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