Why
do
we
see
rainbows,
how
do
they
work?
-We see rainbows
when the sun is behind us and falling rain is in front of
us.
-When sunlight
strikes a falling drop of water it is refracted, changed in
direction,
by the surface of the water.
The light continues
into the drop and is reflected from the back of the drop to the
front. When the beam hits the front it is refracted again and
emerges from the drop as the color spectrum that we see in a
rainbow.
-The water drop
acts like a prism to seperate the light into its different wave
lengths.
DOUBLE
RAINBOW-If
the beam is reflected twice inside of the water drop them it will
cause a secondary rainbow to appear when the light leaves the water
drop. The colors of the secondary ![](doubleraindiag.gif)
rainbow are reversed
in order with violet
on the top and red at
the bottom.
![](double%20rainbow.jpg)
http://acept.la.asu.edu/PiN/modules/light/pattLightOptics.html
As an example of a double
rainbow.
The faded rainbow on the right is the
secondary rainbow.
You can see the reverse in colors on
the secondary rainbow compared to the primary rainbow.
BACK
![](reflection%26refraction.gif)