How big’s your bow?
Question: What determines the size of a rainbow? They obviously vary as shown
by double rainbows.
Answer: The size of a rainbow is fixed by the way the Sun’s rays go through
the raindrops. When a light ray strikes a raindrop, part of it is reflected and
lost and part is refracted into the drop. When this ray hits the back of the
drop, part of it is refracted out and part is reflected back to the front
surface. Part of this reflected ray is again reflected (see later) and part is
refracted back out.
If…
