I have always had an issue with the speed of electricity in a wire.
As an electron has mass (although extremely small) it can not travel at the speed of light (einsteins relativity).
But, a lot of physics teachings have said that conventional electricity is the movement of holes in the atoms...
The best way to describe star grounding is this.
Signals and power generate noise through the copper they are travelling. To eliminate the noise from reaching the outside world you have to match the return path of the signal into opposite direction to the signal. Power out match to ground in...