Why does the clear sky appear blue?

The correct answer is the short waves of blue light are scattered more than the other colours in the spectrum, making the blue light more visible.

Key Points

• The clear sky appears blue because of a phenomenon called Rayleigh scattering.
• In Rayleigh scattering, the shorter wavelengths of light (blue and violet) are scattered more than the longer wavelengths (red, orange, yellow).
• Although violet light is scattered even more than blue light, our eyes are more sensitive to blue light and less sensitive to violet light.
• Additionally, much of the violet light is absorbed by the upper atmosphere, making the blue light more predominant.
• This scattering causes the diffusion of blue light in different directions, making the sky appear blue to our eyes.

 Additional Information

• blue light gets absorbed in the atmosphere
  • This is incorrect because blue light is scattered, not absorbed, by the atmosphere.
• ultraviolet radiations are absorbed in the atmosphere
  • While it is true that ultraviolet (UV) radiation is absorbed by the atmosphere, this does not explain why the sky appears blue.
  • UV radiation is absorbed primarily by the ozone layer and does not contribute to the visible color of the sky.
• light of all other colours is scattered more than the violet and blue colour lights by the atmosphere
  • This is incorrect because it is the opposite of what actually happens. Blue and violet light are scattered more than the other colors.