[Cold Heat]

We did not understand it 35 years ago when I first trained as a electrician. We only knew it did. Or at least some people knew it.

This is why most wire was solid.

We eventually derated the solid wire construction and uprated the stranded, which carried more current with less copper.

The last technical class I had on that subject was in the late eighties, when the phrase, "not completely understood" was used.

Praytell, do you know why?

Specifically why electrons flow on the surface, and not so much down the middle of a conductor....?

[newguy357]

Praytell, do you know why?

Specifically why electrons flow on the surface, and not so much down the middle of a conductor....?

Uhhh, yes. Just like anyone who has taken freshman physics in the last 100 years should. It is taught in the EM portion of freshman physics. It is quite intuitive. Visualize a spherical conductor. Remove an electron from the center. What happens? An electric field is set up from that positive charge. What happens because of that? One of the free flowing electrons in this conductor will move along that electric field into the center where the previous electron was vacated, thus negating the original electric field but creating a new one further out (radially) of the same magnitude as the original. That causes an electron from further out to repeat the above. Do that many times and pretty soon all your charge is on the surface. That is basic physics and no one has questioned it for a century.