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 is a treatise on time and on background independence in physics. It first considers how time is conceived of in each accepted paradigm of physics: Newtonian, special relativity, quantum mechanics (QM) and general relativity (GR). Substantial differences are moreover uncovered between what is meant by time in QM and in GR. These differences jointly source the Problem of Time: Nine interlinked facets which arise upon attempting concurrent treatment of the QM and GR paradigms, (...) as is required in particular for a background independent theory of quantum gravity. A sizeable proportion of current quantum gravity programs - e.g. geometrodynamical and loop quantum gravity approaches to quantum GR, quantum cosmology, supergravity and M-theory - are background independent in this sense. This book's foundational topic is thus furthermore of practical relevance in the ongoing development of quantum gravity programs. This book shows moreover that eight of the nine facets of the Problem of Time already occur upon entertaining background independence in classical (rather than quantum) physics. By this development, and interpreting shape theory as modelling background independence, this book further establishes background independence as a field of study. Background independent mechanics, as well as minisuperspace (spatially homogeneous) models of GR and perturbations thereabout are used to illustrate these points. As hitherto formulated, the different facets of the Problem of Time greatly interfere with each others' attempted resolutions. This book explains how, none the less, a local resolution of the Problem of Time can be arrived at after various reconceptualizations of the facets and reformulations of their mathematical implementation. Self-contained appendices on mathematical methods for basic and foundational quantum gravity are included. Finally, this book outlines how supergravity is refreshingly different from GR as a realization of background independence, and what background independence entails at the topological level and beyond. (shrink)

Responding to Hasok Chang’s vision of the history and philosophy of science as the continuation of science by other means, I illustrate the methods of HPS and their utility through a historico-critical examination of the problem of “time’s arrow‘, that is to say, the problem posed by the claim by Boltzmann and others that the temporal asymmetry of many physical processes and indeed the very possibility of identifying each of the two directions we distinguish in time (...) must have a ground in the laws of nature. I claim that this problem has proved intractable chiefly because the standard mathematical representation of time employed in the formulation of the laws of nature “forgets‘ one of the connotations of the word ”time’ as it is used in ordinary language and in experimental physics. (shrink)

The problem of Time is one of the most fascinating and yet most difficult of those questions to which the human mind applies itself in philosophical thought. Dean Inge, in his Philosophy of Plotinus, has referred to this problem as ‘the hardest in metaphysics,’ and we know that “from the time of Parmenides and Zeno to that of Mr. Bradley and M. Bergson, there has been no other problem that has seemed so baffling as that (...) of Time.”. (shrink)

The problem of Time is one of the most fascinating and yet most difficult of those questions to which the human mind applies itself in philosophical thought. Dean Inge, in his Philosophy of Plotinus , has referred to this problem as ‘the hardest in metaphysics,’ and we know that “from the time of Parmenides and Zeno to that of Mr. Bradley and M. Bergson, there has been no other problem that has seemed so baffling as (...) that of Time.”. (shrink)

The problem of Time is one of the most fascinating and yet most difficult of those questions to which the human mind applies itself in philosophical thought. Dean Inge, in his Philosophy of Plotinus, has referred to this problem as ‘the hardest in metaphysics,’ and we know that “from the time of Parmenides and Zeno to that of Mr. Bradley and M. Bergson, there has been no other problem that has seemed so baffling as that (...) of Time.”. (shrink)

Herman Dooyeweerd approached time in terms of order. By contrast, Dirk Vollenhoven saw time as continuous change and becoming. Hendrik Hart, in his article “Problems of Time: An Essay,” attempts to steer a middle course between Dooyeweerd and Vollenhoven. However, Hart did not sufficiently take into account that temporality is primarily continuous succession in duration and continuous duration in succession. Nor has he been able to come to terms with the root of cosmic time.

A genesis of the ideas concerning Husserl’s concepts of time and reflective structure of consciousness is analysed in this article. There will be taken into account in the article three main texts: ”Vorlesungenzur Phanomenologie des inneren Zeitbewusstseins”, ”Bernauer Manuskripte” and ”C-Manuskripte”. Next topics will be discussed: reflexive structure of consciousness as genetic problem, Ego as an emanate cen-ter of time construction, possibility of the achievement of hyletical, non-reflexive consciousness structure.

In canonical quantum gravity the wave function of the universe is static, leading to the so-called problem of time. We summarize here how Bohmian mechanics solves this problem.

This book explores the problem of time and immanence for phenomenology in the work of Edmund Husserl, Martin Heidegger, Maurice Merleau-Ponty, and Jacques Derrida. Detailed readings of immanence in light of the more familiar problems of time-consciousness and temporality provide the framework for evaluating both Husserl's efforts to break free of modern philosophy's notions of immanence, and the influence Heidegger's criticism of Husserl exercised over Merleau-Ponty's and Derrida's alternatives to Husserl's phenomenology. Ultimately exploring various notions of intentionality, (...) these in-depth analyses of immanence and temporality suggest a new perspective on themes central to phenomenology's development as a movement and raise for debate the question of where phenomenology begins and ends. (shrink)

Symplectic reduction is a formal process through which degeneracy within the mathematical representations of physical systems displaying gauge symmetry can be controlled via the construction of a reduced phase space. Typically such reduced spaces provide us with a formalism for representing both instantaneous states and evolution uniquely and for this reason can be justifiably afforded the status of fun- damental dynamical arena - the otiose structure having been eliminated from the original phase space. Essential to the application of symplectic reduction (...) is the precept that the first class constraints are the relevant gauge generators. This prescription becomes highly problematic for reparameterization invariant theories within which the Hamiltonian itself is a constraint; not least because it would seem to render prima facie distinct stages of a history physically identical and observable functions changeless. Here we will consider this problem of time within non-relativistic me- chanical theory with a view to both more fully understanding the temporal struc- ture of these timeless theories and better appreciating the corresponding issues in relativistic mechanics. For the case of nonrelativistic reparameterization invariant theory application of symplectic reduction will be demonstrated to be both unnec- essary; since the degeneracy involved is benign; and inappropriate; since it leads to a trivial theory. With this anti-reductive position established we will then examine two rival methodologies for consistently representing change and observable func- tions within the original phase space before evaluating the relevant philosophical implications. We will conclude with a preview of the case against symplectic re- duction being applied to canonical general relativity. (shrink)

A survey of the major philosophical and religious views of human life from ancient Greece to the early 20th century. Includes discussions of Plato, Aristotle, Christianity, and existentialism, among other schools of thought. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely (...) copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

The unprecedented growth of the prison population in the United States is a result of complex political and social factors that have contributed to more punitive criminal justice policies. While there has been much attention devoted to examining the possibility of expanding the use of alternatives to incarceration as a means of reducing these numbers, there has been insufficient focus on addressing changes in the length of time served in prison as a strategy for reduced incarceration. The sharp increase (...) in time served in prison in recent years has had no significant effect on recidivism or deterrence, but has been very costly and has contributed to the eroding of ties between people in prison and their families and communities. (shrink)

In this course we will examine several philosophical puzzles concerning time. We all seem to experience time in a very fundamental and direct way. Yet once we begin to reflect on what time really is, it is easy to feel as puzzled as St Augustine was, who wrote: “If no one asks me, I know what [time] is. If I wish to explain it to him who asks me, I do not know.” The first set of (...) issues we will discuss concern the question whether time is ‘real.’ Time appears to consist of past, present and future. But do the past and the future exist in the same way as the present or is only the present real? Does time ‘flow’? In what ways is time different from space? What would it be to ‘spatialize’ time? Next we will ask whether certain views of time imply that there can be no freedom of the will. One might worry that if facts about the future (including facts about what I will do tomorrow) already existed in the same way as facts about the present exist, then I could not be free to choose what I will do. After all, how can I be free to decide to skip class tomorrow, if it is ‘already’ a fact today that I will attend class? What, if anything, is the connection between various views of time and ‘fatalism’? The third topic we will discuss is time travel. First we will ask whether time travel is a conceptual possibility. As we will see, there are certain conceptual puzzles associated with the possibility of time travel. For example, one might think that if time travel is possible, then I should be able to travel back in time and kill my father before the date of my conception. But this scenario seems to lead to a contradiction. Some have taken considerations such as these to argue that the very idea of time travel is incoherent. Is this right? If not, why not? Then we will look at what the theory of relativity says about the nature of time in general and about the physical possibility of time travel more specifically. Finally we will examine several issues concerning the asymmetry of time.. (shrink)

The hard questions regarding identity, explicitly or implicitly, involve questions of time, therefore inheriting the complexities involved in the discussion of the concept of time. This book begins the discussion of the philosophy of time by posing the question of whether time exists or not. In ancient times, the reality of time was presupposed even if the concept did not have a clear-cut definition. Ironically, it was during the time when physicists seemed to gain (...) a better scientific understanding of time that philosophers began questioning the reality of time. The discussion of identity begins with Locke’s notion that the identity of a person consists in nothing but memories and conscious experience, which are independent of the body. (shrink)