•  8
    Cartography of the space of theories: An interpretational chart for fields that are both (dark) matter and spacetime
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 72 217-236. 2020.
  •  19
    Dark matter = modified gravity? Scrutinising the spacetime–matter distinction through the modified gravity/ dark matter lens
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 72 237-250. 2020.
    This paper scrutinises the tenability of a strict conceptual distinction between space and matter via the lens of the debate between modified gravity and dark matter. In particular, we consider Berezhiani and Khoury's novel 'superfluid dark matter theory' as a case study. Two families of criteria for being matter and being spacetime, respectively, are extracted from the literature. Evaluation of the new scalar field postulated by SFDM according to these criteria reveals that it is as much matter…Read more
  •  10
    This paper pushes back against the Democritean-Newtonian tradition of assuming a strict conceptual dichotomy between spacetime and matter. Our approach proceeds via the more narrow distinction between modified gravity/spacetime and dark matter. A prequel paper argued that the novel field Φ postulated by Berezhiani and Khoury's 'superfluid dark matter theory' is as much matter as anything could possibly be, but also below the critical temperature for superfluidity as much spacetime as anything co…Read more
  •  14
    The Equivalence Principle(s)
    In Eleanor Knox & Alistair Wilson (eds.), The Routledge Companion to Philosophy of Physics, . 2021.
    I discuss the relationship between different versions of the equivalence principle in general relativity, among them Einstein's equivalence principle, the weak equivalence principle, and the strong equivalence principle. I show that Einstein's version of the equivalence principle is intimately linked to his idea that in GR gravity and inertia are unified to a single field, quite like the electric and magnetic field had been unified in special relativistic electrodynamics. At the same time, what …Read more
  •  57
    Particle physics after the Higgs discovery: Philosophical perspectives
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 51 69-70. 2015.
  •  44
    Two miracles of general relativity
    with James Read and Harvey R. Brown
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 64 14-25. 2018.
    We approach the physics of \emph{minimal coupling} in general relativity, demonstrating that in certain circumstances this leads to violations of the \emph{strong equivalence principle}, which states that, in general relativity, the dynamical laws of special relativity can be recovered at a point. We then assess the consequences of this result for the \emph{dynamical perspective on relativity}, finding that potential difficulties presented by such apparent violations of the strong equivalence pr…Read more
  •  12
    The problem of motion in general relativity is about how exactly the gravitational field equations, the Einstein equations, are related to the equations of motion of material bodies subject to gravitational fields. This article compares two approaches to derive the geodesic motion of matter from the field equations: the ‘T approach’ and the ‘vacuum approach’. The latter approach has been dismissed by philosophers of physics because it apparently represents material bodies by singularities. I arg…Read more
  •  28
    General relativity as a hybrid theory: The genesis of Einstein's work on the problem of motion
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 67 176-190. 2019.
  •  94
    I argue that, contrary to folklore, Einstein never really cared for geometrizing the gravitational or the electromagnetic field; indeed, he thought that the very statement that General Relativity geometrizes gravity "is not saying anything at all". Instead, I shall show that Einstein saw the "unification" of inertia and gravity as one of the major achievements of General Relativity. Interestingly, Einstein did not locate this unification in the field equations but in his interpretation of the ge…Read more
  •  47
    On Time in Spacetime
    Philosophia Naturalis 49 (2): 225-237. 2012.
    It is often claimed that relativity theory falls short of giving an account of 'the flow of time' and 'the arrow of time'. Some claim that hence either one or both of these concepts do not correspond to objective reality, others infer that relativity theory is wrongfully 'spatialising' time. I investigate of our normal conception of time is enduring in relativity, even in the absence of a clear representation of flow. It is shown that the conformal structure of spacetime allows for a clear disti…Read more
  •  67
    Einstein regarded as one of the triumphs of his 1915 theory of gravity - the general theory of relativity - that it vindicated the action-reaction principle, while Newtonian mechanics as well as his 1905 special theory of relativity supposedly violated it. In this paper we examine why Einstein came to emphasise this position several years after the development of general relativity. Several key considerations are relevant to the story: the connection Einstein originally saw between Mach's analys…Read more
  •  9
    Towards a Theory of Spacetime Theories (edited book)
    with Gregor Schiemann and Erhard Scholz
    Birkhauser. 2016.
    This contributed volume is the result of a July 2010 workshop at the University of Wuppertal Interdisciplinary Centre for Science and Technology Studies which brought together world-wide experts from physics, philosophy and history, in order to address a set of questions first posed in the 1950s: How do we compare spacetime theories? How do we judge, objectively, which is the “best” theory? Is there even a unique answer to this question? The goal of the workshop, and of this book, is to contribu…Read more
  •  96
    Mass‐energy‐momentum: Only there because of spacetime
    British Journal for the Philosophy of Science 62 (3): 453-488. 2011.
    I describe how relativistic field theory generalizes the paradigm property of material systems, the possession of mass, to the requirement that they have a mass–energy–momentum density tensor T µ associated with them. I argue that T µ does not represent an intrinsic property of matter. For it will become evident that the definition of T µ depends on the metric field g µ in a variety of ways. Accordingly, since g µ represents the geometry of spacetime itself, the properties of mass, stress, energ…Read more
  •  147
    The Metaphysics of Super‐Substantivalism
    Noûs 52 (1): 24-46. 2018.
    Recent decades have seen a revived interest in super-substantivalism, the idea that spacetime is the only fundamental substance and matter some kind of aspect, property or consequence of spacetime structure. However, the metaphysical debate so far has misidentified a particular variant of super-substantivalism with the position per se. I distinguish between a super-substantival core commitment and different ways of fleshing it out. I then investigate how general relativity and alternative spacet…Read more