Classical Electrodynamics

by Robert G. Brown Duke University Physics Department Durham, NC 27708-0305 Copyright Robert G. Brown, 2009

Classical Electrodynamics is an online, lecture note style textbook provided for the benefit of my physics classes here at Duke. All students or faculty who discover it online are welcome to use and peruse this textbook online or as a e-book on their own personal computer for the sole purpose of teaching or learning physics.

All other use must conform to the Open Publication License published on this website, which prohibits making and redistributing printed or electronically reproduced copies of this work for your own use or commercial purposes.

Note that this textbook is loosely derived from several sources, particularly J. D. Jackson's Classical Electrodynamics, 2nd and 3rd editions (for which it serves as a study companion that can in a pinch stand alone). However, it is significantly augmented in many places, most notably in its discussion of vector spherical harmonics and Hansen functions, which is derived from Larry Biedenharn's notes on the subject, and in its discussion of radiation reaction and both the Dirac and the Wheeler and Feynman papers. It has also been laboriously converted so that its units are SI throughout, where Jackson is only half converted from the Gaussian units of its early editions.

It also has significantly more material supporting the learning of the required mathematics by the student. Perhaps when Jackson's original book was written, one could be confident that a physics graduate student was versed in tensors and number theory, in partial differential equations and vector calculus. It is at least my experience that this is no longer particularly likely to be so (with a few welcome exceptions in any given class, of course). Tensors and tensor concepts such as outer products and dyads in particular are simply no longer taught at all to most physics majors, which makes learning their use and notation in e.g. relativity theory quite a chore. I have therefore included sections that review the ideas underlying tensors in some detail, as well as sections that review e.g. contour integration and complex variables for students that might be weak there.

For better or worse, classical electrodynamics at the graduate level always ends up being a course in remedial mathematics as much as it ever is in physics, and this textbook attempts in its own small way to give students the resources they need to learn what they are missing on their own without wasting valuable classroom time.