Video: Fields Versus Action at a Distance: How Electromagnetics Works

Presenting at ATLOSCon 2015 (photo credit Arthur Zey).
Presenting at ATLOSCon 2015 (photo credit: Arthur Zey).

Here’s a video version of my May 23 talk at ATLOSCon in Atlanta Georgia on Fields Versus Action at a Distance. I subtitled my talk “How Electromagnetics Works,” because in retrospect, that would have made a better title. My talk discusses the conflict between action at a distance and field-based thinking. I present a novel interpretation of classical electromagnetics that ties the Lagrangian density to reactive fields and energy flow, and I explain why energy flow in classical electromagnetics leads to a picture very similar to the Bohm-DeBroglie Pilot Wave model in quantum mechanics. And I manage to explain it almost entirely using graphical pictures and figures and a bare minimum of equations.

Animimation of impulses interacting with an open and a short. Courtesy, Wikimedia; created by Steven Byrnes.
Animimation of impulses interacting with an open (top) and a short (bottom). Courtesy, Wikimedia; created by Steven Byrnes.

One feature I added to the video and did not include in my talk is the clever animation to the right showing how impulses interact with an open and a short on a transmission line. The animations show the electric field (arrows) and the currents or motion of the charges (dots). These examples illustrate very simply and cleanly how the balance of energy associated with a traveling wave transforms to purely electric energy (in the case of an open) or purely magnetic energy (in the case of a short). The energy comes to a rest instantaneously, before changing direction and giving rise to a reverse propagating wave along the transmission line.

Here’s the video:

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