Why is the Sky Blue?. The color of the sky on Earth is not due to sunlight having a blue tint, but rather to a unique distribution of wavelengths. The light from the Sun scatters and redirected to illuminate the rest of the sky. Blue light is a shorter wavelength than white light, so it more easily scattered and reflects to our eyes.
The air molecules in the atmosphere scatter light, thereby creating a blue color in the sky. Unlike water, air molecules are much smaller than visible light wavelengths. Because of this, some light hits them and bounces off them, but the remaining energy gets absorb by the particles. This called Rayleigh scattering, and is responsible for why the sky is blue. The air in the atmosphere has a high concentration of oxygen and nitrogen, which scatter light and bend it.
Lord Tyndall’s experiments demonstrated that light of shorter wavelengths scatters more than longer wavelengths. So, if you look at a beam of white light, and it is coming from the side, you will see blue light, while light of longer wavelengths will scatter evenly. The blue light scattered in such a way that it causes a saturated sky.
The sky’s color changes according to the wavelength of light. The shorter wavelengths are more visible at sunrise and sunset, while the longer ones scattered near the horizon. The longer wavelengths will eventually overtake the shorter ones.
