My early thought was that, at the very least, Poynting Vectors deserve a video but Transmission Lines also deserve a video. Here's a problem I recall from Jac

My early thought was that, at the very least, Poynting Vectors deserve a video but Transmission Lines also deserve a video. Here's a problem I recall from Jackson which might (or might not) provide a missing link: Given two parallel conductors of arbitrary shape, prove that the product of capacitance-per-unit-length and inductance-per-unit-length is a constant (i.e., independent of profile and separation). I remember finding a suitable answer, but I can't for the life of me remember how.