Gaussian statics law
 

Cecil Moore wrote:
Ian White GM3SEK wrote:
This applies to all forms of EM energy, so let's calculate the 'step
size' in an RF waveform at 10MHz. That will be the energy content of a
single quantum, which turns out to be 0.000 000 000 000 000 000 000
000 0066 joules - which is unimaginably small.

Maybe 40 nano-eV is more imaginable? :-)
For me, it is a lot easier to visualize a cloud
of photons leaving an antenna than it is to visualize
the field lines closing upon themselves (like a soap
bubble) and breaking free of the antenna.


Each to his own imagination. I'd find it hard to keep track of all
10^(30) photons emitted from here this weekend... though some of them
will probably send postcards :-)


Incidentally, your above number is off by 0.3% :-)

Well, imagine that!


--

73 from Ian GM3SEK

Gaussian statics law
 

Cecil Moore wrote:
Ian White GM3SEK wrote:
This applies to all forms of EM energy, so let's calculate the 'step
size' in an RF waveform at 10MHz. That will be the energy content of a
single quantum, which turns out to be 0.000 000 000 000 000 000 000
000 0066 joules - which is unimaginably small.

Maybe 40 nano-eV is more imaginable? :-)
For me, it is a lot easier to visualize a cloud
of photons leaving an antenna than it is to visualize
the field lines closing upon themselves (like a soap
bubble) and breaking free of the antenna.

Incidentally, your above number is off by 0.3% :-)

Well, I am just sitting here with this 120,000 gauss magnet in my hand
and a magnifying glass in the other--attempting to see the photons
shooting from one side of the magnet to the other ... I'd at least think
the dern photons excite the gas and would light up the neon bulb I am
holding next to one side!

JS
--
http://assemblywizard.tekcities.com

Gaussian statics law
 

John Smith I wrote:
Well, I am just sitting here with this 120,000 gauss magnet in my hand
and a magnifying glass in the other--attempting to see the photons
shooting from one side of the magnet to the other ... I'd at least think
the dern photons excite the gas and would light up the neon bulb I am
holding next to one side!

Maybe a quote from "Optics", by Hecht is in order:
"Virtual photons can never escape to be detected
directly by some instrument." Sorry about that.
--
73, Cecil http://www.w5dxp.com

Gaussian statics law
 

Richard Clark wrote:
On Sat, 10 Mar 2007 09:33:46 +0000, Ian White GM3SEK
wrote:

Quantum theory describes electromagnetic energy as being divided into a
series of packets called photons, so (total energy in a stream of
photons) = (number of photons/second) x (energy of individual photons).

Energy is not expressed with a time in the denominator. The standard
quantum theory expression for energy is eV - time is wholly absent as
it should be.


Sorry, that was an editing mistake: obviously it's power that includes
the time dimension, energy does not.


This also means that EM energy doesn't exist in pure sine-waves

EM theory does not exclude the classic description of pure sine waves.
This is not a neither/nor situation.

- the
waveform is actually built up in steps, very much like digitized audio.

This appears to be the beginnings of a description about to fall off
the edge. What waveform? This is a conceit of time.

The step size is the energy content of one quantum.

No, the step size as you describe is the potential difference of
quantization, an engineering term, not a quantum mechanics term. It
is quantisizing an amplitude to construct the wave in a time domain.
Quanta is the complete wave in a frequency domain.


Richard is right about that. Please ignore my remarks about quantization
within the waveform itself. The quantization only affects the total
quantity of energy; or the power level if you wish to consider the rate
of energy transfer.

However, that doesn't affect the main point: at normal radio
frequencies, RF energy is composed of unimaginably small packets, in
unimaginably large numbers. This means that quantization effects in
energy or power levels are utterly negligible, and we can always think
of RF energy or power as a continuous stream.

It's rather similar to being aware that electric current is actually
made up of individual electrons - it's interesting information, but
electronic engineering very rarely needs to acknowledge the existence of
individual electrons. Even less does antenna engineering need to
acknowledge the existence of individual RF photons.

As I said in the previous posting, the energy of EM photons is
proportional to the frequency, so quantization effects only begin to be
noticeable at frequencies of hundreds of gigahertz, and still only as a
small correction in measurements of the very lowest power levels we can
detect.

Richard cited the following as a claimed exception:

A photon is emitted in the cM band when an electron orbiting a
Hydrogen atom flips its magnetic pole. This event is vastly below the
short wavelengths you describe by a million-fold. A good number of
correspondents here are fully capable of detecting this event with
commercial gear already suitable for the Ham market. They could have
done it 50 years ago too.

That is an example of a quantum effect determining the *frequency* of an
RF emission... but the origin of the RF energy doesn't change its
character. If a signal generator is tuned to that frequency, it will
produce exactly the same kind of RF energy - a torrent of quanta so tiny
that their individual existence is irrelevant.



--

73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Gaussian statics law
 

Cecil Moore wrote:

...
Maybe a quote from "Optics", by Hecht is in order:
"Virtual photons can never escape to be detected
directly by some instrument." Sorry about that.

Cecil:

You know me by now, I jest.

If we knew as much (in quantity) as we DON'T know--we'd know enough to
be of importance ... :(

JS
--
http://assemblywizard.tekcities.com

Gaussian statics law
 

On Sun, 11 Mar 2007 21:23:28 +0000, Ian White GM3SEK
wrote:

Richard cited the following as a claimed exception:

A photon is emitted in the cM band when an electron orbiting a
Hydrogen atom flips its magnetic pole. This event is vastly below the
short wavelengths you describe by a million-fold. A good number of
correspondents here are fully capable of detecting this event with
commercial gear already suitable for the Ham market. They could have
done it 50 years ago too.

That is an example of a quantum effect determining the *frequency* of an
RF emission... but the origin of the RF energy doesn't change its
character. If a signal generator is tuned to that frequency, it will
produce exactly the same kind of RF energy - a torrent of quanta so tiny
that their individual existence is irrelevant.

Hi Ian

Determining the *frequency*? That has to be the most obscure
contribution I've ever seen.

The origin in fact does change its character - that is the whole point
and it is an elemental point of sub-atomic physics at that. Can you
offer a counter-example or any example of Photon generation that
leaves no trace of change? I can offer one that doesn't, I can offer
one that does leave a trace (already done), and examples where the
photon originates from non-electron interaction.

For this last, they too inhabit wavelengths that are orders of
magnitude below the visible. Phononic-Photonic interactions may not
fill library shelves, but their several volumes that do fill at least
one shelf are quite thick. Beyond their contributions we find those
from Excitons, Polarons, Polaritons, Plasmons and so on down the
energy band into the less than milli-eV range. Such photon generation
is in a continuum of wavelengths that challenges the simple Lyman
series of discrete resonances (much less all the other series) you
alluded to previously. That continuum extends over great swaths of
the RF spectrum. To your credit, you allude to this spectrum but
underplay the consequences:
noticeable at frequencies of hundreds of gigahertz, and still only as a
small correction in measurements of the very lowest power levels we can
detect.
The effects are not marginally detectable and are the basis of a new
industry called Nanotechnology.

As for a torrent of quanta so tiny that their individual existence is
irrelevant, this distinction could be as easily lost on sunshine, much
less HF wavelengths. One can certainly find a power density from an
HF antenna that equals that of sunshine. The scale of comparing the
number of photons would be the difference between drinking out of a
firehose or a tidal wave. Clearly both have long escaped the
magnitudes of a gulp and to a drowning man, the comparison would be
ironically trivial.

73's
Richard Clark, KB7QHC

Gaussian statics law
 

Richard Clark wrote:
Determining the *frequency*? That has to be the most obscure
contribution I've ever seen.

Richard, do you understand that free electrons can
emit photons of any frequency? i.e. no orbital change
necessary?
--
73, Cecil http://www.w5dxp.com

Gaussian statics law
 

On Mar 11, 12:38 am, Richard Clark wrote:
On Sun, 11 Mar 2007 06:00:27 +0000 (UTC), (John E.


Davis) wrote:
On Sat, 10 Mar 2007 23:21:35 GMT, Dave
wrote:


I will make one last effort to to set the record straight. In volume
II of the Feynman Lectures on Physics, the title of chapter 15,
section 6 is "What is true for statics is false for dynamics". The
5th paragraph of that section states "Gauss' law, [eq omitted]
remains...". Also in that section, he has a table (Table 15-1) that
contains two columns:

FALSE IN GENERAL | TRUE ALWAYS
(true only for statics) |
------------------------------------------------------
Coulomb's Law | Gauss' law
[...] | [...]

At the bottom of that Table is a footnote explaining the bold arrow of
your Gauss' law. It reads:
"The equations marked by an arrow (-») are Maxwell's equations."

The table equation, and the one you reference in the text are both
Maxwell's.

Then in chapter 18, section 1 paragraph 3 you will find the statement:

"In dynamic as well as static fields, Gauss' law is always valid".

That chapter, too, clearly defines the same equation you are making an
appeal to as "Maxwell's equations." Observe Table 18-1 "Classical
Physics"

It is explicitly derived from the treatment as equation 4.1 - also
denoted Maxwell's equations.

"All charges are permanently fixed in space, or if they do move,
they move as a steady flow in the circuit ( so rho and j are
constant in time). In these circumstances, all of the terms in
the Maxwell equations which are time derivatives of the field are
zero."

Equations 4.6 and 4.8, the cross and dot products resolve to zero.

If you crank up the clock, Feynman concludes
"Only when there are sufficiently rapid changes, so that the time
derivatives in Maxwell's equations become significant, will E and
B depend on each other."

We will, of course, recognize this EB relationship as the field of
radiation and further recognize there is no field of radiation without
a significant time factor.

The grad operator, an inverted, enbolded del, is discussed by Feynman
in Chapter 2-4 is a significant element of these equations. The grad
operator obeys the same convention as the derivative notation.

Feynman's instruction clearly shows that Maxwell's treatment (actually
Heaviside's work before him) is a generalization of Gauss to include
time (sorry Art, he got there two centuries ago) and hence describes
Gauss equations as special (zero-time) instances of the generality.

73's
Richard Clark, KB7QHC



I'm easily impressed, but none the less I'm still impressed.

Derek.

Gaussian statics law
 

On 11 Mar, 18:45, Cecil Moore wrote:
Richard Clark wrote:
Determining the *frequency*? That has to be the most obscure
contribution I've ever seen.

Richard, do you understand that free electrons can
emit photons of any frequency? i.e. no orbital change
necessary?
--
73, Cecil http://www.w5dxp.com

Cecil, you should look up the background of JOHN E DAVIS from MIT that
the group just dissed. He is not just a nobody, he has credentials
that should be respected
Art

Gaussian statics law
 

On 12 Mar 2007 08:51:57 -0700, "art" wrote:

Cecil, you should look up the background of JOHN E DAVIS from MIT that
the group just dissed. He is not just a nobody, he has credentials
that should be respected

Hi Art,

Unfortunately John has proven that even (what you assume to be) an MIT
Don can get it wrong. He is not (just a software monkey like a lot of
us.) His references clearly show in exactly the same areas (chapter
and verse) how it is Maxwell's (actually Heavisides') equations that
add time to Gauss. In this case Feynman (the winner of the Nobel
prize in Physics) clearly states the time relationship introduced by
Maxwell two centuries ago.

I am quite sure the very book under your nose says exactly the same
thing, using exactly the same equations.

The long and short of it is exactly the same thing you've been told ad
infinitum, but have spit on those correspondents. The only thing
you've added is shooting sparks (must be related to that spit thing)
and pixie sticks.

Haven't you left yet?

73's
Richard Clark, KB7QHC