Cecil, W5DXP wrote:
"It`s not magic and is explained on the Melles-Groit web page---. (how
the energy magically reverses direction and heads back toward the load.)

I agree. It isn`t magic. Optical examples are good because we can see
reflections.

I think we have impedances which are inherent from the physical and
electrical characteristics that describe the path the electrical energy
takes. The path enforces the voltage to current ratio called impedance.

First example is Zo. Second example is 377 ohms of free-space. Third
example is resistor type resistance. Resistance is a property based on
configuration, dimensions, material, and temperature which make a
certain voltage to current ratio, which is measured in ohms. One ohm is
the resistance at zero degrees C of a uniform column of mercury 106.300
cm long and weighing 14.451 grams. One volt across a resistor of one ohm
causes a current of one ampere.

A wave travels down a transmission line and it consists of a traveling
electric field and an associated traveling magnetic field. Relative
strengths of the electric and magnetic fields on a practical uniform
transmission line are forced into a ratio Zo which is the square root of
the ratio of the inductance per unit length divided by the capacitance
per unit length. Zo is measured in ohms.

If the line is terminated in an impedance other than Zo, one of the two
fields is in limited supply as compared with its travel partner. As the
termination only accepts energy in its fixed ohms ratio of voltage to
current, surplus energy in the ample field is all rejected and reflected
as it has nowhere else to go other than to reverse its course.

The reflected wave must conform to Zo the same as the incident must.

Seems to me there`s no magic. The waves just do what they must.

Best regards, Richard Harrison, KB5WZI