A rainbow is actually circular

The reason is that what is seen as a rainbow is actually light reflected by individual, spherical water droplets. Although each droplet reflects white light, it divides the white light into a spectrum, and the color perceived varies with the angle from which the droplet is viewed, so all droplets viewed from a specific angle are of the same color. The locus of droplets at the same angle relative to one's eye and the sun is a circle; since the Earth obscures the bottom part of the circle, the rainbow must always curve in a certain direction.

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• Nope - Try harder~ for上彎的彩虹 and 上彎的彩虹 only -guest007- ♀ (362 bytes) () 08/13/2010 postreply 13:22:24