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Related papers: Notes on Time's Enigma

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It is often claimed that the fundamental laws of physics are deterministic and time-symmetric and that therefore our experience of the passage of time is an illusion. This paper will critically discuss these claims and show that they are…

Quantum Physics · Physics 2023-04-20 Barbara Drossel

We discuss the appearance of time-asymmetric behavior in physical processes in cosmology and in the dynamics of the Universe itself. We begin with an analysis of the nature and origin of irreversibility in well-known physical processes such…

General Relativity and Quantum Cosmology · Physics 2007-05-23 B. L. Hu

Most attempts to argue for the second law of thermodynamics fail because (1) they use the unviable frequency theory of probability and (2) they do not explain why the arrow of time seen in experiments is aligned with the thermodynamic arrow…

Quantum Physics · Physics 2008-11-24 Alan Forrester

The emergence of a direction of time in statistical mechanics from an underlying time-reversal-invariant dynamics is explained by examining a simple model. The manner in which time-reversal symmetry is preserved and the role of initial…

Statistical Mechanics · Physics 2009-10-31 Vinay Ambegaokar , Aashish Clerk

Attempts to quantize general relativity encounter an odd problem. The Hamiltonian that normally generates time evolution vanishes in the case of general relativity as a result of diffeomorphism invariance. The theory seems to be saying that…

General Relativity and Quantum Cosmology · Physics 2009-04-23 Olaf Dreyer

The problem of the Nature of Time is twofold: whether or not time is a fundamental quantity of Nature, and how does clock time of metrology emerge in the experimental description of dynamics. This work strongly supports the fundamental…

Classical Physics · Physics 2013-11-05 Enrico Prati

Motivated by the mounting evidence for dark energy, here we explore the consequences of a fundamental cosmological constant $\Lambda$ for our universe. We show that when the gravitational entropy of a pure DeSitter state ultimately wins…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Laura Mersini-Houghton

It has often been suggested that retrocausality offers a solution to some of the puzzles of quantum mechanics: e.g., that it allows a Lorentz-invariant explanation of Bell correlations, and other manifestations of quantum nonlocality,…

Quantum Physics · Physics 2012-06-19 Huw Price

Irreversibility remains one of the least understood concepts in physics. One of the main reasons is the fact that the fundamental laws of classical and quantum physics are time symmetric, whereas macroscopic processes evolve in a preferred…

Statistical Mechanics · Physics 2020-09-28 Bertúlio de Lima Bernardo

We discuss the arrow of time in terms of the increase of correlations between the system and its environment. Here we show that the existence of the arrow of time, based on deleting correlations, requires a strict absence of initial…

Quantum Physics · Physics 2016-05-04 Vlatko Vedral

Collapse models are modifications of quantum theory where the wave function is treated as physically real and the collapse of the wave function is a physical process. This appears to introduce a time reversal asymmetry into the dynamics of…

Quantum Physics · Physics 2015-02-25 Daniel Bedingham , Owen Maroney

In this paper we propose that cosmological time is a quantum observable that does not commute with other quantum operators essential for the definition of cosmological states, notably the cosmological constant. This is inspired by…

General Relativity and Quantum Cosmology · Physics 2020-02-11 Joao Magueijo , Lee Smolin

Active matter encompasses systems whose individual consituents dissipate energy to exert propelling forces on their environment. This rapidly developing field harbors a dynamical phenomenology with no counterpart in passive systems. The…

Statistical Mechanics · Physics 2023-12-19 Jérémy O'Byrne , Yariv Kafri , Julien Tailleur , Frédéric van Wijland

The fundamental laws of physics are time-symmetric, but our macroscopic experience contradicts this. The time reversibility paradox is partly a consequence of the unpredictability of Newton's equations of motion. We measure the dependence…

Chaotic Dynamics · Physics 2022-09-09 Simon Portegies Zwart , Tjarda Boekholt

Time can be defined as the duration between events. It is irreversible. When used as a variable in quantifying the changing properties of matter, this irreversibility of time is incompatible with Newton's deterministic mechanics and with…

chao-dyn · Physics 2007-05-23 X. de Hemptinne

The cosmological arrow of time may be linked to the thermodynamic arrow by second law of thermodynamics. The time asymmetry is also associated with dissipative fluid as Tolman introduced a viscous fluid to generate an arrow of time in…

General Physics · Physics 2016-07-21 Bal Krishna Yadav , Murli Manohar Verma

In this essay, we argue that the problem of time should not be regarded as an issue to be resolved within the prevailing framework for studying quantum gravity, but rather as an indication that there is an issue within the framework itself.…

High Energy Physics - Theory · Physics 2025-04-02 Marc S. Klinger , Robert G. Leigh

We argue that space and space-time emerge as a consequence of dynamical collapse of the wave function of macroscopic objects. Locality and separability are properties of our approximate, emergent universe. At the fundamental level,…

Quantum Physics · Physics 2018-10-31 Tejinder P. Singh

Time is, figuratively and literally, becoming the new dimension for crystalline matter. As such, rapid recent progress on time-varying media gave rise to the notion of temporal and spatiotemporal crystals. Fundamentally rethinking the role…

This paper argues that the common identification of time with entropy is a category error. Entropy accounts for the arrow of time but not for time itself. Even in a maximally entropic universe the so called heat death temporal structure…

History and Philosophy of Physics · Physics 2025-08-22 Joseph S. Finberg