The eye of a peacock's feather. The colours are due
to multilayer interference occurring in laminae in the barbules
of the feathers. [See pages 105, 108, Selected Readings.]
The iridescent blue
coloration in the wing of the Morpho butterfly, apparently
caused by three-dimensional diffraction within the rib structure
on the scales of the wing. [See pages 104 -107.]
The remarkable polar distribution of the light reflected
from the Morpho butterfly wing. The wing is mounted
at the centre of a whitened hemisphere and a pencil of light
which passes through a central hole in the hemisphere is incident
normally on the wing. The band of light reflected from the
wing on to the wall of the hemisphere is vertical when the
wing is oriented with the rib structure running horizontally.
[See pages 105-107.]
The Baptistry Window in
Coventry Cathedral, by John Piper. [See page 109.]
