Space, Time, and Location, Part II

Enrico Cinti (Università degli Studi di Urbino), ‘Quantum Location Beyond Quantum Mechanics’

Making sense of the location of subsystems is an outstanding issue when it comes to understanding quantum field theory and, in particular, quantum gravity. This problem takes a particularly deep significance in the gravitational context, where the notion of spacetime itself is argue to disappear, and where various unusual localization schemes, like holography, have been suggested. In this talk, my goal will be to make some first stesso towards making sense of location in quantum field theory and quantum gravity, starting from the example of the timelike tube theorem in algebraic quantum field theory, which displays some exotic features of location in these theories. I will suggest that there are two ways to make sense of location with respect to the timelike tube theorem: a more conservative one, more appropriate for quantum field theory, and a more radical one, necessitated by quantum gravity, and which naturally leads to holography. Along the way, I will discuss some of the metaphysical implications of these constructions, in particular with respect to the ontology of quantum field theory and quantum gravity. ‹back›

Damiano Costa (Università della Svizzera Italiana), ‘The Many-Chairs Interpretation of Relativistic Change’

In this talk, I explore a new solution to Sattig’s problem of relativistic change. First, I provide a reassessment of the problem, according to which the numerically same object appears to have something as a part in one frame but not at another (i.e., its ‘corner slices’). Second, I present a new solution that takes this mereological difference seriously, thus entailing that the relevant ordinary object is frame-bound. Finally, while this solution is naturally coupled with four-dimensionalism, I explore the possibility of coupling it with three-dimensionalism in order to provide an answer to Gilmore’s location question. ‹back›

Maya Eddon (University of Massachusetts, Amherst), ‘Rearrangements Across Spaces’

In recent years there has been some renewed interest in the metaphysics of quantitative features of the world, features that we tend to represent on a numerical scale. One intriguing line of thought is that the metaphysics of quantitative features may be modeled on the metaphysics of spacetime – just as there are spacetime points that stand in certain relations to one another, there are points of a quantity space that stand in certain relations to one another. And just as objects are located at different points in spacetime, so objects are located at different points in quantity space. How far can this model take us? The ontological analogues appear relatively straightforward, but the modal analogues are less so. One apparent difference is that the relations among spacetime points are generally taken to be contingent, whereas the relations among quantitative points are not. This interacts with certain questions involving uniform ‘shifts’ in spacetime, identification of points across worlds, and the individuation of possibilities. I examine some of these issues and identify some key choice points in the dialectic. ‹back›

Marian J R Gilton (University of Pittsburgh), ‘Where Counting Counts: Rehabilitating a Particle Interpretation of Interacting Quantum Field Theory’

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David Glick (University of California, Davis), ‘Quantum Location Is Not Indeterminate Location’

Quantum theory motivates new ways of understanding the location of physical objects. In this paper, I consider two approaches to quantum location: the spanner view and the inexact location view. Each view requires the rejection of intuitively plausible principles in the metaphysics of location. Next, I consider whether these accounts of quantum location give rise to location indeterminacy, that is, metaphysical indeterminacy with respect to the location of physical objects. I contend that they do not. While the inexact location view comes close to positing indeterminacy, one should distinguish inexact from indeterminate location. Ultimately, while quantum theory (under certain interpretations) is at odds with standard approaches to location, it need not be understood as involving location indeterminacy. ‹back›

Jack Himelright (Kansas State University) and Sebastián Murgueitio Ramírez (Purdue University), ‘Shape in Special Relativity’

In this paper, we will introduce a novel argument (the ‘Region Argument’) that objects do not have frame-independent shapes in special relativity. Our ‘Region Argument’ lacks vulnerabilities present in David Chalmers’ argument for that conclusion based on length contraction. We then examine how views on persistence interact with the Region Argument. We argue that this argument and standard four-dimensionalist assumptions entail that nothing in a relativistic world has any shape, not even stages or the regions occupied by them. We also argue that endurantists have viable ways of preserving shape despite the Region Argument. The upshot of these arguments is that contrary to conventional wisdom, considerations about shape in relativity support endurantism rather than four-dimensionalism. We conclude by examining the implications of our discussion for the debate over Edenic shapes, noting that endurantists have a satisfying response to skeptical arguments about shapes similar to the one they have against the Region Argument. ‹back›

Matt Leonard (California Baptist University), ‘Analyzing Parthood and Location’

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Laura Molinaro (Università della Svizzera Italiana), ‘Extensive Abstraction in Location - a Theory of Location Based on L-Containment’

In Enduring Through Gunk (Leonard, 2018), Leonard discussed the case of multilocational endurantism in a gunky spacetime by introducing the primitive of containment (from now on, L-Containment). Inspired by Whitehead’s method of extensive abstraction, he claimed that if spacetime is gunky an object would endure by being L-contained at different sets of temporally converging regions of spacetime. However, while L-containment has been only intuitively sketched, other locative notions have not been defined by using this new primitive. Moreover, beyond the debate on persistence, the idea of adopting Whitehead’s extensive abstraction in location to identify regions of spacetime is worth developing. My presentation aims to develop Leonard’s suggestions proposing a theory of location with extensive abstraction for regions, based on L-containment, and inspired by Parsons’s (2007) work. This theory would allow for gunk, atomism, multilocation, and colocation, it delivers an ‘innocent’ Exactness that does not ban multilocation, and does not imply Functionality. To do so, I will start by introducing the locative notions defined from L-Containment, and propose further developments. ‹back›

Maria Nørgaard (University of Geneva), ‘From Quantum to Classical Location’

The challenge of quantum location is an important issue in the philosophy and metaphysics of quantum mechanics. Quantum phenomena such as superposition and entangled states diverge significantly from classical cases, and raises issues concerning the nature of the quantum position observable; how can we account for the location of quantum systems? Recent literature (Pashby 2016; Calosi and Wilson 2021; Glick 2021) has explored the difficulty of extending classical theories of location to the quantum mechanics, attempting to modify the classical notion of exact location to the quantum domain. In previous work (Nørgaard MS) I argued that classical notions of location should be abandoned and that an entirely novel degree-theoretic notion, quantum location, should be adopted instead. The purpose of this talk is to present a fully developed theory of quantum location and to specify points of divergence between this and a traditional classical theory of location. I aim to explore the similarities and deviations of these theories– and how the classical notions of location may be recovered from quantum ones. ‹back›

Carlo Rossi (Universidad de Santiago de Chile), ‘Location and Naturalness’

Locational notions—and amongst them, the notion of exact location in particular—have come to occupy an important place in a number of contemporary debates on the metaphysics of material objects. For some authors (McDaniel 2007, Effingham 2015), it seems almost an uncontroversial fact to treat exact location as a perfectly natural relation that objects bear to regions. In this paper, I want to present and discuss three objections to that view: the Argument from the Fundamentality of Spacetime, the Argument from Definability, and the Argument from Supersubstantivalism. Of these three objections, I argue that (i) the first and the third one can be defused by appealing to negotiable intuitions about fundamentality, emergence, and naturalness and, consequently, that (ii) the second one, namely, the Argument from Definability, represents the most serious threat for those who take exact location to be a perfectly natural property. Moreover, I argue (iii) that such an objection gains even more strength once we consider certain features of recent theories of location (Eagle 2019, Correia 2022, Loss 2023) which do not take exact location as a primitive locational notion. ‹back›

Raul Saucedo (University of Colorado, Boulder), ‘The Elamite Picture of Reality’

I articulate a novel objection to the argument from vagueness for temporal parts and sketch a new view of temporal reality emerging from this objection. I begin by showing that the argument from vagueness runs together matters of mereology and matters of location in a way that some foes of temporal parts have independent reason to reject. Specifically, it imposes constraints on temporal location that are incompatible with the existence of temporally extended simples. I suggest that friends of such simples may adopt instead a mereologically harmonious constraint on temporal location, and argue that this results in a natural version of their view with the resources to both resist the argument and offer a novel and compelling explanation of where it goes wrong. I then distinguish between three ways of developing this view to accommodate the existence and temporal features of ordinary continuants. Building upon recent discussions about metaphysical priority, I argue that only one of them—which I call the Elamite picture of reality—has adequate resources to do that. On this view, ordinary continuants are neither temporally extended simples nor diachronic fusions thereof. Rather, they are metaphysically derivative from the combined qualitative complexity of such simples and fusions. ‹back›

Gabriel Uzquiano (University of Southern California), ‘On Being in More than One Place at Once’

What would it be for a material object to exactly occupy more than one region of space? One may be inclined to dismiss the question as incoherent—what part of ‘exactly’ do you not understand? But there is no reason to confine attention to spatial location. The word ‘the’ and the universal hydrogen occur more than once in the sentence ‘the coffee is on the counter’ and the structural universal H2O respectively. These claims may in fact be best understood in locative terms, and they seem to concern a relation akin to exact location. The stakes are higher when it comes to temporal location. For one way to make sense of endurance as a model of persistence is as the hypothesis that a material object is exactly located at every time at which it exists. We outline a theory of location, which characterizes exact location in terms of a new primitive relation and makes allowance for multiple exact location. ‹back›

Achille C Varzi (Columbia University), ‘Simple Problems for Self-Connectedness’

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Meg Wallace (University of Kentucky), ‘Transworld Persons’

Transworldism is a theory of modal parts: ordinary objects are mereological sums of individuals across different possible worlds. It is an unusual, ontologically extravagant view that nonetheless provides elegant solutions to problems of coincidence. Yet accepting that persons are transworld gives rise to two intriguing puzzles: (i) a modal problem of the many and (ii) a modal problem of motivational collapse. These puzzles may initially seem to be decisive arguments against transworldism. However, I hope to show that they instead yield consequences for permissive ontologies more broadly. Thus, by using transworldism as our starting point, we gain insight into how certain problems for permissive ontologies are both harder and apply more broadly than typically assumed. ‹back›