I was showing off some unique holiday ribbon today to several
colleagues. This ribbon looks green when seen from one angle and
red when the angle is reversed. Very Cool! On the ribbon this
is caused by the weave showing one thread when viewed from some
particular perspective and another thread when viewed form the
opposite direction. One of the Biology teachers said that this
was like the feathers on some birds, in particular a Mallard
Duck. He indicated that the color was not due to a particular
pigment but rather some other physical characteristic causes the
light reflected back by the feather to be different based on the
angle at which it is viewed. I have to admit that I know
virtually nothing about birds especially ducks so this has left
me rather stumped. Can anyone explain to me what would cause
this kind of effect in the feathers of a bird?
--
Cliff Parker
Never express yourself more clearly than you can think. --
Niels Bohr