Why is the sky blue?

Great question! The sky appears blue mainly because of a phenomenon called **Rayleigh scattering**, which is all about how sunlight interacts with the Earth's atmosphere. Here’s a simple way to understand it: sunlight looks white, but it’s actually made up of many colors, like a rainbow. When sunlight enters our atmosphere, it bumps into tiny gas molecules and particles. These molecules scatter the light in different directions. However, they don’t scatter all colors equally—shorter wavelengths of light, which are blue and violet, scatter much more than longer wavelengths like red or yellow. Even though violet light scatters even more than blue, our eyes are more sensitive to blue, and some violet light gets absorbed higher up in the atmosphere. So, the scattered blue light is what mostly fills the sky and reaches our eyes, making the sky look blue during the day. In short, Rayleigh scattering is why the shorter, blue wavelengths of sunlight get bounced around the atmosphere more, giving the sky its beautiful blue color!