Roy Lewallen wrote:
Similarly, a unit of charge (analogous to the momentum of the rolling
ball) propagates much faster than the electrons. Put a unit of charge in
one end, and a unit of charge pops out the other at near the speed of
light, while the electrons themselves move at something like a few miles
per hour.

That works for DC steady-state. For DC transient-state,
photons come into play because the electrons have been
accelerated by the DC leading-edge step function. The
DC impulse during the transient-state is photonic
energy in action, i.e. electromagnetic wave action.

When a DC impulse is first applied to a transmission
line, the ratio of its E-field to H-field is fixed
at Z0 indicating that the energy transfer is photonic.
During DC steady-state the ratio of its E-field to
H-field is fixed by the load indicating that the energy
transfer is electronic.

For EM waves in free space or in a transmission line,
photonic generation and absorption never ceases because
the electrons are being continually accelerated and
decelerated. The cloud of photons is what transfers
most of the energy and the electronic analogy breaks
down.

It is a mistake to use a DC steady-state analogy for
EM waves. EM waves must obey a strict set of boundary
conditions including a ratio of E-field to H-field
that always depends upon the medium.
--
73, Cecil http://www.w5dxp.com