Sunday, September 30, 2012

Double Rainbow: (downtown Austin, TX)

Late Saturday afternoon 9/29/2012, I was at my favorite coffee shop when, Lo and Behold, a most glorious sight appeared.

When you see a primary rainbow, you are seeing light that has been refracted and reflected through water droplets, however the red color does not come from exactly the same droplets of water as the violet color. If you were able to isolate one particular water drop that produced some of the red color you saw, the violet light from this drop would not meet your eyes - it would travel over your head.

A secondary rainbow is produced when there is one extra reflection of light within the water drop. As some light is lost each time it hits the edge of the drop, the secondary rainbow is fainter than the first. It appears higher in the sky because the light exits the drop at a larger angle (50-53 degrees) than the primary rainbow (40-42 degrees).

Understanding optics: