## About

30

Publications

49,424

Reads

**How we measure 'reads'**

A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more

86

Citations

Citations since 2017

Introduction

Jack Denur is an alumnus of the Department of Physics, University of North Texas. Jack does research in Thermodynamics. The most recent publication is 'Pressure Gradient, Power, and Energy of Vortices'.

**Skills and Expertise**

## Publications

Publications (30)

Perfect (reversible) cyclic heat engines operate at Carnot efficiency. Perfect reversible) nonheat engines and noncyclic heat engines operate at unit (100%) efficiency. But a usually necessary, although not always sufficient, requirement to achieve reversibility is that an engine must operate infinitely slowly, i.e., quasi-statically. And infinitel...

The efficiencies of heat-engine operation employing various numbers (≥ 2) of heat reservoirs are investigated. Operation with the work output of the heat engines sequestered, as well as with it being totally frictionally dissipated, is discussed. We consider mainly heat engines whose efficiencies depend on ratios of a higher and lower temperature o...

Catalysis is usually construed to facilitate equilibrium being attained more easily and quickly, or occasionally less so (anticatalysis), but not to alter the position of equilibrium, i.e., not to alter the equilibrium constant. Indeed, it is sometimes stated that if catalysis could alter , then it could be employed to violate the Second Law of The...

By accounting for the curvature of the Earth, we try to correct the overestimate of sky-brightness of the near-horizon sky at midtotality that is provided by the first-order-scattering model developed by Stanley David Gedzelman (Ref. 1). We also attempt an approximate empirical merger of Gedzelman's model and the second-order scattering model of Gl...

We consider first the absolute zero of temperature and then negative Kelvin temperatures. The unattainability formulation of the Third Law of Thermodynamics is briefly reviewed. It puts limitations on the quest for absolute zero, and in its strongest mode forbids the attainment of absolute zero by any method whatsoever. But typically it is stated p...

The Planck system of units has been recognized as the most fundamental such system in physics ever since Dr. Max Planck first derived it in 1899. The Planck system of units in general, and especially the Planck power in particular, suggest a simple and interesting cosmological model. Perhaps this model may at least to some degree represent the real...

The randomness of Brownian motion at thermodynamic equilibrium can be spontaneously broken by velocity‐dependence of fluctuations, i.e., by dependence of values or probability distributions of fluctuating properties on Brownian‐motional velocity. Such randomness‐breaking can spontaneously obtain via interaction between Brownian‐motional Doppler eff...

The second law of thermodynamics states that processes yielding work or at least capable of yielding work are thermodynamically spontaneous, and that those costing work are thermodynamically nonspontaneous. Whether a process yields or costs heat is irrelevant. Condensation of water vapor yields work and hence is thermodynamically spontaneous only i...

Energy fluctuations in a single classical degree of freedom above the ground state at thermodynamic equilibrium at temperature T are typically of average magnitude {approx}k{sub B}T. However, we show that the average magnitude of such fluctuations can be much larger (or much smaller) than k{sub B}T, indeed, that at least in principle it can be infi...

A system's entropy is maximized not when it is localized in its most
probable macrostate, but when it is in its most probable distribution of
macrostates. This distribution includes all macrostates, including,
albeit typically with much smaller probability than the most probable
macrostate, those far removed from the most probable one. It is this
d...

The thermodynamics of the hurricane--Nature's steam engine--presents surprising contrasts with that of the steam locomotive. The hurricane rejects not only its waste heat at the lowest available temperature (as all heat engines must do to maximize efficiency), but also its work (that is, the kinetic energy of its winds) via frictional dissipation a...

We employ the energy-time uncertainty principle to provide heuristic yet helpful insights into tunneling, Unruh radiation, the Schwinger effect, and the ground state of the electromagnetic field. Nonrelativistic, special-relativistic, and (hypothetical) tachyonic tunneling are discussed. The position-momentum uncertainty principle is employed in au...

We show that the velocity distribution in rarefied (i.e., Knudsen) gases is spontaneously weighted in favor of small speeds
away from the Maxwellian distribution corresponding to the temperature of the container walls—despite thermodynamic equilibrium
with the walls. The consequent paradox concerning the second law of thermodynamics is discussed.

DOI:https://doi.org/10.1103/PhysRevA.41.3390.2

Any object in thermodynamic equilibrium (TEQ) with a heat bath executes thermal (Brownian) motion. This motion is completely random; i.e., the object is equally likely to move in any direction. This motion is completely random because TEQ is the state of maximum randomness (maximum entropy). In this paper, we prove that if the value of an appropria...

A charged parallel-plate vacuum capacitor moves uniformly through an inertial frame. Its field energy alone does not transform according to the familiar law ``energy=gamma× rest energy.'' However, when the stresses in the supports are taken into account, the entire system does satisfy this relation.

Equilibrium blackbody radiation, like all radiation, is, in general, Doppler shifted if it is emitted and/or reflected from a moving body. The relevance of this fact to the analysis of Maxwell's demon, which has been previously neglected, is revealed in this paper. In particular, we find that, by appropriately taking advantage of this fact, Maxwell...

## Questions

Questions (7)

Noether’s Theorem associates a symmetry property with each and every conservation law. For example, according to the usual interpretation of Noether’s Theorem, the time symmetry, i.e., the temporal uniformity, of the laws of physics compels the law of conservation of energy (and vice versa), the spatial symmetry, i.e., the spatial uniformity, of the laws of physics compels the law of conservation of linear momentum (and vice versa), etc. Noether’s Theorem seems to imply that the penalty for violating energy conservation would be the breaking of the temporal uniformity of the laws of physics, that the penalty for violating linear-momentum conservation would be the breaking of the spatial uniformity of the laws of physics, etc. But can Noether’s Theorem be bought off cheaply? Suppose, if only as a thought experiment, that a book of mass m on a desk spontaneously rose through a height h to the ceiling. Not got cooler and rose to the ceiling in violation of the Second Law of Thermodynamics, but just rose to the ceiling in violation of the First Law (energy conservation), with nascent energy mgh created from nothing. Could Noether’s Theorem accept payment in the cheap currency of a new

*initial condition*on the Universe (this additional nascent energy mgh) instead of the expensive currency of breaking of the temporal uniformity of the laws of physics — leaving the temporal uniformity of the laws of physics intact in a Universe modified*only*by the new*initial condition*of this extra nascent energy mgh? (Changing the laws of physics too much would be a death sentence!) In this regard, note that NASA considered the EM and MEGA drives, which claim to violate the law of conservation of linear momentum, seriously enough to fund testing of them. As of this writing, the EM drive seems to have been refuted but the MEGA drive still seems to be under consideration. NASA did not, and does not, seem concerned about Noether’s Theorem. Perhaps NASA’s opinion is that Noether’s Theorem*can*be bought off cheaply — accepting payment in the cheap currency of new initial conditions.Dark matter interacts with ordinary matter (and ordinary energy) via gravity (G), but not via electromagnetism (E), the strong nuclear force (S), or the weak nuclear force (W). But is

*totally*dark matter that does not interact with ordinary matter (and ordinary energy)*at all*,*not even via gravity (G)*, possible or impossible? If*totally*dark matter is possible, could there be other Universes with their own sets of forces (G´, E´, S´, W´), (G´´, E´´, S´´, W´´), etc., coexistent with our own (G, E, S, W) Universe, with each such Universe (including our own) interacting within itself but not with the other Universes? Is this a possible or impossible aspect of the Multiverse?Some theories of physics

*require*(not merely allow) magnetic monopoles. [See, for example, David J. Griffiths, Introduction to Electrodynamics, Fourth (Kindle) Edition (Cambridge University Press, Cambridge, UK, 2017.] But how can a theory that*requires*(not merely allows) magnetic monopoles be consistent with the fact that magnets with circular magnetic fields — and hence with*no*poles (neither a north pole nor a south pole) — exist? Two examples: (i) A horseshoe iron, alnico, or other permanent magnet bent into a circle, with the poles cold-welded together. (Cold welding is possible in a vacuum for surfaces planed very smooth.) (ii) A toroidal-solenoid electromagnet (with or without an enclosed iron core for increased strength). The magnetic field lines in such magnets are circular — and hence with*no*poles — neither a north pole nor a south pole.I have Scientific WorkPlace 5.5 from MacKichan Software. But after 40 years of providing excellent products and service, MacKichan Software is no longer in business. Are there any other companies that can provide support for Scientific WorkPlace?