On Sun, 09 Mar 2008 21:13:54 -0500, Mike Coslo
wrote:

Coherent light is not the half of it!

We are both more and less advanced than we might think.

Hi Mike,

Coherence has become a shallow rhyming proof rendered as
"SoThereIt's!" (a mumbled qed). It is a convenience of a special
solution which requires artificial constraints that over the course of
"debate" have become necessary correlatives to a general "law" of
optics. In fact, few have examined what "coherence" actually means,
but instead it has been Xeroxed by Cecil into the argument.

Both Mike and Tom have been able to disconnect this term as one of
necessity for monochromaticity (not required) and instantaneity (also
not required). This lack of requirement (that requirement having been
artificially injected into the discussion) is historically exhibited
in work going beyond 100 years old. The first work was with
sun/starlight that is neither pulsed nor monochromatic, and yet and
all, interference was clearly found which led us to this discussion.

Even though the classic hologram, developed 60 years ago, or so, was
originally monochromatic; it didn't take much more effort to
accomplish the same photography with white light (1968). Wide band
sources can demonstrate interference as readily there as with the
original Michelson-Morely interferometer. In fact, most here need
only open their wallet to examine a credit card or driver's license to
prove this to themselves under a common table lamp.

Coherence (cross-correlating) is a statistical term for comparing
(0.00 to 1.00) complex waves. You can have temporal coherence,
spacial coherence, spectral coherence and on and on; none of which are
actually named here, but whose various definitions have been
notoriously cross-connected into a hodge-podge argument of no
particular merit.

If we delve into the merits of sun/starlight, we eventually narrow on
into the distinction of these terms of spatial and temporal coherence
and the coherent area/length/volume (where incoherent sunlight is
found to be coherent within 0.02mm) and then into what has already
been identified by Gene with partial coherence (a topic that Wolf
pursued, and at which Born hesitated).

73's
Richard Clark, KB7QHC