Question

How is light scattered by the air?

Answer 1

Scattering:

1. Scattering is an optical event, where the direction of incident light rays changes when they travel through a medium due to the continuous collision between the particles.
2. The intensity of scattered light is defined by the form, $I_{sc}=\frac{A}{{\lambda }^4}$, where A is a constant and $\lambda$ is the wavelength of the light. This scattering is called Rayleigh scattering.

Scattering of light in the air:

1. Air is a mixture of gases(O₂, N₂, H, etc), smoke, dust, and other particles.
2. Light is scattered in the air by collisions of air(gas) - light(photons) molecules.
3. When the rays of light fall on these molecules or particles, these rays are split in all directions.
4. The blue color of our sky is one of the most important examples of the scattering of light by air.

Other example of Rayleigh scattering:

1. Rayleigh scattering in optical fibre: The transmitted light scatters through the fibre due to the presence of inhomogeneities and imperfections during their creation.
2. Optical fibre is made up of irregular connections of molecules, so the molecular density at some regions is higher and at other regions is lower.
3. Thus, refractive index varies resulting in scattering of light.