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Bluff your way in the second law of thermodynamics
 STUD. HIST. PHIL. MOD. PHYS
, 2001
"... The aim of this article is to analyse the relation between the second law of thermodynamics and the socalled arrow of time. For this purpose, a number of different aspects in this arrow of time are distinguished, in particular those of time(a)symmetry and of (ir)reversibility. Next I review versio ..."
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Cited by 13 (2 self)
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The aim of this article is to analyse the relation between the second law of thermodynamics and the socalled arrow of time. For this purpose, a number of different aspects in this arrow of time are distinguished, in particular those of time(a)symmetry and of (ir)reversibility. Next I review versions of the second law in the work of Carnot, Clausius, Kelvin, Planck, Gibbs, Carathéodory and Lieb and Yngvason, and investigate their connection with these aspects of the arrow of time. It is shown that this connection varies a great deal along with these formulations of the second law. According to the famous formulation by Planck, the second law expresses the irreversibility of natural processes. But in many other formulations irreversibility or even timeasymmetry plays no role. I therefore argue for the view that the second law has nothing to do with the arrow of time.
Between classical and quantum
, 2008
"... The relationship between classical and quantum theory is of central importance to the philosophy of physics, and any interpretation of quantum mechanics has to clarify it. Our discussion of this relationship is partly historical and conceptual, but mostly technical and mathematically rigorous, inclu ..."
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Cited by 12 (3 self)
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The relationship between classical and quantum theory is of central importance to the philosophy of physics, and any interpretation of quantum mechanics has to clarify it. Our discussion of this relationship is partly historical and conceptual, but mostly technical and mathematically rigorous, including over 500 references. For example, we sketch how certain intuitive ideas of the founders of quantum theory have fared in the light of current mathematical knowledge. One such idea that has certainly stood the test of time is Heisenberg’s ‘quantumtheoretical Umdeutung (reinterpretation) of classical observables’, which lies at the basis of quantization theory. Similarly, Bohr’s correspondence principle (in somewhat revised form) and Schrödinger’s wave packets (or coherent states) continue to be of great importance in understanding classical behaviour from quantum mechanics. On the other hand, no consensus has been reached on the Copenhagen Interpretation, but in view of the parodies of it one typically finds in the literature we describe it in detail. On the assumption that quantum mechanics is universal and complete, we discuss three ways in which classical physics has so far been believed to emerge from quantum physics, namely
Thermodynamics and Garbage Collection
 In ACM Sigplan Notices
, 1994
"... INTRODUCTION Computer scientists should have a knowledge of abstract statistical thermodynamics. First, computer systems are dynamical systems, much like physical systems, and therefore an important first step in their characterization is in finding properties and parameters that are constant over ..."
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Cited by 11 (0 self)
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INTRODUCTION Computer scientists should have a knowledge of abstract statistical thermodynamics. First, computer systems are dynamical systems, much like physical systems, and therefore an important first step in their characterization is in finding properties and parameters that are constant over time (i.e., constants of motion). Second, statistical thermodynamics successfully reduces macroscopic properties of a system to the statistical behavior of large numbers of microscopic processes. As computer systems become large assemblages of small components, an explanation of their macroscopic behavior may also be obtained as the aggregate statistical behavior of its component parts. If not, the elegance of the statistical thermodynamical approach can at least provide inspiration for new classes of models. 1 Third, the components of computer systems are approaching the same size as the microscopic pr
Inertial mass and the quantum vacuum fields
 Annalen der Physik
"... Abstract — Even when the Higgs particle is finally detected, it will continue to be a legitimate question to ask whether the inertia of matter as a reaction force opposing acceleration is an intrinsic or extrinsic property of matter. General relativity specifies which geodesic path a free particle w ..."
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Abstract — Even when the Higgs particle is finally detected, it will continue to be a legitimate question to ask whether the inertia of matter as a reaction force opposing acceleration is an intrinsic or extrinsic property of matter. General relativity specifies which geodesic path a free particle will follow, but geometrodynamics has no mechanism for generating a reaction force for deviation from geodesic motion. We discuss a different approach involving the electromagnetic zeropoint field (ZPF) of the quantum vacuum. It has been found that certain asymmetries arise in the ZPF as perceived from an accelerating reference frame. In such a frame the Poynting vector and momentum flux of the ZPF become nonzero. Scattering of this quantum radiation by the quarks and electrons in matter can result in an accelerationdependent reaction force. Both the ordinary and the relativistic forms of Newton’s second law, the equation of motion, can be derived from the electrodynamics of such ZPFparticle interactions. Conjectural arguments are given why this interaction should take place in a resonance at the Compton frequency, and how this could simultaneously provide a physical basis for the de Broglie wavelength of a moving particle. This affords a suggestive perspective on a deep connection between electrodynamics, the origin of inertia and the quantum wave nature of matter. Keywords — quantum vacuum — mass — zeropoint field — inertia — gravitation — stochastic electrodynamics 1
Carnot cycle for an oscillator
"... Carnot established in 1824 that the efficiency of cyclic engines operating between a hot bath at absolute temperature Thot and a cold bath at temperature Tcold cannot exceed 1−Tcold/Thot. This result implies the existence of an entropy function S(U) with the property that d 2 S/dU 2 ≤ 0, where U den ..."
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Cited by 2 (0 self)
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Carnot established in 1824 that the efficiency of cyclic engines operating between a hot bath at absolute temperature Thot and a cold bath at temperature Tcold cannot exceed 1−Tcold/Thot. This result implies the existence of an entropy function S(U) with the property that d 2 S/dU 2 ≤ 0, where U denotes the average energy. Linear singlemode systems alternately in contact with hot and cold baths obey these principles. A specific expression of the work done per cycle by an oscillator is derived from a prescription established by Einstein in 1906: heat baths may exchange energy with oscillators at angular frequency ω only by amounts �ω, where 2π � denotes the Planck constant. Nonreversible cycles are illustrated. The paper is essentially selfcontained.
Rate equation theory of subPoissonian laser light
 Opt. Quantum Electron
, 2002
"... Abstract. Lasers essentially consist of singlemode optical cavities containing twolevel atoms with a supply of energy called the pump and a sink of energy, perhaps an optical detector. The latter converts the light energy into a sequence of electrical pulses corresponding to photodetection events. ..."
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Cited by 2 (2 self)
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Abstract. Lasers essentially consist of singlemode optical cavities containing twolevel atoms with a supply of energy called the pump and a sink of energy, perhaps an optical detector. The latter converts the light energy into a sequence of electrical pulses corresponding to photodetection events. It was predicted in 1984 on the basis of Quantum Optics and verified experimentally shortly thereafter that when the pump is nonfluctuating the emitted light does not fluctuate much. Precisely, this means that the variance of the number of photodetection events observed over a sufficiently long period of time is much smaller than the average number of events. Light having that property is said to be “subPoissonian”. The theory presented rests on the concept introduced by Einstein around 1905, asserting that matter may exchange energy with a wave at angular frequency ω only by multiples of �ω. The optical field energy may only vary by integral multiples of �ω as a result of matter quantization and conservation of energy. A number of important results relating to isolated optical cavities containing twolevel atoms are first established on the basis of the laws of Statistical Mechanics. Next, the laser system with a pump and an absorber of radiation is treated. The expression of the photocurrent spectral density found in that manner coincides with the Quantum Optics result. The concepts employed in this paper are intuitive and the algebra is elementary. The paper supplements a previous tutorial paper (Arnaud, 1995) in establishing a connection between the theory of laser noise and Statistical Mechanics.
The ZeroPoint Field and the NASA Challenge to Create the Space Drive
, 1997
"... This NASA Breakthrough Propulsion Physics Workshop seeks to explore concepts that could someday enable interstellar travel. The effective superluminal motion proposed by Alcubierre (1994) to be a possibility owing to theoretically allowed spacetime metric distortions within general relativity has s ..."
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This NASA Breakthrough Propulsion Physics Workshop seeks to explore concepts that could someday enable interstellar travel. The effective superluminal motion proposed by Alcubierre (1994) to be a possibility owing to theoretically allowed spacetime metric distortions within general relativity has since been shown by Pfenning and Ford (1997) to be physically unattainable. A number of other hypothetical possibilities have been summarized by Millis (1997). We present herein an overview of a concept that has implications for radically new propulsion possibilities and has a basis in theoretical physics: the hypothesis that the inertia and gravitation of matter originate in electromagetic interactions between the zeropoint field (ZPF) and the quarks and electrons constituting atoms. A new derivation of the connection between the ZPF and inertia has been carried through that is properly covariant, yielding the relativistic equation of motion from Maxwell’s equations. This opens new possibilites, but also rules out the basis of one hypothetical propulsion mechanism: Bondi’s “negative inertial mass, ” appears to be an impossibility. The objective of this NASA Breakthrough Propulsion Physics Workshop is to explore ideas ranging from extrapolations of known technologies to hypothetical new physics which could someday lead to means for interstellar travel. One concept that has generated interest is the proposal by Alcubierre (1994) that effectively
Manyminds Quantum Mechanics
"... 1.1 Schrödinger and his Equation.................. 5 1.2 The Copenhagen Interpretation................. 6 ..."
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1.1 Schrödinger and his Equation.................. 5 1.2 The Copenhagen Interpretation................. 6
A Model for the Stochastic Origins of Schrödinger’s Equation
 Journal of Mathematical Physics
, 1979
"... A model for the motion of a charged particle in the vacuum is presented which, although purely classical in concept, yields Schrödinger’s equation as a solution. It suggests that the origins of the peculiar and nonclassical features of quantum mechanics are actually inherent in a statistical descrip ..."
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A model for the motion of a charged particle in the vacuum is presented which, although purely classical in concept, yields Schrödinger’s equation as a solution. It suggests that the origins of the peculiar and nonclassical features of quantum mechanics are actually inherent in a statistical description of the radiative reactive force. 1