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Elias P. Gyftopoulos

Publications and source records attributed to Elias P. Gyftopoulos.

18 recordsLinked to original sources
arXiv2007

On Boltzmann's genius and thermodynamics

A recent essay [1] reminds us of how richly Boltzmann deserves to be admiringly commemorated for the originality of his ideas on the occasion of his 150th birthday. Without any doubt, the scientific community owes Boltzmann a great debt of gratitude for his ingenious and pathfinding contributions. However, the essay chooses to illustrate this important memorial by statements and inferences that perhaps are questionable today even to Boltzmann himself. I will comment only on three issues.

physics.hist-ph↗
arXiv2007

Remarks on Our Understanding of Quantum Mechanics

Interpretations of key concepts, such as uncertainty relations, kinetic energy, value of an observable, probability distributions, the projection or collapse of a wave function postulate, and discrete versus continuous values, that appear in several excellent textbooks on quantum mechanics are reviewed and found not to be consistent with our current understanding of quantum theory. Possible alternatives are suggested.

quant-ph↗
arXiv2007

Quantum Limits in Nanomechanical Systems

In two articles, the authors claim that the Heisenberg uncertainty principle limits the precision of simultaneous measurements of the position and velocity of a particle and refer to experimental evidence that supports their claim. It is true that ever since the inception of quantum mechanics, the uncertainty relation that corresponds to a pair of observables represented by non-commuting operators is interpreted by many scientists and engineers, including Heisenberg himself, as a limitation on the accuracy with which observables can be measured. However, such a limitation cannot be deduced from the postulates and theorems of quantum thermodynamics.

physics.gen-ph↗
arXiv2007

Comments on Extraction of Work from a Single Thermal Bath in the Quantum Regime

In a PRL [1], the authors claim to show that "the Clausius inequality can be violated, and that it is even possible to extract work from a thermal bath by cyclic variations of a parameter ("perpetuum mobile"), and that the physical cause for this behavior is traced back to quantum coherence in the presence of the nonequilibrium bath (sic)".

quant-ph↗
arXiv2007

Quantum Coherence Engines

In a report published in Science, Scully et al propose to generate "phaseonium", and "extract work from a single heat bath via vanishing coherence" [1]. On the basis of the laws of physics, such a proposal is futile for at least two reasons.

quant-ph↗
arXiv2007

Quantum Uncertainty and Nonlocality: Are they Correctly Understood?

In a brief article [1], Seife refers to works by Einstein and Schroedinger and concludes that there is a relentless murmur of confusion underneath the chorus of praise for quantum theory. It is noteworthy that a "murmur" is not necessarily a cause for replacement of any scientific theory, and that the issues raised by Einstein, Podolsky, and Rosen, and Schroedinger's responses to the EPR paper have been satisfactorily resolved by Gyftopoulos and von Spakovsky [2] in a manner that renders the relentless murmur mute and unwarranted.

quant-ph↗
arXiv2007

Comments on Violations of the Second Law

The authors of Ref. [1] claim to have experimental verification of violations of the second law of thermodynamics based on the assertions: (i) "for large systems and over long times the entropy production rate is necessarily positive"; (ii) Loschmidt's paradox interpreted as indicating that entropy production can be both positive and negative; (iii) and violations of the second law for small systems over short time scales predicted by the fluctuation theorem FT [2]. Neither the claim nor the assertions are correct.

quant-ph↗
arXiv2007

Comments on Controllable Three-Dimensional Brownian Motors

Upon reviewing the physical review letter which describes the processes involved in "demonstration of a controllable three-dimensional Brownian motor in symmetric potentials" we conclude that such processes are not compatible with what Einstein and many other physicists and engineers define as Brownian motors or Brownian movements.

quant-ph↗
arXiv2007

Comments on the Quantum Afterburner

A process has been proposed to increase the efficiency of an ideal Otto cycle via a quantum heat engine that has no cooler reservoir. We show that such a process is not feasible.

quant-ph↗
arXiv2007

On the lack of relation between physics and "Quantum discord and Maxwell's demons"

The information-theoretic arguments presented in a recent publication on "Quantum discord and Maxwell's demons" are discussed, and found not to address the problem specified by Maxwell. Two interrelated and definitive exorcisms of the demon, one purely thermodynamic, and the other quantum-thermodynamic are briefly discussed. For each of the two exorcisms, the demon is shown to be incapable to accomplish his assignment neither because of limitations arising from information-theoretic tools at his disposal, nor because of the value of his IQ. The limitations are due to the physics of the state of the system on which he is asked to perform his demonic acts.

quant-ph↗
arXiv2006

Thermodynamic and quantum thermodynamic answers to Einstein's concerns about Brownian movement

On the occasion of the 100th anniversary of the beginning of the revolutionary contributions to physics by Einstein, I am happy to respond to a problem posed by him in 1905. He said: In this paper it will be shown that according to the molecular-kinetic theory of heat, bodies of microscopically-visible size suspended in a liquid will perform movements of such magnitude that they can be easily observed in a microscope, on account of the molecular motions of heat....that is, Brownian molecular motion. In this article I provide incontrovertible evidence against molecular-kinetic conception of heat, and a regularization of the Brownian movement that differs from all the statistical procedures and/or analyses that exist in the archival literature to date. The regularization is based on either of two distinct but intimately interrelated revolutionary conceptions of thermodynamics, one is purely thermodynamic and the other is quantum mechanical.

quant-ph↗
arXiv2005

Entropy: An inherent, nonstatistical property of any system in any state

Entropy is the distinguishing and most important concept of our efforts to understand and regularize our observations of a very large class of natural phenomena, and yet, it is one of the most contentious concepts of physics. In this article, we review two expositions of thermodynamics, one without reference to quantum theory, and the other quantum mechanical without probabilities of statistical mechanics. In the first, we show that entropy is an inherent property of any system in any state, and that its analytical expression must conform to eight criteria. In the second, we recognize that quantum thermodynamics: (i) admits quantum probabilities described either by wave functions or by nonstatistical density operators; and (ii) requires a nonlinear equation of motion that is delimited by but more general than the Schroedinger equation, and that accounts for both reversible and irreversible evolutions of the state of the system in time. Both the more general quantum probabilities, and the equation of motion have been defined, and the three laws of thermodynamics are shown to be theorems of this equation.

quant-ph↗
arXiv2005

What is the second law of thermodynamics and are there any limits to its validity?

In the scientific and engineering literature, the second law of thermodynamics is expressed in terms of the behavior of entropy in reversible and irreversible processes. According to the prevailing statistical mechanics interpretation the entropy is viewed as a nonphysical statistical attribute, a measure of either disorder in a system, or lack of information about the system, or erasure of information collected about the system, and a plethora of analytic expressions are proposed for the various measures. In this paper, we present two expositions of thermodynamics (both 'revolutionary' in the sense of Thomas Kuhn with respect to conventional statistical mechanics and traditional expositions of thermodynamics) that apply to all systems (both macroscopic and microscopic, including single particle or single spin systems), and to all states (thermodynamic or stable equilibrium, nonequilibrium, and other states).

quant-ph↗
arXiv2004

Thermodynamic derivation of reciprocal relations

Reciprocal relations correlate fairly accurately a great variety of experimental results. Nevertheless, the concepts of statistical fluctuations, and microscopic reversibility - the bases of the accepted proof of the relations by Onsager - are illusory and faulty, and contradict the foundations of the science of thermodynamics. The definitions, postulates, and main theorems of thermodynamics are briefly presented. It is shown beyond a shadow of a doubt that thermodynamics is a nonstatistical science that applies to all systems (both macroscopic, and microscopic, including systems that consist either of only one structureless particle, or only one spin), to all states (both thermodynamic or stable equilibrium, and not stable equilibrium), and that includes entropy as a well defined, intrinsic, nonstatistical property of any system in any state, at any instant in time. In the light of this novel conception of thermodynamics, we find that reciprocal relations result from a well known mathematical theorem, to wit, given a well behaved analytic function of many variables then the second derivative of the function with respect to any two variables is independent of the order of differentiation, namely, whether the first derivative is taken with respect to the one or the other of the two variables.

physics.chem-ph↗
arXiv2004

Quantum Computation and Quantum Information: Are They Related to Quantum Paradoxology?

We review both the Einstein, Podolsky, Rosen (EPR) paper about the completeness of quantum theory, and Schrodinger's responses to the EPR paper. We find that both the EPR paper and Schrodinger's responses, including the cat paradox, are not consistent with the current understanding of quantum theory and thermodynamics. Because both the EPR paper and Schrodinger's responses play a leading role in discussions of the fascinating and promising fields of quantum computation and quantum information, we hope our review will be helpful to researchers in these fields.

quant-ph↗