The authors survey some debates about the nature and structure of physical theories and about the connections between our physical theories and naturalized metaphysics. The discussion is organized around an “ideal view” of physical theories and criticisms that can be raised against it. This view includes controversial commitments regarding the best analysis of physical modalities and intertheory relations. The authors consider the case in favor of taking laws as the primary modal notion, discussing objections related to alleged violations of the (...) laws, the apparent need to appeal to causality, and the status of probability. The “ideal view” includes a commitment that fundamental physical theories are explanatorily sufficient. The authors discuss several challenges to recovering the manifest image from fundamental physics, along with a distinct challenge to reductionism based on acknowledging the contributions of less fundamental theories in physical explanations. (shrink)

This book defends a relational theory of the passage of time. The realist view of passage developed in this book differs from the robust, substantivalist position. According to relationism, passage is nothing over and above the succession of events, one thing coming after another. Causally related events are temporally arranged as they happen one after another along observers’ worldlines. There is no unique global passage but a multiplicity of local passages of time. After setting out this positive argument for relationism, (...) the author deals with five common objections to it: (a) triviality of deflationary passage, (b) a-directionality of passage, (c) the impossibility of experiencing passage, (d) fictionalism about passage, and (e) the incompatibility of passage with perduring objects. (shrink)

A short review of some recent developments in the philosophy of physics is presented. I focus on themes which illustrate relations and points of common interest between philosophy of physics and three of its `neighboring' elds: Physics, metaphysics and general philosophy of science. The main examples discussed in these three `border areas' are decoherence and the interpretation of quantum mechanics; time in physics and metaphysics; and methodological issues surrounding the multiverse idea in modern cosmology.

This work introduces a causal explanation of the passage of time, and contrasts it with rival explanations. In the causal explanation, laws of physics are shown to entail that events are in causal succession, and the passage of time is defined as their causal succession. The causal explanation is coupled with phenomenology of the passage of time, and contrasted with the project of making sense of the idea that time does not pass.

We regularly talk of the experience of time passing. Some theorists have taken the supposed phenomenology of time passing to provide support for metaphysical accounts of the nature of time; opposing theorists typically granted that there is a phenomenology of time passing while seeking to dispute that any metaphysical conclusions about time can be drawn from this. In recent debates theorists have also begun to dispute that there is a phenomenology of time passing – plausibly, if there is not, then (...) there is no relevant experience to be explained away, or for metaphysical conclusions to be drawn from. In the present paper I offer one explanation of why such disputes about the experience of time passing may seem intractable. However, I suggest that there is a distinct and more tractable issue lurking in this area, concerning our experience of how certain phenomena persist over time. Interestingly, articulating how we experience different phenomena as persisting over time doesn't simply provide a challenge to one metaphysical view of persistence rather than another; instead, it generates an explanatory challenge for a variety of competing views of persistence and, by extension, a challenge for popular combinations of views of the metaphysics of persistence and of time. (shrink)

Philosophical debates about the metaphysics of time typically revolve around two contrasting views of time. On the A-theory, time is something that itself undergoes change, as captured by the idea of the passage of time; on the B-theory, all there is to time is events standing in before/after or simultaneity relations to each other, and these temporal relations are unchanging. Philosophers typically regard the A-theory as being supported by our experience of time, and they take it that the B-theory clashes (...) with how we experience time and therefore faces the burden of having to explain away that clash. In this paper, we investigate empirically whether these intuitions about the experience of time are shared by the general public. We asked directly for people’s subjective reports of their experience of time—in particular, whether they believe themselves to have a phenomenology as of time’s passing—and we probed their understanding of what time’s passage in fact is. We find that a majority of participants do share the aforementioned intuitions, but interestingly a minority do not. (shrink)

We seem to experience time as flowing. Yet according to the leading metaphysical picture of time, the block-universe theory, time in fact does not flow. Block-lovers typically react to this apparent tension by unhitching the sense of flow in our temporal experience from temporal reality, holding that temporal experience is systematically illusory. I shall develop a new block-friendly account of the sense of flow, which preserves a match of temporal experience and temporal reality. According to this account, the sense of (...) flow arises from higher-order temporal experience. (shrink)

Is the objective passage of time compatible with relativistic physics? There are two easy routes to an affirmative answer: (1) provide a deflationary analysis of passage compatible with the block universe, or (2) argue that a privileged global present is compatible with relativity. (1) does not take passage seriously. (2) does not take relativity seriously. This paper is concerned with the viability of views that seek to take both passage and relativity seriously. The investigation proceeds by considering how traditional A-theoretic (...) conceptions of passage might be generalized to relativistic space-times without incorporating a privileged global present. I argue that the most promising position marries the idea that open possibilities for the future are settled as time passes with a ‘non-standard’ interpretation of the relevant formal models. (shrink)

Please imagine a long fuse hanging down from the ceiling. It is a carefully woven tube of fabric that holds a core of gunpowder. We note that it is beautifully made, with brightly colored threads intertwined with the coarser bare cotton. It a masterpiece of the modern weaver's art.

I examine some recent claims put forward by L. A. Paul, Barry Dainton and Simon Prosser, to the effect that perceptual experiences of movement and change involve an (apparent) experience of ‘passage’, in the sense at issue in debates about the metaphysics of time. Paul, Dainton and Prosser all argue that this supposed feature of perceptual experience – call it a phenomenology of passage – is illusory, thereby defending the view that there is no such a thing as passage, conceived (...) of as a feature of mind-independent reality. I suggest that in fact there is no such phenomenology of passage in the first place. There is, however, a specific structural aspect of the phenomenology of perceptual experiences of movement and change that can explain how one might mistakenly come to the belief that such experiences do involve a phenomenology of passage. (shrink)

In philosophical logic and metaphysics there is a long-standing debate around the most appropriate structures to represent indeterministic scenarios concerning the future. We reconstruct here such a debate in a computational setting, focusing on the fundamental difference between moment-based and history-based structures. Our presentation is centered around two versions of an indeterministic scenario in which a programmer wants a machine to perform a given task at some point after a specified time. One of the two versions includes an assumption about (...) the future behaviour of the machine that cannot be encoded in any programming instruction; such version has models over history-based structures but no model over a moment-based structure. Therefore, our work adds a new stance to the debate: moment-based structures can be said to rule out certain indeterministic scenarios that are computationally unfeasible. (shrink)

A basic intuition we have regarding the nature of time is that the future is open whereas the past is fixed. For example, whereas we think that there are things we can do to affect how the future will unfold, we think that there are not things we can do to affect how the past unfolded. However, although this intuition is largely shared, it is not a straightforward matter to determine the nature of the asymmetry it reflects. So, in this (...) paper, I survey various philosophical ways of characterizing the asymmetry between the ‘open future’ and the ‘fixed past’ in order to account for our intuition. In particular, I wonder whether the asymmetry is to be characterized in semantic, epistemic, metaphysical or ontological terms. I conclude that, although many of these characterizations may contribute to a global understanding of the phenomenon, an ontological characterization of the asymmetry is to be preferred, since it is superior to the alternatives in explanatory power, intelligibility, and in how it coheres with interesting senses of openness. (shrink)

A basic intuition we have regarding the nature of time is that the future is open whereas the past is fixed. For example, whereas we think that there are things we can do to affect how the future will unfold (e.g. acting in an environmentally responsible manner), we think that there are not things we can do to affect how the past unfolded (“what is done is done”). However, although this intuition is largely shared, it is not a straightforward matter (...) to determine the nature of the asymmetry it reflects. So, in this paper, I survey various philosophical ways of characterizing the asymmetry between the ‘open future’ and the ‘fixed past’ in order to account for our intuition. In particular, I wonder whether the asymmetry is to be characterized in semantic, epis‐ temic, metaphysical or ontological terms. I conclude that, although many of these characterizations may contribute to a global understanding of the phenomenon, an ontological characterization of the asymmetry is to be preferred, since it is superior to the alternatives in explanatory power, intelligibility, and in how it coheres with interesting senses of openness. (shrink)

The aim of this paper is to make presentism a dynamic view of reality by basing it on a notion of dynamic existence, that is, on a notion of existence which has a dynamic character. The paper shows that both of the notions of existence which are used in metaphysical theories of time have a static character and, while such a notion is useful for eternalists, it is useless for presentists if they want to make their view able to remain (...) in agreement with our everyday experience and self-consistent. It is demonstrated that both empirical and theoretical arguments indicate that the presentist should replace the notion of this static existence with the notion of a dynamic existence and that this maneuver allows the presentist to treat his/her existential thesis as equivalent to the thesis that time flows. Not only does this strategy allow us to express presentism in a simple, homogenous way which remains in agreement with our experience, but also permits us to solve some of the difficult problems which presentism faces, such as, for example, the objection of triviality and the question about the rate of time passage. Moreover, such an approach to presentism allows us to solve fundamental metaphysical problems concerning time such as the problem of the openness of the future and the fixity of the past, direction of causation, and relations between presentism and persistence through time by endurance. (shrink)

It is usual to identify initial conditions of classical dynamical systems with mathematical real numbers. However, almost all real numbers contain an infinite amount of information. I argue that a finite volume of space can’t contain more than a finite amount of information, hence that the mathematical real numbers are not physically relevant. Moreover, a better terminology for the so-called real numbers is “random numbers”, as their series of bits are truly random. I propose an alternative classical mechanics, which is (...) empirically equivalent to classical mechanics, but uses only finite-information numbers. This alternative classical mechanics is non-deterministic, despite the use of deterministic equations, in a way similar to quantum theory. Interestingly, both alternative classical mechanics and quantum theories can be supplemented by additional variables in such a way that the supplemented theory is deterministic. Most physicists straightforwardly supplement classical theory with real numbers to which they attribute physical existence, while most physicists reject Bohmian mechanics as supplemented quantum theory, arguing that Bohmian positions have no physical reality. (shrink)

Experiences of motion and change are widely taken to have a ‘flow-like’ quality. Call this ‘temporal qualia’. Temporal qualia are commonly thought to be central to the question of whether time objectively passes: (1) passage realists take temporal passage to be necessary in order for us to have the temporal qualia we do; (2) passage antirealists typically concede that time appears to pass, as though our temporal qualia falsely represent time as passing. I reject both claims and make the case (...) that passage-talk plays no useful explanatory role with respect to temporal qualia, but rather obfuscates what the philosophical problem of temporal qualia is. I offer a ‘reductionist’ account of temporal qualia that makes no reference to the concept of passage and argue that it is well motivated by empirical studies in motion perception. (shrink)

This paper considers one unique solution to the puzzle of temporal passage in the block universe. argues that, although a precise description of its workings is currently beyond our understanding, time really passes. After introducing Norton’s account, I argue that it both implies a counterintuitive relationship between the “now” and passage and that it leads to an unlikely relationship between our experience and reality. I then propose that, even if one is willing to accept these consequences, there is reason to (...) question whether Norton builds a convincing case for the claim that, since we are not able to find any of the identifying characteristics of an illusion in the case of temporal passage, the passage of time is not an illusion. (shrink)

This paper aims to determine whether we can locate temporal passage in a non-dynamical (block universe) world. In particular, we seek to determine both whether temporal passage can be located somewhere in our world if it is non-dynamical, and also to home in on where in such a world temporal passage can be located, if it can be located anywhere. We investigate this question by seeking to determine, across three experiments, whether the folk concept of temporal passage can be satisfied (...) in our world if it is non-dynamical, and, if it can, what sort of thing in our world satisfies that concept. In particular, we focus on the question of whether that concept (if satisfied) is satisfied by something mind-dependent or something mind-independent. In other words, we ask, is temporal passage something that is at least partially in the mind, or is it entirely external to the mind? We find, contrary to what is often assumed by dynamists and non-dynamists alike, that the folk concept of temporal passage is satisfied in our world conditional on it being non-dynamical, and that the concept is satisfied by something mind-independent. This provides further ammunition for recent deflationary accounts of temporal passage that attempt to locate passage somewhere in our non-dynamical world. (shrink)

In this paper I argue that physics is, always was, and probably always will be voiceless with respect to tense and passage, and that, therefore, if, as I believe, tense and passage are the essence of time, physics’ contribution to our understanding of time can only be limited. The argument, in a nutshell, is that if "physics has no possibility of expression for the Now", to quote Einstein, then it cannot add anything to the study of tense and passage, and (...) specifically, cannot add anything to the debate between deniers and affirmers of the existence or reality of tense and passage. Since relativity theory did not equip physics with a new language with which to speak of tense and passage, I draw the further conclusion that relativity theory has not generated the revolution to our conception of time that is attributed to it. In the last section I discuss the motivations behind the continued but misguided attempts to integrate tense into a relativistic setting, and assess the manners in which relativity theory has nevertheless enhanced, albeit indirectly, our understanding of tense and passage. (shrink)

Presentists believe that only present things exist. Their theories, at first glance, seem to offer many admirable features: a simple ontology, and a meaningful, objective status for key temporal phenomena, such as the present moment and the passage of time. So intuitive is this theory that, as John Bigelow puts it, presentism was “believed by everyone...until at least the nineteenth century”. Yet, in the last 200 years presentism has been beset by criticisms from both physicists and metaphysicians. One of the (...) most significant criticisms is that presentists cannot provide an acceptable system of truthmaking. If there is no past, how can there still be truths about the past? In this paper, I introduce a new theory of presentism, which addresses this problem in a novel way: by simply denying that there are any truths about the past. While prima facie an unintuitive position, I will argue that a sensible presentist philosophy of this kind can be described, so long as it is accompanied by an appropriate system of physics. I will also indicate at certain points that adopting presentism could allow us to understand fundamental physics in new, more intuitive ways. By the end of the paper, I hope to not only show that hard presentism is a defensible theory of time, but also that it could offer a number of advantages to the physicist and the philosopher alike. (shrink)

Cognitive science has recently made some startling discoveries about temporal experience, and these discoveries have been drafted into philosophical service. We survey recent appeals to cognitive science in the philosophical debate over whether time objectively passes. Since this research is currently in its infancy, we identify some directions for future research.

The theory of relativity is often regarded as inhospitable to the idea that there is an objective passage of time in the world. In light of this, many philosophers and physicists embrace a “block universe” view, according to which change and temporal passage are merely a subjective appearance or illusion. My aim in this paper is to argue against such a view, and show that we can make sense of an objective passage of time in the setting of relativity theory (...) by abandoning the assumption that the now must be global, and re-conceiving temporal passage as a purely local phenomenon. Various versions of local becoming have been proposed in the literature. Here I focus on the causal diamond theory proposed by Steven F. Savitt and Richard Arthur, which models the now in terms of a local structure called a causal diamond. After defending the reality of temporal passage and exploring its compatibility with relativity theory, I show how the causal diamond approach can be used to counter the argument for the ideality of time due to Kurt Gödel, based on his “rotating universe” solution to the Einstein field equations. I defend the second component of his argument, the modal step, against the consensus view that finds it wanting, and reject the first step, showing that the Gödel universe is compatible with an objective passage of time as long as the latter is construed locally, along the lines of the causal diamond approach. (shrink)

Ajan luonnetta koskevissa käsityksissä on tyypillistä erottaa kaksi eriävää kantaa: A-teoreettinen presentismi ja B-teoreettinen eternalismi. Edeltävän väitetään tyypillisesti sopivan yhteen inhimillisen ajallisen kokemuksen kanssa ja jälkimmäisen ontologisesti perustavanlaatuisen luonnontieteen kanssa. Ilmikuvamme ajasta sisältää ehdottoman nykyisyyden ja yksisuuntaisen ajan kulun menneestä tulevaan. Tieteellinen kuva ajasta ei sisällä erityistä nykyisyyttä eikä ajan kulun edellyttämää dynaamista aikamuotojen muutosta. Monet ovat pitäneet kokemustamme ajan kulusta illuusiona. Tässä artikkelissa keskitytään A-sarjan mukaisen ajankulun virheteoreettiseen tulkintaan. Tarkastellaan mahdollisuutta, jonka mukaan meillä ei ole kyseistä kokemusta vaan kuvailemme (...) kokemustamme virheellisesti ajan virtaukseen liittyvillä vertauskuvilla. Tätä tukee fysikalistinen argumentti: Jos ajan kulun kokemuksellamme ei ole fysikaalista perustaa, meillä ei voi olla sen mukaista kokemustakaan ajasta. (shrink)

This paper investigates the mathematical representation of time in physics. In existing theories time is represented by the real numbers, hence their formal proper- ties represent properties of time: these are surveyed. The central question of the paper is whether the existing representation of time is adequate, or whether it can or should be supplemented: especially, do we need a physics incorporating some kind of ‘dynamical passage’ of time? The paper argues that the existing mathematical framework is resistant to such (...) changes, and might have to be rejected by anyone seeking a physics of passage. Then it rebuts two common arguments for incorporating passage into physics, especially the claim that it is an element of experience. Finally the paper investigates whether, as has been claimed, ‘causal set theory’ provides a physics of passage. (shrink)

It is often thought that there is little that seems more obvious from experience than that time objectively passes, and that time is, in this respect, quite unlike space. Yet nothing in the physical picture of the world seems to correspond to the idea of such an objective passage of time. In this paper, I discuss some attempts to explain this apparent conflict between appearance and reality. I argue that existing attempts to explain the conflict as the result of a (...) perceptual illusion fail, and that it is, in fact, the nature of memory, rather than perception, that explains why we are inclined to think of time as passing. I also offer a diagnosis as to why philosophers have sometimes been tempted to think that an objective passage of time seems to figure directly in perceptual experience, even though it does not. (shrink)

In this thesis I present a phenomenological investigation of our experience of time – of things as they fall within time – and suggest that something important goes missing in recent debates. This is the notion of a point of view. I believe that articulating the sense in which we have a point of view in time, and what this is a point of view upon, is crucial to an account of how things are for an experiencing subject. In the (...) first chapter, I elucidate the specious present. I argue that theorists appeal to the specious present under two guises without explicitly distinguishing between them; yet these two conceptions are not identical, while one entails the other the reverse is not true. In the second chapter I defend an appeal to the specious present against proponents of what I refer to as snapshot models of temporal experience. I argue that perceptual experience minimally presents something of some non-zero temporal extent as such. In the third chapter I discuss how we are to characterise experience over intervals of time of a greater extent than the specious present. I offer a proposal on which a subject is invariably presented with a positive temporal extent, with this interval marking the partition between the past and the future for the subject. In the fourth chapter I compare and contrast our experience of objects and events, and our experiential point of view in space and in time. Among other things, I argue that getting right how things are for the subject requires an appeal to the subject’s asymmetrical awareness of times either side of the specious present. In fifth and final chapter I demonstrate that appeal to an experiencing subject’s tensed temporal perspective can explain the sense in which time seems to pass. (shrink)

As the past-future asymmetry – that fact that we have records of the past but not the future – is still a puzzle the aim of this paper is twofold: a) to explain the asymmetry and its status in philosophy and physics and to critically review the proposed solutions to this puzzle; b) to advance a dynamic solution to the puzzle in terms of the ‘universality’ of the entropy relation in statistical mechanics.