"Herman Family" <firstname.lastname@example.org/without_any_s/> wrote in message
Re-read the article. Particle size is almost irrelevant. What *does* count
is the number of internal reflections with the water droplet, which (along
with the wavelength) determines the final angle at which the light emerges
from the droplet. Differences in the refractive index of water for
different wavelengths is called "dispersion" and is responsible for the
*separation* of the wavelengths.
Since 'rainbows' are *always* made with distilled water (it doesn't rain oil
on this planet) the refractive index is not significantly variable from one
droplet to another.
Also, the 'color' indigo was included to please a royal patron, since indigo
is the name for 'royal purple' - a shade of blue-violet - and nourished the
ego of a king with a dream of a divine mandate.
Most serious investigators ignore 'indigo' in the rainbow as it is a