CHAT: Ultraviolet (was: Orange)

Lars Henrik Mathiesen scripsit:

> The source I read didn't go into stuff like how many different colours
> he perceived in the new wavelengths, or how much it changed the look
> of everyday objects --- more that his colleagues though it was neat
> how he could calibrate their UV spectrometers without a photometer.
People in this position (and they are not rare; the treatment
for cataract is to remove the lens, and most of us get cataracts in
our 80s if not sooner) don't actually see new colors: they just see
purple further to the right in a spectrum, in an area where the rest
of us see nothing.  Perhaps if one's lenses were removed *early*
enough, while the brain has the flexibility to adapt ... who knows?

IIRC this ability was used in WW II to communicate across the Dover-Calais
straight by blinking a strong UV light in Morse code at night;
the light was just perceptible 30 km away by a UV-seeing person
on the other shore.

--
John Cowan <jcowan@...>     http://www.reutershealth.com
I amar prestar aen, han mathon ne nen,    http://www.ccil.org/~cowan
han mathon ne chae, a han noston ne 'wilith.  --Galadriel, _LOTR:FOTR_