Why is the Sky Blue?

The sun emits a spectrum of light, with blue wavelengths being scattered more due to the size of atmospheric molecules. Early experiments by Tyndall hinted at the role of particles, but it was Rayleigh who revealed that the atmosphere itself causes this scattering effect. Ultimately, the sky appears blue because our eyes are more sensitive to blue light, combined with the sun's greater production of blue compared to indigo or violet.