Standing-Wave Current vs Traveling-Wave Current
 

Gene Fuller wrote:
I see we are back to the old business about colliding waves that
apparently carry vector power. At least it seems that way since the
counter-traveling power can cancel at some points and add up at other
points. I thought we trashed this idea a couple of years ago.

Please cease the obfuscation. It cannot be explained any
better than these two web pages. Please note that "intensity"
is a power density (watts/unit-area) and it is *energy* that
is redistributed, not voltage or current.

www.mellesgriot.com/products/optics/oc_2_1.htm

"Clearly, if the wavelength of the incident light and the
thickness of the film are such that a phase difference exists
between reflections of p, then reflected wavefronts interfere
destructively, and overall reflected intensity is a minimum.
If the two reflections are of equal amplitude, then this
amplitude (and hence intensity) minimum will be zero."
[Referring to 1/4 wavelength thin films.]

"In the absence of absorption or scatter, the principle of
conservation of energy indicates all 'lost' reflected intensity
will appear as enhanced intensity in the transmitted beam. The
sum of the reflected and transmitted beam intensities is always
equal to the incident intensity. This important fact has been
confirmed experimentally."

micro.magnet.fsu.edu/primer/java/scienceopticsu/interference/waveinteractions/index.html

"... when two waves of equal amplitude and wavelength that are
180-degrees ... out of phase with each other meet, they are not
actually annihilated, ... All of the photon energy present in
these waves must somehow be recovered or redistributed in a new
direction, according to the law of energy conservation ... Instead,
upon meeting, the photons are redistributed to regions that permit
constructive interference, so the effect should be considered as
a redistribution of light waves and photon energy rather than
the spontaneous construction or destruction of light."
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:
[...]

Frankly, I like things "simple."

In the standing wave experiment, involving creating a standing wave on a
string with a vibrational apparatus--where would you think one would be
tempted/inclined to attempt a mechanical "contact/connection" with the
string to extract [work,power,energy?]

If anyone elses' inclinations are similar to my own, it would be a
"hump" ...

Regards,
JS

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:

... As I said above, to which
you objected, standing waves cannot exist independently
of their forward and reverse components. I stand by that
statement. Prove it wrong if you can.

The logic in your argument is flawless, in fact, I believe it ...

However, the voltage/current/power/energy/joules given out by my car
alternator cannot exist independently of the petrol powered motor.
Still, I consider that electrical voltage/current/power/energy/joules a
"SEPARATE entity" ...

Yanno, he didn't come last night ... the cookies and milk still sit
before the hearth, no unaccounted gifts clutter the space beneath the
tree ... yet still, I believe! :-P

Regards,
JS

Standing-Wave Current vs Traveling-Wave Current
 

John Smith wrote:
[ramblings]

I remember, back in the early 60's I built a coaxial tank circuit for
the fm band (88-108mc) for a selective receiver ... I wonder ... sound
of books opening--case coming off the old ti-86 ???

JS

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:
Gene Fuller wrote:
Cecil Moore wrote:
The net voltage and net current are real but their independent
existence apart from the underlying traveling waves is just
an illusion.

This sums it up pretty nicely. Reality is an illusion. No wonder many
people have a hard time accepting your nonsense. You have built your
own little world where reality and illusion are randomly intertwined
as suits the needs of the moment.

Reality can certainly contain illusions. Sunrise and sunset
are a couple of examples.

There aren't really any sunrises or sunsets, Cecil?

Magician tricks are another.

Magic tricks aren't illusion, but reality? Those guys are really
working magic? Wow, my entire belief system is crumbling.

Dave K8MN

Standing-Wave Current vs Traveling-Wave Current
 

Dave Heil wrote:
Reality can certainly contain illusions. Sunrise and sunset
are a couple of examples.

There aren't really any sunrises or sunsets, Cecil?

The sun doesn't rise or set. That is just an illusion
caused by the planet upon which we are standing rotating
on its axis.

And Dave, neither does the Sun God ride his flaming
chariot across the sky each day.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:
Roy Lewallen wrote:

The existence of both voltage and current at any point along the line
tells us that there is instantaneous power at that point, ...

Not if the voltage and current are always 90 degrees out of
phase which is a fact of physics for pure standing waves. There
is no power, instantaneous or otherwise, in pure standing waves.
The cosine of 90 degrees is *always* zero.

These comments in total are very interesting, by both authors. Thank
you for them.

It is clear that there is not a standard way of describing energy that
is in the process of being stored in either an inductor or capacitor.
Clearly it is stored, not used (converted) as in a resistor.

Storage of energy in a capacitor (for instance) occurs over time and
requires power to complete. So how do we describe that power if it is
always zero because voltage and current are 90 degrees out of phase?
Should we recognize that only the peak voltage and peak current is 90
degrees out of phase, with the entire charging time occurring within
those two time extremes? Between those two time extremes, the voltage
and current are in phase but at changing impedance, with power flowing
into the capacitor. So think I.

I think of the "standing wave" as being equivalent to the graph on my
power bill that shows power used daily over a month. Granted that the
standing wave is recorded in V or I, but we only need to know the R that
the standing wave is acting through to determine the power that it
represents.

I certainly find this interesting.

73, Roger, W7WKB

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:

... neither does the Sun God ride his flaming
chariot across the sky each day.

Finally, we are in total agreement!

That is Santa, damn idiots believing in some sun god, DUH!

You think he supports Mrs. Santa and the elves off a single days work
per year? ;-)

Regards,
JS

Standing-Wave Current vs Traveling-Wave Current
 

Roger wrote:
So how do we describe that power if it is
always zero because voltage and current are 90 degrees out of phase?

Here's how power engineers solve the problem.
Voltage and Current are phasors.

V*I = volt-amps

V*I*cos(A) = Watts, real power

V*I*sin(A) = VARS, reactive power
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:
Dave Heil wrote:
Reality can certainly contain illusions. Sunrise and sunset
are a couple of examples.

There aren't really any sunrises or sunsets, Cecil?

The sun doesn't rise or set. That is just an illusion
caused by the planet upon which we are standing rotating
on its axis.

Sorry, Cecil, it isn't an illusion. Sunrise and sunset are simply names
we've given to that which you've described. They really take place and
are not at all an illusion.

And Dave, neither does the Sun God ride his flaming
chariot across the sky each day.

Then again, you're the only fellow writing about such. I've made no
mention of anything like that.

What about the magic tricks?

Dave K8MN