American Journal of Physics January 2020January 2020 Issue,

Volume 88, No. 1


Electric field lines of relativistically moving point charges

Generation of electromagnetic fields by moving charges is a fascinating topic where the tight connection between classical electrodynamics and special relativity becomes particularly apparent. One can gain direct insight into the fascinating structure of such fields by visualizing the electric field lines. However, the calculation of electric field lines for arbitrarily moving charges is far from trivial. Here, we derive an equation for the direction that points from the retarded position of a moving charge towards a specific field line position, which allows for a simple construction of these lines. We analytically solve this equation for several special but important cases: for an arbitrary rectilinear motion, for the motion within the wiggler magnetic field of a free electron laser, and for the motion in a synchrotron.



Electric field lines of relativistically moving point charges by Daja Ruhlandt, Steffen Mühle and Jörg Enderlein. DOI: 10.1119/10.0000189

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Determination of permeability using a classic Darcy water column by Fabian B. Wadsworth, Caron E. J. Vossen, Diana Schmid, Mathieu Colombier, Michael J. Heap, Bettina Scheu and Donald B. Dingwell. DOI: 10.1119/10.0000296

Approximate analytic solution of the potential flow around a rectangle by Eunice J. Kim and Ildoo Kim. DOI: 10.1119/10.0000264

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Why are complex numbers needed in quantum mechanics? Some answers for the introductory level by Ricardo Karam. DOI: 10.1119/10.0000258

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Relationship between heat capacities derived by different but connected approaches by Ying Liu, Yue Liu and Michael G. B. Drew. DOI: 10.1119/10.0000305


Conservative numerical methods for nonlinear oscillators by Mark H. Holmes. DOI: /10.1119/10.0000295


Applications of high-speed digital pulse acquisition and software-defined electronics (SDE) in advanced nuclear teaching laboratories by F. D. Becchetti, N. Damron and R. O. Torres-Isea. DOI: 10.1119/1.5125128


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American Journal of Physics 87, 1020 (2019);

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