Cecil Moore wrote:
wrote:
But what I really want to know is how Cecil can have current flowing
both directions at the same instant of time in a single point of single
conductor,
Forward and reflected EM waves, of course. Would you like to deny
the existence of the two waves in the following equation?
I(x,t) = I1*cos(kx+wt) + I2*cos(kx-wt) = Io*cos(kx)*cos(wt)
Those two expressions describe patterns of current over time and
location that produce current in each direction half the time (except
at nodes, where the current is zero).
The amplitude of a current cycle is constant for the first one
(traveling wave), but the phase differs at different locations (by the
amount of kx).
The amplitude of current cycle described by the second one (traveling
wave) varies with location, and the phase has only two possibilities
(one when cos(kx) is positive and 180 degrees different when cos(kx)
is negative). But in both cases, current at any point reverses twice
a cycle (cos(wt)) and charge goes nowhere over a cycle.