Thomas Harriot: The Discovery of Refraction

spectrum of colors from an incident beam of light. Refraction also plays an important role in the formation of a mirage and other optical illusions. The law of refraction is also known as Snell’s Law, named after Willobrord Snell, who discovered the law in 1621. Although Snell’s sine law of refraction is now taught routinely in undergraduate courses, the quest for it spanned many centuries and involved many celebrated scientists. Perhaps the most interesting thing is that the first discovery of the sine law, made by the sixteenth-century English scientist Thomas Harriot (1560-1621), has been almost completely overlooked by physicists, despite much published material describing his contribution. B A contemporary of Shakespeare, Elizabeth I, Johannes Kepler and Galilei Galileo, Thomas Harriot (1560-1621) was an English scientist and mathematician. His principal biographer, J. W. Shirley, was quoted saying that in his time he was “England’s most profound mathematician, most imaginative and methodical experimental scientist”. As a mathematician, he contributed to the development of algebra, and introduced the symbols of ”>”, and ”<” for ”more than” and ”less than.” He also studied navigation and astronomy. On September 17, 1607,…