How was infrared light discovered?
In 1665, a great plague occurred in London, England, killing more than 100,000 people. Newton, 22, returned home to escape the plague. During this time he did a dispersion experiment to study the composition of sunlight. He let a beam of white light pass through a prism and found that there were actually seven beams coming out of the prism—red, orange, yellow, green, blue, indigo, and violet. Where does the white light go? Is it the technique of shadow avatar, one is divided into seven, or is it produced by some kind of reaction with the prism? He let these colorful lights converge through a convex lens, and then through a prism, and the white light came back. (Shocked) So he came to a conclusion that white light is a mixture of seven colors of light.
The world can deceive you not only with your mouth, but also with your most trusted eyes. The invisible is pure, so the invisible really does not exist? 100 years later, Herschel in the United Kingdom conducted an experiment to see which of the seven types of light could heat an object the fastest. He first dispersed the white light into seven kinds of light, and then measured the temperature rise when placing a thermometer in the place where each light was irradiated. As a comparison, a thermometer was also placed on both sides of the seven kinds of light. The experimental result shocked him, it was actually red light The thermometer in the invisible place next to it heats up the fastest. What the hell? He understood that it was the eyes that deceived him, that there was light in invisible places, and this light exposure made the temperature rise the fastest, and he named this light infrared. The same is true for the naming of UV rays
