Space, Time, and Location

Sam Baron (ACU), ‘Spacetime: Functionalism and Fundamentality’

According to spacetime functionalism, spacetime is whatever plays the spacetime role. Spacetime functionalism has been used to understand how spacetime emerges from a more fundamental, non-spatiotemporal reality described by a theory of quantum gravity. It has been argued, however, that spacetime functionalism cannot capture spacetime emergence, because it requires that the more fundamental quantum gravity ontology is spatiotemporal after all. I will provide a response to this argument. The key is to distinguish between different ways in which the ontology of a theory of quantum gravity might be considered more fundamental. I suggest that for the right understanding of fundamentality, spacetime functionalism can indeed be used to understand the emergence of spacetime.

Sara Bernstein (Notre Dame), ‘What is Hypertime?’

Recent models of time travel – Goddu (2003), van Inwagen (2010), Bernstein (2017), Effingham (2021) – make use of the notion of hypertime, roughly, an extra temporal dimension against which time can be measured. But the nature of hypertime itself is underexplored. This talk will outline several possible answers to the question ‘What is hypertime?’, ranging from the deflationary to the ontologically maximalist. After laying out some versions of the concept, I discuss several new problems involving space-time location for the friend of hypertime.

David Builes (Princeton), ‘Non-Humeanism and Determinism’

According to Non-Humean theories of natural necessity, there is some sort of fundamental natural necessity in the world, which is supposed to guarantee the regularity of the universe. The goal of this paper is to explore a potential tension between Non-Humean theories and the empirical possibility that the laws of physics are deterministic. I begin by presenting a dilemma for the combination of Non-Humeanism and determinism, and then I explore several potential ways out of the dilemma. Although deciding which way out is most appealing will depend on one’s background metaphysical views, I tentatively conclude that the best way forward is to adopt a view according to which reality is fundamentally non-spatiotemporal and determinism is only true at a non-fundamental level of description.

Claudio Calosi (Geneva), ‘Omnipresence’

The paper develops a new logic of omnipresence and addresses several metaphysical issues related to it along the way. It then applies the new logic to the paradigmatic case of divine omnipresence. (Based on joint work with Fabrice Correia.)

Brigitte C Everett (Sydney), ‘Making Temporal Passage Illusionism Intelligible’

Famously, Thomas Nagel (1974) argued that we cannot know what it is like to be a bat. In other words, while I can (in some sense) know what it would be like for me to be a bat, I cannot know what it is like for a bat to be bat. The thought here is that, while we might have some idea of what it would be like for me to have certain experiences that I don’t actually, I can’t know what another person or creature’s experience is like. Given Nagel’s view and the work that has been done in more recent years, one might think that the temporal passage illusionist’s claim that we have experiences as of robust temporal passage, when such r-passage does not exist, is false. After all, given the actual non-existence of r-passage, it seems that I would have no way of knowing what it is like to be a person who has experiences as of r-passage. This is the intelligibility problem facing the illusionist about r-passage (Hoerl 2014; Prosser 2016). I suggest that the intelligibility problem only goes through if we think that what it is to have experiences as of r-passage is to have experiences that are indistinguishable from or identical to the experiences as of being a person having a veridical experience as of r-passage. I argue, then, that all that we need to have illusory experiences as of being a bat, for example, or having experiences as of r-passage is to have experiences as of me being a bat or as of me perceiving r-passage. I claim that such experiences don’t require knowledge of what it is like to be a person having veridical experiences as of robust temporal passage. Robust temporal passage illusionism, I argue, is intelligible.

Yanssel Garcia (Nebraska Omaha) ‘Endurantism, Presentism, and the Problem of Temporary Intrinsics’

The most common form of endurantism takes enduring objects to be wholly located at every time they occupy. Such a view is believed to give rise to a problem concerning intrinsic change. My laptop may have been shut before, but it is currently open. Yet, if we understand endurantism as above, then my laptop is in possession of two contradictory properties: the shapes of being open and shut. This problem is known as the ‘problem of temporary intrinsics’, and, to avoid it, two major kinds of moves have been made. The first is to meddle with the relationship between an enduring object and its properties by, for instance, claiming enduring objects bear their properties relationally to times rather than intrinsically. Many who have found this move unappealing have instead turned to presentism, claiming that endurantists should be presentists to avoid the problem. I take it that while both options can work, neither is optimal. Instead, I argue in favor of an alternative understanding of endurantism that allows endurantists to have it all: there is a version of endurantism that leaves the intrinsic properties of objects untouched, avoids the problem of temporary intrinsics, and does not require adopting presentism.

Jacopo Giraldo (Padua), ‘Geometry and Measure of Spatial Extension’

In this paper I present a novel account of spatial extension according to which to be Spatially Extended just is to be Extended Simpliciter (SEES), i.e., to have a one-dimensional projection of the exact location of at least one of its parts that is Lebesgue extended. There are two accounts of spatial extension mainly discussed in the literature: Spatial Extension as Mereological Extension (SEME) and Spatial Extension as Lebesgue Extension (SELE): a spatial entity is mereologically extended if and only if its exact spatial location has at least one proper part, whereas a spatial entity is Lebesgue-extended if and only if its exact location’s Lebesgue measure, relative to a given dimension, is greater than 0. In contrast to SEME, SEES is based on a measure of spatial extension. Unlike SELE, SEES conceives spatial extension as absolute rather than relative to geometrical dimension. I defend that being based on a measure and being absolute are essential to a correct characterization of spatial extension, both being features of SEES. Therefore, I conclude that, ceteris paribus, SEES is a better candidate than both SEME and SELE.

Jordan Lee-Tory (Sydney) ‘Coincidence, Temporal Parts, and the Grounding Problem’

One might be tempted to think that cases of partial temporal coincidence in which some objects coincide at some but not all times involve numerically distinct objects. This move is made in response to the differences in properties that can be identified in these cases. If we are convinced by such an account, naturally, the question arises of what it is in virtue of that these objects have these distinct properties. The Grounding problem is an issue of identifying plausible grounds for such properties given that these objects coincide at some times and hence at those times, have identical microphysical structures. The thought goes at these times, there are no actual physical differences that can serve as the grounds for the fact that they have these other differences. One response is to appeal to a perdurantist account of persistence such that the distinct temporal parts. Firstly, I will argue that appealing to only the distinctive temporal parts seems unmotivated. If temporal parts are the right kinds of grounds for such properties, then all of the temporal parts should do the grounding work leading to both numerically distinct objects having all of the same properties at the times at which they overlap. This is undesirable for those who take these property differences seriously. If one appeals to only the distinctive part as the grounds of these properties it is totally opaque how such a view is supposed to go. I will present some examples that home in on this worry and ultimately conclude that even if temporal parts can be the grounds, simply pointing to them makes no progress in resolving the grounding problem. What is needed is further elaboration on why these are the right grounds, which the likelihood of providing such an account seems dubious.

Daniel Nolan (Notre Dame), ‘Parsons, Location and Method’

This paper will contrast two strands of Josh Parsons’s thought: the search for conceptual truths about location, and the rejection of a range of putative conceptual truths about composition. I will argue that the spirit of Parsons’s suspicions (of some kinds) of conceptual truths in the theory of parts and wholes, if accepted, would undercut the claims he wished to make about location. Siding with Parsons’s more suspicious approach to conceptual truths in metaphysics, I want to suggest that we should reconceive the contribution Parsons’s work makes to theories of location.

Maria Nørgaard (Geneva) ‘Quantum Location and the Challenge of Quantum Persistence’

In the debate on quantum mechanics, an important question has so far remained almost completely unaddressed: how do quantum systems persist? Persistence is a central issue in metaphysics, and despite the development of several formal accounts in recent years (Gilmore 2008; Balashov 2010; Calosi and Correia MS), only a handful of papers have been dedicated to the specific investigation of the persistence of quantum systems (Pashby 2013; 2016). This paper aims to examine quantum persistence more carefully. I argue that while the extensive literature on persistence has proved effective for classical systems, it does not successfully extend its application to interpretations of quantum mechanics that allow for quantum position indefiniteness. In order to overcome the challenge of quantum persistence, an account of indefinite location must first be provided.

I investigate three available accounts of quantum position indefiniteness: (i) Quantum Exact Location (Pashby 2016), (ii) Degree Location (Calosi & Wilson 2021), and (iii) the Sparse View (Glick 2017; 2021). I argue that while these positions provide an unsatisfactory account, each captures something significant about the nature of location in the quantum domain: (1) the locative properties of quantum systems can be determined using the Born rule, (2) location may be a matter of degrees, and (3) position indefinite quantum systems do not have exact locations. I use these insights to construct a novel theory of location: Quantum Location, which can account for the locative properties of quantum systems. This account of location may provide a solution to the challenge of persistence and provide new ontological insights.

Phil Pickering (UWA), ‘Nonlocality in General Relativity’

Since Howard clarified the distinction in 1989, nonlocality is typically taken to follow from the violation of one of two principles: the principle of local action or the principle of separability. Different interpretations of quantum theory violate one or both of these principles, while our best theory of spacetime – General Relativity (GR) – is thought to strictly adhere to both. I claim, to the contrary, that the joint system states of GR violate the principle of separability and should be considered just as (non)local as entangled quantum states. I review the concept of nonseparability, landing on a sufficient condition that tells us (roughly) that the state of two systems is nonseparable if the joint state does not supervene on the states of the systems individually. I examine spatiotemporal joint states in GR, including the fact that they are only well-defined with respect to a parallel transport map, which does not supervene on the states of the individual systems. I show how the joint states of entangled quantum systems have the same nonseparable structure as those of GR, albeit with a mapping function determined by the systems’ interactions with other systems (a ‘measurement map’). I conclude by defending against two important objections.

Jessica Pohlmann (ACU), ‘Mereological Models of Spacetime Emergence’

Approaches to quantum gravity suggest that spacetime or spatiotemporal properties may not be fundamental. Philosophical interest in spacetime emergence focuses on the idea that spacetime metaphysically depends on something that is non-spatiotemporal. Philosophers have expressed suspicion toward the idea that spacetime is mereologically composed of non-spatiotemporal parts. In particular, it has been claimed that emergent spacetime is unlike ordinary cases of composition, that mereological models of spacetime are unmotivated, and that mereology is naive to physics. I explore these complaints and suggest that we can defend the use of composition to model spacetime emergence against such worries.

Oliver Pooley (Oxford), ‘Self Location and the Myth of Passage’

If there is agreement that time seems to pass, there is much less agreement about what it is about our experience of the world that makes it seem to do so. On the face of it, the seeming passing of time supports an A-theoretic, dynamical metaphysics of time. Many B-theorists accept the need to explain (away) apparent passage.

This talk will outline my own favoured B-theoretic account. A necessary condition for the success of such an account is that it differentiate time from space: time seems to pass but there is no analogue spatial phenomenon. Several proposals fail this test. The key to a more satisfying story involves recognising certain distinctive features of how temporal and spatial locations are given (or not given!) in experience as related to the location of the subject of that experience. I also reconcile talk of the experiential disclosure of spatial locations with the relativistic fact that nothing given in experience is, strictly speaking, spatially related to the spacetime location of the subject of that experience.

Emily Thomas (Durham) ‘Origins of the A-B Theory Debate and G. E. Moore’

The 2023 Gavin David Young Lecture in Philosophy:

J M E McTaggart’s 1908 ‘The Unreality of Time’ is rightly recognised as sparking the debate between philosophers who hold the ‘real nature’ of time to be an A-series, and those who take it to be a B-series. Bertrand Russell has been described as the ‘father’ of B-theory, but the parentage of A-theory is murky. This paper argues we should look to fellow ‘new realist’ G E Moore, who espoused anti-realism about time until late 1898 and then became a ‘common-sense’ A-theorist and presentist. I put Moore’s shifting views in context, explore his positions, and argue he owes a great debt to ‘old realist’ Henry Sidgwick.

Danny Wardle (ACU), ‘Locating Groups and Their Members’

In this paper, I attempt to address what Hindricks (2011) calls the ‘location problem in social ontology’ for social groups and institutions. Are social groups located in spacetime? And if so, where are they located? Are they located exactly where their members are and at no other regions of spacetime? I suggest that the problem seems to arise due to the context sensitivity of locative expressions. In different contexts, we can truthfully talk about the same group being located at different places. There are also good reasons to think that it’s often vague which social group we refer to and which regions of spacetime the group is located at. Many of the puzzles regarding group location dissipate when using more precise language, e.g., ‘I saw Port Adelaide Football Club’ vs. ‘I saw Port Adelaide Football Club’s players in the hotel lobby’. I also contend that the general notions of group membership that social ontologists use are unhelpful in dealing with the location problem and shouldn’t be confused with the use of phrases like ‘member of’ in natural language. In addition, I claim that many groups cannot be assigned a context invariant exact location.