scholarly journals On the electromagnetic fields due to variable electric charges and the intensities of spectrum lines according to quantum theory

1935 ◽  
Vol 148 (864) ◽  
pp. 453-470
Keyword(s):  
Quantum Theory ◽  
Electromagnetic Fields ◽  
The Other ◽  
Spatial Extent ◽  
Classical Formula ◽  
Electric Moment ◽  
Spectrum Line ◽  
Usual Procedure ◽  
The One ◽  
Rigorous Method

1. During 1933 two papers with the above title, the one by Schott and the other by Fock, were published. Schott in his paper criticizes the usual procedure adopted in the Quantum Theory for the estimation of the intensities of a spectrum line according to the classical formula of Hertz, viz.., 2 p ..2 /3 c 3 , where p is the electric moment of the distribution producing the spectrum line, which necessarily assumes that the distribution can be concentrated in a dipole of the same moment p. In view of this criticism he develops a more rigorous method for calculating the electromagnetic fields due to variable electric charges. His method is based upon Maxwell's theory, as represented by his elctromagnetic equations and their solutions in terms of the classical retarded potential integrals and no initial assumptions are made respecting the spatial extent or the rate of variation of the electric distributions considered.

scholarly journals Statistical experiments on the motion of electrons in gases

1928 ◽  
Vol 119 (782) ◽  
pp. 335-348 ◽  
Keyword(s):  
High Pressure ◽  
Quantum Theory ◽  
The Other ◽  
Metastable States ◽  
Free Electrons ◽  
Critical Potential ◽  
Statistical Experiments ◽  
The Subject ◽  
The One

While the Quantum Theory is now almost universally accepted as the basis of discussion, when any question of energy-interchanges between molecules and free electrons is being considered, there is one collection of papers, of quite appreciable extent, that claims to treat part of the subject on totally different assumptions; these are the papers describing experiments performed in the laboratory of Prof. Townsend in Oxford. They do not claim to account for any of the results obtained by investigators elsewhere, but they do claim to have established phenomena which it is quite impossible to fit into the otherwise universally accepted views, and which necessitate, or at least justify, a number of different assumptions which Prof. Townsend formulates. The position can only be cleared up by reconciling the experiments of the one party with the theories of the other, and it is this task which will here be attempted. The experiments to be considered are of a quite different type from those which claimed to establish the existence of critical potentials; moreover, if the Quantum Theory statements are broadly correct, they are of a type unsuited to the problem. None the less, they would probably have led unaided, if not to the same conclusions, at least to the discovery of their own unsuitability, if it had not been for a somewhat unfortunate coincidence. This is, to put it briefly, the fact that the term-systems of the principal gases studied contain metastable states among their lowest excited levels. This fact is relatively unimportant in the critical potential work, but effects an enormous, and apparently quite unsuspected, disturbance when statistical high-pressure methods are employed, as is always the case in the work of Prof. Townsend.

scholarly journals Application of Johnson distributions to describe noise in the problem of information protection from leakage due to the side electromagnetic fields of the USB keyboard

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
A. S. Chechko ◽  
Keyword(s):  
Electromagnetic Fields ◽  
Personal Computer ◽  
Computer Technology ◽  
Random Processes ◽  
The Other ◽  
Information Protection ◽  
Complete Protection ◽  
Negative Effects ◽  
Useful Signal ◽  
The One

The problem of the description of artificially present industrial noises which are available at operation of personal computers is considered in work. These noises have both positive and negative effects when protecting the information typed by the user by means of the USB keyboard interface. The difficulties that arise in this case are due to the fact that the indirect radiation of electromagnetic fields is observed during the operation of all elements of computer technology. On the one hand, the presence of these noises distorts the useful signal, which in turn prevents the attacker from detecting reliable information that is transmitted. On the other hand, these noises prevent the creation of appropriate measures to ensure complete protection when typing by a user of a personal computer. The paper proposes to consider industrial noise in the form of three random processes, which are described by Johnson distributions.

scholarly journals Observability, Unobservability and the Copenhagen Interpretation in Dirac's Methodology of Physics

Quanta ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 68-87 ◽  
Author(s):  
Andrea Oldofredi ◽  
Michael Esfeld
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Close Contact ◽  
Copenhagen Interpretation ◽  
The Other ◽  
Interpretation Of Quantum Mechanics ◽  
Present Essay ◽  
Other Hand ◽  
Methodological Principles ◽  
The One

Paul Dirac has been undoubtedly one of the central figures of the last century physics, contributing in several and remarkable ways to the development of quantum mechanics; he was also at the centre of an active community of physicists, with whom he had extensive interactions and correspondence. In particular, Dirac was in close contact with Bohr, Heisenberg and Pauli. For this reason, among others, Dirac is generally considered a supporter of the Copenhagen interpretation of quantum mechanics. Similarly, he was considered a physicist sympathetic with the positivistic attitude which shaped the development of quantum theory in the 1920s. Against this background, the aim of the present essay is twofold: on the one hand, we will argue that, analyzing specific examples taken from Dirac's published works, he can neither be considered a positivist nor a physicist methodologically guided by the observability doctrine. On the other hand, we will try to disentangle Dirac's figure from the mentioned Copenhagen interpretation, since in his long career he employed remarkably different—and often contradicting—methodological principles and philosophical perspectives with respect to those followed by the supporters of that interpretation.Quanta 2019; 8: 68–87.

WHY IRREVERSIBILITY? THE FORMULATION OF CLASSICAL AND QUANTUM MECHANICS FOR NONINTEGRABLE SYSTEMS

1995 ◽  
Vol 05 (01) ◽  
pp. 3-16 ◽  
Author(s):  
ILYA PRIGOGINE
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Quantum Dynamics ◽  
Probability Distributions ◽  
Classical Trajectory ◽  
Wave Functions ◽  
The Other ◽  
Density Matrices ◽  
The One ◽  
Classical And Quantum Mechanics

Nonintegrable Poincaré systems with continuous spectrum (so-called Large Poincaré Systems, LPS) lead to the appearance of diffusive terms in the framework of dynamics. These terms break time symmetry. They lead, therefore, to limitations to classical trajectory dynamics and of wave functions. These diffusive terms correspond to well-defined classes of dynamical processes (i.e., so-called “vacuum-vacuum” transitions). The diffusive effects are amplified in situations corresponding to persistent interactions. As a result, we have to include already in the fundamental dynamical description the two aspects, probability and irreversibility, which are so conspicuous on the macroscopic level. We have to formulate both classical and quantum mechanics on the Liouville level of probability distributions (or density matrices). For integrable systems, we recover the usual formulations of classical or quantum mechanics. Instead of being irreducible concepts, which cannot be further analyzed, trajectories and wave functions appear as special solutions of the Liouville-von Neumann equations. This extension of classical and quantum dynamics permits us to unify the two concepts of nature we inherited from the 19th century, based on the one hand on dynamical time-reversible laws and on the other on an evolutionary view associated to entropy. It leads also to a unified formulation of quantum theory avoiding the conventional dual structure based on Schrödinger’s equation on the one hand, and on the “collapse” of the wave function on the other. A dynamical interpretation is given to processes such as decoherence or approach to equilibrium without any appeal to extra dynamic considerations (such as the many-world theory, coarse graining or averaging over the environment). There is a striking parallelism between classical and quantum theory. For LPS we have, in general, both a “collapse” of trajectories and of wave functions for LPS. In both cases, we need a generalized formulation of dynamics in terms of probability distributions or density matrices. Since the beginning of this century, we know that classical mechanics had to be generalized to take into account the existence of universal constants. We now see that classical as well as quantum mechanics also have to be extended to include unstable dynamical systems such as LPS. As a result, we achieve a new formulation of "laws of physics" dealing no more with certitudes but with probabilities. The formulation is appropriate to describe an open, evolving universe.

scholarly journals On the Problem of He–He Bond in the Endohedral Fullerene He2@C60

2018 ◽  
Vol 63 (4) ◽  
pp. 288 ◽  
Author(s):  
G. A. Dolgonos ◽  
E. S. Kryachko ◽  
T. Yu. Nikolaienko
Keyword(s):  
Computer Simulation ◽  
Quantum Theory ◽  
Charge Transfer ◽  
Ground State ◽  
The Other ◽  
Endohedral Fullerene ◽  
Helium Atoms ◽  
Recent Developments ◽  
The One ◽  
Fullerene Stability

For more than twenty years, the endohedral fullerene cavity is attracting a permanent attention of experimenters and theorists, computational chemists and physicists, who apply their efforts to simulate encapsulated atoms and molecules in the fullerene cavity on computers and analyze the arising phenomena of atomic bonding. In this work, recent developments concerning the endohedral fullerene He2@C60, in particular, its experimental observation and relevant computational works, are reviewed. On the one hand, the dihelium He2 embedded into the C60 cavity is observed experimentally. On the other hand, the computer simulation shows that each of the He atoms is characterized by an insignificant charge transfer to C60, so that the He dimer exists as a partially charged (He+b)2 entity. The key issue of the work concerns the existence of a bond between those two helium atoms. Since the bond is created between two particles, we assert that it suffices to define the bond on the basis of the molecular L¨owdin’s postulate and use it to study the He dimer in the C60 cavity in terms of the He–He potential energy well. It was analytically demonstrated that this well can contain at least one bound (ground) state. Therefore, according to L¨owdin’s postulate, which is naturally anticipated in quantum theory, the conclusion is drawn that the (He+b)2 entity is a diatomic molecule, in which two heliums are bound with each other. On the basis of those arguments, the concept of endohedral fullerene stability is proposed to be extended.

scholarly journals On the electromagnetic fields due to variable electric charges and the intensities of spectrum lines according to the quantum theory

1933 ◽  
Vol 141 (845) ◽  
pp. 550-553
Keyword(s):  
Quantum Theory ◽  
Hydrogen Atom ◽  
Electromagnetic Fields ◽  
Classical Result ◽  
Usual Method ◽  
Quantum Mechanical ◽  
Electric Moment ◽  
Correct Calculation ◽  
Mechanical Expression ◽  
Special Case

In a recent paper under the same title, G. A. Schott finds that the usual method of calculating the intensities of spectrum lines is liable to lead to gross errors. Although one would expect from general reasons that any improvement of the usual method would only lead to small corrections and that, therefore, Schott’s conclusion cannot be free from error, it may not be devoid of interest to show that a correct calculation starting with Schott’s formulæ leads, in contradiction to Schott’s conclusion, to the generally accepted classical result. The aim of Schott’s calculations is to obtain a quantum mechanical expression for the energy radiated by an atom, which is classically given by R=2/3C 3 {р(t-r/c)} 2 , (1) p( t ) being the electric moment of a dipole representing the atom. Schott considers the special case of a hydrogen atom emitting a radiation corresponding to a transition from the centrosymmetrical state 1 =A f (r) (2)

scholarly journals Location of the city bike station as an element of shaping the communication policy in cities

2019 ◽  
Vol 24 (6) ◽  
pp. 394-399 ◽  
Author(s):  
Marzenna Dębowska-Mróz ◽  
Piotr Lis ◽  
Sebastian Pawłowski
Keyword(s):  
Spatial Relations ◽  
Urban Transport ◽  
The Other ◽  
Spatial Extent ◽  
Transport Systems ◽  
Communication Policy ◽  
Communication Efficiency ◽  
Bicycle Infrastructure ◽  
The One ◽  
The City

Efficient implementation of displacements in cities requires, on the one hand, understanding in terms of transport needs, time of their formation, frequency, spatial extent (determining spatial relations) and, on the other hand, proper linking of all available methods of solving problems related to communication efficiency of urban transport systems. In recent years, the approach to the preferred forms of displacement in cities has changed. More and more often, residents use bicycles to implement everyday displacements. An important role in changing the approach to the method of displacement is played by the popularity and development of city bike systems. The article presents the results of research carried out on the occasion of social consultations regarding Radom Municipal Bike and the expected changes regarding the development of bicycle infrastructure in Ra-dom. The detailed characteristics of selected Radomski Rower Miejski stations in Radom were also presented.

scholarly journals On Tubes of Force in a special class of electromagnetic fields

1922 ◽  
Vol 41 ◽  
pp. 100-107
Author(s):  
G. S. Eastwood
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Electromagnetic Force ◽  
Special Class ◽  
Royal Society ◽  
Space Time ◽  
The Other ◽  
Family Meeting ◽  
The One

Professor Whittaker, in a paper entitled “On Tubes of Electromagnetic Force” {see Proceedings of the Royal Society of Edinburgh, Vol. XLII., Part I. (No 1)}, introduces certain surfaces, which he names calamoids, in connection with an electromagnetic field in the four-dimensional world of space-time. The calamoids consist of “a convariant family of surfaces which when the field is purely electrostatic or purely magnetostatic reduce to the ordinary Faraday tubes of force.” Professor Whittaker, in the paper referred to, also introduces two sets of surfaces, each a covariant family of ∞2 surfaces, one of them named the electropotential surfaces, and the other family the magnetopotential surfaces of the electromagnetic field. The electropotential surfaces and the magnetopotential surfaces are shown to be everywhere absolutely orthogonal. (One member of each family meeting at a point, any line from this point in the one family is orthogonal to every line through the point in the other family). Moreover, a “calamoid, at every one of its points, is half-parallel and half-orthogonal to the electropotential surface which passes through the point, and is also half-parallel and half-orthogonal to the magnetopotential surface which passes through the point.”

scholarly journals On the electromagnetic fields due to variable electric charges and the intensities of spectrum lines according to the quantum theory

1933 ◽  
Vol 139 (837) ◽  
pp. 37-56 ◽  
Keyword(s):  
Electromagnetic Field ◽  
Quantum Theory ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Electric Moment ◽  
Spectrum Line ◽  
Small Quantum ◽  
Classical Expression ◽  
Spatially Extended ◽  
As If

1. The procedure usually adopted in the Quantum Theory for the estimation of the intensities of a spectrum line includes two stages : (1) the electric moment, p, of the distribution responsible for the spectrum line is calculated by means of Schrodinger’s integrals or some equivalent method ; (2) the rate of loss of energy due to radiation is calculated by the classical formula due to H. Hertz, viz., 2p 2 /3c 3 , just as if the distribution were concentrated in a dipole of precisely the same moment p. The first stage involves no difficulties beyond those met with in the evaluation of the integrals or matrices with which we are concerned, the only principles needed being those of the particular quantum theory adopted. But the second stage is open to grave objections and can only be justified on the ground of necessity owing to the absence of any completely satisfactory quantum theory of the electromagnetic field. Sometimes an appeal is made to Bohr’s Correspondence Principle, but this itself involves a somewhat hazardous extrapolation from infinitely large down to small quantum numbers and cannot take the place of a rigorous calculation. A logically consistent method is possible, based on Maxwell’s theory as represented by his electromagnetic equations and their solutions in terms of the classical retarded potential integrals. It may be objected that we do not know how far Maxwell’s equations can be applied to the interiors of atoms, in particular to distributions like those of Schrodinger, but precisely the same objection applies to the customary use of the classical expression for the radiation from an oscillating dipole. Moreover, the attempts made by Heisenberg and Pauli, Dirac and others to formulate a quantum theory of the electromagnetic field have all been based on the assumption that such a theory must be consistent with Maxwell’s equations. The direct application of the methods of classical electromagnetic theory to Schrodinger’s distributions can be justified at least as a rigorous attempt to determine their electromagnetic field and the radiation from them, and the validity of the procedure will have to be judged by the agreement, or otherwise, of the results obtained with experience. In this way we avoid the assumption that a spatially extended distribution can be treated as if its electric moment were concentrated in a point; in fact, the results obtained in this paper for the more important spectrum line series show definitely that the assumption is false, because it leads to results in many cases quite inconsistent with a rigorous application of Maxwell’s theory.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

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