Force law in material media, hidden momentum and quantum. According to classical electrodynamics, electric and mag. This book begins with a detailed analysis of these equations, and proceeds to examine their farreaching consequences. Electric and magnetic dipoles in the lorentz and einstein. The force law of maxwells classical electrodynamics does not agree with. In contrast, the einsteinlaub formulation does not invoke hidden entities. Dec 01, 2010 in this paper we demonstrate the conservation of energy and linear momentum under the most general circumstances conceivable in classical electrodynamics. Classical electrodynamics the classical electromagnetism as used nowadays is not the theory as developed by j. Omission of the hidden momentum is contrary to the position of standard modern electrodynamics texts, and leads to violation of newtons law of action and reaction, negating thomass result. Pdf hidden momentum and the electromagnetic mass of a charge. Hidden momentum and the electromagnetic mass of a charge and current carrying body. Griffiths emeritus professor of physics, reed college hidden momentum, field momentum, and electromagnetic impulse.
We highlight that the emergence of this force component is required by the general theorem, deriving zero total momentum for any static configuration of chargescurrents. I understand from basic conservation of energy and momentum considerations, it is clear in classical electrodynamics that the fields should be able to have energy and momentum. We address to the force law in classical electrodynamics of material media, paying attention on the force term due to time variation of hidden momentum of. We address to the force law in classical electrodynamics of material media, paying attention on the force term due to time variation of hidden momentum of magnetic dipoles. According to classical electrodynamics, electric and magnetic fields e and b store linear. The magnet is at rest and contains electromagnetic momentum, but there was no. In the classical electrodynamics of maxwell and lorentz, the socalled. The chargemagnet paradoxes of classical electrodynamics. Pdf hidden momentum and the electromagnetic mass of a. Whereas maxwells macroscopic equations relate the electric and magnetic fields to their material sources i. In such analysis the mechanical energy momentum of gas should be taken in the same form 2 for both. The sole energyrelated postulate that will be invoked is the definition of the poynting vector s r, t as the rate of flow of electromagnetic energy per unit area per unit time. The discovery and proof that light is an electromagnetic.
In is more mature work, published in 1873, maxwell used the lagrangian formalism to avoid any specific mechanical model of the medium that. Classical electrodynamics is one of the most beautiful things in the world. The classical theory of electrodynamics is built upon maxwells equations and the concepts of electromagnetic em field, force, energy, and momentum, which are intimately tied together by poyntings theorem and by the lorentz force law. Hidden momentum in electromechanical systems is discussed in the examples following lecture 24 of ph206501, electrodynamics. Ab the lorentz force of classical electrodynamics, when applied to magnetic materials, gives rise to hidden energy and hidden momentum.
Field, force, energy and momentum in classical electrodynamics revised edition the classical theory of electrodynamics is based on maxwells equations and the lorentz law of force. Shockleys famous 1967 paper, where he introduced the notion of hidden momentum in electromagnetic systems. While the lorentz law requires the introduction of hidden energy and hidden momentum in situations where an electric field acts on a magnetic material, the. This comprehensive textbook gives refreshing insights into classical electrodynamics, with emphasis on the physics without sacrificing mathematical rigor. He attributed the momentum imbalance to a certain amount of hidden momentum residing inside magnetic media subjected to electric. The possible relation between these models is also discussed.
Ab the lorentz law of force is the fifth pillar of classical electrodynamics, the other four being maxwells macroscopic equations. In summary, mollers special relativistic hidden position, extended to include rotation, leads to hidden momentum and hidden energy, whose quantum version leads to the usual spinorbit term as well as a new expression for the interaction of the electron spin with the spin angular momentum of the electromagnetic field. Not only is the einsteinlaub formula consistent with special relativity, it also solves the longstanding problem of hidden momentum in classical electrodynamics. Sep 19, 2017 the classical theory of electrodynamics is built upon maxwells equations and the concepts of electromagnetic em field, force, energy, and momentum, which are intimately tied together by poyntings theorem and by the lorentz force law. I particularly like the numerous worked examples and sections on applications, which show the relevance of the topics to modern research. At the same time, we disclose the impossibility to. Mansuripur poynting vector lorentz law nature of dipoles arxiv.
Among the recent theoretical and experimental investigations in this field, we focus on a modified version of the troutonnoble experiment for which a nonnull result is predicted. Force, torque, linear momentum, and angular momentum in. In the classical electrodynamics of maxwell and lorentz, the socalled microscopic equations are. Hidden momentum and the momentum of a static electromagnetic field are indispensable concepts of direct physical significance in classical electrodynamics. J griffiths, introduction to electrodynamics, 3rd ed. Introduction according to classical electrodynamics, electric and magnetic.
The classical theory of electromagnetism is based on maxwells macroscopic equations, an energy postulate, a momentum postulate, and a generalized form of the lorentz law of force. Whereas maxwells equations relate the fields to their material sources, poyntings theorem governs the flow of em energy and its exchange between fields and. The lorentz force law of classical electrodynamics requires the introduction of hidden energy and hidden momentum in situations where an electric field acts on a magnetic material. This leads to the usual poynting vector and energy density relations for electromagnetic fields. In special relativity, hidden momentum or hidden mechanical momentum is the mechanical momentum mass times velocity that is unaccounted for by newtonian mechanics. But locating this hidden momentum can be subtle and difficult. Whereas maxwells equations relate the fields to their material sources, poyntings theorem governs the flow of em energy and its exchange between fields and material media, while the lorentz law regulates the backandforth transfer of momentum. Classical electrodynamics in agreement with newtons. The classical theory of electrodynamics is built upon maxwells equations and the concepts of electromagnetic em field, force, energy, and momentum, which are intimately tied together by. Whereas maxwells equations relate the fields to their material sources, poyntings theorem governs the flow of em energy and its exchange between fields and material media, while the lorentz law regulates the backandforth transfer. Electromagnetic force and torque in lorentz and einsteinlaub. Including the hidden momentum results in linear momentum conservation, but in the presence of thomas precession, the total angular momentum is not.
While the lorentz law requires the introduction of hidden energy and hidden momentum in situations where an electric field acts on a magnetic. Electron interaction with the spin angular momentum of the. Models of the classical electron after a century springerlink. Four simple vector equations or one tensor equation and an asssociated dual describe the uni.
It displays a series of fundamental characteristics, which have been con rmed by various experimental measurements. The relation between classical and quantum electrodynamics. Electromagnetic energy and momentum conservation of energy. Is a classical electrodynamics law incompatible with special. Pdf force, torque, linear momentum, and angular momentum in. Apparent paradoxes in classical electrodynamics 11 of the em. May 24, 2012 another equally important issue is the longstanding problem of hidden momentum, in which he shows that the lorentz law fails to conserve momentum in certain situations involving magnetic. The classical theory of electrodynamics is built upon maxwells equations and the concepts of electromagnetic field, force, energy, and momentum, which are intimately tied together by poyntings. Contrary to classical electrodynamics, the electron does not radiate when it orbits the nucleus in stationary orbits.
Dec 11, 20 the classical theory of electrodynamics is built upon maxwells equations and the concepts of electromagnetic field, force, energy, and momentum, which are intimately tied together by poyntings theorem and the lorentz force law. On the influence of hidden momentum and hidden energy in the classical analysis of spinorbit coupling in hydrogenlike atoms more by david lush in a recent article, kholmetskii, missevitch and yarmin on the classical analysis of spinorbit coupling in hydrogenlike atoms, am. Until recently there were only classical models for hidden momentum. The lorentz force law and its connections to hidden momentum. Electromagnetic field momentum princeton university.
Pdf the energetics of the an exb propulsor that avoids the. Energy, momentum, and force in classical electrodynamics. Pdf kineticenergymomentum tensor in electrodynamics. Feynmans relativistic electrodynamics paradox and the. Classical theory of electric and magnetic phenomena. The classical theory of electrodynamics cannot explain the existence and structure of electric and magnetic dipoles, yet it incorporates such dipoles into its fundamental equations, simply by postulating their existence and properties, just as it postulates the existence and properties of electric charges and currents. The classical theory of electrodynamics is built upon maxwells equations and the concepts of electromagnetic force, energy, and momentum, which are intimately tied field, together by poyntings theorem and the lorentz force law. Classical electrodynamics duke physics duke university. Download fulltext pdf download fulltext pdf read fulltext. Kemp2, 1 college of sciences and mathematics, arkansas state university, arkansas 72467, usa 2 college of engineering, arkansas state university, arkansas 72467, usa received may 2015. Pdf the contribution of the electromagnetic selffield to the energy and. Regarding llewellyn thomass paper of 1927 and the hidden. Force and hidden momentum for classical microscopic dipoles.
The problems inherent to each model with respect to selfinteraction are disclosed and the possible solutions are analysed. Whereas maxwells equations relate the fields to their material sources, poyntings theorem governs the flow of em energy and its exchange between fields and material media, while the lorentz law regulates the backandforth transfer of momentum between the. Energy, momentum, and force in classical electrodynamics arxiv. Until recently there were only classical models for hidden momentum 5,18. Maxwells macroscopic equations are mathematically exact and self. We argue that a totally electromagnetic electron, as well as a point electron, is beyond the scope of classical electrodynamics. These seven postulates constitute the foundation of a complete and consistent theory, thus eliminating the need for. Under certain circumstances involving magnetic matter in the presence of an electric. Removing the contributions of hidden entities from the poynting vector, from the electromagnetic em momentum density, and from the lorentz force and torque densities simplifies the equations of the classical theory. Classical electrodynamics, quantum mechanics, elementary particles.
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