Why is the sky blue: If you’ve ever sprawled on

If you’ve ever sprawled on the ground and stared up on a bright afternoon, you’ve probably wondered why the sky chooses blue and not green or pink. The truth is, the colour above us is a kind of optical trick, performed by sunlight and air working together. The more molecules of gas the blue light hits, the more times it scatters and re-scatters. All of this scattering mixes some of light's individual color wavelengths together again, which is why the blue appears to be diluted. Now that you have a clear understanding of why the sky is blue, you may wonder what happens at sunset to make it turn red... So, in short, the sky is blue because of Rayleigh scattering, which causes shorter blue wavelengths of light to scatter more than other colors. Our eyes are tuned to see blue more clearly, and the Sun emits more blue than violet light, which is why our daytime sky isn’t purple. The sky appears red because small particles of dust, pollution, or other aerosols also scatter blue light, leaving more purely red and yellow light to go through the atmosphere.