scholarly journals Entropy and Time

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 430 ◽  
Author(s):  
Arieh Ben-Naim
Keyword(s):  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Arrow Of Time ◽  
H Theorem ◽  
The Universe ◽  
Entropy Of The Universe ◽  
Time’S Arrow

The idea that entropy is associated with the “arrow of time” has its roots in Clausius’s statement on the Second Law: “Entropy of the Universe always increases.” However, the explicit association of the entropy with time’s arrow arises from Eddington. In this article, we start with a brief review of the idea that the “increase in entropy” is somehow associated with the direction in which time increases. Then, we examine three different, but equivalent definitions of entropy. We find that none of these definitions indicate any hint of a relationship between entropy and time. We can, therefore, conclude that entropy is a timeless quantity. We also discuss the reasons as to why some scientists went astray in associating entropy with time’s arrow. Finally, we shall discuss Boltzmann’s H-Theorem, which is viewed by many as a proof of the Second Law of Thermodynamics.

Time’s Arrow and Statistical Uncertainty in Physics and Philosophy

2020 ◽  
pp. 204-241
Author(s):  
Theodore M. Porter
Keyword(s):  
Free Will ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Statistical Uncertainty ◽  
Newtonian Mechanics ◽  
Historical School ◽  
James Clerk Maxwell ◽  
Objective Chance ◽  
The Universe ◽  
Time’S Arrow

This chapter explores how German economists and statisticians of the historical school viewed the idea of social or statistical law as the product of confusion between spirit and matter or, equivalently, between history and nature. That the laws of Newtonian mechanics are fully time-symmetric and hence can be equally run backwards or forwards could not easily be reconciled with the commonplace observation that heat always flows from warmer to cooler bodies. James Clerk Maxwell, responding to the apparent threat to the doctrine of free will posed by thermodynamics and statistics, pointed out that the second law of thermodynamics was only probable, and that heat could be made to flow from a cold body to a warm one by a being sufficiently quick and perceptive. Ludwig Boltzmann resisted this incursion of probabilism into physics but in the end he was obliged, largely as a result of difficulties presented by the issue of mechanical reversibility, to admit at least the theoretical possibility of chance effects in thermodynamics. Meanwhile, the American philosopher and physicist C. S. Pierce determined that progress—the production of heterogeneity and homogeneity—could never flow from rigid mechanical laws, but demanded the existence of objective chance throughout the universe.

scholarly journals Thermodynamics of the $$R_{\mathrm{h}}=ct$$ Universe: a simplification of cosmic entropy

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Fulvio Melia
Keyword(s):  
Standard Model ◽  
Second Law Of Thermodynamics ◽  
Big Bang ◽  
Second Law ◽  
Arrow Of Time ◽  
Physical Conditions ◽  
The Standard Model ◽  
The Big Bang ◽  
Low Entropy ◽  
The Universe

AbstractIn the standard model of cosmology, the Universe began its expansion with an anomalously low entropy, which then grew dramatically to much larger values consistent with the physical conditions at decoupling, roughly 380,000 years after the Big Bang. There does not appear to be a viable explanation for this ‘unnatural’ history, other than via the generalized second law of thermodynamics (GSL), in which the entropy of the bulk, $$S_\mathrm{bulk}$$ S bulk , is combined with the entropy of the apparent (or gravitational) horizon, $$S_{\mathrm{h}}$$ S h . This is not completely satisfactory either, however, since this approach seems to require an inexplicable equilibrium between the bulk and horizon temperatures. In this paper, we explore the thermodynamics of an alternative cosmology known as the $$R_{\mathrm{h}}=ct$$ R h = c t universe, which has thus far been highly successful in resolving many other problems or inconsistencies in $$\varLambda $$ Λ CDM. We find that $$S_{\mathrm{bulk}}$$ S bulk is constant in this model, eliminating the so-called initial entropy problem simply and elegantly. The GSL may still be relevant, however, principally in selecting the arrow of time, given that $$S_{\mathrm{h}}\propto t^2$$ S h ∝ t 2 in this model.

The Analogical Turn (1884–1887)

2018 ◽  
Author(s):  
Olivier Darrigol
Keyword(s):  
Boltzmann Equation ◽  
Statistical Mechanics ◽  
Mechanical System ◽  
Thermal Equilibrium ◽  
Special Kind ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Equipartition Theorem ◽  
Royal Road ◽  
H Theorem

This chapter recounts how Boltzmann reacted to Hermann Helmholtz’s analogy between thermodynamic systems and a special kind of mechanical system (the “monocyclic systems”) by grouping all attempts to relate thermodynamics to mechanics, including the kinetic-molecular analogy, into a family of partial analogies all derivable from what we would now call a microcanonical ensemble. At that time, Boltzmann regarded ensemble-based statistical mechanics as the royal road to the laws of thermal equilibrium (as we now do). In the same period, he returned to the Boltzmann equation and the H theorem in reply to Peter Guthrie Tait’s attack on the equipartition theorem. He also made a non-technical survey of the second law of thermodynamics seen as a law of probability increase.

Evolution of the universe from the perspective of entropy and information

2021 ◽  
pp. 2150111
Author(s):  
Fei-Quan Tu ◽  
Bin Sun ◽  
Meng Wan ◽  
Qi-Hong Huang
Keyword(s):  
Information Entropy ◽  
Second Law Of Thermodynamics ◽  
Boltzmann Entropy ◽  
Evolution Of The Universe ◽  
Thermodynamic Entropy ◽  
Entire Universe ◽  
Low Entropy ◽  
The Relationship ◽  
The Universe ◽  
Entropy Of The Universe

Entropy is a key concept widely used in physics and other fields. At the same time, the meaning of entropy with different names and the relationship among them are confusing. In this paper, we discuss the relationship among the Clausius entropy, Boltzmann entropy and information entropy and further show that the three kinds of entropy are equivalent to each other to some extent. Moreover, we point out that the evolution of the universe is a process of entropy increment and life originates from the original low entropy of the universe. Finally, we discuss the evolution of the entire universe composed of the cosmological horizon and the space surrounded by it and interpret the entropy as a measure of information of all microstates corresponding to a certain macrostate. Under this explanation, the thermodynamic entropy and information entropy are unified and we can conclude that the sum of the entropy of horizon and the entropy of matter in the space surrounded by the horizon does not decrease with time if the second law of thermodynamics holds for the entire universe.

Dynamics of membrane processes

1968 ◽  
Vol 1 (2) ◽  
pp. 127-175 ◽  
Author(s):  
A. Katchalsky ◽  
R. Spangler
Keyword(s):  
Biological Evolution ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Membrane Processes ◽  
Biological Phenomena ◽  
Living Organisms ◽  
The Universe ◽  
Intrinsic Contradiction

I. I. In his illuminating book onThe Nature of Thermodynamics, Bridgeman (1941) points out an intrinsic contradiction between the concepts of physical and biological evolution. In his words: ‘The view that the universe is running down into a condition where its entropy and the amount of disorder are as great as possible has had a profound effect on the views of many biologists on the nature of biological phenomena. It springs to the eye, however, that the tendency of living organisms is to organize their surroundings—that is to “produce” order where formerly there was disorder. Life then appears in some way to oppose the otherwise universal drive to disorder. Does it mean that living organisms do, or may violate the second law of thermodynamics?…’

scholarly journals A Study of Universal Thermodynamics in Brane World Scenario

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Saugata Mitra ◽  
Subhajit Saha ◽  
Subenoy Chakraborty
Keyword(s):  
Second Law Of Thermodynamics ◽  
Chaplygin Gas ◽  
Brane World ◽  
Second Law ◽  
Modified Chaplygin Gas ◽  
Thermodynamical Equilibrium ◽  
Brane Model ◽  
Generalized Second Law ◽  
Frw Model ◽  
The Universe

A study of Universal thermodynamics is done in the framework of RSII brane model and DGP brane scenario. The Universe is chosen as FRW model bounded by apparent or event horizon. Assuming extended Hawking temperature on the horizon, the unified first law is examined for perfect fluid (with constant equation of state) and Modified Chaplygin Gas model. As a result there is a modification of Bekenstein entropy on the horizons. Further the validity of the generalized second law of thermodynamics and thermodynamical equilibrium are also investigated.

scholarly journals VISCOUS DARK ENERGY AND GENERALIZED SECOND LAW OF THERMODYNAMICS

2010 ◽  
Vol 19 (07) ◽  
pp. 1205-1215 ◽  
Author(s):  
M. R. SETARE ◽  
A. SHEYKHI
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Time Evolution ◽  
Casimir Effect ◽  
Apparent Horizon ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Total Entropy ◽  
Generalized Second Law ◽  
The Universe

We examine the validity of the generalized second law of thermodynamics in a non-flat universe in the presence of viscous dark energy. First we assume that the universe is filled only with viscous dark energy. Then, we extend our study to the case where there is an interaction between viscous dark energy and pressureless dark matter. We examine the time evolution of the total entropy, including the entropy associated with the apparent horizon and the entropy of the viscous dark energy inside the apparent horizon. Our study shows that the generalized second law of thermodynamics is always protected in a universe filled with interacting viscous dark energy and dark matter in a region enclosed by the apparent horizon. Finally, we show that the the generalized second law of thermodynamics is fulfilled for a universe filled with interacting viscous dark energy and dark matter by taking into account the Casimir effect.

A unified picture of cosmological entropy on apparent horizon in F(R, G) gravity

2017 ◽  
Vol 32 (33) ◽  
pp. 1750182 ◽  
Author(s):  
Ali İhsan Keskin ◽  
Irfan Acikgoz
Keyword(s):  
Apparent Horizon ◽  
Second Law Of Thermodynamics ◽  
Hawking Temperature ◽  
Second Law ◽  
Field Equations ◽  
Frw Universe ◽  
Generalized Second Law ◽  
History Of ◽  
The Universe ◽  
Friedmann Robertson Walker

In this study, the validity of the generalized second law of thermodynamics (GSLT) has been investigated in F(R, G) gravity. We consider that the boundary of the universe is surrounded by an apparent horizon in the spatially flat Friedmann–Robertson–Walker (FRW) universe, and we take into account the Hawking temperature on the horizons. The unified solutions of the field equations corresponding to gravity theory have been applied to the validity of the GSLT frame, and in this way, both the solutions have been verified and all the expansion history of the universe has been shown in a unified picture.

A Scientific Reading of Levinas’ Response to Heidegger: The Redemptive Edge of Time

KronoScope ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 73-89
Author(s):  
David Grandy
Keyword(s):  
Nineteenth Century ◽  
Martin Heidegger ◽  
Emmanuel Levinas ◽  
Physical Science ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Arrow Of Time ◽  
Self Identity ◽  
Heat Death

AbstractIn responding to Martin Heidegger, Emmanuel Levinas characterized time as revelatory and redemptive. For Levinas, Heideggerian being was self-contained and self-identical, and therefore unable to generate the sense of novel possibility which occasions the fleeting present. Something similar to Heideggerian Being may be said to have taken hold in the nineteenth century with the development of thermodynamics. The second law of thermodynamics was portrayed as the “arrow of time” moving inevitably toward universal heat death—cosmic stasis or self-identity. I argue that modern physical science itself does not fully validate this portrayal. There are, at the metaphysical level, explanatory gaps or openings which suggest other, more hopeful possibilities. These openings, I submit, are analogous to the ruptures of otherness which Levinas identified with the generosity of being and time’s redemptive aspect.

Cosmology in scalar–tensor–vector theory via thermodynamics

2018 ◽  
Vol 33 (24) ◽  
pp. 1850137 ◽  
Author(s):  
Onur Siginc ◽  
Mustafa Salti ◽  
Hilmi Yanar ◽  
Oktay Aydogdu
Keyword(s):  
Apparent Horizon ◽  
Second Law Of Thermodynamics ◽  
Entropy Function ◽  
Second Law ◽  
Generalized Second Law ◽  
Vector Theory ◽  
Theory Of Gravity ◽  
The Universe ◽  
Non Equilibrium

Assuming the universe as a thermodynamical system, the second law of thermodynamics can be extended to another form including the sum of matter and horizon entropies, which is called the generalized second law of thermodynamics. The generalized form of the second law (GSL) is universal which means it holds both in non-equilibrium and equilibrium pictures of thermodynamics. Considering the universe is bounded by a dynamical apparent horizon, we investigate the nature of entropy function for the validity of GSL in the scalar–tensor–vector (STEVE) theory of gravity.

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