Note on the Antecedents of Clerk-Maxwell's Electrodynamical-Wave-Equations

1895 ◽  
Vol 20 ◽  
pp. 213-214 ◽  
Author(s):  
Tait
Keyword(s):  
Maxwell’S Equations ◽  
Wave Equations ◽  
Maxwell's Equations ◽  
Magnetic Force ◽  
Elastic Solid ◽  
Point Of View ◽  
Polarised Light ◽  
The Way

The first obvious difficulty which presents itself, in trying to derive Clerk-Maxwell's equations from those of the elastic-solid theory, appears in the fact that the latter, being linear, do not impose any relations among simultaneous disturbances. Thus, for instance, they indicate no reason for the associated disturbances which, in Maxwell's theory, constitute a ray of polarised light. Hence it appears that we must look on the vectors of electric and magnetic force, if they are to be accounted for on ordinary dynamical principles, as being necessary concomitants, qualities, or characteristics of one and the same vector-disturbance of the ether, and not themselves primarily disturbances. From this point of view the disturbance, in itself, does not correspond to light, and may perhaps not affect any of our senses. And the very form of the elastic equation at once suggests any number of sets of two concomitants of the desired nature, which are found to be related to one another in the way required by Maxwell's equations.

XXVI.—On a Polarised Light Quantum

1927 ◽  
Vol 46 ◽  
pp. 306-313
Author(s):  
J. M. Whittaker
Keyword(s):  
Electromagnetic Waves ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Point Of View ◽  
Light Quantum ◽  
Electric Force ◽  
Polarised Light

In the theory of radiation recently advanced by Sir J. J. Thomson it is supposed that electromagnetic waves and quanta are both present in a beam of light. The quanta, which are responsible for the photoelectric effects, are closed rings of electric force propagated in the direction normal to the plane of the ring. Professor Whittaker has discussed this conception from the point of view of Maxwell's equations, and has shown that it is consistent with them ; or rather with an extension of them in which a magnetic density μ analogous to the electric density ρ is introduced.

WAVE AND MAXWELL'S EQUATIONS IN CARNOT GROUPS

2012 ◽  
Vol 14 (05) ◽  
pp. 1250032 ◽  
Author(s):  
BRUNO FRANCHI ◽  
MARIA CARLA TESI
Keyword(s):  
Vector Potential ◽  
Maxwell’S Equations ◽  
Wave Equations ◽  
Maxwell's Equations ◽  
Evolution Equations ◽  
Differential Forms ◽  
Higher Order ◽  
Carnot Groups ◽  
New Class ◽  
Euclidean Setting

In this paper we define Maxwell's equations in the setting of the intrinsic complex of differential forms in Carnot groups introduced by M. Rumin. It turns out that these equations are higher-order equations in the horizontal derivatives. In addition, when looking for a vector potential, we have to deal with a new class of higher-order evolution equations that replace usual wave equations of the Euclidean setting and that are no more hyperbolic. We prove equivalence of these equations with the "geometric equations" defined in the intrinsic complex, as well as existence and properties of solutions.

scholarly journals Extension of the electrodynamics in the presence of the axion and dark photon

2019 ◽  
Vol 34 (03n04) ◽  
pp. 1950012 ◽  
Author(s):  
Fa Peng Huang ◽  
Hye-Sung Lee
Keyword(s):  
Magnetic Field ◽  
Maxwell’S Equations ◽  
Wave Equations ◽  
Maxwell's Equations ◽  
Dark Photon

We present the extended electrodynamics in the presence of the axion and dark photon. We derive the extended versions of Maxwell’s equations and dark Maxwell’s equations (for both massive and massless dark photons) as well as the wave equations. We discuss the implications of this extended electrodynamics including the enhanced effects in the particle conversions under the external magnetic or dark magnetic field. We also discuss the recently reported anomaly in the redshifted 21 cm spectrum using the extended electrodynamics.

Homogeneous dynamos and terrestrial magnetism

1954 ◽  
Vol 247 (928) ◽  
pp. 213-278 ◽  
Keyword(s):  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Point Of View ◽  
Hydrodynamic Equations ◽  
Dynamo Theory ◽  
Homogeneous Fluid ◽  
Terrestrial Magnetism ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Linear Differential

The main object of the paper is to discuss the possibility of a body of homogeneous fluid acting as a self-exciting dynamo. The discussion is for the most part confined to the solution of Maxwell’s equations for a sphere of electrically conducting fluid in which there are specified velocities. Solutions are obtained by expanding the velocity and the fields in spherical harmonics to give a set of simultaneous linear differential equations which are solved by numerical methods. Solutions exist when harmonics up to degree four are included. The convergence of the solutions when more harmonics are included is discussed, but convergence has not been proved. The simultaneous solution of Maxwell’s equations and the hydrodynamic equations has not been attempted, but a velocity system has been chosen that seems reasonable from a dynamical point of view. A parameter in the velocity system has been adjusted to satisfy the conservation of angular momentum in a rough way. Orders of magnitude are derived for a number of quantities connected with the dynamo theory of terrestrial magnetism. It is concluded that the dynamo theory does provide a self-consistent account of the origin of the earth’s magnetic field and raises no insuperable difficulties in other directions.

Some applications of Maxwell’s equations in matter

2018 ◽  
Author(s):  
J. Pierrus
Keyword(s):  
Electromagnetic Field ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Differential Forms ◽  
Geometrical Optics ◽  
Time Dependent ◽  
Matching Conditions ◽  
The Way

This chapter comprises questions of a miscellaneous nature. They mostly have little in common except that all processes are time-dependent and occur within matter. The first few questions introduce some important preliminaries. For example, modifying Maxwell’s equations to include the effect of matter. The behaviour of the electromagnetic field at the boundary between two media having different properties is an important topic. The matching conditions (as they are known) are derived from both the integral and differential forms of Maxwell’s equations. Certain specific examples then follow, including some simple applications involving conductors, dielectrics and tenuous electronic plasmas. Along the way, the connection between Maxwell’s electrodynamics and the laws of geometrical optics is demonstrated explicitly.

A theory of magnetic-like fields for viscoelastic fluids

2019 ◽  
Vol 865 ◽  
pp. 460-491
Author(s):  
Thibault Vieu ◽  
Innocent Mutabazi
Keyword(s):  
Magnetic Field ◽  
Stress Tensor ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Viscoelastic Fluids ◽  
Point Of View ◽  
Viscoelastic Flows ◽  
Maxwell Stress Tensor ◽  
Viscoelastic Instability ◽  
Theoretical Issues

We formulate the Oldroyd-B model for viscoelastic fluids in terms of magnetic-like fields obeying a set of equations analogous to Maxwell’s equations. In the limit of infinite relaxation time for the polymer, the polymeric stress tensor can be identified with the Maxwell stress tensor of a magnetic field. Away from this asymptotic case, the stress tensor of the polymer cannot be decomposed in terms of a tensor product of a magnetic field any more and several theoretical issues arise. We show that the analogy between the Oldroyd-B model and Maxwell’s equations can still be rigorously extended provided that one defines three magnetic-like fields obeying Maxwell’s equations with magnetic currents and charges. This solves the theoretical caveats and leads to a better understanding of the viscoelastic instability. In particular, we evidence a gauge symmetry which unifies some previous works, and we investigate several gauge choices. As an illustration we apply our method to viscoelastic Taylor–Couette flow but this theory of ‘viscoelastic fields’ is general and may be useful in a large variety of viscoelastic flows. The present study may also be of interest from the electromagnetic point of view, as it provides real systems possessing magnetic-like charges (monopoles) and currents.

scholarly journals Internal stabilization of Maxwell's equations in heterogeneous media

2005 ◽  
Vol 2005 (7) ◽  
pp. 791-811 ◽  
Author(s):  
Serge Nicaise ◽  
Cristina Pignotti
Keyword(s):  
Maxwell’S Equations ◽  
Wave Equations ◽  
Maxwell's Equations ◽  
Heterogeneous Media ◽  
Space Variable ◽  
Smooth Boundary ◽  
Variable Coefficients ◽  
Bounded Region ◽  
Scalar Wave ◽  
Internal Stabilization

We consider the internal stabilization of Maxwell's equations with Ohm's law with space variable coefficients in a bounded region with a smooth boundary. Our result is mainly based on an observability estimate, obtained in some particular cases by the multiplier method, a duality argument and a weakening of norm argument, and arguments used in internal stabilization of scalar wave equations.

scholarly journals Formulation of Time-Fractional Electrodynamics Based on Riemann-Silberstein Vector

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 987
Author(s):  
Tomasz P. Stefański ◽  
Jacek Gulgowski
Keyword(s):  
Wave Propagation ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Momentum Conservation ◽  
Point Of View ◽  
Classical Electrodynamics ◽  
Classical Solutions ◽  
Systems With Memory ◽  
Energy And Momentum ◽  
With Memory

In this paper, the formulation of time-fractional (TF) electrodynamics is derived based on the Riemann-Silberstein (RS) vector. With the use of this vector and fractional-order derivatives, one can write TF Maxwell’s equations in a compact form, which allows for modelling of energy dissipation and dynamics of electromagnetic systems with memory. Therefore, we formulate TF Maxwell’s equations using the RS vector and analyse their properties from the point of view of classical electrodynamics, i.e., energy and momentum conservation, reciprocity, causality. Afterwards, we derive classical solutions for wave-propagation problems, assuming helical, spherical, and cylindrical symmetries of solutions. The results are supported by numerical simulations and their analysis. Discussion of relations between the TF Schrödinger equation and TF electrodynamics is included as well.

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