Bob Masta said:
Mike, the speed of the carrier in a wire is the electron drift
velocity, which is ridiculously slow in "normal" cases. The
speed of information is close to the speed of light. That's
all I was trying to convey.
That is incorrect in detail. the quantity "c" is the phase velocity.
The speed of information transfer is the group velocity.
In free space, TEM waves are propagated without dispersion. In that
case both those velocities are c.
In a wave guide supporting a wave with a longitudinal component of
either E or H, those two velocities differ from one another and
neither of them is equal to c, even when the guide is evacuated.
Franz