (...) of a given type, such as the Einstein pseudotensor, in _every_ coordinate system. This solution to the gauge covariance problem is easily adapted to any pseudotensorial expression (Landau-Lifshitz, Goldberg, Papapetrou or the like) or to any tensorial expression built with a background metric or connection. Thus the specific functional form can be chosen on technical grounds such as relating to Noether's theorem and yielding expected values of conserved quantities in certain contexts and then rendered covariant using the procedure described here. The application to angular momentum localization is straightforward. Traditional objections to pseudotensors are based largely on the false assumption that there is only one gravitational energy rather than infinitely many. (shrink)
Motivated by examples from general relativity and Newtonian gravitation, this essay attempts to distinguish between the dynamical structure associated with a theory in physics, and its kinematical structure. This enables a distinction to be made between a structural realist interpretation of a theory based on its dynamical structure, and a structural realist interpretation of spacetime, as described by a theory, based on its kinematical structure. I offer category-theoretic formulations of dynamical and kinematical structure and indicate the extent to which (...) such formulations deflect recent criticism of the radical ontic structural realist's conception of structure as "relations devoid of relata". (shrink)
‘Quantum Gravity’ does not denote any existing theory: the field of quantum gravity is very much a ‘work in progress’. As you will see in this chapter, there are multiple lines of attack each with the same core goal: to find a theory that unifies, in some sense, general relativity (Einstein’s classical field theory of gravitation) and quantum field theory (the theoretical framework through which we understand the behaviour of particles in non-gravitational fields). Quantum field theory and general relativity (...) seem to be like oil and water, they don’t like to mix—it is fair to say that combining them to produce a theory of quantum gravity constitutes the greatest unresolved puzzle in physics. Our goal in this chapter is to give the reader an impression of what the problem of quantum gravity is; why it is an important problem; the ways that have been suggested to resolve it; and what philosophical issues these approaches, and the problem itself, generate. This review is extremely selective, as it has to be to remain a manageable size: generally, rather than going into great detail in some area, we highlight the key features and the options, in the hope that readers may take up the problem for themselves—however, some of the basic formalism will be introduced so that the reader is able to enter the physics and (what little there is of) the philosophy of physics literature prepared. I have also supplied references for those cases where I have omitted some important facts. Hence, this chapter is intended primarily as a catalyst for future research projects by philosophers of physics, both budding and well-matured. (shrink)
Where to begin? I’ll take three books from my shelves. First, now nearly forty years old, a little book of television lectures by the great physicist Richard Feynman, The Character of Physical Law. He talks about the laws of motion, the inverse square law of gravitation, conservation laws, symmetry principles and the various ways these all hang together. Feynman obviously takes it that it is a prime aim of science to discover such laws. But what are laws? He writes (...) – and this is about his one and only shot at a characterization at the level of abstraction that we might think of as philosophical –. (shrink)
My Representing and Intervening (1983) concludes with what it calls an experimental argument for scientific realism about entities. The argument is evidently inapplicable to extragalactic astrophysics, but leaves open the possibility that there might be other grounds for scientific realism in that domain. Here I argue for antirealism in astrophysics, although not for any particular kind of antirealism. The argument is conducted by a detailed examination of some current research. It parallels the last chapter of (1983). Both represent the methodological (...) opinion that abstract or semantic realism/antirealism debates are empty, and typically lead to confused or wrong conclusions because they pay so little attention to the details of a science. (shrink)
Peirce's Sign Theory, or Semiotic, is an account of signification, representation, reference and meaning. Although sign theories have a long history, Peirce's accounts are distinctive and innovative for their breadth and complexity, and for capturing the importance of interpretation to signification. For Peirce, developing a thoroughgoing theory of signs was a central philosophical and intellectual preoccupation. The importance of semiotic for Peirce is wide ranging. As he himself said, “[…] it has never been in my power to study anything,—mathematics, ethics, (...) metaphysics, gravitation, thermodynamics, optics, chemistry, comparative anatomy, astronomy, psychology, phonetics, economics, the history of science, whist, men and women, wine, metrology, except as a study of semiotic”. (SS 1977, 85–6). Peirce also treated sign theory as central to his work on logic, as the medium for inquiry and the process of scientific discovery, and even as one possible means for 'proving' his pragmatism. Its importance in Peirce's philosophy, then, cannot be underestimated. -/- Across the course of his intellectual life, Peirce continually returned to and developed his ideas about signs and semiotic and there are three broadly delineable accounts: a concise Early Account from the 1860s; a complete and relatively neat Interim Account developed through the 1880s and 1890s and presented in 1903; and his speculative, rambling, and incomplete Final Account developed between 1906 and 1910. The following entry examines these three accounts, and traces the changes that led Peirce to develop earlier accounts and generate new, more complex, sign theories. However, despite these changes, Peirce's ideas on the basic structure of signs and signification remain largely uniform throughout his developments. Consequently, it is useful to begin with an account of the basic structure of signs according to Peirce. (shrink)
Immanuel Kant's Metaphysical Foundations of Natural Science (1786) provides metaphysical foundations for the application of mathematics to empirically given nature. The application that Kant primarily has in mind is that achieved in Isaac Newton's Principia (1687). Thus, Kant's first chapter, the Phoronomy, concerns the mathematization of speed or velocity, and his fourth chapter, the Phenomenology, concerns the empirical application of the Newtonian notions of true or absolute space, time, and motion. This paper concentrates on Kant's second and third chapters—the Dynamics (...) and the Mechanics, respectively—and argues that they are best read as providing a transcendental explanation of the conditions for the possibility of applying the (mathematical) concept of quantity of matter to experience. Kant again has in mind the empirical measures of this quantity that Newton fashions in the Principia, and he aims to make clear, in particular, how Newton achieves a universal measure for all bodies whatsoever by projecting the static quantity of terrestrial weight into the heavens by means of the theory of universal gravitation. Kant is not attempting to prove a priori what Newton has established empirically but, rather, to clarify the character of Newton's mathematization by building Newton's empirical measures into the very concept of matter that is articulated in the Metaphysical Foundations. (shrink)
Newton’s argument for universal gravitation in the Principia eventually rested on the third “Rule of Philosophizing,” which warrants the generalization of “qualities of bodies.” An analysis of the rule and the history of its development indicate that the term ‘quality’ should be taken to include both inherent properties of bodies and relations among systems of bodies, generalized into `laws'. By incorporating law‐induction into the rule, Newton could legitimately rebuff objections to his theory by claiming that universal gravitation was (...) justified by his method even if he could not specify the cause of gravity . †To contact the author, please write to: Department of Philosophy, Duke University, 201 West Duke Building, Box 90743, Durham, NC 27708; e‐mail: firstname.lastname@example.org. (shrink)
Those looking for holism in contemporary physics have focused their attention primarily on quantum entanglement. But some gauge theories arguably also manifest the related phenomenon of nonseparability. While the argument is strong for the classical gauge theory describing electromagnetic interactions with quantum “particles”, it fails in the case of general relativity even though that theory may also be formulated in terms of a connection on a principal fiber bundle. Anandan has highlighted the key difference in his analysis of a supposed (...) gravitational analog to the Aharonov-Bohm effect. By contrast with electromagnetism in the original Aharonov-Bohm effect, gravitation is separable and exhibits no novel holism in this case. Whether the nonseparability of classical gauge theories of non-gravitational interactions is associated with holism depends on what counts as the relevant part-whole relation. Loop representations of quantized gauge theories of non- gravitational interactions suggest that these conclusions about holism and nonseparability may extend also to quantum theories of the associated fields. (shrink)
Is thermodynamics true of self-gravitating systems? Or better put, does equilibrium statistical mechanics, the theory describing the microscopic basis of thermal phenomena, apply when the dominant coupling in a system is via (classical) gravitation? This question is the subject of increasing interest in astrophysics, but it is rarely pursued from a foundational perspective. From this standpoint, the issue is not only fascinating in its own right, but it is an important prism through which to view other foundational projects in (...) statistical mechanics. By considering it, we increase our understanding of the conditions under which a thermodynamic description of the world can emerge. (shrink)
Machine generated contents note: Introduction Andrew Janiak and Eric Schliesser; Part I. Newton and his Contemporaries: 1. Newton's law-constitutive approach to bodies: a response to Descartes Katherine Brading; 2. Leibniz, Newton and force Daniel Garber; 3. Locke's qualified embrace of Newton's Principia Mary Domski; 4. What geometry postulates: Newton and Barrow on the relationship of mathematics to nature Katherine Dunlop; Part II. Philosophical Themes in Newton: 5. Cotes' queries: Newton's Empiricism and Conceptions of Matter Zvi Biener and Chris Smeenk; 6. (...) Newton's Scientific Method and the Universal Law of Gravitation Ori Belkind; 7. Measurement and method: some remarks on Newton, Huygens and Euler on natural philosophy William Harper; 8. What did Newton mean by 'Absolute Motion'? Nick Huggett; 9. From velocities to fluxions Marco Panza; Part III. The Reception of Newton: 10. Newton, Locke, and Hume Graciela de Pierris; 11. Maupertuis on attraction as an inherent property of matter Lisa Downing; 12. The Newtonian refutation of Spinoza: Newton's Challenge and the Socratic Problem Eric Schliesser; 13. Dispositional explanations: Boyle's problem, Newton's solution, Hume's response Lynn Joy; 14. Newton and Kant on Absolute Space: from theology to transcendental philosophy Michael Friedman; 15. How Newton's Principia changed physics George Smith; Bibliography. (shrink)
Here, we examine hole-freeness - a condition sometimes imposed to rule out seemingly artificial spacetimes. We show that under existing definitions (and contrary to claims made in the literature) there exist inextendible, globally hyperbolic spacetimes which fail to be hole-free. We then propose an updated formulation of the condition which enables us to show the intended result. We conclude with a few general remarks on the strength of the definition and then formulate a precise question which may be interpreted as: (...) Are all physically reasonable spacetimes hole-free? (shrink)
The Past Hypothesis is the claim that the Boltzmann entropy of the universe was extremely low when the universe began. Can we make sense of this claim when *classical* gravitation is included in the system? I first show that the standard rationale for not worrying about gravity is too quick. If the paper does nothing else, my hope is that it gets the problems induced by gravity the attention they deserve in the foundations of physics. I then try to (...) make plausible a very weak claim: that there is a well-defined Boltzmann entropy that *can* increase in *some* interesting self-gravitating systems. More work is needed before we can say whether this claim answers the threat to the standard explanation of entropy increase. (shrink)
Throughout the history of the Western world, science has possessed an extraordinary amount of authority and prestige. And while its pedestal has been jostled by numerous evolutions and revolutions, science has always managed to maintain its stronghold as the knowing enterprise that explains how the natural world works: we treat such legendary scientists as Galileo, Newton, Darwin, and Einstein with admiration and reverence because they offer profound and sustaining insight into the meaning of the universe. In The Intelligibility of Nature (...) , Peter Dear considers how science as such has evolved and how it has marshaled itself to make sense of the world. His intellectual journey begins with a crucial observation: that the enterprise of science is, and has been, directed toward two distinct but frequently conflated ends—doing and knowing. The ancient Greeks developed this distinction of value between craft on the one hand and understanding on the other, and according to Dear, that distinction has survived to shape attitudes toward science ever since. Teasing out this tension between doing and knowing during key episodes in the history of science—mechanical philosophy and Newtonian gravitation, elective affinities and the chemical revolution, enlightened natural history and taxonomy, evolutionary biology, the dynamical theory of electromagnetism, and quantum theory—Dear reveals how the two principles became formalized into a single enterprise, science, that would be carried out by a new kind of person, the scientist. Finely nuanced and elegantly conceived, The Intelligibility of Nature will be essential reading for aficionados and historians of science alike. (shrink)
I look at the ‘flavour-oscillation clocks’ proposed by D. V. Ahluwalia and two of his arguments suggesting that such clocks might behave in a way that threatens the geometricity of general relativity (GR). The first argument states that the behaviour of these clocks in the vicinity of a rotating gravitational source implies a non-geometrical element of gravity. I argue that the phenomenon is best seen as an instance of violation of the ‘clock hypothesis’ and therefore does not threaten the geometrical (...) nature of gravitation. Ahluwalia’s second argument, for the ‘incompleteness’ of general relativity, involves the idea that flavour-oscillation clocks can detect constant gravitational potentials. I argue that the purported ‘incompleteness-establishing’ result is in fact one that applies to all clocks. It is entirely derivable from general relativity, does not result in the observability of the potential, and is not at odds with any of general relativity’s foundations. (shrink)
In her 1996 book, Error and the Growth of Experimental Knowledge, Deborah Mayo argues that use- (or heuristic) novelty is not a criterion we need to consider in assessing the evidential value of observations. Using the notion of a ''severe'' test, Mayo claims that such novelty is valuable only when it leads to severity, and never otherwise. To illustrate her view, she examines the historical case involving the famous 1919 British eclipse expeditions that generated observations supporting Einstein's theory of (...) class='Hi'>gravitation over Newton's. My plan here is to defend use-novelty as a valuable methodological principle. I begin by exposing a weakness in Mayo's criticism of use-novelty. Remedying this weakness re-establishes the worth of use-novelty under specific conditions; in particular, heuristically novel data are to be preferred, as I will say, ''prima facie''. Armed with this revised version of use-novelty, I re-examine the history of the eclipse experiments and offer an interpretation of this episode that to an extent-and contrary to Mayo-restores the mildly heretical, Earman/Glymour evaluation of this episode offered in their (1980). I conclude by responding to criticism of my assessment of Mayo's work. (shrink)
This survey article is divided into two parts. In the first (section 2), I give a brief account of the structure of classical relativity theory. In the second (section 3), I discuss three special topics: (i) the status of the relative simultaneity relation in the context of Minkowski spacetime; (ii) the ``geometrized" version of Newtonian gravitation theory (also known as Newton-Cartan theory); and (iii) the possibility of recovering the global geometric structure of spacetime from its ``causal structure".
Popper's account of refutation is the linchpin of his famous view that the method of science is the method of conjecture and refutation. This thesis critically examines his account of refutation, and in particular the practice he deprecates as avoiding a refutation. I try to explain how he comes to hold the views that he does about these matters; how he seeks to make them plausible; how he has influenced others to accept his mistakes, and how some of the ideas (...) or responses to Popper of such people are thus similarly mistaken. I draw some distinctions necessary to the provision of an adequate account of the so-called practice of avoiding a refutation, and try to rid the debate about this practice of at least one red herring. I analyse one case of 'avoiding' a refutation in detail to show how the rationality of scientific practice eludes both Popper and many of his commentators. Popper's skepticism about contingent knowledge prevents him from providing an acceptable account of contingent refutation, and so his method is really the method of conjecture and conjecture. He cannot do without the concepts of knowledge and refutation, however, if his account of science is to be plausible or persuasive, and so he equivocates between, amongst other things, refutation as disproof and refutation as the weaker notion of discorroboration. I criticise David Stove's account of this matter, in particular to show how he misses this point. An additional advantage Popper would secure from this equivocation is that if refutations were mere discorroborations they would be easier to achieve, and hence more common in science, than is the case. On Popper's weak notion of refutation, it would be possible to refute true theories since corroboration does not entail truth. There are two other related doctrines Popper holds about refutation which, if accepted, make some refutations seem easier to obtain than is the case. I call these doctrines 'Strong Popperian Falsificationism' (SPF) and 'Weak Popperian Falsificationism' (WPF). SPF is the false doctrine that if a prediction from some theory is refuted then that theory is refuted. Popper does not always endorse SPF. In particular, when confronted with a counterexample to it, he retreats to WPF, which is the false doctrine that if a prediction from some theory is refuted then that theory is prima facie refuted. WPF , or even SPF, can seem plausible if one has in mind predictions derived from theories in strong or conclusive tests of those theories, which I suggest Popper characteristically does. v Popper is disposed to describe any such case of predictive failure which does not lead to the refutation of the theory concerned as one in which that refutation has been avoided. To reinforce his portrayal of the refutation, or the attempted refutation, of major scientific theories as the rational core of scientific practice, Popper treats the so-called practice of avoiding a refutation as untypical of science, and much so-called avoidance he dismisses as unscientific or pseudo-scientific. I argue that his notion of avoiding a refutation is incoherent. Popper is further driven to believe that such avoidance is possible, however, because he conflates sentences with propositions and propositions with propositional beliefs. Also, he wishes to avoid being saddled with the relativisim that is a consequence of his weak account of refutation as discorroboration. Popper believes that ad hoc hypotheses are the most important of the unscientific means of avoiding a refutation. I argue that his account of such hypotheses is also incoherent, and that several hypotheses thought to be ad hoc in his sense are not. Such hypotheses appear to be so largely because of Popper's use of rhetoric and partly because these hypotheses are unacceptable for other reasons. I conclude that to know that a hypothesis is ad hoc in Popper's sense does not illuminate scientific practice. Popper has also attempted to explicate ad hocness in terms of some undesirable, or allegedly undesirable, properties of hypotheses or the explanations they would provide. The first such property is circularity, which is undesirable; the second such property is reduction in empirical content, which is not. In the former case I argue that non-circularity is clearly preferable to non-ad hocness as a criterion for a satisfactory explanation or explanans, as the case may be, and in the latter case that Popper is barking up the wrong tree. Some cases of so-called avoidance are obviously not unscientific. The discovery of Neptune from a prediction based on the reasonable belief that there were residual perturbations in the motion of Uranus is an important case in point, and one that is much discussed in the literature. The manifest failure of astronomers to account for Uranus's motion did not lead to the refutation of Newton's law of gravitiation, yet significant scientific progress obviously did result. Retreating to WPF, Popper claims that Newton's law was prima facie refuted. In general, astronomers have never shared this view, and they are correct in not doing so. I argue that the law of gravitation would have been prima facie refuted only if there had been good reason at the time to believe as false what is true, namely, that an unknown trans-Uranian planet was the cause of those Uranian residuals. Knowledge of the trans-Uranian region was then so slight that it was merely a convenient assumption, one which there was little reason to believe was false, that the known influences on Uranus's motion were the only such influences. I conclude that in believing vi or supposing that it was this assumption that was false, rather than the law of gravitation, Leverrier and Adams, the co-predictors of Neptune, were acting rationally and intelligently. Popper's commentators offer a variety of accounts of the alleged practice of avoiding a refutation, and of this case in particular. I analyse a sample of their accounts to show how common is the acceptance of some of Popper's basic mistakes, even amongst those who claim to reject his falsificationism, and to display the effects on their accounts of this acceptance of his mistakes. Many commentators recognize that anomalies are typically dealt with by changes in the boundary conditions or in other of the auxiliary propositions employed. Where many still go wrong, however, is in retaining the presupposition of WPF which encouraged Popper to hold the contradictory view about anomalies in the first place. Thus Imre Lakatos and others, for example, have developed a 'siege mentality' about major scientific theories; they see them as under continual threat of refutation from anomalies, and so come to believe that dogmatism is essential in science if such theories are to survive as they do. I examine various such doomed attempts to reconcile Popper with the history of science. It is a common failure in this literature to conflate or to fail to see the need to distinguish a belief from a supposition, and an epistemic reason from a pragmatic reason. I argue that only if one does draw these distinctions can one give an adequate account of how anomalies are rationally dealt with in science. The other important strand in Popper's thinking about 'avoidance' of refutation which has seriously misled some of his commentators is his unfounded belief in the dangers of ad hoc hypotheses. I examine the accounts that a sample of such commentators provide of the trans-Uranian planet hypotheses of Leverrier and Adams. These commentators imply or assert what Popper only hints at, namely, that there is something fishy about this hypothesis. I provide a further defence of the rationality of entertaining this hypothesis at the time. I conclude with a few remarks about Popper's dilemma in respect of scientific practice and his long standing emphasis on refutations. (shrink)
In 1922 in The Principle of Relativity, Whitehead presented an alternative theory of gravitation in response to Einstein’s general relativity. To the latter, he objected on philosophical grounds—specifically, that Einstein’s notion of a variable spacetime geometry contingent on the presence of matter (a) confounds theories of measurement, and, more generally, (b) is unacceptable within the bounds of a reasonable epistemology. Whitehead offered instead a theory based within a comprehensive philosophy of nature. The formulal Whitehead adopted for the gravitational field (...) has been described as involving both the flat metric nu, of Minkowski spacetime and a dynamic metric gu, dependent on the presence of source masses. The ontological relationship between the two must be fleshed out in the context of Whitehead’s philosophy of nature. The relationship is of some importance, not only in casting Whitehead’s theory within its proper metaphysical context vis-d—vis Einstein, but also in judging how the theory has faired empirically with respect to general relativity (GR hereafter). It makes the same predictions as GR with respect to the perihelion advance, the deflection of light rays and the gravitational red-shift; indeed, Eddington (1924) has shown that it is equivalent to the Schwarzschild solution of Einstein’s held equations for the one-body problem. However, it also appears to predict an anisotropy in the locally measured gravitational constant y that is in conflict.. (shrink)
I take Newton's arguments to inverse square centripetal forces from Kepler's harmonic and areal laws to be classic deductions from phenomena. I argue that the theorems backing up these inferences establish systematic dependencies that make the phenomena carry the objective information that the propositions inferred from them hold. A review of the data supporting Kepler's laws indicates that these phenomena are Whewellian colligations-generalizations corresponding to the selection of a best fitting curve for an open-ended body of data. I argue that (...) the information theoretic features of Newton's corrections of the Keplerian phenomena to account for perturbations introduced by universal gravitation show that these corrections do not undercut the inferences from the Keplerian phenomena. Finally, I suggest that all of Newton's impressive applications of Universal gravitation to account for motion phenomena show an attempt to deliver explanations that share these salient features of his classic deductions from phenomena. (shrink)
ABSTRACT. May scientists rely on substantive, a priori presuppositions? Quinean naturalists say "no," but Michael Friedman and others claim that such a view cannot be squared with the actual history of science. To make his case, Friedman offers Newton's universal law of gravitation and Einstein's theory of relativity as examples of admired theories that both employ presuppositions (usually of a mathematical nature), presuppositions that do not face empirical evidence directly. In fact, Friedman claims that the use of such presuppositions (...) is a hallmark of "science as we know it." But what should we say about the special sciences, which typically do not rely on the abstruse formalisms one finds in the exact sciences? I identify a type of a priori presupposition that plays an especially striking role in the development of empirical psychology. These are ontological presuppositions about the type of object a given science purports to study. I show how such presuppositions can be both a priori and rational by investigating their role in an early flap over psychology's contested status as a natural science. The flap focused on one of the field's earliest textbooks, William James's Principles of Psychology. The work was attacked precisely for its reliance on a priori presuppositions about what James had called the "mental state," psychology's (alleged) proper object. I argue that the specific presuppositions James packed into his definition of the "mental state" were not directly responsible to empirical evidence, and so in that sense were a priori; but the presuppositions were rational in that they were crafted to help overcome philosophical objections (championed by neo-Hegelians) to the very idea that there can be a genuine science of mind. Thus, my case study gives an example of substantive, a priori presuppositions being put to use—to rational use—in the special sciences. In addition to evaluating James's use of presuppositions, my paper also offers historical reflections on two different strands of pragmatist philosophy of science. One strand, tracing back through Quine to C. S. Peirce, is more naturalistic, eschewing the use of a priori elements in science. The other strand, tracing back through Kuhn and C. I. Lewis to James, is more friendly to such presuppositions, and to that extent bears affinity with the positivist tradition Friedman occupies. (shrink)
Universally recognized as bringing about a revolutionary transformation of the notions of space, time, and motion in physics, Einstein's theory of gravitation, known as "general relativity," was also a defining event for 20th century philosophy of science. During the decisive first ten years of the theory's existence, two main tendencies dominated its philosophical reception. This book is an extended argument that the path actually taken, which became logical empiricist philosophy of science, greatly contributed to the current impasse over realism, (...) whereas new possibilities are opened in revisiting and reviving the spirit of the more sophisticated tendency, a cluster of viewpoints broadly termed transcendental idealism, and furthering its articulation. It also emerges that Einstein, while paying lip service to the emerging philosophy of logical empiricism, ended up siding de facto with the latter tendency. Ryckman's work speaks to several groups, among them philosophers of science and historians of relativity. Equations are displayed as necessary, but Ryckman gives the non-mathematical reader enough background to understand their occurrence in the context of his wider philosophical project. (shrink)
John Norton has recently argued that Newtonian gravitation theory (at least as applied to cosmological contexts where one envisions the possibility of a homogeneous mass distribution throughout all of space) is inconsistent. I am not convinced. Traditional formulations of the theory may seem to break down in cases of the sort Norton considers. But the difficulties they face are only apparent. They are artifacts of the formulations themselves, and disappear if one passes to the so-called "geometrized" formulation of the (...) theory. (shrink)
Touch and sight : the earth and the heavens -- What happens and what is observed -- The velocity of light -- Clocks and foot-rules -- Space-time -- The special theory of relativity -- Intervals in space-time -- Einstein's law of gravitation -- Proofs of Einstein's law of gravitation -- Mass, momentum, energy, and action -- The expanding universe -- Conventions and natural laws -- The abolition of "force" -- What is matter? -- Philosophical consequences.
An acceptable empiricist account of laws of nature would havesignificant implications for a number of philosophical projects. For example, such an account may vitiate argumentsthat the fundamental constants of nature are divinelydesigned so that laws produce a life permittinguniverse. On an empiricist account, laws do not produce the universe but are designed by us to systematize theevents of a universe which does in fact contain life; so any ``fine tuning'' of natural law has a naturalistic explanation.But there are problems for (...) the empiricist project. This paper develops a ``perspectival'' version of the Humean bestsystem approach and argues that this version solves the standard problems faced by the empiricist project.Furthermore, the paper argues, this version is best able to answer the proponents of divine design while leaving scientificlaw a suitably objective matter.[I]t is possible tocondense the enormous mass of results to a large extent – that is to find laws which summarize ...Richard Feynman (1963)It has become fashionable in some circles to argue thatscience is ultimately a sham, that we scientists read order into nature, not out of nature, and that the laws of physicsare our laws, not nature's. I believe this is arrant nonsense. You would be hard-pressed to convince a physicist thatNewton's inverse square law of gravitation is a purely cultural concoction. The laws of physics, I submit, reallyexist in the world out there, and the job of the scientist is to uncover them, not invent them. True, at any giventime, the laws you find in the textbooks are tentative and approximate, but they mirror, albeit imperfectly, a reallyexisting order in the physical world. Of course, many scientists do not recognize that in accepting the reality of anorder in nature-the existence of laws `out there' – they are adopting a theological world view. P. C. W. Davies (1995). (shrink)
This paper examines Newton's argument from the phenomena to the law of universal gravitation-especially the question how such a result could have been obtained from the evidential base on which that argument rests. Its thesis is that the crucial step was a certain application of the third law of motion-one that could only be justified by appeal to the consequences of the resulting theory; and that the general concept of interaction embodied in Newton's use of the third law most (...) probably evolved in the course of the very investigation that led to this theory. (shrink)
By analysing the historical case of the proportionality between inertia and gravitation, it is possible to reconstruct one of the most relevant moments in the history of physics, that is to say, the one linked with Eötvös' experiments. At the same time, this reconstruction offers the opportunity to carry out philosophical considerations about the relationship between theory and experiment and about the concept of incommensurability.
Newton and Einstein each in his way showed us the following: an epistemologically responsible physicist adopts the most measured understanding possible of spacetime structure. The proper way to infer a doctrine of spacetime is by a kind of measuring inference -- a deduction from phenomena. Thus it was (I argue) by an out-and-out deduction from the phenomena of inertiality (as colligated by the three laws of motion) that Newton delineated the conceptual presuppositions concerning spacetime structure that are needed before we (...) can actually think coherently about these phenomena. And Einstein (I argue) very much recapitulated this argument pattern, twice over in fact, recolligating the phenomena first so as to add something from the laws of electromagnetism, and then so as to add everything about gravitation, into what he understood by inertiality. Notably, to deduce one’s theoretical conclusions from phenomena is both more cautious and more cogent than to "infer to the best explanation". And in the context of the development of a doctrine of spacetime, deductions from phenomena lay before us formal rather than causal understanding. Deductions from phenomena tell us, in this context, not what things or what causes there are, but rather what our concepts should be like. The more measured the inference is, however, the more definitively it tells us this. For these reasons the most measured understanding of spacetime lies on a line between conventionalism and realism, between relationalism and absolutism, and indeed (as I demonstrate) between empiricism and rationalism. Spacetime is understood as neither merely immanent in material goings-on, nor truly transcendent of them either. In order to explain this understanding as adequately as I can and in order to remark its excellences most fully, I consider some respects in which the tertium quid between metaphysical realism and strict empiricism about spacetime is wise in the sense of practical wisdom. The wisest understanding of spacetime illustrates, I argue, an original and fundamental connection that epistemology has with ethics. (shrink)
The dark matter problem in astrophysics exposes an underappreciated weakness in the evidential warrant for General Relativity (GR). The "dark matter double bind" entails that GR gets no differential evidential support from dynamical phenomena occurring at scales larger than our solar system, as compared to members of a significant class of rival gravitation theories. These rivals are each empirically indistinguishable from GR for phenomena taking place at solar system scales, but make predictions that may differ radically from GR's at (...) larger scales. Thus the typical confidence in the universal applicability of GR is insufficiently warranted in the present evidential context. (shrink)
The existence of fields besides gravitation may provide us with a way to decide empirically whether spacetime is really a nonflat Riemannian manifold or a flat Minkowskian manifold that appears curved as a result of gravitational distortions. This idea is explained using a modification of Poincaré's famous 'diskworld'.
Recession of the galaxies indicates a repulsive force and suggests that Newton's formulation of gravitation is not complete. A possible modification is proposed, and this Neo-Newtonian equation allows a quantitative treatment of Mach's principle. It also limits the velocity of matter to c and gives a correct prediction for the perihelion of Mercury.
The Akaike Information Criterion can be a valuable tool of scientific inference. This statistic, or any other statistical method for that matter, cannot, however, be the whole of scientific methodology. In this paper some of the limitations of Akaikean statistical methods are discussed. It is argued that the full import of empirical evidence is realized only by adopting a richer ideal of empirical success than predictive accuracy, and that the ability of a theory to turn phenomena into accurate, agreeing measurements (...) of causally relevant parameters contributes to the evidential support of the theory. This is illustrated by Newton's argument from orbital phenomena to the inverse-square law of gravitation. (shrink)
It is often claimed that the bulk of the laws of physics –including such venerable laws as Universal Gravitation– are violated in many (or even all) circumstances because they havecounter-instances that result when a system is not isolated fromother systems. Various accounts of how one should interpretthese (apparently) violated laws have been provided. In thispaper, I examine two accounts of (apparently) violated laws, thatthey are merely ceteris paribus laws and that they aremanifestations of capacities. Through an examination of theprimary (...) example that motivated these views, I show that given aproper understanding of the situation, neither view is optimalbecause the law is not even apparently violated. Along the way, Iam able to diagnose what has led to the mistaken belief: I showthat it originates from an element of the standard empiricistconception of laws. I then evaluate the suggestions of how tointerpret violated laws with respect to other examples and findthem wanting there too. (shrink)
Newton rested his theory of mechanics on distinct metaphysical and epistemological foundations. After Leibniz's death in 1716, the Principia ran into sharp philosophical opposition from Christian Wolff and his disciples, who sought to subvert Newton's foundations or replace them with Leibnizian ideas. In what follows, I chronicle some of the Wolffians' reactions to Newton's notion of absolute space, his dynamical laws of motion, and his general theory of gravitation. I also touch on arguments advanced by Newton's Continental followers, such (...) as Leonhard Euler, who made novel attempts to defend his mechanical foundations against the pro-Leibnizian attack. This examination grants us deeper insight into the fate of Newton's mechanics on the Continent during the early eighteenth century and, more specifically, sheds needed light on the conflicts and tensions that characterized the reception of Newton's philosophy of mechanics among the Leibnizians. (shrink)
Faraday's field concept presupposes that field stresses should share the axial symmetry of the lines of force. In the present article, the field dynamics is similarly required to depend only on field properties that can be tested through the motion of test-particles. Precise expressions of this 'Faradayan' principle in field-theoretical language are shown to severely restrict the form of classical field theories. In particular, static forces must obey the inverse square law in a linear approximation. Within a Minkowskian and Lagrangian (...) framework, the Faradayan principle automatically leads to Maxwell's theory of electromagnetism and to Einstein's theory of gravitation, without appeal to the equivalence principle. A comparison is drawn between this, Feynman's, and Einstein's way to arrive at general relativity. (shrink)
Hartry Field  has developed an interesting nominalization strategy for Newtonian gravitation theory -- a strategy that reformulates the theory without quantification over abstract entities. According to David Malament , Field’s strategy cannot be extended to quantum mechanics (QM), and so it only has a limited scope. In a recent work, Mark Balaguer has responded to Malament’s challenge, by indicating how QM can be nominalized, and by “doing much of the work needed to provide the nominalization” (Balaguer , 114). (...) In this paper, I critically assess Balaguer’s proposal, and argue that it ultimately fails. Balaguer’s strategy is incompatible with a number of interpretations of QM, in particular with Bas van Fraassen’s version of the modal interpretation. And given that Balaguer’s strategy invokes physically real propensities, it is unclear whether it is even compatible with nominalism. I conclude that the nominalization of QM still remains a major problem for the nominalist. (shrink)
A closer examination of scientific practice has cast doubt recently on the thesis that observation necessarily fails to determine theory. In some cases scientists derive fundamental hypotheses from phenomena and general background knowledge by means of demonstrative induction. This note argues that it is wrong to interpret such an argument as providing inductive support for the conclusion, e.g. by eliminating rival hypotheses. The examination of the deduction of the inverse square law of gravitation due to J. Bertrand, and R. (...) Fowler's deduction of the quantization of the linear harmonic oscillator's energy spectrum from Planck's radiation law illustrates this point. It is suggested that demonstrative induction is a computational step in fitting a theoretical model and a set of phenomena, with little direct confirmational impact. The thesis of underdetermination, whatever one may think of it, is not threatened by demonstrative induction. (shrink)