Keith Dysart wrote:

[...]

Notice a key point about this description. It is completely in
terms of charge. There is not a single mention of EM waves,
travelling or otherwise.

Now we expand the experiment by placing a pulse generator at each
end of the line and triggering them to each generate a 50V one
second pulse at the same time. So after one second a pulse has
completely entered each end of the line and these pulse are racing
towards each other at the speed of light (in the line). In another
second these pulses will collide at the middle of the line.

What will happen? Recall one of the basics about charge: like
charge repel. So it is no surprise that these two pulses of charge
bounce off each and head back from where they came.

[...]

Keith

Keith, your model is not realistic. As you know, any signal you
impose on a conductor will form an electromagnetic wave. This is the
combination of electrostatic and electromagnetic fields, and it
propagates at the normal velocity for that medium.

However, electromagnetic waves do not interact with each other, and
they cannot bounce off each other.

Recall that light from stars is electromagnetic. It travels many
light-years before it reaches your eyes. If electromagnetic waves
interacted, you would not be able to see individual stars - they
would merge into a blur.

Similarly, the signals reaching your antenna and traveling down the
coax to your receiver do not interact with each other. As long as
your receiver is not overloaded, the signals remain separate no
matter how many stations are on the air at the moment.

So the statement that like charges repel does not apply to
electromagnetic waves, and the pulses cannot bounce off each other.

Regards,

Mike Monett