A typical television remote control uses infrared energy at a wavelength around 940 nanometers. While you cannot “see” the light emitting from a remote, some digital and cell phone cameras are sensitive to that wavelength of radiation. Try it out!
Infrared lamps heat lamps often emit both visible and infrared energy at wavelengths between 500nm to 3000nm in length. They can be used to heat bathrooms or keep food warm. Heat lamps can also keep small animals and reptiles warm or even to keep eggs warm so they can hatch.
Credit: Troy Benesch
In 1800, William Herschel conducted an experiment measuring the difference in temperature between the colors in the visible spectrum. He placed thermometers within each color of the visible spectrum. The results showed an increase in temperature from blue to red. When he noticed an even warmer temperature measurement just beyond the red end of the visible spectrum, Herschel had discovered infrared light!