Tom Watson wrote:
I had a conversation with a friend of mine today who has a masters in
electrical engineering.

This degree was conferred by the same school that I went to
(Villanova) about a hundred years ago, so I must inherently trust him.

Yet...

The question that I asked him, which I thought to be simple enough,
was - do the electrons travel down the circumference of the wire, or
do they travel through the core of the wire?

He told me that that is an unknown.

This was very surprising to me as I thought that it would be easily
tested.

Could we not create a wire of a core of inert material and coat it
with a conductor and measure the difference between a wire of the pure
element and that of the coated variety?

This seemed to be not within his reckoning.

The reason that it is important, to me, is that, if the electrons only
travel on the circumference, that circumference may be folded into a
smaller section than that described by the original, and wires would
not have to be so thick.

http://en.wikipedia.org/wiki/Skin_depth

This is a clear description of the effect but ignoring the math, the
chart shows that at 60Hz, the current in the middle of a 3/4" diameter
copper conductor is still about 37% of the surface value.
For typical wires 12 to 18 gauge wires at 60 Hz you can treat the
current density as uniform as it is at DC. For high frequency RF the
current is almost entirely in the outer few micro-inches which is why
high performance RF conductors are silver plated to take advantage of
the greater conductivity of silver compared to copper without the cost
of solid silver.

Robert Bonomi wrote:

Yes he did!

Have I not been paying attention or have you been away?

If away, then welcome back!

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/