Directionality of wire

Manufacturers of "directional" cables argue that it is the direction of the energy flow that is important (from wall to power amp, from power amp to speakers etc). This way they can market their AC power cables, speaker cables etc. They conveniently ignore the fact that the energy flow takes place in the dielectric surrounding the conductors -- including the surrounding air. Any asymmetry in the crystal structure of the conductors themselves would only impact electron motion and would likely result in undesirable diode behavior.

sfroyen
Manufacturers of "directional" cables argue that it is the direction of the energy flow that is important (from wall to power amp, from power amp to speakers etc). This way they can market their AC power cables, speaker cables etc. They conveniently ignore the fact that the energy flow takes place in the dielectric surrounding the conductors -- including the surrounding air. Any asymmetry in the crystal structure of the conductors themselves would only impact electron motion and would likely result in undesirable diode behavior.

>>>>>>Listen, pal, we got enough trouble with skeptics of skin effect who insist all audio signals must travel BELOW the conductor surface, totally inside the conductor. We don’t need any wild theories about the energy traveling outside the conductor. If that were true we could fake out the energy and make cables entirely out of dielectric and skip the metal. The energy wouldn’t have a clue. And it would be lot cheaper, too, you know, not having the costs of super pure copper, silver or gold to worry about. In fact, you could sell cables made entirely of air.

But seriously, we already know the velocity of photons traveling through copper conductors (circa 70% speed of light in vacuum) and it’s consistent with the photons traveling through the metal conductor itself, NOT through the dielectric and NOT through air, which would be a much higher percentage of the speed of light in a vacuum, no? It's the same situation for audio over copper wires in telephony, too. The velocity over copper wires in the telephone system is consistent with the signal traveling through copper itself. Electrons? They hardly move at all so we can ignore them.

Assuming you are serious :-)

I'm distinguishing between the electron motion, which, of course happens inside the conductor, and the flow of energy that powers, e.g., the speakers. The latter is carried by the electromagnetic field that is generated by the electron motion, but is located outside the conductors. This follows from Maxwell's equations which are valid from DC to any frequency of relevance to EE and breaks down only when describing certain quantum effects (see QED).

In the case of an electrical signal (or AC power) that is being conducted via wires the energy is conveyed in the form of an electromagnetic wave, which travels outside the conductor itself. That wave propagates at a substantial fraction (generally somewhere between 50% to 98%) of the speed of light in a vacuum. The exact speed depends primarily on the "dielectric constant" of the particular insulation.

Any electromagnetic wave can be considered to be comprised of photons, although the term photons is most commonly associated with a particular kind of electromagnetic wave, namely light.

As I indicated in an earlier post in this thread, in the case of an electrical signal that is being conducted via wires the near light speed propagation of that electromagnetic wave is intimately related to movement of electrons within the conductor, even though that electron movement occurs at a **vastly** slower speed.

Sfroyen’s comment that "the energy flow takes place in the dielectric surrounding the conductors -- including the surrounding air" is absolutely correct. Photons do not travel within metallic conductors, electrons do. Ralph (Atmasphere) has made the same point, btw, in prior threads here that have involved similar controversies.

Regards,
-- Al