Re: [Phys-l] physics of dissipation

[chuck britton <cvbritton@mac.com>]

JD writes:

> Nyquist's model can be boiled down to a single sentence:  An
> ohm is an ohm is an ohm, and a coaxial cable is 50 ohms.  That
> is, we model the energy being "dissipated" in terms of energy
> being _radiated_ into an infinitely-long piece of coax.
>
> This gives a perfect model of dissipation.

Yes, I've wondered about '50 ohm' coax and such.
Isn't this '50 Ohms' somewhat frequency dependent?

Or is it as simple and universal concept as you imply?