"AI4QJ" wrote in
:
Thanks Mike, such information makes me interested in trying it out and
sorry on my part too for any miscommunication and statements about
11m. I am from a generation where computer models had many limitations
but I am now convinced that EZNEC has probably long overcome the
weaknesses of the past.

I think you'll like it. There are some things that it won't do, but I
think that on the whole, it is pretty capable.

It took me from absolutely clueless to neophyte pretty quickly. I
can't keep up when the gurus here start badgering each other, but I can
put something up, and have some understanding about what I'm doing.

- 73 de Mike N3LI -

Cecil Moore wrote:
On Jan 11, 8:27 pm, Gene Fuller wrote:
Everything I said above is exactly correct.

Sorry Gene, almost everything you said about standing waves is false
and some simple math will prove it. Please stop acting like a spoiled
brat long enough to understand the following facts of physics.

[Usual nonsense snipped]


I believe that, in the long run, the technical truth will will out
over all the ignorance, obfuscation, and ad hominem attacks.
--
73, Cecil, w5dxp.com

Cecil,

That is certainly an interesting characterization. Is your position that
anyone who disagrees with you must be a spoiled brat? And who provided
the ad hominem attack in this thread?

You are of course able to believe anything you wish. However, all of
your handwaving explanations about reflections and phase shifts and
phasors will not be found in ordinary discussions about the Poynting
vector. Your "simple math" proves nothing at all, not even close. It is
not reasonable to substitute current and voltage for E-field and H-field
when considering the Poynting vector. The vector nature of the fields is
essential to properly determine the cross product. Go take a look at the
actual field configurations for a TEM wave, which includes standing
waves, and report back to us.

Everything I said in my previous post is exactly correct.

73,
Gene
W4SZ

Cecil Moore wrote:
On Jan 11, 8:32 pm, Gene Fuller wrote:
Wave-particle duality means that light and other electromagnetic
phenomena can be described in terms of waves or in terms of photons.
There is no need to use both descriptions at the same time. The laws of
physics are complete for either.

Actually, what you don't seem to realize is that exactly the same laws
apply to both at the same time and all those laws are perfectly
consistent. Photons cannot stand still. Therefore, standing waves are
not photonic, i.e. they are not EM waves. That you assert the standing
wave E-field and H-field are 90 degrees apart is insanity (in addition
to being completely false).
--
73, Cecil, w5dxp.com

Cecil,

You keep ignoring the "sloshing" explanation. Actually, you did not
totally ignore it; you did indeed criticize the choice of the
descriptive word "sloshing".

The standing wave envelope may be stationary, but the fields are not.
There is no conflict with your photonic requirements.

Since this discussion about fields and waves seems to annoy some of the
"good buddy" crowd around here, I will quit now and let you win by default.

73,
Gene
W4SZ

On Jan 14, 10:59 am, Gene Fuller wrote:
You keep ignoring the "sloshing" explanation. Actually, you did not
totally ignore it; you did indeed criticize the choice of the
descriptive word "sloshing".

Look up the word "slosh" in the dictionary, Gene. It is impossible for
EM energy to "slosh". While you are at it, you might as well assert
that photons smell bad.

EM (photonic) waves do NOT change direction unless a change in medium
is encountered. "Sloshing" requires a change in direction in the
complete absence of a medium change. It is a very ignorant, impossible
concept.

The standing wave envelope may be stationary, but the fields are not.

There is no net energy movement in the kx direction as evidenced by
the equation: cos(kx)*cos(wt). All the energy movement is between the
E-field and H-field at any fixed point along the wire.

There is no conflict with your photonic requirements.

Of course there is and I proved it with math. If you want to prove me
wrong, prove my math wrong. Good luck on that one.

Since this discussion about fields and waves seems to annoy some of the
"good buddy" crowd around here, I will quit now and let you win by default.

Translation: I have discovered my error. The standing-wave E-field and
H-field really are either 0 or 180 degrees apart. Drawing those fields
on paper and superposing them proves it.
--
73, Cecil, w5dxp.com

On Jan 14, 10:53 am, Gene Fuller wrote:
Is your position that
anyone who disagrees with you must be a spoiled brat?

The day you decided that you already know everything there is to know
is the day you started getting more and more ignorant and started
acting like a spoiled brat. Instead of screaming in anger that I am
wrong, I challenge you to produce the math that proves me wrong.

It is
not reasonable to substitute current and voltage for E-field and H-field
when considering the Poynting vector.

Please prove that strange assertion. Is the voltage not proportional
to the E-field? Is the current not proportional to the H-field? For
traveling waves, is not Z0 = V/I and proportional to E/H?

Go take a look at the
actual field configurations for a TEM wave, which includes standing
waves, and report back to us.

That's what I did already, Gene. You should take your own advice. It's
a little harder to visualize than voltage and current but follows
exactly the same concepts plus the right hand rule. Let's take two
equal coherent TEM plane waves forming standing waves in free space as
described by Hecht in "Optics". At one point the forward wave E-field
is at 135 degrees which puts the H-field at -135 degrees. The
reflected wave E-field is at 45 degrees which puts the H-field at -45
degrees.

Efor at 135 deg + Eref at 45 deg = |Efor|+|Eref| at 90 degrees

Hfor at -135 deg + Href at -45 deg = |Hfor|+|Href| at - 90 degrees

For standing waves, the H-field is 180 degrees offset from the E-
field. The power in the standing wave is ExH = E*H*sin(180) = ZERO.
Your assertion that the E-field and H-field are 90 degrees apart for
standing waves is simply FALSE! Please prove fact of physics that for
yourself.

Standing waves do not meet the requirements for an EM wave! Hecht was
right about that.

Feel free to do something besides wave your hands, mount ad hominem
attacks, and engage in obfuscation.
--
73, Cecil, w5dxp.com



c

Cecil Moore wrote:
On Jan 11, 4:04 pm, Jim Kelley wrote:

Cecil Moore wrote:

A standing wave has an associated envelope but the envelope is *NOT*
the wave itself.

No, it's plot of the equation - just like any other plot one might
make of it. It simply a plot of amplitude vs position at a fixed time.


I'm glad you finally agree.

I'm glad you finally understand.

73, ac6xg

On Jan 14, 2:37*pm, Cecil Moore wrote:
It is impossible for EM energy to "slosh".
[gratuitous insult snipped]
EM (photonic) waves do NOT change direction unless a change in medium
is encountered. "Sloshing" requires a change in direction in the
complete absence of a medium change.
[gratuitous insult snipped]
There is no net energy movement in the kx direction as evidenced by
the equation: cos(kx)*cos(wt). All the energy movement is between the
E-field and H-field at any fixed point along the wire.

As you say, the energy moves between the E-field and the H-field,
but the locations of maximum energy along the line for each of these
fields is different, so the energy changes position on the line with
each cycle. The energy at any point on the line is not constant.

E-field energy will peak at the voltage maximums.
H-field energy will peak at the current maximums.
These are at different places (90 degrees apart).
So energy does move within the line, though no energy crosses a point
where the voltage or current is always 0.

http://www.eznec.com/misc/rraa/TLVis1.exe Demo #2 is a simulation that
helps visualize this change in the location of the energy.

...Keith

Cecil Moore wrote:

Standing waves do not meet the requirements for an EM wave!

Here's a perfect example of what you're saying:

http://id.mind.net/~zona/mstm/physic.../StandingWaves

A standing wave, yet presumably not an electromagnetic wave! ;-)

ac6xg

Jim Kelley wrote:

...
http://id.mind.net/~zona/mstm/physic.../StandingWaves


A standing wave, yet presumably not an electromagnetic wave! ;-)

ac6xg

That page is coming up "Not Found." on my browser; Is there an error in
the URL? I am asking because, too often, my browser is giving me this
error on URLs' posted by people ... I can't find any reason for it.

Thanks in advance,
warmest regards,
JS

On Mon, 14 Jan 2008 12:40:39 -0800 (PST)
Keith Dysart wrote:

snip...............
As you say, the energy moves between the E-field and the H-field,
but the locations of maximum energy along the line for each of these
fields is different, so the energy changes position on the line with
each cycle. The energy at any point on the line is not constant.

E-field energy will peak at the voltage maximums.
H-field energy will peak at the current maximums.
These are at different places (90 degrees apart).
So energy does move within the line, though no energy crosses a point
where the voltage or current is always 0.

I can understand no energy crossing a zero current point, but how do you justify no energy crossing a zero voltage point when current IS observed? Current is defined as movement of charges, and charges have energy by definition (how can they be charges without energy?).

Another point, the current is observed to change directions during the cycles, polarity also changes on each side of the zero voltage point. Where might the polarized energy come from if it does not cross the zero voltage point?

I can kinda see how like charges could repell so that waves of like polarity might "bounce" but I can't see how waves of opposite polarity might "bounce". If waves of opposite polarity "bounced", why would the polarity change during the cycle on each side of the "bounce" point?

To me, it is much more rewarding to work with traveling waves that pass through one another, interacting to create standing waves.

Would it help your visualization process to observe that when two waves of SAME POLARITY but traveling in opposite directions cross, the currents accompaning the waves are moving in opposite directions both before and after crossing? When two waves of OPPOSITE POLARITY but traveling in opposite directions cross, the currents are moving in the same direction both before and after crossing.

If we were talking about water, water behind a dam is like voltage, with the height of the water the potential energy, measured in head (feet), or PSI if measured at the bottom of the dam. A pipe to the bottom of the dam will squirt water at a high velocity but no head or PSI. The potential energy of the water behind the dam has been converted to kinetic energy measued in velocity of a moving mass. The moving water can be stopped, and if carefully done, the static head reached by stopping the water will nearly reach the original water level behind the dam. It would reach the same level if it were not for friction losses. Electrical current is something like that moving water.


http://www.eznec.com/misc/rraa/TLVis1.exe Demo #2 is a simulation that
helps visualize this change in the location of the energy.

...Keith

73, Roger, W7WKB