Is the Superposition Principle invalid?
 

"Dave" wrote ...

"Cecil Moore" wrote

Keith Dysart wrote:
Superposition of voltages and currents seems to be quite
accepted and is an excellent tool for circuit and transmission
line analysis.

Do you really expect us to believe that those voltages
and currents can exist without energy? Maybe an example
of EM voltage and EM current existing without ExB joules/sec
would help.
--
and yet again you cross up terms... voltage and current are on wires. E
and B are fields between or outside of wires. while they can be handled
similarly they should not be compared directly as you are asking. and
yes, there is at least one very good example of a voltage without ExB...
just charge a balloon up with some stray electrons and leave it alone long
enough to reach steady state... voila, E with no B. Please do this
experiment and reply when you have truly reached steady state.
I've been waiting for someone to open the door so that Art could take
part in this thread.Dave, your use of the balloon as an example will do the
job nicely. Art will now be able to contribute quite a lot, although I'm not
sure that he ever reaches steady state!

Mike W5CHR

Is the Superposition Principle invalid?
 

Keith Dysart wrote:
So some times
Ptot = Pf - Pr

Waves traveling in opposite directions have no effect
on each other. The result is standing waves.

while at other times
Ptot = P1 + P2 + Pfudge

Actually, Ptot = P1 + P2 +/- Pinterference

Coherent waves traveling in the same direction have an
effect on each other. As quoted from "Optics", the last
term in the irradiance (power) equation is known as the
"interference term".

Neither of the equations is the "algebraic sum".

Of course not, power does not follow the superposition
principle. The irradiance (power) equation is the correct
way to add the power scalars that exist in superposed waves.

I'm posting an energy brain teaser problem under a new
thread by that name. Try solving the problem by conventional
methods and then try an energy analysis.
--
73, Cecil http://www.w5dxp.com

Is the Superposition Principle invalid?
 

Cecil Moore wrote:
Gene Fuller wrote:
Even if you could separate the forward and reverse waves the Poynting
vector energy calculation would still come out to exactly zero for
each component as well as the sum of the components.

Forward and reflected waves are easily separated by a
circulator so their existence is difficult to deny.

So net energy equals zero? So what! We are NOT discussing net
energy here. We are discussing the forward Poynting vector
and the reflected Poynting vector as described in "Fields and
Waves ...", by Ramo and Whinnery. The Superpositon Principle
gives us permission to do so and the final result is identical
to any other valid analysis. Why are you guys so irrationally
afraid of the wave reflection model? What is your ulterior
motive in denying the existence of reflected waves during
steady-state? It has seemingly turned into a steady-state
religion administered by the steady-state high priests.


Cecil,

I guess I was not quite clear. I don't care if you are talking net
energy, gross energy, with or without circulators, or anything else. As
long as there are no sources or sinks of energy in the region of
interest, the Poynting vector tells you absolutely nothing about energy
balance or conservation of energy.

You could have a completely incorrect analysis of forward and reverse
waves, and the Poynting analysis will not reveal the error. The required
integral will still come out to exactly zero.

Radio amateurs and radio charlatans love to talk about Poynting vectors,
but it is obvious that most of those folks simply don't understand the
full picture. Just forget about ExB (or more commonly, ExH). It is
completely useless in support for the typical RRAA discussions.

73,
Gene
W4SZ

Is the Superposition Principle invalid?
 

Gene Fuller wrote:
I guess I was not quite clear. I don't care if you are talking net
energy, gross energy, with or without circulators, or anything else. As
long as there are no sources or sinks of energy in the region of
interest, the Poynting vector tells you absolutely nothing about energy
balance or conservation of energy.

That's not the point at all. The question is pretty
simple. Does the principle of superposition give us
permission to analyze the individual forward and
reflected waves separately and then superpose the
results? If you say "no", then you don't accept the
superposition principle. If you say "yes", then
please stop harping that the only valid way to solve
a problem is your way.

Just forget about ExB (or more commonly, ExH).

Your advice is to forget acquired knowledge and tools
and put one's trust in who? You?
--
73, Cecil http://www.w5dxp.com

Is the Superposition Principle invalid?
 

Cecil Moore wrote:
Gene Fuller wrote:
I guess I was not quite clear. I don't care if you are talking net
energy, gross energy, with or without circulators, or anything else.
As long as there are no sources or sinks of energy in the region of
interest, the Poynting vector tells you absolutely nothing about
energy balance or conservation of energy.

That's not the point at all. The question is pretty
simple. Does the principle of superposition give us
permission to analyze the individual forward and
reflected waves separately and then superpose the
results? If you say "no", then you don't accept the
superposition principle. If you say "yes", then
please stop harping that the only valid way to solve
a problem is your way.

Just forget about ExB (or more commonly, ExH).

Your advice is to forget acquired knowledge and tools
and put one's trust in who? You?

Cecil,

I have said many times that you can choose to analyze the individual
components or you can analyze the superposed combination, i.e., a
standing wave. It is purely a matter of mathematical convenience.
However, if you get different answers, including more or less
completeness, then you have made an error. That is the essence of
superposition. If that property was not true, then superposition would
be of little value.

It is rather ironic that you are accusing *me* of allowing only one
valid method when I have repeatedly stated a flexible approach. Is that
some sort of debating technique you learned?

Are you instead seeing a reflection of yourself? Is this some sort of
mirror trick?

8-)

73,
Gene
W4SZ

Is the Superposition Principle invalid?
 

Gene Fuller wrote:
I have said many times that you can choose to analyze the individual
components or you can analyze the superposed combination, i.e., a
standing wave. It is purely a matter of mathematical convenience.
However, if you get different answers, including more or less
completeness, then you have made an error. That is the essence of
superposition. If that property was not true, then superposition would
be of little value.

An energy analysis yields exactly the same results as any
other valid method of analysis and is often much easier.
There are no "different answers", yet you imply there are.
An energy analysis obeys all of the principles of physics.
Optical physicists have been solving energy analysis
problems for centuries.

It's a simply yes/no question: Does the analysis of the
forward wave and reflected wave separately abide by the
rules of the principle of superposition? The answer is
obviously "yes" because identical results are obtained
using either method.

It is rather ironic that you are accusing *me* of allowing only one
valid method when I have repeatedly stated a flexible approach.

Stated, yes. Practiced, no. I don't attack your methods,
Gene, yet you repeatedly attack other valid methods that
yield results identical to yours with less effort. You
only pay lip service to your "flexible approach". Your
practiced approach is pretty narrow-minded - your way or
no way.
--
73, Cecil http://www.w5dxp.com

Is the Superposition Principle invalid?
 

On Mar 31, 10:33 am, Cecil Moore wrote:
Gene Fuller wrote:
I have said many times that you can choose to analyze the individual
components or you can analyze the superposed combination, i.e., a
standing wave. It is purely a matter of mathematical convenience.
However, if you get different answers, including more or less
completeness, then you have made an error. That is the essence of
superposition. If that property was not true, then superposition would
be of little value.

An energy analysis yields exactly the same results as any
other valid method of analysis and is often much easier.

A strange assertion given that in another thread your energy
analysis was incapable of producing any result while alternative
techniques could readily answer the question.

....Keith

Is the Superposition Principle invalid?
 

On Mar 31, 9:18 am, Cecil Moore wrote:
Keith Dysart wrote:
Neither of the equations is the "algebraic sum".

Of course not, power does not follow the superposition
principle.

Well that is a great leap forward. Since that was the point
of my response to your first post, I am curious as to why
you chose to object.

Do you now agree?

....Keith

Is the Superposition Principle invalid?
 

Keith Dysart wrote:
A strange assertion given that in another thread your energy
analysis was incapable of producing any result while alternative
techniques could readily answer the question.

Strange that you are willing to accept your erroneous
results based on mixing virtual and physical reflection
coefficients in the same example. Your "alternative
techniques" yielded a bogus answer.
--
73, Cecil http://www.w5dxp.com

Is the Superposition Principle invalid?
 

Keith Dysart wrote:
Well that is a great leap forward. Since that was the point
of my response to your first post, I am curious as to why
you chose to object.

Exactly what is it that I objected to?

Do you now agree?

Old, worn out, diversionary technique. Doesn't work.
If you can prove that I ever said power can be
superposed, I will send you a $100 bill.

Have you stopped beating your girlfriend? See,
I know how to do that also.
--
73, Cecil http://www.w5dxp.com