crystalcatalyst

What materials does this apply to? The permittivity of a metal is infinite. I'm a little confused by this.

Well, let me try to clarify something. Look at this wikipedia article.

https://en.wikipedia.org/wiki/Speed_of_electricity

Scroll down to the part where it talks about the speed of electromagnetic waves in good dielectrics and conductors. Are they talking about the speed which the signal is traveling ALONG the circuit or the field that propagates AWAY from the circuit? I am rather confused. I am guessing the electric field travels along the circuit and the magnetic field travels away from the circuit.

Well I have been doing some digging on how fast magnetic waves travel through metals based upon various wavelengths and it is, well, complicated to say the least. Let me start here with "The speed of electricity" from wikipedia.

https://en.wikipedia.org/wiki/Speed_of_electricity

Now I am not interested in how quickly the electric field travels along the current. They already provide the formulas for that. What I am interested in is in the next paragraph.

Quote

In the theoretical investigation of electric circuits, the velocity of propagation of the electromagnetic field through space is usually not considered; the field is assumed, as a precondition, to be present throughout space. The magnetic component of the field is considered to be in phase with the current, and the electric component is considered to be in phase with the voltage. The electric field starts at the conductor, and propagates through space at the velocity of light (which depends on the material it is traveling through)

Now, I am interested in knowing how quickly it travels through something OTHER than empty space, like a conductive metal. I want to know how fast that would travel so I did some digging.

https://physics.stackexchange.com/questions/270476/does-the-medium-a-magnetic-field-is-propagating-through-affect-its-speed

But I can't use these equations because the electric constant for metals are infinity, and therefore I cannot use these calculations.

So then I was prompted by this link to look up the index of refraction of metals.

http://electron9.phys.utk.edu/optics421/modules/m1/emwaves.htm

So then I did and I found this reference:

https://refractiveindex.info/?shelf=3d&book=metals&page=copper

But these are correlated to extremely small wavelengths. The wavelengths I am trying to focus on are around oh say 60Hz to 11KHz.

Any thoughts, suggestions, or any other advise? Any help would be greatly appreciated.