FEATURE ARTICLE
Herschel and the Puzzle of Infrared
An astronomer took a mental leap to first connect light and heat
Jack R. White
Most encyclopedias and physics books credit the great British astronomer, Sir William Herschel, with the discovery of infrared radiation. It’s a nice story, but it trivializes the real significance of what Herschel found. Using only a prism and mercury-in-glass thermometers, Herschel found the first definitive evidence that light and what he called “radiant heat” are the same quantity that we now know to be electromagnetic radiation. White explains that Herschel found the first piece in one of the great puzzles of physics that would take another century and the discovery of the quantum theory to solve.
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