16,599 research outputs found

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

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    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.Comment: 13 page

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

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    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.Comment: I added an explicit analytical explanation in the section Quantum thermodynamic analysis of Brownian movemen

    Quantum Uncertainty and Nonlocality: Are they Correctly Understood?

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    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.Comment: 2 page

    Quantum Limits in Nanomechanical Systems

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    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.Comment: 2 page

    Thermodynamic and Quantum Thermodynamic Analyses of Brownian Movement

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    Thermodynamic and quantum thermodynamic analyses of Brownian movement of a solvent and a colloid passing through neutral thermodynamic equilibrium states only. It is shown that Brownian motors and E. coli do not represent Brownian movement

    Thermodynamic derivation of reciprocal relations

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    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.Comment: The only revision was an addition to the abstract. The paper remains the sam

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

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    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.Comment: 6 page

    iVAMS 1.0: Polynomial-Metamodel-Integrated Intelligent Verilog-AMS for Fast, Accurate Mixed-Signal Design Optimization

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    Electronic circuit behavioral models built with hardware description/modeling languages such as Verilog-AMS for system-level simulations are typically functional models. They do not capture the physical design (layout) information of the target design. Numerous iterations of post-layout design adjustments are usually required to ensure that design specifications are met with the presence of layout parasitics. In this paper a paradigm shift of the current trend is presented that integrates layout-level information in Verilog-AMS through metamodels such that system-level simulation of a mixed-signal circuit/system is realistic and as accurate as true parasitic netlist simulation. The simulations performed with these parasitic-aware models can be used to estimate system performance without layout iterations. We call this new form of Verilog-AMS as iVAMS (i.e. Intelligent Verilog-AMS). We call this iVAMS 1.0 as it is simple polynomial-metamodel integrated Intelligent Verilog-AMS. As a specific case study, a voltage-controlled oscillator (VCO) Verilog-AMS behavioral model and design flow are proposed to assist fast PLL design space exploration. The PLL simulation employing quadratic metamodels achieves approximately 10X speedup compared to that employing the layout extracted, parasitic netlist. The simulations using this behavioral model attain high accuracy. The observed error for the simulated lock time and average power dissipation are 0.7% and 3%, respectively. This behavioral metamodel approach bridges the gap between layout-accurate but fast simulation and design space exploration. The proposed method also allows much shorter design verification and optimization to meet stringent time-to-market requirements. Compared to the optimization using the layout netlist, the runtime using the behavioral model is reduced by 88.9%.Comment: 25 pages, 13 figure

    Computations with one and two real algebraic numbers

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    We present algorithmic and complexity results concerning computations with one and two real algebraic numbers, as well as real solving of univariate polynomials and bivariate polynomial systems with integer coefficients using Sturm-Habicht sequences. Our main results, in the univariate case, concern the problems of real root isolation (Th. 19) and simultaneous inequalities (Cor.26) and in the bivariate, the problems of system real solving (Th.42), sign evaluation (Th. 37) and simultaneous inequalities (Cor. 43)

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

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    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)
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