Keith Dysart wrote:

On Jan 3, 1:07am, Mike Monett wrote:

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.

That is the standard description, but it seems to have some
weaknesses.

No, there are no weaknesses. Maxwell's equations have stood the test
of time.

Recall that light from stars is electromagnetic. It tra vels 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.

This would seem to me to depend on the nature of the interaction.
Clearly the interaction represented by the term "bounce" (for lack
of a better word) would have to be such as to not violate any of
these observed behaviours.

The term "bounce" means they interact. Electromagnetic signals do
not interact. They superimpose. Each is completely unaware and
unaffected by the other.

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 sep
arate 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,

Q1. Are you saying that it is inappropriate to view a transmission
line as distributed capacitance and inductance and analyze its
behaviour using charge stored in the capacitance and moving in the
inducatance?

That is not what you are saying. You are ignoring the magnetic
field.

If such analysis is appropriate, then it seems to me that a pulse
can be viewed as a chunk of charge moving down the line.

Q2. Is this an appropriate view?

No. You need to include the associated magnetic field.

Q3. If so, then what happens when two such chunks of charge
collide in the middle of the line?

Electromagnetic signals do not collide. They superimpose.

The existing analysis techniques tell us that no current ever
flows at the mid-point of the line, this means no charge crosses
the mid-point.

Q4. Is this correct?

That statement has no meaning.

Q5. If no charge crosses the mid-point, then how do the pulses,
made up of chunks of charge. pass the mid-point?

The pulses are not chunks of charge. They are the combination of
electrostatic and electromagnetic fields. You cannot separate the
two.

Q6. If they do not pass the mid-point, then what happens to them?

That statement has no meaning.

I have offerred a somewhat intuitive explanation.

Your explanation does not work.

Other explanations are welcome.

Any explanation that does not involve charge will immediately
cause me to ask Q1 again.

Please study Maxwell's equations and how they are derived.

Keith

Regards,

Mike Monett