Conceptual Understanding for Voltage in a Circuit

[davenn]

I was using "EM field" as shorthand for electric and magnetic. I wasn't implying traveling waves.

then you are confusing the issue ... be clear

Errrrr ... I can only presume you have not been reading the previous posts here.

yeah I have and all I have seen is your constant argument against what everyone else is saying

The very point of this discussion is that it is NOT the electrons providing the energy, but instead the Poynting vector, I.e. ExB traveling through space.

well that's pretty vague

 

[rumborak]

Well, I can say I'm in good company with Richard Feynman, and the guys at that Israeli university who wrote the paper I linked to. All I see here is a ton of hand-waving, or plain promotion of wrong notions such as that it's the electrons transferring the energy from the battery in a "pushing down the wire" way.

To quote Feynman:

" So our “crazy” theory says that the electrons are getting their energy to generate heat because of the energy flowing into the wire from the field outside. Intuition would seem to tell us that the electrons get their energy from being pushed along the wire, so the energy should be flowing down (or up) along the wire. But the theory says that the electrons are really being pushed by an electric field, which has come from some charges very far away, and that the electrons get their energy for generating heat from these fields. The energy somehow flows from the distant charges into a wide area of space and then inward to the wire."

And my additional "wrinkle" here is that since the Poynting vector involves the static magnetic field, clearly that must be part of the mechanism of energy transfer too.

 

[sophiecentaur]

That's what was mysterious

There are many situations in Science where we have this problem. In this situation, what is actually worrisome? The 'speed' involved with the transfer of Power in a steady state situation is, I would say, not relevant because speed /velocity involves identifying how the 'location' of something is changing in time. In a DC situation, there is nothing that can be identifiable; everything is unchanging. We have already discarded the description of an EM wave as a stream of photons / little bullets and we can't approach it that way, as with water molecules in a constant flowing river. At DC, of course, the photon energy is Zero! (=hf=h0=0) so they have no meaning, in any case. The only way to approach this impasse is, I think, to consider an AC signal and see what happens as f→0. The velocity, of the wave in that case, would be c and, as there are no continually flowing DC circuits (f≠0, ever), in real life that could be good enough for us.
Perhaps it would be better to ignore the concept of any Power flowing at a 'speed' and say that the only speed involved with Power Flow from A to B is the speed of propagation of a change in Power. It may be irksome to accept that there is no 'motion' of the Power but you have to examine why we want an answer to that question. We all feel the need to leave things 'tidy' in our minds. QM is another example where this self indulgence cannot be allowed and we just have to 'Get Over It', perhaps.