Once I was taught that light is physically made up of in-phase E and B fields oscillating perpendicularly, it was a little baffling because I always thought fields were just analysis tools (or even just a helpful perspective) for the direction/strength of forces for a given charge / charge moving. This kind of goes into transmission line theory in electrical engineering I suppose, but when a change in voltage occurs and propagates through a medium at c... what exactly is the entity--which carries a change in voltage--that travels? Should it just be accepted at face-value by students that electric and magnetic fields are physical things, in real life, that move at the speed of and also in fact are light?
Also, considering an electrical signal traveling through a wire medium: is the electric field in the direction of the current/signal? The answer to this might seem obviously to be yes; however, if electrical signals are carried as light, then by the directional definition of E x B = wave propagation direction shouldn't the electric fields (and magnetic fields) be perpendicular to the wire / direction of the signal? Or are these EM-wave-intrinsic E/B fields different from the electric field that relates to the current's/signal's direction?
Thanks, -A curious and constructivist EE major, who hopes to someday understand electricity electron-by-electron