Rainbow god circle

[Jeffrey Reid]

On Mon, 6 May 1996, Andrew Dinn wrote:
> > 	Not exactly.  Rainbbows don't exist so much as appear.  You
> > physical one.  They are not located up in the sky.  If they can be
> > said to be located anywhere at all, it is on the retina.
> For goodness sake! Isn't the moon's pale fire also an optical
> phenomenon not a physical one? Does this locate moonlight on yer
> eyeball?  Rainbows do of course exist just as much as sunlight or the
> the particular shade of red used on Prentice Hall computer science
> texts (variant lighting conditions notwithstanding) or the concept of
> optical phenomena or whatever else. Watch that baby, what with that
> plug hole right next door.
>
I think what the original poster meant is that a rainbow is a 'virtual
object' (using optics speak) which just looks like it exists let's say
100 yards away, but actually the convergence of the light rays being
diffracted by the water in the air is being interpreted by your brain as
emanating from a source 100 yards away.  This is quite different from
seeing an actual object like your CS book which is reflecting light to
your eye where your brain correctly interprets it as emanating from a
physical object.

Jeff

---------------------------------------------------------------
Jeffrey G Reid       			jgreid at u.washington.edu
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"O holy mathematics, may I for the rest of my days be consoled
 by perpetual intercourse with you, consoled for the wickedness
 of man and the injustice of the Almighty!"  -- Isidore Ducasse