How Electricity Actually Works

While the conversation, in the link I'm going to post, regards some very high freqs: keep in mind how very harmonically complex the signals carrying our music are and that Poynting Vectors are affected by frequency shifts.

    Just my own opinion, but: seems to me an excellent rationale for the careful selection of cable materials,

I won't repeat the joke about opinions. However I will say that fortunately opinions only carry weight in physics and engineering when they come from experienced knowledgeable people. Audio with all it's audible harmonics is all low frequency in a discussion of dielectrics.  When doing our test fixtures and test boards for semis standard PCB material was used up to 100s of MHz. RF substrates were only used for high frequency RF products.

If it not quantified to a number and related back to audio it is just marketing. It's not real.

@jea48 I will respond to your question when I am at keyboard

@jea48 ,

I am going to start with a simple explanation. There are probably people much better at me in teaching this topic. However, I think some basics will move you much farther ahead:

- Electrons are charged particles. An electric field will cause the movement of charged particles. Larger the field greater the total movement.

- Moving charged particles are what causes a magnetic field

- If something is preventing the easy movement of those charges, something we lump together and call resistance, then naturally there are less overall charges moving in total in a given direction.

- The Poynting vector which represent power, is the cross product of the electric field and magnetic field. If the electric field changes polarity, the magnetic field does too, but the product always is in the same direction.  As the power is a function of electrical field and magnetic field, the power is directly related to both. No charges moving, no magnetic field, no power.

- It is better to say that power (energy) is transformed by the load, than consumed. Thermodynamics, conservation of energy. From a basic electrodynamic view, for resistance, the electrons "collide" with atoms, and give up their energy, key note, kinetic energy, which results in heat (referred to as Joule heating). However, that energy can be transformed through through the magnetic fields or electrical fields such that those electrons slow, and other accelerate (transformers, motors, energy transfer through a capacitor, etc).

The quantum mechanical view of how the electrons transfer their energy is much more complicated but really also not necessary for the discussion.

A point or two:

- A conductor, having no voltage field differential (effectively), means the electric field within the conductor is 0-small. Hence the transfer of "conduction" of energy from the electric field to the electrons happens on the surface/outside the conductor. This is also why poor conductors have a much deeper skin depth. The electric field extends into the conductor because there is a voltage field differential in the conductor.

- From above, we can ascertain that the energy is predominantly transferred outside the wire, not in the wire.

- There is energy in the moving electrons, kinetic, but the energy is predominantly in the EM field.

Clear as mud?

I gave an analogy once as electricity, fields, resistance and electrons are like modern banking and finance. Entities with real assets are the fields. The electrons are like a modern bank. They hold no actual money (energy), but they facilitate the transfer of energy (money), and they take their cut (resistance).