Answers

2015-08-31T21:26:38+05:30
Allow a ray of light to to enter through a small hole of a window of an darkened room . no place an equilateral prism in the path of light . the light emerging out should be falled on a screen . now you can found that the white screen has a band of seven colors (VIBGYOR) but they are arranged in ROYGBIV . 
THIS WAS FIRST DONE BY ISAAC NEWTON.
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