DISCOVERING INFRARED LIGHT
FIGURE 14.5 Using an ingenious device of his own design, Fredrick William Herschel accidentally discovered the existence of invisible infrared light in 1800 while measuring the heat content of light bands within the visible spectrum. In the part of his experiments shown here, one of the thermometers is positioned just beyond the red portion of the spectrum, where Herschel measured higher temperatures than in any of the visible parts of the solar spectrum.
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