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Related papers: New Difficulties for the Past Hypothesis

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One of the most difficult problems in the foundations of physics is what gives rise to the arrow of time. Since the fundamental dynamical laws of physics are (essentially) symmetric in time, the explanation for time's arrow must come from…

History and Philosophy of Physics · Physics 2021-10-26 Eddy Keming Chen

There is a paradox in the standard model of cosmology. How can matter in the early universe have been in thermal equilibrium, indicating maximum entropy, but the initial state also have been low entropy (the "past hypothesis"), so as to…

General Relativity and Quantum Cosmology · Physics 2023-12-21 Jordan Scharnhorst , Anthony Aguirre

Physics takes for granted that interacting physical systems with no common history are independent, before their interaction. This principle is time-asymmetric, for no such restriction applies to systems with no common future, after an…

Quantum Physics · Physics 2007-05-23 Huw Price

The second law of thermodynamics is asymmetric with respect to time as it says that the entropy of the universe must have been lower in the past and will be higher in the future. How this time-asymmetric law arises from the time-symmetric…

Statistical Mechanics · Physics 2021-06-07 Sivapalan Chelvaniththilan

The evident contrast between the time symmetry of fundamental microscopic laws and the time asymmetry of macroscopic processes is a challenging physical problem. The observation of unitary evolution of a general physical system by an…

Statistical Mechanics · Physics 2022-02-24 Miroslav Holeček

It is widely accepted that temporal asymmetry is largely a cosmological problem; the task of explaining temporal asymmetry reduces in the main to that of explaining an aspect of the condition of the early universe. However, cosmologists who…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Huw Price

This thesis addresses two major problems in the philosophy of physics. The first is how to identify the minimal physical content of a theory; that is, what features of a theory are truly needed to make predictions, and what can be removed…

History and Philosophy of Physics · Physics 2025-09-19 Sean Gryb

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

If an asymmetry in time does not arise from the fundamental dynamical laws of physics, it may be found in special boundary conditions. The argument normally goes that since thermodynamic entropy in the past is lower than in the future…

Quantum Physics · Physics 2024-07-23 Jim Al-Khalili , Eddy Keming Chen

The physical models of a successful unified theory about the Universe must operate in different phase of matter evolution and different fields of physics. The attempts to build such wide range theory as a bunch of theories developed for…

General Physics · Physics 2007-05-23 S. Sarg

An asymmetry exists between time and space in the sense that physical systems inevitably evolve over time whereas there is no corresponding ubiquitous translation over space. The asymmetry, which is presumed to be elemental, is represented…

Quantum Physics · Physics 2016-01-25 Joan A. Vaccaro

The only widely accepted explanation for the various arrows of time that everywhere and at all epochs point in the same direction is the `past hypothesis': the Universe had a very special low-entropy initial state. We present the first…

General Relativity and Quantum Cosmology · Physics 2014-12-11 Julian Barbour , Tim Koslowski , Flavio Mercati

As a basis for epistemological study of ``time,'' we analyze three suspect phenomena introduced by modern physics: non-locality, asymmetric aging and advanced interaction. It is shown that all three arise in connection with what has to be…

Quantum Physics · Physics 2007-05-23 A. F. Kracklauer

It is argued that a fundamental time asymmetry could arise from the global structure of the space manifold. The proposed mechanism relies on the CPT anomaly of certain chiral gauge theories defined over a multiply connected space manifold.…

General Relativity and Quantum Cosmology · Physics 2009-11-07 F. R. Klinkhamer

Current theories of particle physics lead to the unavoidable conclusion that there must have been several phase transitions in the early universe. Further, in the context of these theories, it is possible that cosmological phase transitions…

High Energy Physics - Phenomenology · Physics 2009-10-31 Tanmay Vachaspati

In the context of a parametric theory (with the time being a dynamical variable) we consider the coupling between the quantum vacuum and the background gravitation that pervades the universe (unavoidable because of the universality of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Antonio F. Ranada , Alfredo Tiemblo

I discuss some central issues in particle physics which are potentially relevant to cosmology. I first briefly review the present (glorious) experimental status of the Standard Model, emphasizing that it provides a firm foundation both for…

High Energy Physics - Phenomenology · Physics 2007-05-23 Frank Wilczek

Bayesian inference --- although becoming popular in physics and chemistry --- is hampered up to now by the vagueness of its notion of prior probability. Some of its supporters argue that this vagueness is the unavoidable consequence of the…

Data Analysis, Statistics and Probability · Physics 2008-02-03 O. -A. Al-Hujaj , H. L. Harney

This essay examines our fundamental conceptions of time, spacetime, the asymmetry of time, and the motion of a quantum mechanical particle. The concept of time has multiple meanings and these are often confused in the literature and must be…

General Relativity and Quantum Cosmology · Physics 2014-08-15 Gerald E. Marsh

We present a scenario in $1 + 1$ and $3 + 1$ dimensional space time which is paradoxical in the presence of a time machine. We show that the paradox cannot be resolved and the scenario has {\em no} consistent classical solution. Since the…

General Relativity and Quantum Cosmology · Physics 2009-09-25 S. Kalyana Rama , Siddhartha Sen
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