Keith wrote:
"---it is this cyclical variation in energy flow which prompted power
dudes to invent three phase lines in which energy flow does not vary
cycillaly, power is constant."

It`s true the wires are shared by multiple phases which peak 120-degrees
apart in the 3-phase case. This distributes power flow more evenly with
respect to time and reduces peak loads since the phases never coicide.
Tesla figured this out 100 years ago.

Coincidences of incident and reflected waves are very different from the
cyclical variations of a-c.

Incident and reflected waves have cyclical voltages and currents. As the
reflected wave is just a delayed incident wave, the period is the same
for both.

In those line spots where the total reflected voltage is 180-degrees
different in phase from the incident wave, the net voltage is always
zero during the cycle if the reflection is complete on a lossless line.

The power is not zero at points where the voltage is always zero because
the voltages that add to zero are not zero. In the lossless line, these
voltages are full strength, as are the currents at a current null, some
90-degrees away in space from the voltage null on the line.

Fact is, both the forward power and the reflected power would measure
the same at any point along the line.

The wave action has been observed and documented for more than a
century. The explanations withstand all arguments, so far. Something new
will be needed to replace the ancient wave theory to win acceptance.
Keith`s zero power at zero null spots won`t persuade.

The power appearing to null is not the whole story when there are
forward and reflected powers, each having electric and magnetic fields
with phase differences all around.

Best regards, Richard Harrison, KB5WZI