arXiv subjects

Gerald E. Marsh

Publications and source records attributed to Gerald E. Marsh.

At least 19 recordsLinked to original sources

arXiv2025

Plasma Core Rocket Engines

The basic physics for plasma core rocket engines was already completed in 1985. At the time successful containment of a fissioning uranium hexafluoride U(93%)F6 plasma was achieved for ~120 seconds using an argon vortex. Unfortunately, hydrodynamic confinement of a fissioning fuel in a gas core nuclear rocket without uranium loss is probably unachievable. This article proposes a plasma core that is magnetically contained and uses one of many possible stable force-free magnetic field configurations.

physics.gen-ph↗

arXiv2024

The Origin of Dark Matter and the Cosmological Constant

The concept of exotic charged dust is introduced here to represent dark matter. The term "exotic" means that the dust is not composed of normal matter, and the charge--for lack of a better term--is not an electric charge. It is also shown that the often-used approximate expression for dark matter density corresponds to an exact solution of the coupled Einstein-Maxwell equations for charged dust. The Einstein field equations tells us is that for a flat universe the cosmological constant acts as a gravitating negative energy distribution that is gravitationally repulsive; following Schwinger, it is shown that the vacuum must have a negative energy spectrum if QFT is to be gauge invariant.

physics.gen-ph↗

arXiv2023

A Force-Free Magnetic Field Solution in Cyclidal Coordinates

There are no known analytic solutions to the force-free magnetic field equations in coordinates representing Dupin cyclides. The fact that the curvature lines of Dupin cyclides are all circles is used here to derive a force-free magnetic field on the surface of an elliptic Dupin cyclide.

physics.gen-ph↗

arXiv2023

A Force-Free Magnetic Field Solution in Toroidal Coordinates

While there are no known analytic solutions for force-free fields in toroidal coordinates, with a reasonable boundary condition it is possible to find a solution for the surface field and, with a restriction on the form of the field, to the interior of the torus as well.

physics.gen-ph↗

arXiv2022

Quantum Fluctuations, The Casimir Effect and The Historical Burden

It has been argued since 1948, when it was experimentally demonstrated, that the Casimir effect-where two non-charged conducting plates have a weak but measurable force on each other dependent on the inverse fourth power of the distance between them-shows the reality of vacuum zero-point fluctuations. This "proof" of the reality of vacuum fluctuations has been repeated in many quantum field theory books and papers subsequent to 1948. The attractive force is generally ascribed to the difference in zero-point energy of the electromagnetic field between the plates and the vacuum external to them. As is well known, zero-point vacuum fluctuations are incompatible with relativistic physics and are at the root of the "cosmological constant" problem. Most texts on quantum mechanics and quantum field theory eliminate the vacuum energy by normal ordering or some other mechanism. These issues are explored in this paper and it is pointed out that a means to resolve them already exists.

physics.gen-ph↗

arXiv2022

Thermodynamics and the Origin of Life

Modern developments in nonequilibrium thermodynamics have significant implications for the origins of life. The reasons for this are closely related to a generalized version of the second law of thermodynamics recently found for entropy production during irreversible evolution of a given system such as self-replicating RNA. This paper is intended to serve as an introduction to these developments.

physics.gen-ph↗

arXiv2020

Higher Order Lamb-Chaplygin Vortices, Chaplygin Antisymmetric Vortices, and Atmospheric Blocking

The equations describing the two-dimensional vortices first described by Chaplygin in 1899 and 1903 are shown to have solutions of higher order that differ from a simple dipole. It is also shown that for these higher-order vortices a very small asymmetry dramatically changes the topology of the stream function. These vortices could be important for understanding the phenomenon of atmospheric blocking.

physics.flu-dyn↗

arXiv2020

Irradiance Variations due to Orbital and Solar Inertial Motion: The Effect on Earth's Surface Temperature

Variation in total solar irradiance is thought to have little effect on the Earth's surface temperature because of the thermal time constant--the characteristic response time of the Earth's global surface temperature to changes in forcing. This time constant is large enough to smooth annual variations but not necessarily variations having a longer period such as those due to solar inertial motion; the magnitude of these surface temperature variations is estimated.

astro-ph.EP↗

arXiv2019

Strings, Topological Change and Dark Matter

Dark matter, first postulated by Jacobus Kapteyn in 1922 and later by Fritz Zwicky in 1933, has remained an enigma ever since proof of its existence was confirmed in 1970 by Vera Rubin and Kent Ford by plotting the rotation curve for the Andromeda galaxy. Here, some concepts from string theory and topological change in quantum cosmology are used to formulate a new model for dark matter. The density profiles of dark matter halos are often modeled as an approximate solution to the Lane-Emden equation. Using the model proposed here for dark matter, coupled with previous work showing that the approximate solution to the Lane-Emden equation can be an exact solution of the Einstein-Maxwell equations, provides a new insight into the possible nature of dark matter.

physics.gen-ph↗

arXiv2018

The Enigma of Saturn's North-Polar Hexagon

It has been suggested that the north-polar hexagon found on Saturn is an unusual Rossby wave. If this is to be the case, one must not only explain how a Rossby wave can be hexagonal in shape, albeit with curved corners, but also why it is hexagonal rather than in the form of some other polygon. It is likely that a spectrum of Rossby waves with different amplitudes and wavelengths resulting from the velocity profile of the hexagonal jet is responsible for its shape.

physics.ao-ph↗

arXiv2017

The Chiral Anomaly, Dirac and Weyl Semimetals, and Force-Free Magnetic Fields

The chiral anomaly is a purely quantum mechanical phenomenon that has a long history dating back to the late 1960s. Surprisingly, it has recently made a macroscopic appearance in condensed matter physics. A brief introduction to the relevant features of this anomaly is given and it is shown that its appearance in condensed matter systems must involve force-free magnetic fields, which may help explain the long current relaxation times in Dirac and Weyl semimetals.

physics.gen-ph↗

arXiv2016

The Particle Enigma

The idea that particles are the basic constituents of all matter dates back to ancient times and formed the basis of physical thought well into modern times. The debate about whether light was a wave or a stream of particles also lasted until relatively recently. It was the advent of de Broglie's work and its implications that revolutionized the concept of an elementary particle -- but unfortunately did not banish the idea of a point particle despite its difficulties in both classical and quantum physics. Some of these problems are discussed in this essay, which covers chiral oscillations, Penrose's "zigzag" picture of particles satisfying the Dirac equation, and some ideas derived from string theory.

physics.gen-ph↗

arXiv2014

Space-Time-Matter

This essay examines our fundamental conceptions of time, spacetime, the asymmetry of time, and the motion of a quantum mechanical particle. The concept of time has multiple meanings and these are often confused in the literature and must be distinguished if any light is to be thrown on this age-old issue. The asymmetry of time also has different meanings that depend on context-although the fundamental time asymmetry is associated with the expansion of the universe. These and related issues are discussed in both classical and quantum mechanical contexts.

gr-qc↗

arXiv2014

Rigid Rotation and the Kerr Metric

The Einstein field equations have no known and acceptable interior solution that can be matched to an exterior Kerr field. In particular, there are no interior solutions that could represent objects like the Earth or other rigidly rotating astronomical bodies. It is shown here that there exist closed surfaces upon which the frame-dragging angular velocity and the red-shift factor for the Kerr metric are constant. These surfaces could serve as a boundary between rigidly rotating sources for the Kerr metric and the Kerr external field.

gr-qc↗

arXiv2013

Seawater pH and Anthropogenic Carbon Dioxide

In 2005, the Royal Society published a report titled "Ocean acidification due to increasing atmospheric carbon dioxide". The report's principal conclusion-that average ocean pH could decrease by 0.5 units by 2100-is demonstrated here to be consistent with a linear extrapolation of very limited data. It is also shown that current understanding of ocean mixing, and of the relationship between pH and atmospheric carbon dioxide concentration, cannot justify such an extrapolation.

physics.gen-ph↗

arXiv2013

The Demystification of Emergent Behavior

Emergent behavior that appears at a given level of organization may be characterized as arising from an organizationally lower level in such a way that it transcends a mere increase in the behavioral degree of complexity. It is therefore to be distinguished from systems exhibiting chaotic behavior, for example, which are deterministic but unpredictable because of an exponential dependence on initial conditions. In emergent phenomena, higher-levels of organization are not determined by lower-levels of organization; or, more colloquially, emergent behavior is often said to be "greater than the sum of the parts". The concept plays an especially important but contentious role in the biological sciences. This essay is intended to demystify at least some aspects of the mystery of emergence.

physics.gen-ph↗

arXiv2012

The Problem of the "Prebiotic and Never Born Proteins"

It has been argued that the limited set of proteins used by life as we know it could not have arisen by the process of Darwinian selection from all possible proteins. This probabilistic argument has a number of implicit assumptions that may not be warranted. A variety of considerations are presented to show that the number of amino-acid sequences that need have been sampled during the evolution of proteins is far smaller than assumed by the argument.

physics.gen-ph↗

arXiv2011

Electromagnetic and Gravitational Waves: the Third Dimension

Plane electromagnetic and gravitational waves interact with particles in such a way as to cause them to oscillate not only in the transverse direction but also along the direction of propagation. The electromagnetic case is usually shown by use of the Hamilton-Jacobi equation and the gravitational by a transformation to a local inertial frame. Here, the covariant Lorentz force equation and the second order equation of geodesic deviation followed by the introduction of a local inertial frame are respectively used. It is often said that there is an analogy between the motion of charged particles in the field of an electromagnetic wave and the motion of test particles in the field of a gravitational wave. This analogy is examined and found to be rather limited. It is also shown that a simple special relativistic relation leads to an integral of the motion, characteristic of plane waves, that is satisfied in both cases.

physics.gen-ph↗