How Electricity Actually Works

@jw944ts ,

How does the insulation and multistrand design of most of our cables enter into this discussion? 

How? Well if I am trying to sell cables that realistically don't sound any different from anyone else, but I want to make it seem like maybe, perhaps it does, then I will bring up insulation, and all kinds of other things that technically have a measurable impact on the wires, but for the purposes of analog audio are completely meaningless so that I can appear differentiated.

multistrand design

Flexibility and does improve skin effect but I expect skin effect is not an issue unless you are running a single solid core 18awg, which I don't think anyone is are they?  That was a quick back of envelope estimate for where it may be an issue.

Secondly, in light of the role of the fields around the wires, does the separation of the two wires ultimately have an effect?

Yes it increases inductance. In any normal construction this is likely to have no audible impact. A poor cable and electrostatic speakers from my limited research may have an issue. I did a quick review of a bunch of speakers impedance plots after my discovery about the high Fidelium resistance.

I will raise the issue that for all the marketing claims of cables, the only specifications I could find where inductance, resistance and capacitance. One or two alluded to skin effect, but nothing concrete. No other parameters were provided.

@deludedaudiophile , thank you

We as a species don't know a tenth of a percent about anything? Pretty pessimistic view of Homosapiens.

I am just an engineer. I worked chemical, electrical, and mechanical engineering. Part of my career I designed Mobile Electric Power equipment, I designed generators. Not just any generator, but one that was hard to detect. The technology is referred to as Low Observable. There are some interesting and amusing arguments regarding E and B fields and their uses in this thread. Some of what I read here makes me seriously wonder about our education system.

@barts -

                          You mentioned not knowing a tenth of a percent.

     The percentage of what we know about our universe, is recognized by Scientists/Physicists as 4-5%.

     Multiple Billions have been/are being spent, in an effort to find out what exactly comprises the other 96%, of the matter and energy, Physicists know surrounds us.

     Einstein recognized there was a whole lot of stuff missing, when he came up with his Math on gravity and considered it his greatest blunder (having to add Lambda/the Cosmological Constant) 

                          Too bad he didn't live to see that proven!

        There are some interesting theories, as to what's going on around us:

 https://science.time.com/2013/02/20/telescope-to-hunt-for-missing-96-of-the-universe/

https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy

https://www.livescience.com/multiverse

https://www.vox.com/2015/6/29/8847863/holographic-principle-universe-theory-physics

http://httpblogsscientificamericancomdegrees-of-freedom20110725what-do-you-mean-the-universe-is-flat-part-i/#

https://www.livescience.com/strange-theories-about-the-universe.html