InfraRed Light - William Herschel Experiment

How Was Infrared Light Discovered?

The Experiment of William Herschel

• A glass prism can separate sunlight into its colors or wavelengths, demonstrating the principle behind the discovery of infrared light.

• Astronomer William Herschel conducted an experiment using black-painted thermometers to project the solar spectrum and identify which color was warmest.

• To his surprise, he found that the warmest color was actually an invisible one beyond red, which he termed "calorific rays."

• Herschel's findings revealed a new form of invisible light that had not been previously recognized.