Reign Beaus

[P3D Peter Abrahams <telscope@xxxxxxxxxx>]

Rainbows form some unique visual geometry, to be sure.  The rays are not
parallel to one viewer, they converge at 42 degrees to form a cone, and the
drops that form the rainbow are at a measurable distance.
If you have two observers, separated by 1/4 mile, looking at a rainbow, yes
their direction of sight will be parallel, towards the sun.  If they both
look at the left leg of their rainbows, they will be gazing in the same
direction.  
But...the bows take up half the sky, so the vast field leaves lots of room
for depth cues.
And..but... they'll be seeing two different sets of drops as 'their'
rainbow, as pointed out before.   No convergence of view, but as with much
distant stereo, the offset of background & foreground will provide the depth.

It is also 'fun' to speculate on the rainbows formed when the sun is at your
back, the "glory".  Here you'd have the same image reversal (except no
imaging) that you have with a mirror.  So would there be depth reversal, or
some other pseudoscopy or something, if you 'hypered' the photography enough
to really see depth?

A good article on the subject is in
Scientific American, 4/77; Nussenzveig, Theory of the Rainbow.  Apparently
it is considered scattered light, not refracted.
  Halos are rainbow effects formed from ice crystals, by refraction.
Rainbows are far more complex, involving total internal reflection,
refraction, diffraction, and surface waves (that travel around just under
the drop 'skin' before exiting.)  They occur at many wavelengths.  The
near-ultraviolet rainbow in the sky has been photographed, there are also
atomic rainbows, where scattered particles form patterns very like rainbows.

Let's stick to something simpler, like stereoscopy of mirages.
\\\\\\\\\\\\\\\\\\\\////////////////////
  Peter Abrahams    telscope@xxxxxxxxxx
the history of the telescope, the microscope,
   and the prism binocular


------------------------------