Dave wrote:
forget power, forget energy, they are products of other calculations. all
that is needed is impedance and voltage OR current. once you know voltage
OR current and the impedance you can calculate all the rest.

What would you do if you were dealing with EM light waves
instead of EM RF waves? Optical physicists don't have the
luxury of dealing with "impedance and voltage OR current".
They are forced to deal with the essence of EM waves which
is photonic energy. They have done it for over a century
and have learned a lot about the nature of EM waves. They
did not "forget power, forget energy".
--
73, Cecil http://www.w5dxp.com