Newton's Decomposition of Sunlight with a Prism1

　　Isaac Newton was born the year Galileo died2. He graduated from Trinity College, Cambridge,

　　in 1665, then holed up3 at home for a couple of years waiting out the plague. He had no trouble keeping himself occupied.

　　The common wisdom held that white light is the purest form (as Aristotle said) and that colored light must therefore have been altered somehow.

　　To test this hypothesis, Newton shined a beam of sunlight through a glass prism and found that it decomposed into a spectrum cast on the wall. People already knew about rainbows, of course, but they were considered to be little more than pretty aberrations4. Actually, Newton concluded, it was these colors—red, orange, yellow, green, blue, indigo, violet and the gradations5 in between—that were fundamental. What seemed simple on the surface, a beam of white light, was, if one looked deeper, beautifully complex.(Ranking: 4）