[mercuryrising]

What do you mean by doubling the AC voltage to decrease the weight by 25%? If I continue doubling, will I eventually not need a conductor?

The true power of AC is the fact that the energy is transmitted through the electric and magnetic fields (Poynting vector). DC needs to push everything down a little copper tube. When you start oscillating things though, the effective area of your conductor increases greatly (you start using the air as a transmission medium). This is why you can do things like this (http://hacknmod.com/hack/field-of-fluorescent-tubes-powered-...).

[dhughes]

I'm just going by my textbook, I'm still new to this.

I understand what you're saying about AC creating an emf and pushing itself through a conductor via magnetism and frequency. The skin effect would play a big role in this too. As I say I'm still new to this, I know enough to be dangerous.

Here's the exact quote in case you are interested:

"The weight of a conductor required to transmit a given amount of power a given distance with a fixed loss varies inversely as the square of the transmission voltage."

[mercuryrising]

Ah ha! That's actually kind of cool.

Power's given as: P = V^2 * R R is given as: R = rhoL/(pir^2) Substituting: and clumping constants: P = (V^2 / r^2) * (rho*L/pi) Weight is proportional to r^2, we can see that voltage and weight are inverses of one another, and increasing the voltage for a fixed amount of power decreases the radius necessary to transmit it, decreasing the weight.

I really wish I still had my lecture notes about the energy flow through free space, this is the best I could find online - http://amasci.com/elect/poynt/poynt.html.

[Retric]

Graph 0.75^(log X) : http://www.google.com/search?q=0.75%5E+log+x

Anyway, DC current is still mostly a magnetic interaction. Actual electrons rarely get above a few cm/s.