FINDING INFRARED

British astronomer Sir William Herschel is responsible for the discovery of infrared radiation in 1800. Through a series of experiments, Herschel set a prism at a south-facing window in direct sunlight to direct and separate light into the different wavelengths, and subsequently different colours, that make up visible light. He then exposed a thermometer to each of the different colours to see how they might change the temperature displayed. However, he found that when the thermometer was placed outside the visible light past the red end of the light spectrum, the temperatures continued to increase. What he had discovered was infrared radiation.

William Herschel conducting experiments that exposed the electromagnetic spectrum