Keith Dysart wrote:
On Jun 4, 1:26 pm, K1TTT wrote:
On Jun 4, 2:12 pm, Cecil Moore wrote:
Thanks David, that's good news. It apparently means that the arguments
based on energy not crossing a current node boundary in a standing
wave are invalid - since that singular condition violates the boundary
conditions for Maxwell's equations. So does the "standing wave energy
standing still" argument. Not only does the photonic nature of EM
waves require them to travel at the speed of light in the medium, but
so does Maxwell's equations.
definately. another simple condition shows this can't be correct
since current nodes correspond with voltage peaks in the standing wave
pattern, so while energy in the magnetic field is a minimum the energy
in the electric field is a maximum.

And yet....

It is generally accepted that power = volts times current (P=VI) and
that
power is energy flowing, so if the voltage or current is always 0,
there
must be no energy flowing.

Consider two equal valued resistors connected in series. Connect one end
of the pair to +12 volts, connect the other end of the pair to -12
volts. The voltage at the center is 0. There is certainly current
flowing. There clearly is power dissipated in the circuit.



The presence of voltage without current, or current without voltage is
an indication that energy is stored, not that energy is flowing.

The above example has current but no voltage, There are no storage
elements, only resistors.

Inductance and capacitance are storage elements. You might find those in
a model of a transmission line, but not in this example.



So are you really prepared to give up on P=VI so that energy can be
flowing (i.e. there is power) when the voltage or current is zero?

...Keith

I think you are looking to hard at a small part of the picture and not
seeing what else is going on.