Pierre Duhem’s philosophy of science has influenced many philosophers in the twentieth century, and even today. Many of the subjects he addressed are still highly discussed today, especially the distinction between science and metaphysics. My aim in this paper will be to motivate a naturalistic approach where the difference between physics and metaphysics is only a matter of degree. I focus on whether it would be possible to articulate this gradual distinction from a duhemian point of view. Although Duhem thought (...) that metaphysics is an entirely different and more excellent activity than physics, I believe that Duhem’s philosophy of science also supports a naturalistic distinction in terms of degrees. I offer three reasons to justify this conclusion: Duhem’s notion of common sense; Duhem’s holism and his views on the generality of our theories, and Duhem’s notion of natural classification. At the end of the paper I will argue that a naturalistic approach accomplishes must of what Duhem wanted to achieve with his distinction. (shrink)

Time is what clocks are used to measure. Information about time tells the durations of events and when they occur and which events happen before which others, so time plays a very significant role in the universe’s structure, including the structure of our personal lives. But carefully describing time’s properties has led to many unresolved issues, both philosophical and scientific.

This paper defends a relational view of time based on recent work on quantum gravity. Julian barbour's relational approach to physical theory, in particular, is developed as a basis for a relational, rather than anti-realist, metaphysics of time.

In this critical notice we argue against William Craig's recent attempt to reconcile presentism (roughly, the view that only the present is real) with relativity theory. Craig's defense of his position boils down to endorsing a ‘neo-Lorentzian interpretation’ of special relativity. We contend that his reconstruction of Lorentz's theory and its historical development is fatally flawed and that his arguments for reviving this theory fail on many counts. 1 Rival theories of time 2 Relativity and the present 3 Special relativity: (...) one theory, three interpretations 4 Theories of principle and constructive theories 5 The relativity interpretation: explanatorily deficient? 6 The relativity interpretation: ontologically fragmented? 7 The space-time interpretation: does God need a preferred frame of reference? 8 The neo-Lorentzian interpretation: at what price? 9 The neo-Lorentzian interpretation: with what payoff? 10 Why we should prefer the space-time interpretation over the neo-Lorentzian interpretation 11 What about general relativity? 12 Squaring the tenseless space-time interpretation with our tensed experience. (shrink)

Work in quantum gravity suggests that spacetime is not fundamental. Rather, spacetime emerges from an underlying, non-spatiotemporal reality. After clarifying the type of emergence at issue, I argue that standard conceptions of emergence available in metaphysics won’t work for the emergence of spacetime. I go on to consider spacetime functionalism as a way to make sense of spacetime emergence. I argue that a functionalist approach to spacetime modelled on mental state functionalism is not a viable alternative to the standard conception (...) of emergence in metaphysics. I go on to consider an alternative: ‘partial’ functionalism, whereby certain aspects of spacetime are functionalised, rather than spacetime as a whole. (shrink)

All physical theories, from classical Newtonian mechanics to relativistic quantum field theory, entail propositions concerning the geometric structure of spacetime. To give an example, the general theory of relativity entails that spacetime is curved, smooth, and four-dimensional. In this dissertation, I take the structural commitments of our theories seriously and ask: how is such structure instantiated in the physical world? Mathematically, a property like 'being curved' is perfectly well-defined insofar as we know what it means for a mathematical space to (...) be curved. But what could it mean to say that the physical world is curved? Call this the problem of physical geometry. The problem of physical geometry is a plea for foundations--a request for fundamental truth conditions for physical-geometric propositions. My chief claim is that only a substantival theory of spacetime--a theory according to which spacetime is an entity in its own right, existing over and above the material content of the world--can supply the necessary truth conditions. (shrink)

The goal of this essay is twofold. First, it provides a quick look at the foundations of modern relational mechanics by tracing its development from Julian Barbour and Bruno Bertotti's original ideas until present-day's pure shape dynamics. Secondly, it discusses the most appropriate metaphysics for pure shape dynamics, showing that relationalism is more of a nuanced thesis rather than an elusive one. The chapter ends with a brief assessment of the prospects of pure shape dynamics in light of quantum physics.

The `problem of time' is a cluster of interpretational and formal issues in the foundations of general relativity relating to both the representation of time in the classical canonical formalism, and to the quantization of the theory. The purpose of this short chapter is to provide an accessible introduction to the problem.

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)

By analyzing the meaning of time I argue, without endorsing operationalism, that time is necessarily related to physical systems which can serve as clocks. This leads to a version of relationism about time which entails that there is no time 'before' the universe. Three notions of metaphysical 'time' (associated, respectively, with time as a mathematical concept, substantivalism, and modal relationism) which might support the idea of time 'before' the universe are discussed. I argue that there are no good reasons to (...) believe that metaphysical 'time' can be identified with what we ordinarily call time. I also briefly review and criticize the idea of time 'before' the big bang, associated with some recent speculative models in modern cosmology, and I argue that if the big bang model is a (roughly) correct description of our universe, then the best current answer to the question in the title is that time did have a beginning. (shrink)

In physics, free will is debated mainly in regard to the observer-dependent effects. To eliminate them from quantum mechanics, superdeterminism postulates that the universe is a computation, and consciousness is an automaton. As a result, free will is impossible. Quantum no-go theorems tell us that the only natural phenomenon that might be able to account for every bit of freedom in the universe is quantum randomness. With randomness in Nature, the universe could not have been predetermined completely in the sense (...) that it should be impossible in principle to compute from the big bang or at any later moment whether live and conscious observers might or might not appear there. After all, superdeterminism comes to be either self-inconsistent by assuming randomness, at least, at the initial conditions of the big bang, or untestable and mysterious by pushing every bit of freedom in back to the prerequisites of the universe “designed” in the big bang. (shrink)

In his book Objective Becoming (Skow 2015), Bradford Skow has offered a rich and systematic treatment of the passage of time. We learn much about what objective passage could and could not amount to from engaging with his careful work. Skow’s overall conclusion is that the ‘block universe’ deflationary theory of passage is stronger than any currently available version of the recently-popular moving spotlight theory of temporal passage. To help establish this conclusion, Skow provides a taxonomy of theories of temporal (...) passage, including some new and unfamiliar theories that he classifies as versions of the moving spotlight view. These new theories are worthy of further study; however, in this commentary I will argue that they suffer from some problems that render them uncongenial to committed believers in temporal passage (Sections 2–5). I’ll also make a few brief remarks about some other arguments in the book, concerning branching time (Section 6), relativistic presentness (Section 7), and temporal experience (Section 8). (shrink)

This is a discussion of how we can understand the world-view given to us by the Everett interpretation of quantum mechanics, and in particular the role played by the concept of 'world'. The view presented is that we are entitled to use 'many-worlds' terminology even if the theory does not specify the worlds in the formalism; this is defended by means of an extensive analogy with the concept of an 'instant' or moment of time in relativity, with the lack of (...) a preferred foliation of spacetime being compared with the lack of a preferred basis in quantum theory. Implications for identity of worlds over time, and for relativistic quantum mechanics, are discussed. (shrink)

What ontology does realism about the quantum state suggest? The main extant view in contemporary philosophy of physics is wave-function realism . We elaborate the sense in which wave-function realism does provide an ontological picture, and defend it from certain objections that have been raised against it. However, there are good reasons to be dissatisfied with wave-function realism, as we go on to elaborate. This motivates the development of an opposing picture: what we call spacetime state realism , a view (...) which takes the states associated to spacetime regions as fundamental. This approach enjoys a number of beneficial features, although, unlike wave-function realism, it involves non-separability at the level of fundamental ontology. We investigate the pros and cons of this non-separability, arguing that it is a quite acceptable feature, even one which proves fruitful in the context of relativistic covariance. A companion paper discusses the prospects for combining a spacetime-based ontology with separability, along lines suggested by Deutsch and Hayden. (shrink)

I analyse the conceptual and mathematical foundations of Lagrangian quantum field theory (QFT) (that is, the ‘naive’ (QFT) used in mainstream physics, as opposed to algebraic quantum field theory). The objective is to see whether Lagrangian (QFT) has a sufficiently firm conceptual and mathematical basis to be a legitimate object of foundational study, or whether it is too ill-defined. The analysis covers renormalisation and infinities, inequivalent representations, and the concept of localised states; the conclusion is that Lagrangian QFT (at least (...) as described here) is a perfectly respectable physical theory, albeit somewhat different in certain respects from most of those studied in foundational work. (shrink)

The consensus among spacetime substantivalists is to respond to Leibniz's classic shift arguments, and their contemporary incarnation in the form of the hole argument, by pruning the allegedly problematic metaphysical possibilities that generate these arguments. Some substantivalists do so by directly appealing to a modal doctrine akin to anti-haecceitism. Other substantivalists do so by appealing to an underlying hyperintensional doctrine that implies some such modal doctrine. My first aim in this paper is to pose a challenge for all extant forms (...) of this consensus position. My second aim is to show what form substantivalism must take in order to uphold the consensus while addressing this challenge. The result is a novel "plenitudinous" substantivalist view, which predicts that certain modal facts about spacetime are vague or indeterminate. I then argue against this view on independent grounds, concluding that substantivalists should reject the consensus position. The paper also discusses the way forward for substantivalists in light of this conclusion. (shrink)

The purpose of this paper is two fold: first, I look to show Oaklander’s theory of time to be false. Second, I show that the only way to salvage the B-theory is via the adopting of the causal theory of time, and allying this to Oaklander’s claim that tense is to be eliminated. I then raise some concerns with the causal theory of time. My conclusion is that, if one adopts eternalism, the unreality of time looks a better option than (...) the B-theory. (shrink)

This paper is an attempt to answer the question, ‘could there be causation in a timeless world?’ My conclusion: tentatively, yes. The paper and argument have three parts. Part one introduces salient issues and spells out the importance of this line of investigation. Section two of the paper reviews recent arguments due to Baron and Miller, who argue in favour of the possibility of causation in a timeless world, and looks to reject their arguments developed there. Section three is a (...) response to a response. In their, Baron and Miller also argue that an argument in favour of the possibility of causation at timeless worlds, that I put forward, is an argument that fails. In section three, my response to Baron and Miller is that their argument against me succeeds, but that there is a nearby argument that we can appeal to in order to demonstrate the possibility of causation at timeless worlds. (shrink)

Within the philosophy of time there has been a growing interest in positions that deny the reality of time. Those positions, whether motivated by arguments from physics or metaphysics, have a shared conclusion: time is not real. What has not been made wholly clear, however, is exactly what it entails to deny the reality of time. Time is unreal, sure. But what does that mean? There has been only one sustained attempt to spell out exactly what it would mean to (...) endorse a temporal error theory; a theory that denies the reality of time—Baron & Miller’s ‘What is temporal error theory?’. Despite the fact that their paper makes significant strides in spelling out what would be required of a temporal error theory, my claim in this paper is that their position must be rejected and replaced. As well as looking to reject Baron and Miller’s position, I also look to provide that replacement. (shrink)

This essay explores the possibility of constructing a structural realist interpretation of spacetime theories that can resolve the ontological debate between substantivalists and relationists. Drawing on various structuralist approaches in the philosophy of mathematics, as well as on the theoretical complexities of general relativity, our investigation will reveal that a structuralist approach can be beneficial to the spacetime theorist as a means of deflating some of the ontological disputes regarding similarly structured spacetimes.

Sklar ([1974]) claimed that relationalism about ontology-the doctrine that space and time do not exist-is compatible with Newtonian mechanics. To defend this claim he sketched a relationalist interpretation of Newtonian mechanics. In his interpretation, absolute acceleration is a fundamental, intrinsic property of material bodies; that a body undergoes absolute acceleration does not entail that space and time exist. But Sklar left his proposal as just a sketch; his defense of relationalism succeeds only if the sketch can be filled in. I (...) argue that this cannot be done. There can be no (relationalist) dynamical laws of motion based on Sklar's proposal that capture the content of Newton's theory. So relationalists must look elsewhere for a relationalist interpretation of Newtonian mechanics. (shrink)

Is there anything more to temperature than the ordering of things from colder to hotter? Are there also facts, for example, about how much hotter (twice as hot, three times as hot...) one thing is than another? There certainly are---but the only strong justification for this claim comes from statistical mechanics. What we knew about temperature before the advent of statistical mechanics (what we knew about it from thermodynamics) provided only weak reasons to believe it.

Reception of the Bohm-Hiley interpretation of quantum mechanics has a curiously Janus faced quality. On the one hand, it is frequently derided as a conservative throwback to outdated classical patterns of thought. On the other hand, it is equally often taken to task for encouraging a wild quantum mysticism, often regarded as anti-scientific. I will argue that there are reasons for this reception, but that a proper appreciation of the dual scientific and philosophical aspects of the view reveals a powerful (...) and extremely interesting metaphysical view of the world. This view is akin to that of Russellian Monism, in which the empirical world studied by science is restricted to relational features that stand in need of some background intrinsic properties to ground their reality. This allows for a theory that can embrace a world which exhibits a reasonable and plausible sort of emergence (especially of domains that fall under classical concepts) while also making room for distinctive and scientifically intransigent properties such as consciousness. (shrink)

What is the relation between material objects and spacetime regions? Supposing that spacetime regions are one sort of substance, there remains the question of whether or not material objects are a second sort of substance. This is the question of dualistic versus monistic substantivalism. I will defend the monistic view. In particular, I will maintain that material objects should be identified with spacetime regions. There is the spacetime manifold, and the fundamental properties are pinned directly to it.

The true nature of space and time has been a topic of natural philosophy, passed down since the presocratic era. In modern times reflection has particularly been inspired by the physical theories of Newton and Einstein and, more recently, by the quest for a theory of quantum gravity. In this paper we want to specify the idea that material systems and their spatio-temporal distances emerge from quantum-events. We will show a mechanism, by which quantum-events induce a metric field between material (...) systems, which is governed by Einstein's equation including a cosmological constant. (shrink)

In this manuscript we initiate a systematic examination of the physical basis for the time concept in cosmology. We discuss and defend the idea that the physical basis of the time concept is necessarily related to physical processes which could conceivably take place among the material constituents available in the universe. As a consequence we motivate the idea that one cannot, in a well-defined manner, speak about time ‘before’ such physical processes were possible, and in particular, the idea that one (...) cannot speak about a time scale ‘before’ scale-setting physical processes were possible. It is common practice to link the concept of cosmic time with a space-time metric set up to describe the universe at large scales, and then define a cosmic time t as what is measured by a comoving standard clock. We want to examine, however, the physical basis for setting up a comoving reference frame and, in particular, what could be meant by a standard clock. For this purpose we introduce the concept of a `core' of a clock and we ask if such a core can - in principle - be found in the available physics contemplated in the various `stages' of the early universe. We find that a first problem arises above the quark-gluon phase transition where there might be no bound systems left, and the concept of a physical length scale to a certain extent disappears. A more serious problem appears above the electroweak phase transition believed to occur at $\sim 10^{-11}$ seconds. At this point the property of mass disappears and it becomes difficult to identify a physical basis for concepts like length scale, energy scale and temperature - which are all intimately linked to the concept of time in modern cosmology. This situation suggests that the concept of a time scale in `very early' universe cosmology lacks a physical basis or, at least, that the time scale will have to be based on speculative new physics. (shrink)

I distinguish two types of reduction within the context of quantum-classical relations, which I designate “formal” and “empirical”. Formal reduction holds or fails to hold solely by virtue of the mathematical relationship between two theories; it is therefore a two-place, a priori relation between theories. Empirical reduction requires one theory to encompass the range of physical behaviors that are well-modeled in another theory; in a certain sense, it is a three-place, a posteriori relation connecting the theories and the domain of (...) physical reality that both serve to describe. Focusing on the relationship between classical and quantum mechanics, I argue that while certain formal results concerning singular \ limits have been taken to preclude the possibility of reduction between these theories, such results at most provide support for the claim that singular limits block reduction in the formal sense; little if any reason has been given for thinking that they block reduction in the empirical sense. I then briefly outline a strategy for empirical reduction that is suggested by work on decoherence theory, arguing that this sort of account remains a fully viable route to the empirical reduction of classical to quantum mechanics and is unaffected by such singular limits. (shrink)

The Lorentz transformation of space and time between two reference frames is one of the pillars of the special relativity theory. As a result of the Lorentz transformation, space and time are only relative and are entangled, while the Minkowski metric is Lorentz invariant. For this reason, the Lorentz transformation is one of the major obstructions in the development of physical theories with quantized space and time. Here is described the Lorentz transformation of a physical system with a discrete dynamical (...) time and a continuous space that fulfills Lorentz invariance while approximating the Lorentz transformation at the time continuous limit and the Galilei transformation at the classical limit. Furthermore, the discreteness of time is not mixed with the continuous nature of space, making time distinct from space. (shrink)

Doubts are raised concerning Rickles' claim that ``an exact analog of the hole argument can be constructed in the loop representation of quantum gravity'' (Rickles, `A new spin on the hole argument', Studies in History and Philosophy of Modern Physics 36 (2005) 415–434).

This article aims to contribute to the ongoing task of clarifying the relationships between reality, probability, and nonlocality in quantum physics. It is in part stimulated by Khrennikov’s argument, in several communications, for “eliminating the issue of quantum nonlocality” from the analysis of quantum entanglement. I argue, however, that the question may not be that of eliminating but instead that of further illuminating this issue, a task that can be pursued by relating quantum nonlocality to other key features of quantum (...) phenomena. I suggest that the following features of quantum phenomena and quantum mechanics, distinguishing them from classical phenomena and classical physics— the irreducible role of measuring instruments in defining quantum phenomena, discreteness, complementarity, entanglement, quantum nonlocality, and the irreducibly probabilistic nature of quantum predictions—are all interconnected, so that it is difficult to give an unconditional priority to any one of them. To argue this case, I shall consider quantum phenomena and quantum mechanics from a nonrealist or, in terms adopted here, “reality-without-realism” perspective. This perspective extends Bohr’s view, grounded in his analysis of the irreducible role of measuring instruments in the constitution of quantum phenomena. (shrink)

This paper considers a problem for dynamic presentism that has received little attention: its apparent inability to accommodate the duration of events (such as conscious experiences). After outlining the problem, I defend presentism from it. This defence proceeds in two stages. First, I argue the objection rests on a faulty assumption: that duration is temporal extension. The paper challenges that assumption on several different ways of conceiving of temporal extension. This is the negative case and forms the bulk of the (...) paper. Second, after diagnosing the error leading to the identification of duration with temporal extension, I outline a new presentist-friendly account of duration that avoids the problem. In particular, a non-reductive account of duration is offered that treats it as a primitive quality which bestows its possessor with a certain modal quality: that the possessor potentially does not change whilst there are changes in its environs. This is the positive case. Together the positive and negative cases provide presentism with an interesting and novel way of overcoming the problem of duration. (shrink)

Ulrich Meyer's book The Nature of Time uses tense logic to argue for a `modal' view of time, which replaces substantial times with `ersatz times' constructed using conceptually basic tense operators. He also argues against Bertrand Russell's relationist theory, in which times are classes of events, and against the idea that relativity compels the integration of time and space. I find fault with each of these negative arguments, as well as with Meyer's purported reconstruction of empty spacetime from tense operators (...) and substantial spatial points. I suggest that Meyer's positive project is best conceived as an elimination of time in the mode of Julian Barbour's The End of Time. (shrink)

La interpretación modal-hamiltoniana fue introducida para resolver ciertos problemas de interpretación vinculados a su ontología y a la medición cuántica. Su regla de actualización establece que todo sistema cerrado tiene su energía bien definida, y debido a la indeterminación entre la energía y el tiempo esto plantea un interrogante respecto a la situación temporal de estos sistemas. En este trabajo se analiza el problema del tiempo en sistemas cerrados y se propone la reconstrucción de un tiempo relacional compatible con la (...) perspectiva holista. (shrink)

Appeals to the ‘common sense’, or ‘naïve’, or ‘folk’ concept of time, and the purported phenomenology as of time passing, play a substantial role in philosophical theorising about time. When making these appeals, philosophers have been content to draw upon their own assumptions about how non-philosophers think about time. This paper reviews a series of recent experiments bringing these assumptions into question. The results suggest that the way non-philosophers think about time is far less metaphysically demanding than philosophers have assumed.

By considering situations from the paradox of the twins in relativity, it is shown that time passes at different rates along different world lines, answering some well-known objections. The best explanation for the different rates is that time indeed passes. If time along a world line is something with a rate, and a variable rate, then it is difficult to see it as merely a unique, invariant, monotonic parameter without any further explanation of what it is. Although it could, conceivably, (...) be explained by the flow of something, it is better explained by the passing of a point present, which faces the problem that there is no absolute simultaneity in special relativity so that the present for an object is confined to just that object. This raises problems about presentism, eternalism, simultaneity, and special relativity. These issues are addressed first by giving accounts of presentism and eternalism and then an account of existence and times for objects relative to world lines. Finally, an analogy between a world of relativistic objects and Leibniz’s ontology of monads. (shrink)

This paper delves into McTaggart’s metaphysical account of reality without time, and compares and contrasts McTaggart’s account with the account of reality given by modern physics. This comparison is of interest, because there are suggestions from contemporary physics that there is no time at the fundamental level. Physicists and philosophers of physics recognize that we do not have a good understanding of how the world could be such that time is unreal. I argue that, from the perspective of one who (...) is trying to understand modern physics, McTaggart’s metaphysical views do provide some insight into how reality can be timeless at the fundamental level, but the insight that they provide is limited. (shrink)

We find the claim that time is not real in both western and eastern philosophical traditions. In what follows I will call the view that time does not exist temporal error theory. Temporal error theory was made famous in western analytic philosophy in the early 1900s by John McTaggart (1908) and, in much the same tradition, temporal error theory was subsequently defended by Gödel (1949). The idea that time is not real, however, stretches back much further than that. It is (...) common to hear it said that according to Buddhist philosophy (as though that were a monolithic view) time is illusory. While it is not true that, in general, either contemporary or ancient Buddhist scholars have thought time to be illusory, there are certainly some schools of Buddhist thought, such as that of traditional Dzogchen practitioners, according to which there is no time. This paper is an attempt to set out a taxonomy of different views about what it takes for there to be time and, alongside that, a taxonomy of views about whether there is time or not, and if there is time what it is like. (shrink)

Absolutism about mass claims that mass ratios obtain in virtue of absolute masses. Comparativism denies this. Dasgupta, Oxford studies in metaphysics, Oxford University Press, Oxford, 2013) argues for comparativism about mass, in the context of Newtonian Gravity. Such an argument requires proving that comparativism is empirically adequate. Dasgupta equates this to showing that absolute masses are undetectable, and attempts to do so. This paper develops an argument by Baker to the contrary: absolute masses are in fact empirically meaningful, that is (...) detectable. Additionally, it is argued that the requirement of empirical adequacy should not be cashed out in terms of undetectability in the first place. The paper closes by sketching the possible strategies that remain for the comparativist. Along the way a framework is developed that is useful for thinking about these issues: Ozma games—how could one explain to an alien civilisation what an absolute mass is? (shrink)

Laplace wondered about the minimal choice of initial variables and parameters corresponding to a well-posed initial value problem. Discussions of Laplace’s problem in the literature have focused on choosing between spatiotemporal variables relative to absolute space or merely relative to other material bodies and between absolute masses or merely mass ratios. This paper extends these discussions of Laplace’s problem, in the context of Newtonian Gravity, by asking whether mass needs to be included in the initial state at all, or whether (...) a purely spatiotemporal initial state suffices. It is argued that mass indeed needs to be included; removing mass from the initial state drastically reduces the predictive and explanatory power of Newtonian Gravity. (shrink)

Eternalism, the view that what we regard locally as being located in the past, the present and the future equally exists, is the best ontological account of temporal existence in line with special and general relativity. However, special and general relativity are not fundamental theories and several research programs aim at finding a more fundamental theory of quantum gravity weaving together all we know from relativistic physics and quantum physics. Interestingly, some of these approaches assert that time is not fundamental. (...) If time is not fundamental, what does it entail for eternalism and the standard debate over existence in time? First, I will argue that the non-fundamentality of time to be found in string theory entails standard eternalism. Second, I will argue that the non-fundamentality of time to be found in loop quantum gravity entails atemporal eternalism, namely a novel position in the spirit of standard eternalism. (shrink)

What it would take to vindicate folk temporal error theory? This question is significant against a backdrop of new views in quantum gravity—so-called timeless physical theories—that claim to eliminate time by eliminating a one-dimensional substructure of ordered temporal instants. Ought we to conclude that if these views are correct, nothing satisfies the folk concept of time and hence that folk temporal error theory is true? In light of evidence we gathered, we argue that physical theories that entirely eliminate an ordered (...) substructure vindicate folk temporal error theory. (shrink)

We investigated, experimentally, the contention that the folk view, or naïve theory, of time, amongst the population we investigated is dynamical. We found that amongst that population, ~ 70% have an extant theory of time that is more similar to a dynamical than a non-dynamical theory, and ~ 70% of those who deploy a naïve theory of time deploy a naïve theory that is more similar to a dynamical than a non-dynamical theory. Interestingly, while we found stable results across our (...) two experiments regarding the percentage of participants that have a dynamical or non-dynamical extant theory of time, we did not find such stability regarding which particular dynamical or non-dynamical theory of time they take to be most similar to our world. This suggests that there might be two extant theories in the population—a broadly dynamical one and a broadly non-dynamical one—but that those theories are sufficiently incomplete that participants do not stably choose the same dynamical theory as being most similar to our world. This suggests that while appeals to the ordinary view of time may do some work in the context of adjudicating disputes between dynamists and non-dynamists, they likely cannot do any such work adjudicating disputes between particular brands of dynamism. (shrink)

In this survey, we discuss and analyze foundational issues of the problem of time and its asymmetry from a unified standpoint. Our aim is to discuss concisely the current theories and underlying notions, including interdisciplinary aspects, such as the role of time and temporality in quantum and statistical physics, biology, and cosmology. We compare some sophisticated ideas and approaches for the treatment of the problem of time and its asymmetry by thoroughly considering various aspects of the second law of thermodynamics, (...) nonequilibrium entropy, entropy production, and irreversibility. The concept of irreversibility is discussed carefully and reanalyzed in this connection to clarify the concept of entropy production, which is a marked characteristic of irreversibility. The role of boundary conditions in the distinction between past and future is discussed with attention in this context. The paper also includes a synthesis of past and present research and a survey of methodology. It also analyzes some open questions in the field from a critical perspective. (shrink)

Cerebral energy supply is insufficient to support continuous neuronal processing of the plethora of time-constant objects that we are aware of. As a result, the brain is forced to limit processing resources to cases of change. The neuronally generated world is thus temporally discontinuous. This parallels the fact that, in all relevant microscopic fundamental equations of nature, temporal change plays a dominant role. When a scientist calculates a “solution” to such an equation, integration over time is an essential step. The (...) present Hypothesis expresses that the step from neuronal activity to phenomenal content of consciousness is reflective of a “solution:” the main source of the incomprehensibility of consciousness is proposed to result from the introduction of phenomenal time-constant entities. These are “filled-in” via integration, even though neuronal data only exists for changes to these entities. In this way, a temporally continuous picture of the world phenomenally appears. Qualia are “initial conditions,” which are required for integration and cannot be deduced from present data. Phenomenal “identity” is related to qualia. Inattentive visual perception, which is only rarely investigated, offers insights into these relationships. Introspectively, unattended vision appears rich because percepts are cumulated over long time spans, whereas attentive perception relies purely on present neuronal signals. The present Hypothesis is that a brief neuronal activity can signify long-lasting and constant phenomenal content of consciousness. Experimental support is presented that comes from discrepancies between neuronal activity and perception: transient neuronal responses to sustained stimuli, “filling-in,” change blindness, identity vs. close resemblance. (shrink)

Newton’s First Law of Motion is typically understood to govern only the motion of force-free bodies. This paper argues on textual and conceptual grounds that it is in fact a stronger, more general principle. The First Law limits the extent to which any body can change its state of motion –– even if that body is subject to impressed forces. The misunderstanding can be traced back to an error in the first English translation of Newton’s Principia, which was published a (...) few years after Newton’s death. (shrink)

The conceptual and technical difficulties involved in creating a quantum theory of gravity have led some physicists to question, and even in some cases to deny, the reality of time. More surprisingly, this denial has found a sympathetic audience among certain philosophers of physics. What should we make of these wild ideas? Does it even make sense to deny the reality of time? In fact physical science has been chipping away at common sense aspects of time ever since its inception. (...) Section 1 offers a brief survey of the demolition process. Section 2 distinguishes a tempered from an extremely radical form that a denial of time might take, and argues that extreme radicalism is empirically self-refuting. Section 3 begins an investigation of the prospects for tempered radicalism in a timeless theory of quantum gravity. (shrink)