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Relativistic electromagnetism is a modern teaching strategy for developing electromagnetic field theory from Coulomb's law and Lorentz transformations. ==Electromechanics== After Maxwell proposed the differential equation model of the electromagnetic field in 1873, the mechanism of action of fields came into question, for instance in the Kelvin’s master class held at Johns Hopkins University in 1884 and commemorated a century later.〔Robert Kargon and Peter Achinstein (1987) ''Kelvin’s Baltimore Lectures and Modern Theoretical Physics: historical and philosophical perspectives'', MIT Press ISBN 0-262-11117-9〕 The requirement that the equations remain consistent when viewed from various moving observers led to special relativity, a geometric theory of 4-space where intermediation is by light and radiation.〔What led me more or less directly to the special theory of relativity was the conviction that the electromotive force acting on a body in motion in a magnetic field was nothing else but an electric field. Albert Einstein (1953) 〕 The spacetime geometry provided a context for technical description of electric technology, especially generators, motors, and lighting at first. The Coulomb force was generalized to the Lorentz force. For example, with this model transmission lines and power grids were developed and radio frequency communication explored. An effort to mount a full-fledged electromechanics on a relativistic basis in seen in the work of Leigh Page, from the project outline in 1912〔If the principle of relativity had been enunciated before the date of Oersted’s discovery, the fundamental relations of electrodynamics could have been predicted on theoretical grounds as a direct consequence of the fundamental laws of electrostatics, extended so as to apply to charges relatively in motion as well as charges relatively at rest. Leigh Page (1912) "Derivation of the Fundamental Relations of Electrodynamics from those of Electrostatics", American Journal of Science 34: 57–68〕 to his textbook ''Electrodynamics'' (1940)〔Leigh Page & Norman Ilsley Adams (1940) ''Electrodynamics'', D. Van Nostrand Company〕 The interplay (according to the differential equations) of electric and magnetic field as viewed over moving observers is examined. What is charge density in electrostatics becomes proper charge density〔Richard A. Mould (2001) ''Basic Relativity'', §62 Lorentz force, Springer Science & Business Media ISBN 0387952101 〕〔Derek F. Lawden (2012) ''An Introduction to Tensor Calculus: Relativity and Cosmology'', page 74, Courier Corporation ISBN 0486132145 〕〔Jack Vanderlinde (2006) ''Classical Electromagnetic Theory'', § 11.1 The Four-potential and Coulomb’s Law, page 314, Springer Science & Business Media ISBN 1402027001 〕 and generates a magnetic field for a moving observer. A revival of interest in this method for education and training of electrical and electronics engineers broke out in the 1960s after Richard Feynman’s textbook.〔Richard Feynman (1964) The Feynman Lectures on Physics, volume 2, chapter 13-6〕 Rosser’s book ''Classical Electromagnetism via Relativity'' was popular,〔W.G.V. Rosser (1968) ''Classical Electromagnetism via Relativity'', Plenum Press〕 as was Anthony French’s treatment in his textbook〔Anthony French (1968) ''Special Relativity'', chapter 8, W. W. Norton & Company〕 which illustrated diagrammatically the proper charge density. The use of retarded potentials to describe electromagnetic fields from source-charges is an expression of relativistic electromagnetism. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Relativistic electromagnetism」の詳細全文を読む スポンサード リンク
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