The Physics of Electricity

For the record, I disagree with just about everything in Geoff's recent posts in this thread.  However I have no interest in engaging in further discussion of these matters, as I would rather focus on threads and discussions that have the potential to be constructive.

Before taking my leave of this thread, though, I'll quote a statement by a world renowned author, consultant, lecturer, and expert on numerous branches of electrical engineering, Ralph Morrison.  This was quoted by member Jea48 in another recent thread, entitled "directional-cables-what-does-that-really-mean?"  Geoff participated extensively in that thread.

Ralph Morrison

"The laws I want to talk about are the basic laws of electricity. I’m not referring to circuit theory laws as described by Kirchhoff or Ohm but the laws governing the electric and magnetic fields. These fields are fundamental to all electrical activity whether the phenomenon is lightning, electrostatic display, radar, antennas, sunlight, and power generation, analog or digital circuitry.

These laws are often called Maxwell’s equations. Light energy can be directed by lenses, radar energy can be directed by waveguides and the energy and power frequencies can be direct conductors. Thus we direct energy flow at different frequencies by using different material.

For utility power the energy travels in the space between the conductors not in the conductors. In digital circuits the signal and energy travel in the spaces between the traces or between the traces and the conducting surfaces.  Buildings have halls and walls. People move in the halls not the walls.  Circuits have traces and spaces, signals and energy moves in the spaces not the traces."

Sound System Engineering 4e

And this from Wikipedia, which Jea48 also quoted in the thread I referred to:

"In physics, the Poynting vector represents the directional energy flux (the energy transfer per unit area per unit time) of an electromagnetic field. The SI unit of the Poynting vector is the watt per square metre (W/m2). It is named after its discoverer John Henry Poynting who first derived it in 1884. Oliver Heaviside and Nokolay Umov also independently discovered the Poynting vector. 

... For example, the Poynting vector within the dielectric insulator of a coaxial cable is nearly parallel to the wire axis (assuming no fields outside the cable and a wavelength longer than the diameter of the cable, including DC). Electrical energy delivered to the load is flowing entirely through the dielectric between the conductors. Very little energy flows in the conductors themselves, since the electric field strength is nearly zero. The energy flowing in the conductors flows radially into the conductors and accounts for energy lost to resistive heating of the conductor. No energy flows outside the cable, either, since there the magnetic fields of inner and outer conductors cancel to zero."

Poynting vector - Wikipedia

I will have no further comments in this thread.

Regards,
-- Al

almarg
For the record, I disagree with just about everything in Geoff’s recent posts in this thread. However I have no interest in engaging in further discussion of these matters, as I would rather focus on threads and discussions that have the potential to be constructive.

>>>>Thanks for not engaging me on this subject, Al. You’re the best. By the way, if you disagree with just about everything I said surely I must be on the right track. 🤗

There are differences that can matter mainly shielding from noise,  ability to establish a sound electrical contact on both ends and ability to deliver current when needed.    None of this is rocket science and requires  just a good quality power cord designed to do the  job well which has some cost but need not cost a fortune.  Current delivery will in practice matter more for power amps whereas shielding and ability to make a good contact may matter more in general.  

A few comments. The subject of the thread is speaker cables or wires, and the audio signal, not power cords. Also, why do cables with shielding often sound worse than cables without shielding if shielding is supposed to be all that? Finally, the subject is how electricity works; shielding is pretty much another topic or sub-topic.