XIX. On the electromagnetic theory of the reflection and refraction of light

1880 ◽  
Vol 171 ◽  
pp. 691-711 ◽  
Keyword(s):  
Electromotive Force ◽  
Electric Displacement ◽  
Electromagnetic Theory ◽  
Point Of View ◽  
Electrostatic Energy ◽  
Magnetic Media ◽  
Reflection And Refraction ◽  
Electricity And Magnetism

In the second volume of his ‘Electricity and Magnetism’ Professor J. Clerk Maxwell has proposed a very remarkable electromagnetic theory of light, and has worked out‘ the results as far as the transmission of light through uniform crystalline and magnetic media are concerned, leaving the questions of reflection and refraction untouched. These, however, may be very conveniently studied from his point of view. If we call W the electrostatic energy of the medium, it may be expressed in terms of the electromotive force and the electric displacement at each point as is done in Professor Maxwell’s ‘Electricity and Magnetism,’ vol. ii., part iv., ch. 9. I shall adopt his notation and call the electromotive force and its components P, Q, R, and the electric displacement D and its components f, g, h . As several of the results of this paper admit of a very elegant expression in Quaternion notation I shall give the work and results in both Cartesian and Quaternion form, confining the German letters to the Quaternion notation. Between these quantities then we have the equation W = -1/2∭S D . dxdydz = 1/2∭(P f + Q y + R h ) dxdydz

GALILEO FERRARIS (1847-1897) TRA SCIENZA E TECNOLOGIA

Nuncius ◽  
1999 ◽  
Vol 14 (1) ◽  
pp. 121-132
Author(s):  
ARCANGELO ROSSI
Keyword(s):  
Induction Motor ◽  
Science And Technology ◽  
Electromagnetic Theory ◽  
Point Of View ◽  
Innovative Teaching ◽  
Practical Point ◽  
New Device ◽  
Electric Induction ◽  
Xix Century ◽  
Mathematical Physicist

Abstracttitle SUMMARY /title Galileo Ferraris (1847-1897), the most eminent Italian electrician in the last quarter of the XIX Century, is wrongly considered a pure technician who invented a new kind of electric induction motor. Instead, in introducing the new device, he also contributed, as a valuable mathematical physicist, to the deepening of Maxwell's electromagnetic theory itself, and, if ever, he did not draw all consequences of his invention from a practical point of view. Here are well exemplified the main characteristics of the beginning of Italian politechnical culture at the end of the XIX Century, which was also characterized by G. Ferrari's deep engagement in innovative teaching of electrical science and technology.

Models, structure, and generality in Clerk Maxwell’s theory of electromagnetism

2017 ◽  
Author(s):  
Olivier Darrigol
Keyword(s):  
Physical Theory ◽  
Electromagnetic Theory ◽  
System Of Equations ◽  
Structural Requirements ◽  
Electricity And Magnetism ◽  
Lagrangian Form ◽  
Gradual Development ◽  
William Thomson ◽  
Fundamental Equations ◽  
Lines Of Force

This article examines the gradual development of James Clerk Maxwell’s electromagnetic theory, arguing that he aimed at general structures through his models, illustrations, formal analogies, and scientific metaphors. It also considers a few texts in which Maxwell expounds his conception of physical theories and their relation to mathematics. Following a discussion of Maxwell’s extension of an analogy invented by William Thomson in 1842, the article analyzes Maxwell’s geometrical expression of Michael Faraday’s notion of lines of force. It then revisits Maxwell’s honeycomb model that he used to obtain his system of equations and the concomitant unification of electricity, magnetism, and optics. It also explores Maxwell’s view about the Lagrangian form of the fundamental equations of a physical theory. It shows that Maxwell was guided by general structural requirements that were inspired by partial and temporary models; these requirements were systematically detailed in Maxwell’s 1873 Treatise on electricity and magnetism.

scholarly journals III. On the reflection and refraction of light at the surface of a magnetised medium

1891 ◽  
Vol 49 (296-301) ◽  
pp. 76-78 ◽  
Keyword(s):  
Magnetic Force ◽  
Electromagnetic Theory ◽  
Theoretical Explanation ◽  
Reflection And Refraction ◽  
Polarised Light ◽  
Series Of Experiments ◽  
Polished Plate ◽  
Reflecting Surface

The object of the present paper is to endeavour to ascertain how far the electromagnetic theory of light, as at present developed, is capable of giving a theoretical explanation of Dr. Kerr’s experiments on the effect of magnetism on light. In first series of experiments, polarised light was reflected from the polished pole of an electromagnet, so that the lines of magnetic force were perpendicular to the reflecting surface; and in the second series, the light was reflected from a polished plate of soft iron laid upon the poles of a horseshoe electromagnet, so that the lines of magnetic force were parallel to the reflecting surface.

scholarly journals A rush to explore protein–ligand electrostatic interaction energy with Charger

2021 ◽  
Vol 77 (10) ◽  
pp. 1292-1304 ◽  
Author(s):  
Vedran Vuković ◽  
Theo Leduc ◽  
Zoe Jelić-Matošević ◽  
Claude Didierjean ◽  
Frédérique Favier ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Interaction Energy ◽  
Electrostatic Interaction ◽  
Glutathione Transferase ◽  
Multipole Moment ◽  
Point Of View ◽  
Electrostatic Energy ◽  
Electron Densities ◽  
Acta Cryst ◽  
Ligand Interaction

The mutual penetration of electron densities between two interacting molecules complicates the computation of an accurate electrostatic interaction energy based on a pseudo-atom representation of electron densities. The numerical exact potential and multipole moment (nEP/MM) method is time-consuming since it performs a 3D integration to obtain the electrostatic energy at short interaction distances. Nguyen et al. [(2018), Acta Cryst. A74, 524–536] recently reported a fully analytical computation of the electrostatic interaction energy (aEP/MM). This method performs much faster than nEP/MM (up to two orders of magnitude) and remains highly accurate. A new program library, Charger, contains an implementation of the aEP/MM method. Charger has been incorporated into the MoProViewer software. Benchmark tests on a series of small molecules containing only C, H, N and O atoms show the efficiency of Charger in terms of execution time and accuracy. Charger is also powerful in a study of electrostatic symbiosis between a protein and a ligand. It determines reliable protein–ligand interaction energies even when both contain S atoms. It easily estimates the individual contribution of every residue to the total protein–ligand electrostatic binding energy. Glutathione transferase (GST) in complex with a benzophenone ligand was studied due to the availability of both structural and thermodynamic data. The resulting analysis highlights not only the residues that stabilize the ligand but also those that hinder ligand binding from an electrostatic point of view. This offers new perspectives in the search for mutations to improve the interaction between the two partners. A proposed mutation would improve ligand binding to GST by removing an electrostatic obstacle, rather than by the traditional increase in the number of favourable contacts.

V. On the reflection and refraction of light

1894 ◽  
Vol 55 (331-335) ◽  
pp. 26-30
Keyword(s):  
Elastic Solid ◽  
Electromagnetic Theory ◽  
Ether Theory ◽  
Reflection And Refraction ◽  
Variable Layer

The object of this paper is to examine the consequences of supposing the transition between different refractive media to be effected continuously through a thin variable layer, to deduce expressions for the amplitudes and changes of phase of the reflected and refracted light, and to compare them with the results of experiments hitherto made on that subject. The theories examined are the elastic solid theories, both those assuming large velocities for the pressural wave, including Green’s, Voigt’s, and K. Pearson’s theories, and also Lord Kelvin’s contractile ether theory, and then the electromagnetic theory, in the form given by Hertz, which, it may be remarked, leads to the same equations as the contractile ether theory.

scholarly journals XI. On the refraction of plane polarized light at the surface of a uniaxal crystal

1882 ◽  
Vol 173 ◽  
pp. 595-620 ◽  
Keyword(s):  
Electromotive Force ◽  
Magnetic Force ◽  
Electric Displacement ◽  
Polarized Light ◽  
The Other ◽  
Magnetic Disturbance ◽  
Dielectric Media ◽  
Magnetic Theory ◽  
Electro Magnetic ◽  
Refracted Waves

The laws of the reflexion and refraction of polarized light at the surface of a crystal in accordance with the electro-magnetic theory of light have been discussed by Lorentz (Schlömilch Zeitschrift, vol. xxii.), Fitzgerald (Phil. Trans., Vol. 171, 1880), and myself (Proc. Camb. Phil. Society, 1881). When a plane wave of electro-magnetic disturbance falls on the surface of separation between two different dielectric media six equations of condition are obtained. Three of these express the conditions that the electric displacement perpendicular to the surface and the electromotive force along the surface should be the same in the two media, while the other three do the same for the magnetic force and displacement. In all cases the six equations reduce to only four. Let us suppose we know the amount and direction of the electric displacement in the incident wave. If both media are isotropic, these four equations give us the amounts and directions of the electric displacements in the reflected and refracted waves.

On Extreme Density of Data Storage in Patterned Magnetic Media

2000 ◽  
Vol 614 ◽  
Author(s):  
E. Meilikhov ◽  
B. Aronzon ◽  
B. Gurovich ◽  
E. Kuleshova
Keyword(s):  
Data Storage ◽  
Activation Barrier ◽  
Magnetic Moments ◽  
Thermal Relaxation ◽  
Exchange Interactions ◽  
Point Of View ◽  
Magnetic Media ◽  
Physical Point ◽  
Magnetization Relaxation ◽  
Negative Role

ABSTRACTA patterned magnetic medium is the next step to significantly increasing data storage density. To attain extreme density, it is necessary to deal with the smallest granules (each storing a bit of information) admissible from the physical point of view. It is well known that the volume of such granules, and their aspect ratio, have to be large enough to prevent thermally activated magnetization relaxation. However, these requirements are not exhaustive. A patterned recording medium is a set of closely-spaced, aligned magnetic granules, with the random (“up” and “down”) orientations of granules' magnetic moments. Though the exchange interactions between the granules may be neglected, there are long-range intergranular dipole-dipole interactions (DDI) which lead to significant lowering of activation barrier preventing thermal relaxation. Those interactions limit the acceptable density of ferromagnetic granules, and hence, reduce the extreme density of data storage. Our numerical calculations estimate the negative role of DDI for the particular case of a two-dimensional set of ellipsoidal magnetic granules and allow us to determine the extreme density of data storage.

Sign in / Sign up

Export Citation Format

Share Document