Why do rainbows form?

This is why we see rainbows as a continuous band of colors with red on top and violet on the bottom. A typical raindrop is also spherical and therefore its effect on sunlight is symmetrical about an imagined axis connecting the center of the drop and the sun. read more

A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun. Rainbows can be full circles. read more

Rainbows can also be seen against the spray of a waterfall. A single, or primary, rainbow has red on the outside or top of the bow and blue on the inside. Usually the radius of the arc is equal to about one-fourth of the visible sky, or 42 degrees, to the red. read more