On Jan 3, 1:07*am, 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.

* 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.

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.

* 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,

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?

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?

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

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?

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

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

I have offerred a somewhat intuitive explanation.
Other explanations are welcome.

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

...Keith