* Sunlight is composed of all colors of the rainbow. When sunlight enters the Earth's atmosphere, it interacts with the tiny molecules of air, primarily nitrogen and oxygen.
* Rayleigh scattering occurs when light interacts with particles much smaller than its wavelength. These air molecules are much smaller than the wavelengths of visible light.
* Blue light has a shorter wavelength than other colors. Because of its shorter wavelength, blue light is scattered more strongly by air molecules than other colors. This means that blue light is scattered in all directions, making the sky appear blue.
* Other colors are scattered less. Red, orange, and yellow light have longer wavelengths and are scattered less by air molecules. This is why sunsets often appear reddish-orange, as the sun's light has to travel through more atmosphere to reach our eyes, scattering away most of the blue light.
In summary, the blue color of the sky is a result of the preferential scattering of blue light by the air molecules in the Earth's atmosphere.
