Choose the correct option from the below which explains the reason for us to perceive the day sky as blue.

options

1. As sunlight passes through the atmosphere, shorter wavelengths, such as blue are scattered more than other colors.
2. The sky appears blue because all colors are scattered equally, but blue light is stronger and more visible to the human eye.
3. The blue color of the sky is due to longer wavelengths like red and orange scattering more than shorter wavelengths, making blue stand out more.
4. The atmosphere contains blue-colored particles that give the sky its blue appearance.

As sunlight passes through the atmosphere, shorter wavelengths, such as blue are scattered more than other colors.

Reason — When sunlight enters the Earth’s atmosphere, it interacts with tiny air molecules and dust particles which is known as Rayleigh scattering.

The amount of scattering is inversely proportional to the fourth power of the wavelength, meaning shorter wavelengths (like blue and violet) are scattered much more than longer wavelengths (like red and yellow).

Although violet light is scattered even more than blue, our eyes are more sensitive to blue light.

Therefore, the sky appears blue to us during the day due to difference in scattering amount for different colours (wavelengths).