On Mon, 12 Mar 2007 23:21:32 +0000, Ian White GM3SEK
wrote:

The point I was making was that 1.42GHz radiation generated in this
particular manner has no special properties other than its frequency. It
is exactly the same kind of RF energy as you'd get from a signal
generator tuned to the same frequency.

Hi Ian,

So, the photon thus emitted is indistinguishable from any signal
generator's output. Neither of us is surprised, granted.

What distinction are you trying to make that is not already obvious?
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.
This is nothing more than a tautology. No one is going to be
surprised by this event either.

Can you give us an example of "special properties" that differentiates
a photon from an EM wave? On the face of it, that question is absurd,
but I see nothing distinctive about your comments except in this fine
parsing of "special properties" that seem to vanish (no pun) for
longer wavelengths.

It means that whenever there is a transition between two energy levels,
a photon is emitted whose frequency is uniquely determined by the
difference between those energy levels.

If this is the "special property" and hyperfine are not, then I
suppose it could as easily be called "very special property" to no
less acclaim. The production of photons through a myriad of other
interactions that I offered rather makes this "special property"
rather banal, because those interactions also present harmonic
relationships and are not uniquely determined by transitions - and yet
they remain photons none the less. Would I be overstepping to call
them "extraordinary properties?"

I must presume this casts back to your comment:
Quantum
theory was developed to explain observations like some kinds of light
being emitted in a series of sharp spectral lines, which cannot be
explained by a wave-only theory. Instead, it has to be thought of as
being built up of individual photons/quanta which can only have certain
"allowed" energy levels.
My presumption is that "special properties" and "some kinds of light"
are congruent. Again, it appears to be as tautological as might my
examples of "extraordinary properties."

Where does this lead us?

73's
Richard Clark, KB7QHC