•  68
    Some Philosophical Prehistory of the (Earman-Norton) hole argument
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 70 79-87. 2020.
    The celu of the philosophical literature on the hole argument is the 1987 paper by Earman \& Norton ["What Price Space-time Substantivalism? The Hole Story" Br. J. Phil. Sci.]. This paper has a well-known back-story, concerning work by Stachel and Norton on Einstein's thinking in the years 1913-15. Less well-known is a connection between the hole argument and Earman's work on Leibniz in the 1970s and 1980s, which in turn can be traced to an argument first presented in 1975 by Howard Stein. Remar…Read more
  •  45
    In recent years, philosophers of science have explored categorical equivalence as a promising criterion for when two theories are equivalent. On the one hand, philosophers have presented several examples of theories whose relationships seem to be clarified using these categorical methods. On the other hand, philosophers and logicians have studied the relationships, particularly in the first order case, between categorical equivalence and other notions of equivalence of theories, including defini…Read more
  •  46
    Why Be regular?, part I
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 65 (C): 122-132. 2019.
  •  17
    Why be regular? Part II
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 65 (C): 133-144. 2019.
  •  32
    A classic problem in general relativity, long studied by both physicists and philosophers of physics, concerns whether the geodesic principle may be derived from other principles of the theory, or must be posited independently. In a recent paper [Geroch & Weatherall, "The Motion of Small Bodies in Space-Time", Comm. Math. Phys. ], Bob Geroch and I have introduced a new approach to this problem, based on a notion we call "tracking". In the present paper, I situate the main results of that paper w…Read more
  •  88
    We study the Johansen–Ledoit–Sornette model of financial market crashes :219–255, 2000). On our view, the JLS model is a curious case from the perspective of the recent philosophy of science literature, as it is naturally construed as a “minimal model” in the sense of Batterman and Rice :349–376, 2014) that nonetheless provides a causal explanation of market crashes, in the sense of Woodward’s interventionist account of causation.
  •  66
    I review the philosophical literature on the question of when two physical theories are equivalent. This includes a discussion of empirical equivalence, which is often taken to be necessary, and sometimes taken to be sufficient, for theoretical equivalence; and "interpretational" equivalence, which is the idea that two theories are equivalent just in case they have the same interpretation. It also includes a discussion of several formal notions of equivalence that have been considered in the rec…Read more
  •  244
    Scientific polarization
    with Cailin O’Connor
    European Journal for Philosophy of Science 8 (3): 855-875. 2017.
    Contemporary societies are often “polarized”, in the sense that sub-groups within these societies hold stably opposing beliefs, even when there is a fact of the matter. Extant models of polarization do not capture the idea that some beliefs are true and others false. Here we present a model, based on the network epistemology framework of Bala and Goyal, 784–811 1998), in which polarization emerges even though agents gather evidence about their beliefs, and true belief yields a pay-off advantage.…Read more
  •  45
    Would two dimensions be world enough for spacetime?
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 63 100-113. 2018.
    We consider various curious features of general relativity, and relativistic field theory, in two spacetime dimensions. In particular, we discuss: the vanishing of the Einstein tensor; the failure of an initial-value formulation for vacuum spacetimes; the status of singularity theorems; the non-existence of a Newtonian limit; the status of the cosmological constant; and the character of matter fields, including perfect fluids and electromagnetic fields. We conclude with a discussion of what cons…Read more
  •  52
    Classical Spacetime Structure
    In Eleanor Knox & Alastair Wilson (eds.), The Routledge Companion to Philosophy of Physics, Routledge. 2022.
    I discuss several issues related to "classical" spacetime structure. I review Galilean, Newtonian, and Leibnizian spacetimes, and briefly describe more recent developments. The target audience is undergraduates and early graduate students in philosophy; the presentation avoids mathematical formalism as much as possible.
  •  16
    We consider the motion of small bodies in general relativity. The key result captures a sense in which such bodies follow timelike geodesics. This result clarifies the relationship between approaches that model such bodies as distributions supported on a curve, and those that employ smooth fields supported in small neighborhoods of a curve. This result also applies to "bodies" constructed from wave packets of Maxwell or Klein-Gordon fields. There follows a simple and precise formulation of the o…Read more
  •  21
    The Peculiar Logic of the Black-Scholes Model
    Philosophy of Science 85 (5): 1152-1163. 2018.
    The Black-Scholes model of options pricing establishes a theoretical relationship between the “fair” price of an option and other parameters characterizing the option and prevailing market conditions. Here I discuss a common application of the model with the following striking feature: the output of analysis apparently contradicts one of the core assumptions of the model on which the analysis is based. I will present several attitudes one might take toward this situation and argue that it reveal…Read more
  •  101
    Regarding the ‘Hole Argument’
    British Journal for the Philosophy of Science 69 (2): 329-350. 2018.
    I argue that the hole argument is based on a misleading use of the mathematical formalism of general relativity. If one is attentive to mathematical practice, I will argue, the hole argument is blocked. _1._ Introduction _2._ A Warmup Exercise _3._ The Hole Argument _4._ An Argument from Classical Spacetime Theory _5._ The Hole Argument Revisited
  •  48
    We discuss some recent work by Tim Maudlin concerning Black Hole Information Loss. We argue, contra Maudlin, that there is a paradox, in the straightforward sense that there are propositions that appear true, but which are incompatible with one another. We discuss the significance of the paradox and Maudlin's response to it.
  •  35
    A brief comment on Maxwell[-Huygens] spacetime
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 63 34-38. 2018.
    I provide an alternative characterization of a "standard of rotation" in the context of classical spacetime structure that does not refer to any covariant derivative operator.
  •  36
    Conservation, inertia, and spacetime geometry
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 67 144-159. 2017.
    As Harvey Brown emphasizes in his book Physical Relativity, inertial motion in general relativity is best understood as a theorem, and not a postulate. Here I discuss the status of the "conservation condition", which states that the energy-momentum tensor associated with non-interacting matter is covariantly divergence-free, in connection with such theorems. I argue that the conservation condition is best understood as a consequence of the differential equations governing the evolution of matter…Read more
  •  13
    Relativistic causality
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 48 (2): 101. 2014.
  •  177
    On G.E. Moore’s ‘Proof of an External World’
    Pacific Philosophical Quarterly 98 (2). 2017.
    A new reading of G.E. Moore's ‘Proof of an External World’ is offered, on which the Proof is understood as a unique and essential part of an anti-sceptical strategy that Moore worked out early in his career and developed in various forms, from 1909 until his death in 1958. I begin by ignoring the Proof and by developing a reading of Moore's broader response to scepticism. The bulk of the article is then devoted to understanding what role the Proof plays in Moore's strategy, and how that role is …Read more
  •  133
    I argue that a criterion of theoretical equivalence due to Glymour :227–251, 1977) does not capture an important sense in which two theories may be equivalent. I then motivate and state an alternative criterion that does capture the sense of equivalence I have in mind. The principal claim of the paper is that relative to this second criterion, the answer to the question posed in the title is “yes”, at least on one natural understanding of Newtonian gravitation.
  •  115
    The Geometry of Conventionality
    Philosophy of Science 81 (2): 233-247. 2014.
    There is a venerable position in the philosophy of space and time that holds that the geometry of spacetime is conventional, provided one is willing to postulate a “universal force field.” Here we ask a more focused question, inspired by this literature: in the context of our best classical theories of space and time, if one understands “force” in the standard way, can one accommodate different geometries by postulating a new force field? We argue that the answer depends on one’s theory. In Newt…Read more
  •  43
    Inertial motion, explanation, and the foundations of classical spacetime theories
    In Dennis Lehmkuhl, Gregor Schiemann & Erhard Scholz (eds.), Towards a Theory of Spacetime Theories, Birkhauser. pp. 13-42. 2017.
    I begin by reviewing some recent work on the status of the geodesic principle in general relativity and the geometrized formulation of Newtonian gravitation. I then turn to the question of whether either of these theories might be said to ``explain'' inertial motion. I argue that there is a sense in which both theories may be understood to explain inertial motion, but that the sense of ``explain'' is rather different from what one might have expected. This sense of explanation is connected with …Read more
  •  52
    A classic result in the foundations of Yang-Mills theory, due to J. W. Barrett ["Holonomy and Path Structures in General Relativity and Yang-Mills Theory." Int. J. Th. Phys. 30, ], establishes that given a "generalized" holonomy map from the space of piece-wise smooth, closed curves based at some point of a manifold to a Lie group, there exists a principal bundle with that group as structure group and a principal connection on that bundle such that the holonomy map corresponds to the holonomies …Read more
  •  37
    What Is a Singularity in Geometrized Newtonian Gravitation?
    Philosophy of Science 81 (5): 1077-1089. 2014.
    I discuss singular space-times in the context of the geometrized formulation of Newtonian gravitation. I argue first that geodesic incompleteness is a natural criterion for when a model of geometrized Newtonian gravitation is singular, and then I show that singularities in this sense arise naturally in classical physics by stating and proving a classical version of the Raychaudhuri-Komar singularity theorem
  •  114
    On (Some) Explanations in Physics
    Philosophy of Science 78 (3): 421-447. 2011.
    I offer an explanation of why inertial and gravitational mass are equal in Newtonian gravitation. I then argue that this is an example of a kind of explanation that is not captured by standard philosophical accounts of scientific explanation. Moreover, this form of explanation is particularly important, at least in physics, because demands for this kind of explanation are used to motivate and shape research into the next generation of physical theories. I suggest that explanations of the sort I …Read more
  •  97
    Categories and the Foundations of Classical Field Theories
    In Elaine Landry (ed.), Categories for the Working Philosopher, Oxford University Press. forthcoming.
    I review some recent work on applications of category theory to questions concerning theoretical structure and theoretical equivalence of classical field theories, including Newtonian gravitation, general relativity, and Yang-Mills theories.
  •  26
    The Motion of a Body in Newtonian Theories
    Journal of Mathematical Physics 52 (3): 032502. 2011.
    A theorem due to Bob Geroch and Pong Soo Jang [“Motion of a Body in General Relativity.” Journal of Mathematical Physics 16, ] provides the sense in which the geodesic principle has the status of a theorem in General Relativity. Here we show that a similar theorem holds in the context of geometrized Newtonian gravitation. It follows that in Newtonian gravitation, as in GR, inertial motion can be derived from other central principles of the theory.
  •  55
    Interpreting Quantum Theories
    Philosophical Review 124 (2): 275-278. 2015.
  •  47
    A Brief Remark on Energy Conditions and the Geroch-Jang Theorem
    Foundations of Physics 42 (2): 209-214. 2012.
    The status of the geodesic principle in General Relativity has been a topic of some interest in the recent literature on the foundations of spacetime theories. Part of this discussion has focused on the role that a certain energy condition plays in the proof of a theorem due to Bob Geroch and Pong-Soo Jang [“Motion of a Body in General Relativity.” Journal of Mathematical Physics16(1) (1975)] that can be taken to make precise the claim that the geodesic principle is a theorem, rather than a post…Read more
  •  91
    On the status of the geodesic principle in Newtonian and relativistic physics
    Studies in History and Philosophy of Science Part A 42 (4): 276-281. 2011.
    A theorem due to Bob Geroch and Pong Soo Jang ["Motion of a Body in General Relativity." Journal of Mathematical Physics 16, ] provides a sense in which the geodesic principle has the status of a theorem in General Relativity. I have recently shown that a similar theorem holds in the context of geometrized Newtonian gravitation [Weatherall, J. O. "The Motion of a Body in Newtonian Theories." Journal of Mathematical Physics 52, ]. Here I compare the interpretations of these two theorems. I argue …Read more
  •  77
    Collective Belief, Kuhn, and the String Theory Community
    In Michael S. Brady & Miranda Fricker (eds.), The Epistemic Life of Groups, Oxford University Press. pp. 191-217. 2016.
    One of us [Gilbert, M.. “Collective Belief and Scientific Change.” Sociality and Responsibility. Lanham, MD: Rowman & Littlefield. 37-49.] has proposed that ascriptions of beliefs to scientific communities generally involve a common notion of collective belief described by her in numerous places. A given collective belief involves a joint commitment of the parties, who thereby constitute what Gilbert refers to as a plural subject. Assuming that this interpretive hypothesis is correct, and that s…Read more