The physics of time asymmetry has never been a single well-defined subject, but more a collection of consistency problems which arise in almost all branches ...

A monumental work on the flow of time, from the universe's creation to "Now," by the best-selling author of Physics for Future Presidents. "Now" is a simple concept--you're reading this sentence now. Yet a real definition of "now" has eluded even the great Einstein. We know that time stretches and is affected by gravity and velocity. Yet, as eminent physicist Richard A. Muller points out, it is only today that we have all the physics at hand--relativity, (...) entropy, entanglement, antimatter, and the Big Bang--to explain the flow of time. With these building blocks in place, Muller reaches a startling conclusion: our expanding universe is continuously creating not only new space but also new time. The front edge of this new time is what we call "now," and this moment is truly unique--it is the only moment in which we can exercise our free will. Muller's thought-provoking vision is a powerful counter to established theories in science and philosophy, and his arguments will spark major debate about the most fundamental assumptions of our universe. (shrink)

It has been advocated that Einstein's theory of special relativity implies a view of the universe as a space-time-block (block universe). Accordingly the flow of time is only a subjective and unreal phenomenon. An interpretation of the second law of thermodynamics leads to a completely different view, stating that the flow of time and the difference between past and present are fundamental phenomena. This article argues that this view has priority over the view of the block universe. (...) /// Segundo o autor do artigo, há investigadores que defendem a ideia de que a teoria da relatividade especial de Einstein implica uma visão do universo como um bloco espácio-temporal (universo bloco). Nesse sentido, o fluxo do tempo seria apenas um fenómeno subjectivo e irreal. Ora uma interpretação da segunda lei da termodinâmica conduz a uma visão completamente diferente, afirmando que o fluxo do tempo e a diferença entre passado e presente constituem fenómenos fundamentais. Assim, o presente artigo defende que esta visão tem prioridade sobre a visão do universo como bloco. (shrink)

Our article is an overview of a selection of findings in physics relating to the issue of time—we do not present in it any “time theory” of our own. After making some general remarks on the issue of time, we present historical outline and a brief description of the current state of time interval measurements. Subsequently, we go on to discuss certain (relating to the concept of time) consequences of both theories of relativity: special (...) and general. Here, time is a geometrical component of space-time continuum. Following section is dedicated to time in the so-called Hamiltonian formulations of the theory of particles, where it appears as a parameter of evolution. The last section contains remarks referring to certain attempts of going beyond the recognized physical theories relating to the question of time. (shrink)

Our article is an overview of a selection of findings in physics relating to the issue of time—we do not present in it any “time theory” of our own. After making some general remarks on the issue of time, we present historical outline and a brief description of the current state of time interval measurements. Subsequently, we go on to discuss certain (relating to the concept of time) consequences of both theories of relativity: special (...) and general. Here, time is a geometrical component of space-time continuum. Following section is dedicated to time in the so-called Hamiltonian formulations of the theory of particles, where it appears as a parameter of evolution. The last section contains remarks referring to certain attempts of going beyond the recognized physical theories relating to the question of time. (shrink)

Attributed to Alexander of Aphrodisias -the leading ancient commentator on Aristotle -the Quaestiones exemplify the process through which Aristotle's thought was organized and came to be interpreted as "Aristotelianism." This volume of R.W. Sharples's translation, together with his earlier translation of Quaestiones 1.1-2.15, makes the Quaestiones available in its entirety for the first time in a modern language. The Quaestiones are concerned with problems of physics and metaphysics, psychology and divine providence. Readers interested in Aristotle's psychological views will (...) find the second half of the Quaestiones particularly valuable. Ten of the problems discussed involve issues raised in Aristotle's On the Soul, including the unity of apperception and the transition from first to second actuality in the act of contemplation. An additional twelve problems relate to aspects of physical theory such as infinity, necessity, and potentiality. Quaestio 2.21 concerns divine providence and helps supplement our knowledge of Alexander's position. A study of the Quaestiones also suggests how interpretations of Aristotle were influenced by doctrines of Hellenistic philosophy. Translated first into Arabic and then into Latin, excerpts from the Quaestiones played a significant role in the transmission of ancient Greek philosophy to the medieval world. (shrink)

Why is the future so different from the past? Why does the past affect the future and not the other way round? The universe began with the Big Bang - will it end with a `Big Crunch'? Now in paperback, this book presents an innovative and controversial view of time and contemporary physics. Price urges physicists, philosophers, and anyone who has ever pondered the paradoxes of time to look at the world from a fresh perspective, and throws (...) fascinating new light on some of the great mysteries of the universe. (shrink)

This chapter explores the concept of time itself, as physicists understand it. Einstein's special theory of relativity requires worldlines of physical objects to be timelike; the field equations of his general theory of relativity predict that massive bodies such as stars and black holes distort space‐time and bend worldlines. Suppose space‐time becomes so distorted that some worldlines form closed loops. If one tried to follow such a closed timelike curve (or CTC) exactly, all the way around, one (...) would bump into ones former selves and get pushed aside. But by following part of a CTC, we could return to the past and participate in events there. According to a recent calculation by J. Richard Gott of Princeton, a cosmic string passing rapidly by another would generate CTCs. The chapter concludes that if time travel is impossible, then the reason has yet to be discovered. (shrink)

As one of the earliest Western physics teachers, Richard Rufus of Cornwall helped transform Western natural philosophy in the 13th century. But despite the importance of Rufus's works, they were effectively lost for 500 years, and the Physics commentary is the first complete work of his ever to be printed. Rufus taught at the Universities of Paris and Oxford from 1231 to 1256, at the very time when exposure to Aristotle's libri naturales was revolutionizing the academic curriculum; (...) indeed Rufus gave the earliest surviving lectures on physics and metaphysics. Rufus's challenges to the views of Aristotle and the commentator Averroes proved to be enormously influential: his accounts of projectile motion, the place of the heavens, and creation, were to be taken up by the likes of Franciscus de Marchia, Roger Bacon, Thomas Aquinas and Bonaventure. (shrink)

This is an invited commentary on "Physical Time within Human Time" (Gruber, Block, & Montemayor, 2022) and "Bridging the Neuroscience and Physics of Time" (Buonomano & Rovelli, 2021). I’m very sympathetic to aspects of each proposal. In this article, I offer some comments, starting with (Buonomano & Rovelli, 2021).

Structured time (hyle) and its relationship to other elements of physics: matter, energy, space, etc.

Every process studied in any science other than physics defines an arrow of time – to say nothing for the directedness of the processes of causation, inference, memory, control, and counterfactual dependence that occur in everyday life. The discussion in this chapter is confined to the arrow of time as it occurs in physics. The chapter briefly discusses those features of microscopic physics, which seem to conflict with time asymmetry. It explains just how this (...) conflict plays out in the important context of thermodynamics and statistical mechanics. The chapter then reviews the main strategies available for resolving the conflict between reversible microdynamics and irreversible macrodynamics, working within the context of the quantitative, time‐irreversible evolution laws that seem to apply to large‐scale phenomena. Finally, it offers a broad the discussion covering other arrows of time within physics. (shrink)

A Brief History of Time: From the Big Bang to Black Holes is a popular-science book on cosmology (the study of the origin and evolution of the universe) by British physicist Stephen Hawking. It was first published in 1988. Hawking wrote the book for readers who have no prior knowledge of the universe and people who are interested in learning.

Based on the hypothesis that the (non-reversible) arrow of time is intrinsic in any system, no matter how small, the consequences are discussed. Within the framework of local quantum physics it is shown how such a semi-group action of time can consistently be extended to that of the group of spacetime translations in Minkowski space. In presence of massless excitations, however, there arise ambiguities in the theoretical extensions of the time translations to the past. The corresponding (...) loss of quantum information on states upon time is determined. Finally, it is explained how the description of operations in classical terms combined with constraints imposed by the arrow of time leads to a quantum theoretical framework. These results suggest that the arrow of time is fundamental in nature and not merely a consequence of statistical effects on which the Second Law is based. (shrink)

In the present paper the relation between objective and subjective time is studied from a neutral non-dualist perspective Adoption of the relational concept of time leads to fundamental problems of time measurement of the uniformity of time measures, and of a native measure of duration in subjective experience. Experimental data on discrimination and reproduction of time intervals are reviewed and relevant models of internal time representations are discussed. Special attention is given to the 'dual (...) klepsydra model' (DKM)and to the outstanding properties of the reproduction func- tion yielded by the DKM Time scales generated by a DKM-based reproduction mechanisms are studied It is shown that such 'klepsydraic clocks' generate time measures which are non-uniform with respect to objective time yet internally consistent within an ensemble of such clocks and in this sense 'quasi-uniform' . Competing concepts of subjective time and modeling principles of internal time representation are briefly discussed Some interesting parallels be- tween our psychophysical approach and E.A. Milne's treatment of the problem of uniform time are drawn in the Appendix. (shrink)

In a revolutionary new book, a theoretical physicist attacks the foundations of modern scientific theory, including the notion of time, as he shares evidence of ...

It is commonly held that there is no place for the 'now’ in physics, and also that the passing of time is something subjective, having to do with the way reality is experienced but not with the way reality is. Indeed, the majority of modern theoretical physicists and philosophers of physics contend that the passing of time is incompatible with modern physical theory, and excluded in a fundamental description of physical reality. This book provides a forceful (...) rebuttal of such claims. In successive chapters the author explains the historical precedents of the modern opposition to time flow, giving careful expositions of matters relevant to becoming in classical physics, the special and general theories of relativity, and quantum theory, without presupposing prior expertise in these subjects. Analysing the arguments of thinkers ranging from Aristotle, Russell, and Bergson to the proponents of quantum gravity, he contends that the passage of time, understood as a local becoming of events out of those in their past at varying rates, is not only compatible with the theories of modern physics, but implicit in them. (shrink)

This thesis introduces and defends a ‘C theory’ of time. The metaphysics of time literature is primarily concerned with the distinction between the A and B theories of time, with the disagreement concerning whether the passage of time is an objective feature of reality. I argue that the distinction between the B and C theories—in terms of whether time has a ‘privileged’ direction—is of more obvious relevance to the philosophy of physics than is the (...) distinction between the A and B theories. The thesis has three main contentions. (1) In order to maintain a substantial metaphysical dispute between the different theories of time, they must be defined in terms of structural properties, and the naturalistic metaphysics of time direction involves the assessment of these structures in light of contemporary physics. (2) The A theory of time requires a model with two temporal dimensions, and although such a model provides a resolution to a number of problems faced by standard A theories, it is not motivated by physical theory. (3) The dispute between the B and C theories of time is of direct relevance to the philosophy of physics: the B theorist’s assumption of the existence of a privileged temporal direction is of explanatory relevance to physics; and a comparison between unidirectional and adirectional explanations in physics can in principle shed light on whether time is B- or C-theoretic. (shrink)

Time's mysteries seem to resist comprehension and what remains, once the familiar metaphors are stripped away, can stretch even the most profound philosopher. In Of Time and Lamentation, Raymond Tallis rises to this challenge and explores the nature and meaning of time and how best to understand it. The culmination of some twenty years of thinking, writing and wondering about (and within) time, it is a bold, original, and thought-provoking work. With characteristic fearlessness, Tallis seeks to (...) reclaim time from the jaws of physics. For most of us, time is composed of mornings, afternoons, and evenings and expressed in hurry, hope, longing, waiting, enduring, planning, joyful expectation, and grief. Thinking about it is to meditate on our own mortality. Yet, physics has little or nothing to say about this time, the time as it is lived. The story told by caesium clocks, quantum theory, and Lorentz coordinates, Tallis argues, needs to be supplemented by one of moss on rocks, tears on faces, and the long narratives of our human journey. Our temporal lives deserve a richer attention than is afforded by the equations of mathematical physics.The first part of the book, "Killing Time" is a formidable critique of the spatialized and mathematized account of time arising from physical science. Part 2, "Human Time" examines tensed time, the reality of time as it is lived: what we mean by "now", how we make sense of past and future events, and the idea of eternity. (shrink)

Philosophy -- Entry foundations -- Phenomenology of immediacy -- Polarized braids and little primoridal frames -- Emergence of primordial minkowski frames -- Majorana space-time spinors -- Color braids -- Motion and method -- Envisioned memory.

Visit the author's Web site at www.11PicsOfTime.com Time is a mystery that has perplexed humankind since time immemorial. Resolving this mystery is of significance not only to philosophers and physicists but is also a very practical concern. Our perception of time shapes our values and way of life; it also mediates the interaction between science and religion both of which rest fundamentally on assumptions about the nature of time. C K Raju begins with a critical exposition (...) of various time-beliefs, ranging from the earliest times through Augustine, Newton and Einstein to Stephen Hawking and current notions of chaos and time travel. He traces the role of organised religion in subverting time beliefs for its political ends. The book points out how this resulted in a facile dichotomy between 'linear' and 'cyclic' time, thereby inaugurating a confusion which, according to the author, has handicapped Western thought ever since, eventually influencing the content of science itself. Thus, this book daringly asserts that physical theory, traditionally regarded as amoral and objective, has depended on cultural beliefs about time. The author points out that time beliefs are again being manipulated today as the credibility of science is being exploited to promote a picture of time and, hence, a pattern of human behaviour which is convenient to the agenda of globalisation of culture. The linkages between modern theology and this 'brave new physics' are traced against the wider context of the so-called 'clash of civilisations', and the attempts to remake the world order. The conclusions point to the need to de-theologise time. The author challenges Einstein's understanding of relativity theory and suggests that a 'tilt in the arrow of time', or a small tendency towards cyclicity, will help repair the prevalent confusion about time. A 'tilt' also enables a physics that permits both memory and creativity, so that purpose and spontaneous growth of order are returned to human life. The book ends with a vision of Man as Creator, surprising God. Extensive research in physics, the history of science, comparative religions, and sociology lend weight to the important and challenging conclusions reached by the author. Written as a rejoinder to Stephen Hawking's A Brief History of Time, this book goes much further and, unlike any previous book, it gives a critical exposition of various world religions-Buddhism, Christianity, Hinduism, Islam, and Jainism-while exploring their intricate links, through time beliefs, to current physics on the one hand, and to global political and economic trends, on the other. This book will appeal to scholars and laypersons equally. It will fascinate anyone who reads it and will teach its readers to question the unquestionable. (shrink)

Bridging from Husserl to Iamblichus, this book contributes phenomenological readings of Plotinus, Aristotle, Parmenides, and Heraclitus, in which prevalent misconceptions about the very identity of time in the phenomena of motion are corrected, and time's role in Greek philosophy recovered.

In Physics IV 14, 223a16-223a29 Aristotle raises two questions: (Q1) How is time related to the soul? (Q2) Why is time thought to be in everything? Aristotle's juxtaposition of these questions indicates some relation between them. I argue that Aristotle is committed to the claim that time only exists where change is countable. Aristotle must answer (Q2) in a way that doesn't conflict with this commitment. Aristotle's answer to (Q1) offers him such a way. Since (...) class='Hi'>time is change qua countable, time is dependent on souls capable of counting. But the thing that time is, change, is not so dependent. Likewise, time is not located in everything, but change, the substratum of time, is. This answers (Q2) in a way that's compatible with Aristotle's commitments. (shrink)

Physics IV.10 (217b30–218a30) is pivotal in Aristotle’s discussion of time, preceding his own account from IV.11 onward. Aristotle presents three puzzles about the existence of time with reference to the “Now”. Modern interpretations often view this section as an aporetic prelude with Aristotle’s failure to provide explicit solutions. This paper examines Simplicius’ alternative interpretation, which draws upon the theory of proof and the syllogistic model from the Posterior Analytics. Simplicius contends that the arguments’ failure lies in their (...) inability to fit within the suitable syllogistic framework to establish a demonstrable definition of time, not in their aporetic nature. Every science has to prove the relation between (i) establishing whether X exists and (ii) showing what X is by establishing what the cause of X is. In evaluating Simplicius’ interpretation, this paper addresses two key aspects of the exegesis of IV.10: firstly, Simplicius can show why the “Now” is not part of the definition of time, and secondly, the ancient commentator underscores the close connection between the arguments in Physics IV.10 and the broader context of Aristotle’s discussion of time. Modern interpreters fail to address both of these issues. (shrink)

We review the current situation in the philosophy of time, partly to investigate Michael Dummett’s complaint that the philosophy of physics has become too specialized and technical to be able to communicate with mainstream philosophy. We conclude that the situation in this case is different: there is no special difficulty of intelligibility---the obstacle for communication between science and philosophy here is rather that what physics, or science in general, tells us is prima facie in conflict with common (...) sense and intuition. We argue that this difficulty is indeed prima facie: on closer inspection it appears that the scientific B-theory may explain our intuition better than the A-theory, even though the latter at first sight seems to completely mirror our direct experience. (shrink)

Now available in an updated addition: ""Integrating concepts of time derived from the physical sciences and world religions, "The Becoming of Time" examines ...

This essay offers a meta-level analysis in the sociology and history of physics in the context of the "Arrow of Time" or so-called "Two Times" problem. In effect, it argues that the two topics are intertwined, and it is only by coming to grips with the sociological aspects, involving adherence to certain metaphysical, epistemological and methodological beliefs and practices, that real progress can be made in the physics.

'The arrow of time' refers to the curious asymmetry that distinguishes the future from the past. Reversing the Arrow of Time argues that there is an intimate link between the symmetries of 'time itself' and time reversal symmetry in physical theories, which has wide-ranging implications for both physics and its philosophy. This link helps to clarify how we can learn about the symmetries of our world, how to understand the relationship between symmetries and what is (...) real, and how to overcome pervasive illusions about the direction of time. Roberts explains the significance of time reversal in a way that intertwines physics and philosophy, to establish what the arrow of time means and how we can come to know it. This book is both mathematically and philosophically rigorous yet remains accessible to advanced undergraduates in physics and the philosophy of physics. This title is also available as Open Access on Cambridge Core. (shrink)

Time as the key to a theory of everything became recently a renewed topic in scientific literature. Social constructivism applied to physics abandons the inevitable essentials of nature. It adopts uncertainty in the scope of the existential activity of scientific research. We have enlightened the deep role of social constructivism of the predetermined Newtonian time and space notions in natural sciences. Despite its incompatibility with determinism governing the Newtonian mechanics, randomness and entropy are inevitable when negative localized (...) energy is transformed into spatially dissipative heat. In sharp contrast to the Newtonian notion, social constructivism makes room for the temporal twin of cyclic conservation and pseudo-linearly structural evolution both reconciling mechanical order and thermodynamic chaos in Leibnizian space-time. In the broad scope of natural sciences this triad nature of time produces a multiple reality and gives appropriate answers on virtual physical paradoxes. (shrink)

A review of Huw Price's Time's Arrow and Archimedes' Point.

Understanding of time, construed as movement, change and becoming, is explained taking examples from natural sciences. Durational and metrical aspects of time are elaborated. General assumptions about passage of time are listed. Indian, Chinese and later insights of path of passage of time are figured. Physical and psychological times are differentiated and explained using Energy-Presence (Being) and Energy-Transformation (Becoming) concepts. Concepts of Time at rest and Time in motion are proposed. -/- . The meanings (...) of time-space, time-flow, different phases of time-conscious and time-transcendent mind and thought processes are interpreted from basic physics principles and Upanishadic awareness -/- An attempt is made to present a comprehensive insight of nature of time, thought process and conscious states (phases) of mind. (shrink)

This thesis is a study of the notion of time in modern physics, consisting of two parts. Part I takes seriously the doctrine that modern physics should be treated as the primary guide to the nature of time. To this end, it offers an analysis of the various conceptions of time that emerge in the context of various physical theories and, furthermore, an analysis of the relation between these conceptions of time and the more (...) orthodox philosophical views on the nature of time. In Part II I explore the interpretation of nonrelativistic quantum mechanics in light of the suggestion that an overly Newtonian conception of time might be contributing to some of the difficulties that we face in interpreting the quantum mechanical formalism. In particular, I argue in favour of introducing backwards-in-time causal influences as part of an alternative conception of time that is consistent with the picture of reality that arises in the context of the quantum formalism. Moreover, I demonstrate that this conception of time can already be found in a particular formulation of classical mechanics. One might see that one of the central themes of Part II originates from a failure to heed properly the doctrine of Part I: study into the nature of time should be guided by modern physics and thus we should be careful not to insert a preconceived Newtonian conception of time unwittingly into our interpretation of the quantum mechanical formalism. Thus, whereas Part I is intended as a demonstration of methodology with respect to the study of time, Part II in a sense explores a confusion that can be seen as arising in the absence of this methodology. (shrink)

At a certain stage of advance in any science it may be well to re-examine and perhaps to rearrange its fundamentals. One seeks an ideal, logical order of development, which may or may not be the best pedagogical order. Many a high school beginner in physics has become acquainted with “force” as something that gets in between two bodies of matter and pulls them together or pushes them apart, like himself between two carts or like “magnetism” between two magnets. (...) Whether or not this might ever be a proper view, the mature student of today will consider that for him, a knowledge of accelerations and strains, inter alia, is prerequisite to a knowledge of force. (shrink)

Through a comparison between phenomenology and quantum physics, the paper aims to show that naturalising phenomenology can also mean bringing it into a critical and fruitful relationship with some of the most complex and fundamental questions of contemporary physics, thus showing both the truly ever-open potential of Husserlian and Heideggerian thinking and the need for the sciences to receive a theoretical light without which they risk remaining either magical, arbitrary and esoteric knowledge or technical, reductionist and epistemologically sterile.

This open access monograph offers a detailed study and a systematic defense of a key intuition we typically have, as human beings, with respect to the nature of time: the intuition that the future is open, whereas the past is fixed. For example, whereas it seems unsettled whether there will be a fourth world war, it is settled that there was a first world war. -/- The book contributes, in particular, three major and original insights. First, it provides a (...) coherent, non-metaphorical, and metaphysically illuminating elucidation of the intuition. Second, it determines which model of the temporal structure of the world is most appropriate to accommodate the intuition, and settles on a specific version of the Growing Block Theory of time (GBT). Third, it puts forward a naturalistic foundation for GBT, by exploiting recent results of our best physics (viz. General Relativity, Quantum Mechanics, and Quantum Gravity). Three main challenges are addressed: the dismissal of temporal asymmetries as non-fundamental phenomena only (e.g., thermodynamic or causal phenomena), the epistemic objection against GBT, and the apparent tension between GBT and relativistic physics. It is argued that the asymmetry between the open future and the fixed past must be grounded in the temporal structure of the world, and that this is neither precluded by our epistemic device, nor by the latest approaches to Quantum Gravity (​e.g., the Causal Set Theory). -/- Aiming at reconciling time as we find it in ordinary experience and time as physics describes it, this ​innovative book ​will raise the interest of both academic researchers and ​graduate students working on the philosophy of time. More generally, it ​presents contents of interest for all metaphysicians and non-dogmatic philosophers of physics. (shrink)