Results 21 to 30 of about 12,793 (259)

Where Was Past Low-Entropy?

open access: yesEntropy, 2019
Where was the past low-entropy of the early universe located? Contrary to some popular answers, I argue that that the dominant source of low-entropy is the fact that a single degree of freedom, the scale factor, was not at equilibrium.
Carlo Rovelli
doaj   +1 more source

Maxwell’s Demon in Quantum Mechanics

open access: yesEntropy, 2020
Maxwell’s Demon is a thought experiment devised by J. C. Maxwell in 1867 in order to show that the Second Law of thermodynamics is not universal, since it has a counter-example. Since the Second Law is taken by many to provide an arrow of time, the
Orly Shenker, Meir Hemmo
doaj   +1 more source

Entropy, Biological Evolution and the Psychological Arrow of Time

open access: yesJournal of Modern Physics, 2016
We argue that in Universes where future and past differ only by the entropy content a psychological arrow of time pointing in the direction of entropy increase can arise from natural selection in biological evolution. We show that this effect can be demonstrated in very simple toy computer simulations of evolution in an entropy increasing or decreasing
Heinrich, Torsten   +2 more
openaire   +3 more sources

Pre-Big-Bang Black-Hole Remnants and Past Low Entropy

open access: yesUniverse, 2018
Dark matter could be composed by black-hole remnants formed before the big-bang era in a bouncing cosmology. This hypothetical scenario has implications on the issue of the arrow of time: it upsets a common attribution of past low entropy to the state of
Carlo Rovelli, Francesca Vidotto
doaj   +1 more source

The holographic space-time and black hole remnants as dark matter

open access: yesPhysics Letters B, 2022
The holographic space-time approach to inflation provides a well defined and self-contained framework to study the early universe. Based on a quasi-local quantum gravity theory generalizing string theory beyond AdS backgrounds, it addresses fundamental ...
Aurélien Barrau
doaj   +1 more source

About some Entropy Aspects of Dissipative Systems [PDF]

open access: yesTheoretical and Applied Economics, 2006
This paper is aspiring to get a logical explanation on the entropy velocity (i.e. on the entropy acceleration) in a Universe “endowed” with a dissipative system.
Emil Dinga
doaj   +1 more source

Fidelity Mechanics: Analogues of the Four Thermodynamic Laws and Landauer’s Principle

open access: yesEntropy, 2022
Fidelity mechanics is formalized as a framework for investigating critical phenomena in quantum many-body systems. Fidelity temperature is introduced for quantifying quantum fluctuations, which, together with fidelity entropy and fidelity internal energy,
Huan-Qiang Zhou   +2 more
doaj   +1 more source

Pre-bangian origin of our entropy and time arrow [PDF]

open access: yesPhysics Letters B, 1999
I argue that, in the chaotic version of string cosmology proposed recently, classical and quantum effects generate, at the time of exit to radiation, the correct amount of entropy to saturate a Hubble (or holography) entropy bound (HEB) and to identify, within our own Universe, the arrow of time.
openaire   +2 more sources

Stressful Events Reported by Childhood Cancer Survivors and Community Controls From the St. Jude Lifetime (SJLIFE) Cohort: A Mixed Method Study

open access: yesPediatric Blood &Cancer, EarlyView.
ABSTRACT Introduction Characterizing stressful events reported by childhood cancer survivors experienced throughout the lifespan may help improve trauma‐informed care relevant to the survivor experience. Methods Participants included 2552 survivors (54% female; 34 years of age) and 469 community controls (62% female; 33 years of age) from the St.
Megan E. Ware   +13 more
wiley   +1 more source

Entropy production in systems with unidirectional transitions

open access: yesPhysical Review Research, 2020
The entropy production is one of the most essential features for systems operating out of equilibrium. The formulation for discrete-state systems goes back to the celebrated Schnakenberg's work and hitherto can be carried out when for each transition ...
D. M. Busiello, D. Gupta, A. Maritan
doaj   +1 more source

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