Some amazing facts I learned about rainbows:
- a rainbow is sunlight spread out into its spectrum of colors and diverted to the eye of the observer by water droplets. When the white sunlight is intercepted by a drop of water in the atmosphere, some of the light refracts into the drop, reflects from the drop's inner surface and then refracts out of the drops.
- The colors can be seen only when the angle of reflection between the sun, the drop of water, and the observer's line of vision is between 40° and 42°.
- to see a rainbow, one has to have rain and sunshine
- two observers do not, and cannot, see the same rainbow. In fact, each eye sees its own rainbow(Your rainbow is for your eyes only! Amazing isn't it?)
- the sun is always behind you when you face a rainbow from the ground
- the center of the circular arc of the rainbow is in the direction opposite to that of the sun
- the rain is always in the direction of the rainbow
- you will only be able to find rainbow at ground if the sun is less than 42 degree above the ground (early morning or before sun set)
- primary rainbow is always brighter than the secondary rainbow
- primary rainbows have red on the outside arc
- the colors of the secondary rainbows are reversed
I once saw a primary and secondary rainbow near our house in QC just before the rain pours... I was so fascinated by its beauty and fell in love with it...