[71 dB]

Wake me up when we start talking about home audio again.

Yeah. Given the frequency range of audio and typical cable lengths, speed of electricity can be considered infinite and everybody can move on...

 

[71 dB]

Does someone actually know how far electrons travel at 60hz AC in one half cycle? i mean, some talked about electrons "wiggling" around (i would assume a few mm here) but 1/120 of a second is probably much larger distance for electrons than a few mm

Edit: So with electrons traveling at 300.000km / s .... 1/120 of that is 2,5km, so could we assume with AC electrons travel 2,5km before they turn around?

Electrons move very slowly, a small fraction of a millimetre during a 50 Hz/60 Hz cycle. The movement of electrons (negative charges) is opposite to the direction of electric current which is defined as the movement of positive charge.

300.000 km/s is the propagation speed of electromagnetic fields in vacuum. In glass this speed drops to 150.000-215.000 km/s (depending on the type of glass) due to the electromagnetic field interacting with the atoms in the glass. The electrons in the glass react to the electromagnetic field and start to wiggle along. this generates a new electromagnetic field which summed to the original one creates a new electromagnetic field that is phase-shifted (delayed). This happens continuously as the electromagnetic field propagates in the glass resulting a group velocity smaller than 300.000 km/s. Glass is an insulator. There is almost zero current through glass. The electrons in glass wriggle around their atoms, but they don't jump to other atoms. They can't create electric current.

Electrons can't even move at the speed of light, because they have rest mass. The relativistic mass would become infinite. If we had electrons moving in a cable close to the speed of light, the energy levels would insane. The cable would vaporise instantly I believe. Power cables can get warm even when electrons move very slowly.