A rainbow is one of the most amazing things you can see in the sky. However, many people don't know how rainbows are formed. To begin with, I'll start by explaining how rainbows are formed. A rainbow forms as a result of the refraction and scattering of white light as it passes through a prism. Since a prism has two indices, their difference causes the light to diverge at different angles when it exits the prism. This divides the white color into many components, which are different colors. Since a raindrop contains two refractive indices, it produces different colors when hit by sunlight. These colors are what we see as a rainbow. Now, to understand how light can be refracted at different angles, it is important to understand Snell's law which states that the angle of refraction always depends on the index of refraction of both mediums. Now, the index of refraction keeps changing depending on the wavelength of light passing through it. Light, as we know, is a wave that has a different wavelength. Each wavelength represents a different color. Therefore, different colors will have a different refractive index when passing through the same medium. It is important to note that light is normally refracted twice when traveling through a prism, once when it enters and when it travels back. So how can we see a rainbow in the sky? The first condition that must be met is that the sun is shining, furthermore, the sun must be behind you and raindrops must be present in the sky. When these three conditions are present, the sun will shine on the small droplets which act like a prism. The rays will be refracted twice, thus producing different varieties of colors. However, each drop will only produce one color, so…half the paper…is generally known as Rayleigh scattering. The blue color, which is observed in the sky, is due to Rayleigh scattering. As light travels through the atmosphere, it encounters gas molecules that absorb most colors with a shorter wavelength. Colors such as red, orange, yellow are absorbed less. Blue, being a short wavelength color, is absorbed into the molecule. It is then radiated in all directions. Now, this is the color that reaches our eyes because it spreads in all directions, so a blue sky. However, sometimes, the sky will have a pale blue color. This is because the scattered blue colors must pass through other gas molecules and, in turn, spread further. It's like dividing a particular mass into many pieces, and the end result will be tiny masses. This is how the blue color splits before reaching our eyes.