Keith wrote:
"At the quarter wave points where voltage and current are always zero,
there is no energy flowing. Period."

Yes there is energy flowing, and it is flowing in both directions if it
is flowing in one direction. Otherwise there would be no standing wave.

The waves flow right through each other so long as the impedance is
uniform. Energy flow is unabated at those points of illusory zeros.
Those zeros are not zeros at all in the forward and reverse waves. They
only appear as zeros when your sensor can`t separate the forward from
the reverse. Get a proper directional sensor and the forward wave is
sensed as full amplitude as is the reverse wave.

Best regards, Richard Harrison, KB5WZI