Histories, dynamical laws, and initial conditions −Invariance under time-reversibility and its failure in Markov processes, with application to the second law of thermodynamics and the past hypothesis

2020 ◽  
Vol 69 ◽  
pp. 26-31
Author(s):  
Elliott Sober
Keyword(s):  
Markov Processes ◽  
Initial Conditions ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Time Reversibility ◽  
The Past ◽  
Past Hypothesis

scholarly journals Dissipative-type theories for Bjorken and Gubser flows

2020 ◽  
Vol 35 (14) ◽  
pp. 2050074 ◽  
Author(s):  
Lucas Cantarutti ◽  
Esteban Calzetta
Keyword(s):  
Type Theory ◽  
Initial Conditions ◽  
Second Law Of Thermodynamics ◽  
Second Law

We use the dissipative-type theory (DTT) framework to solve for the evolution of conformal fluids in Bjorken and Gubser flows from isotropic initial conditions. The results compare well with both exact and other hydrodynamic solutions in the literature. At the same time, DTTs enforce the Second Law of thermodynamics as an exact property of the formalism, at any order in deviations from equilibrium, and are easily generalizable to more complex situations.

scholarly journals General Psychology Walks Again

2018 ◽  
Vol 26 (1) ◽  
pp. 74-96 ◽  
Author(s):  
Niels Engelsted
Keyword(s):  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Present Moment ◽  
Human Consciousness ◽  
Evolutionary Sequence ◽  
General Psychology ◽  
The Past ◽  
Herbert Spencer ◽  
History Of ◽  
Crisis Of Psychology

Explaining the role, importance, and basic layout of general psychology, the paper has two parts. In the first part, told as a ghost story, we visit the long history of general psychology and its usual absence, aka the crisis of psychology. Drawing on the insights of among others George Henry Lewes, Herbert Spencer, Karl Bühler, and Lev Vygotsky, a number of requirements are listed that the author believes are necessary for a general psychology. In the second part is sketched the author’s proposal for such a general psychology. Built on Aristotle’s taxonomy of bio-psyches, the proposal divides psychology into four subdomains, each in need of explanation. In evolutionary sequence: Sentience, which posits the psychological present moment or now. Intentionality, which posits the future. Mind, which posits the past. Human consciousness, which posits the view from without. Sentience remains unexplained. Intentionality is linked to the second law of thermodynamics. Mind is linked to REMS in mammals. Human consciousness is linked to a new understanding of human evolution in which all the defining attributes of the human being – society, consciousness, and language – arrive all at once and together.

scholarly journals NONEXISTENCE OF IRREVERSIBLE PROCESSES IN COMPACT SPACE–TIME

2007 ◽  
Vol 22 (32) ◽  
pp. 6227-6241 ◽  
Author(s):  
HOLGER B. NIELSEN ◽  
MASAO NINOMIYA
Keyword(s):  
Compact Space ◽  
Initial Conditions ◽  
Physical Space ◽  
Second Law Of Thermodynamics ◽  
Space Time ◽  
Classical Field ◽  
Irreversible Processes ◽  
Second Law ◽  
Field Equations ◽  
Time Direction

It is shown that if physical space–time were truly compact there would only be of the order-of-one solutions to the classical field equations with a weighting to be explained. But that would not allow any peculiar choice of initial conditions that could support a nontrivial second law of thermodynamics. We present a no-go theorem: irreversible processes would be extremely unlikely to occur for the almost unique solution for the intrinsically compact space–time world, although irreversible processes are well known to occur in general. What we assume here — the compact space–time — is that universe could not exist eternally. In other word if universe stays on forever (i.e. noncompact in time direction) our no-go theorem is not applicable.

scholarly journals Natural selection for least action

2008 ◽  
Vol 464 (2099) ◽  
pp. 3055-3070 ◽  
Author(s):  
Ville R.I Kaila ◽  
Arto Annila
Keyword(s):  
Natural Selection ◽  
Shortest Paths ◽  
Second Law Of Thermodynamics ◽  
Integral Form ◽  
Second Law ◽  
Least Action ◽  
The Past ◽  
New Findings ◽  
Principle Of Least Action ◽  
Selection For

The second law of thermodynamics is a powerful imperative that has acquired several expressions during the past centuries. Connections between two of its most prominent forms, i.e. the evolutionary principle by natural selection and the principle of least action, are examined. Although no fundamentally new findings are provided, it is illuminating to see how the two principles rationalizing natural motions reconcile to one law. The second law, when written as a differential equation of motion, describes evolution along the steepest descents in energy and, when it is given in its integral form, the motion is pictured to take place along the shortest paths in energy. In general, evolution is a non-Euclidian energy density landscape in flattening motion.

scholarly journals Thawing and freezing quintessence models: a thermodynamic consideration

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Tanima Duary ◽  
Ananda Dasgupta ◽  
Narayan Banerjee
Keyword(s):  
Scalar Field ◽  
Field Model ◽  
Second Law Of Thermodynamics ◽  
Matter Content ◽  
Second Law ◽  
Correct Description ◽  
Thermodynamic Consideration ◽  
Scalar Field Model ◽  
The Past ◽  
Generalized Second Law

Abstract Thawing and freezing quintessence models are compared thermodynamically. Both of them are found to disobey the generalized second law of thermodynamics. However, for freezing models, there is still a scope as this breakdown occurs in the past, deep inside the radiation dominated era, when a standard scalar field model with a pressureless matter is not a correct description of the matter content. The thawing model has a pathological breakdown in terms of thermodynamics in a finite future.

First and second laws of thermodynamics: relationship, “inconsistency”, hidden effects

2020 ◽  
pp. 63-73
Author(s):  
A. M. Savchenko ◽  
Yu. V. Konovalov ◽  
A. V. Laushkin
Keyword(s):  
Free Energy ◽  
Internal Energy ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Entropy Of Mixing ◽  
Ideal Mixing ◽  
Laws Of Thermodynamics ◽  
Relationship Of ◽  
The Relationship

The relationship of the first and second laws of thermodynamics based on their energy nature is considered. It is noted that the processes described by the second law of thermodynamics often take place hidden within the system, which makes it difficult to detect them. Nevertheless, even with ideal mixing, an increase in the internal energy of the system occurs, numerically equal to an increase in free energy. The largest contribution to the change in the value of free energy is made by the entropy of mixing, which has energy significance. The entropy of mixing can do the job, which is confirmed in particular by osmotic processes.

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.

First and Second Law Analysis of a Flat Plate Collector Working With Nanofluids

2018 ◽  
Author(s):  
M. T. Nitsas ◽  
I. P. Koronaki ◽  
L. Prentza
Keyword(s):  
Flat Plate ◽  
Second Law Of Thermodynamics ◽  
Climatic Conditions ◽  
Working Fluid ◽  
Second Law ◽  
Inlet Temperature ◽  
Water Tank ◽  
Systems Quality ◽  
Typical Day ◽  
Flat Plate Collector

The utilization of solar energy in thermal energy systems was and always be one of the most effective alternative to conventional energy resources. Energy efficiency is widely used as one of the most important parameters in order to evaluate and compare thermal systems including solar collectors. Nevertheless, the first law of thermodynamics is not solely capable of describing the quantitative and qualitative performance of such systems and thus exergy efficiency is used so as to introduce the systems’ quality. In this work, the performance of a flat plate solar collector using water based nanofluids of different nanoparticle types as a working fluid is analyzed theoretically under the climatic conditions in Greece based on the First and Second Law of Thermodynamics. A mathematical model is built and the model equations are solved iteratively in a MATLAB code. The energy and exergy efficiencies as well as the collector losses coefficient for various parameters such as the inlet temperature, the particles concentration and type are determined. Moreover, a dynamic model is built so as to determine the performance of a flat plate collector working with nanofluids and the useful energy that can be stored in a water tank. The exergy destruction and exergy leakage are determined for a typical day in summer during which high temperatures and solar intensity values are common for the Greek climate.

Sign in / Sign up

Export Citation Format

Share Document