Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.9
2.1
Journals
Entropy
Special Issues
Time and Temporal Asymmetries
entropy-logo
Submit to Special Issue Submit Abstract to Special Issue Review for Entropy Propose a Special Issue

Journal Menu

► Journal Menu

Journal Browser

► Journal Browser
share announcement

Time and Temporal Asymmetries

A special issue of Entropy (ISSN 1099-4300). This special issue belongs to the section "Time".

Deadline for manuscript submissions: 15 December 2024 | Viewed by 8823

Special Issue Editors

Prof. Dr. Olimpia Lombardi

E-Mail Website
Guest Editor
Institute of Philosophy, CONICET and University of Buenos Aires, Buenos Aires 1406, Argentina
Interests: problem of the arrow of time; interpretation of quantum mechanics; nature of information; foundations of statistical mechanics; philosophy of chemistry
Special Issues, Collections and Topics in MDPI journals
Dr. Cristian López

E-Mail Website
Guest Editor
Department of Philosophy, University of Lausanne, Anthropole, 1015 Lausanne, Switzerland
Interests: philosophy of time; philosophy of quantum mechanics; metaphysics; the relation between metaphysics and science

Special Issue Information

Dear Colleagues,

Time is probably one of the most mysterious ingredients of the universe. On the one hand, time is unique and elusive. On the other, it seems to be an intrinsic, familiar part of our lives and world. It is then no surprise that philosophers and scientists have found in the nature of time a fertile terrain for philosophical and scientific inquiry. However, the more we dig into the nature of time, the more mysteries emerge. It is plain that time seems to pass by, but how? What does it mean that time ‘passes by’? What is the physics behind the seeming passing of time? It is also plain that time is directed, pointing to the future, flying away from the past, but how? Does time really have a direction? What physical evidence do we have at disposal to make sense of the idea of a ‘direction of time’? May time be directionless?

Time is not only mysterious by itself, but also for its relations to many temporal asymmetries. Philosophers and scientists alike have suggested that time could be related to the increase of entropy in isolated systems, to the expansion of the universe, to electromagnetic radiation, to the geometry of space-time, etc. Yet, any of these temporal asymmetries involves further issues: symmetric boundary conditions or time-reversal invariant dynamics speak against, rather than in favor of, temporal asymmetries and many properties of time. Even more, according to cutting-edge science, as some theories of quantum gravity suggest, time might even dilute at the fundamental level, being considered as an emergent feature of reality. However, what is the relation between time and temporal asymmetries? Does time explain them? Or do they explain what time is? If time does not exist at the fundamental level, how do all the temporal asymmetries we have experience of emerge at the macroscopic level? Can we dispense with time to do science and philosophy?

The aim of this Special Issue is to explore these scientific and philosophical problems in an interdisciplinary manner by counting on the collaboration of scientists and philosophers working in the field. Scientific aspects of time and temporal asymmetries as well as more philosophically oriented discussions are thus equally welcome and strongly encouraged.

Prof. Dr. Olimpia Lombardi
Dr. Cristian López
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Entropy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • direction of time
  • time-reversal invariance
  • irreversibility
  • entropy
  • quantum gravity
  • general relativity
  • thermodynamics
  • statistical mechanics
  • metaphysics of time
  • substantivalism vs. relationalism
  • topology of time
  • presentism, eternalism and block universe
  • time travel

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (7 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

19 pages, 377 KiB  
Article
Modeling the Arrows of Time with Causal Multibaker Maps
by Aram Ebtekar and Marcus Hutter
Entropy 2024, 26(9), 776; https://doi.org/10.3390/e26090776 - 10 Sep 2024
Viewed by 1241
Abstract
Why do we remember the past, and plan the future? We introduce a toy model in which to investigate emergent time asymmetries: the causal multibaker maps. These are reversible discrete-time dynamical systems with configurable causal interactions. Imposing a suitable initial condition or “Past [...] Read more.
Why do we remember the past, and plan the future? We introduce a toy model in which to investigate emergent time asymmetries: the causal multibaker maps. These are reversible discrete-time dynamical systems with configurable causal interactions. Imposing a suitable initial condition or “Past Hypothesis”, and then coarse-graining, yields a Pearlean locally causal structure. While it is more common to speculate that the other arrows of time arise from the thermodynamic arrow, our model instead takes the causal arrow as fundamental. From it, we obtain the thermodynamic and epistemic arrows of time. The epistemic arrow concerns records, which we define to be systems that encode the state of another system at another time, regardless of the latter system’s dynamics. Such records exist of the past, but not of the future. We close with informal discussions of the evolutionary and agential arrows of time, and their relevance to decision theory. Full article
(This article belongs to the Special Issue Time and Temporal Asymmetries)
►▼ Show Figures

Figure 1

14 pages, 251 KiB  
Article
Local versus Global Time in Early Relativity Theory
by Dennis Dieks
Entropy 2024, 26(7), 608; https://doi.org/10.3390/e26070608 - 18 Jul 2024
Viewed by 851
Abstract
In his groundbreaking 1905 paper on special relativity, Einstein distinguished between local and global time in inertial systems, introducing his famous definition of distant simultaneity to give physical content to the notion of global time. Over the following decade, Einstein attempted to generalize [...] Read more.
In his groundbreaking 1905 paper on special relativity, Einstein distinguished between local and global time in inertial systems, introducing his famous definition of distant simultaneity to give physical content to the notion of global time. Over the following decade, Einstein attempted to generalize this analysis of relativistic time to include accelerated frames of reference, which, according to the principle of equivalence, should also account for time in the presence of gravity. Characteristically, Einstein’s methodology during this period focused on simple, intuitively accessible physical situations, exhibiting a high degree of symmetry. However, in the final general theory of relativity, the a priori existence of such global symmetries cannot be assumed. Despite this, Einstein repeated some of his early reasoning patterns even in his 1916 review paper on general relativity and in later writings. Modern commentators have criticized these arguments as confused, invalid, and inconsistent. Here, we defend Einstein in the specific context of his use of global time and his derivations of the gravitational redshift formula. We argue that a detailed examination of Einstein’s early work clarifies his later reasoning and demonstrates its consistency and validity. Full article
(This article belongs to the Special Issue Time and Temporal Asymmetries)
11 pages, 207 KiB  
Article
Temporal Direction, Intuitionism and Physics
by Yuval Dolev
Entropy 2024, 26(7), 594; https://doi.org/10.3390/e26070594 - 11 Jul 2024
Viewed by 665
Abstract
In a recent paper, Nicolas Gisin suggests that by conducting physics with intuitionistic rather than classical mathematics, rich temporality—that is, passage and tense, and specifically the future’s openness—can be incorporated into physics. Physics based on classical mathematics is tenseless and deterministic, and that, [...] Read more.
In a recent paper, Nicolas Gisin suggests that by conducting physics with intuitionistic rather than classical mathematics, rich temporality—that is, passage and tense, and specifically the future’s openness—can be incorporated into physics. Physics based on classical mathematics is tenseless and deterministic, and that, so he holds, renders it incongruent with experience. According to Gisin, physics ought to represent the indeterminate nature of reality, and he proposes that intuitionistic mathematics is the key to succeeding in doing so. While I share his insistence on the reality of passage and tense and on the future being real and open, I argue that the amendment he offers does not work. I show that, its attunement to time notwithstanding, intuitionistic mathematics is as tenseless as classical mathematics and that physics is bound to remain tenseless regardless of the math it employs. There is much to learn about tensed time, but the task belongs to phenomenology and not to physics. Full article
(This article belongs to the Special Issue Time and Temporal Asymmetries)
14 pages, 301 KiB  
Article
A Review of the Concept of Time Reversal and the Direction of Time
by Cristian López and Olimpia Lombardi
Entropy 2024, 26(7), 563; https://doi.org/10.3390/e26070563 - 30 Jun 2024
Viewed by 1299
Abstract
Abstract: In the debate about the direction of time in physics, the concept of time reversal has been central. Tradition has it that time-reversal invariant laws are sufficient to state that the direction of time is non-fundamental or emergent. In this paper, we [...] Read more.
Abstract: In the debate about the direction of time in physics, the concept of time reversal has been central. Tradition has it that time-reversal invariant laws are sufficient to state that the direction of time is non-fundamental or emergent. In this paper, we review some of the debates that have gravitated around the concept of time reversal and its relation to the direction of time. We also clarify some of the central concepts involved, showing that the very concept of time reversal is more complex than frequently thought. Full article
(This article belongs to the Special Issue Time and Temporal Asymmetries)
19 pages, 327 KiB  
Article
Relativistic Consistency of Nonlocal Quantum Correlations
by Christian Beck and Dustin Lazarovici
Entropy 2024, 26(7), 548; https://doi.org/10.3390/e26070548 - 27 Jun 2024
Viewed by 812
Abstract
What guarantees the “peaceful coexistence” of quantum nonlocality and special relativity? The tension arises because entanglement leads to locally inexplicable correlations between distant events that have no absolute temporal order in relativistic spacetime. This paper identifies a relativistic consistency condition that is weaker [...] Read more.
What guarantees the “peaceful coexistence” of quantum nonlocality and special relativity? The tension arises because entanglement leads to locally inexplicable correlations between distant events that have no absolute temporal order in relativistic spacetime. This paper identifies a relativistic consistency condition that is weaker than Bell locality but stronger than the no-signaling condition meant to exclude superluminal communication. While justifications for the no-signaling condition often rely on anthropocentric arguments, relativistic consistency is simply the requirement that joint outcome distributions for spacelike separated measurements (or measurement-like processes) must be independent of their temporal order. This is necessary to obtain consistent statistical predictions across different Lorentz frames. We first consider ideal quantum measurements, derive the relevant consistency condition on the level of probability distributions, and show that it implies no-signaling (but not vice versa). We then extend the results to general quantum operations and derive corresponding operator conditions. This will allow us to clarify the relationships between relativistic consistency, no-signaling, and local commutativity. We argue that relativistic consistency is the basic physical principle that ensures the compatibility of quantum statistics and relativistic spacetime structure, while no-signaling and local commutativity can be justified on this basis. Full article
(This article belongs to the Special Issue Time and Temporal Asymmetries)
23 pages, 331 KiB  
Article
Memory Systems, the Epistemic Arrow of Time, and the Second Law
by David H. Wolpert and Jens Kipper
Entropy 2024, 26(2), 170; https://doi.org/10.3390/e26020170 - 16 Feb 2024
Cited by 1 | Viewed by 1801
Abstract
The epistemic arrow of time is the fact that our knowledge of the past seems to be both of a different kind and more detailed than our knowledge of the future. Just like with the other arrows of time, it has often been [...] Read more.
The epistemic arrow of time is the fact that our knowledge of the past seems to be both of a different kind and more detailed than our knowledge of the future. Just like with the other arrows of time, it has often been speculated that the epistemic arrow arises due to the second law of thermodynamics. In this paper, we investigate the epistemic arrow of time using a fully formal framework. We begin by defining a memory system as any physical system whose present state can provide information about the state of the external world at some time other than the present. We then identify two types of memory systems in our universe, along with an important special case of the first type, which we distinguish as a third type of memory system. We show that two of these types of memory systems are time-symmetric, able to provide knowledge about both the past and the future. However, the third type of memory systems exploits the second law of thermodynamics, at least in all of its instances in our universe that we are aware of. The result is that in our universe, this type of memory system only ever provides information about the past. We also argue that human memory is of this third type, completing the argument. We end by scrutinizing the basis of the second law itself. This uncovers a previously unappreciated formal problem for common arguments that try to derive the second law from the “Past Hypothesis”, i.e., from the claim that the very early universe was in a state of extremely low entropy. Our analysis is indebted to prior work by one of us but expands and improves upon this work in several respects. Full article
(This article belongs to the Special Issue Time and Temporal Asymmetries)
21 pages, 2427 KiB  
Article
Nonlocality, Superposition, and Time in the 4+1 Formalism
by Filip Strubbe
Entropy 2023, 25(11), 1493; https://doi.org/10.3390/e25111493 - 29 Oct 2023
Viewed by 1225
Abstract
The field of quantum gravity struggles with several problems related to time, quantum measurement, nonlocality, and realism. To address these issues, this study develops a 4+1 formalism featuring a flat 4D spacetime evolving with a second form of time, τ, worldlines that [...] Read more.
The field of quantum gravity struggles with several problems related to time, quantum measurement, nonlocality, and realism. To address these issues, this study develops a 4+1 formalism featuring a flat 4D spacetime evolving with a second form of time, τ, worldlines that locally conserve momentum, and a hypersurface representing the present. As a function of τ, worldlines can spatially readjust and influences can travel backward or forward in the time dimension along these worldlines, offering a physical mechanism for retrocausality. Three theoretical models are presented, elucidating how nonlocality in an EPR experiment, the arrival time problem, and superposition in a Mach–Zehnder interferometer can be understood within this 4+1 framework. These results demonstrate that essential quantum phenomena can be reproduced in the 4+1 formalism while upholding the principles of realism, locality, and determinism at a fundamental level. Additionally, there is no measurement or collapse problem, and a natural explanation for the quantum-to-classical transition is obtained. Furthermore, observations of a 4D block universe and of the flow of time can be simultaneously understood. With these properties, the presented 4+1 formalism lays an interesting foundation for a quantum gravity theory based on intuitive principles and compatible with our observation of time. Full article
(This article belongs to the Special Issue Time and Temporal Asymmetries)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-7
Back to TopTop