Why do rainbows form?
Rainbow formation is a beautiful meteorological process. It is formed due to the light refraction. The situations that can cause the rainbow formation are the sun being at the horizon and the fog or mist or rain drops being just opposite to the sun. The rainbow is observed as an arc with all the colors of the visible spectrum. The real cause of the rainbow was not understood until the study of physics has been explored very deeply. The study on the properties of light has revealed the cause for rainbow formation.
It is observed and studied that the rainbow is formed by the reflection of light through the drops of water. When the sunlight enters the water droplet, it gets reflected by the walls of the water drop. When the light is reflected back, the refraction of light occurs, which will filter the light into various colors. This light that is refracted will be arranged with red color at the top and violet at the bottom. Red has longer wavelength and violet has shorter wavelength.
Sometimes two rainbows are observed when the light refracts twice from the drops. Rarely triple rainbow also may form. If the drops of water get distributed or if the sun is hidden by the clouds or the light disappears, then the rainbow also disappears. This is because the water drops can no longer refract the light as the light is absent. If anyone wants to see a rainbow, it is essential to go out and look for it when the sun reaches the horizon and there is a heavy rain at that time. At that time, if the observer stands with his or her back to the sun and look at the front for a rainbow, he or she can find it. The top of the rainbow arc will be facing opposite to the sun.