Question

What do you mean by the scattering of light?

Answer 1

Hint: Think about the reason why the sky looks blue. It has something to do with the scattering of light. It can be thought of in this way- a glass on a table takes less space, but if it is hit by a bullet, it will break and the pieces will scatter in all directions, thus effectively increasing the coverage area of the glass.

Complete step by step answer:
When light waves pass through some material medium which has some particles of considerable size, then the light rays get deflected from a straight path and scattered into all directions.
This happens because light is absorbed by the particles in the form of energy. Then the particles reflect and emit the light again in all directions. This phenomenon is called the scattering of light.
For example, the sky is a material medium with particles such as dust particles, water droplets (in clouds). Light is scattered extensively in the atmosphere.
Additional information:
Scattering of light is the cause of many natural phenomena. A law called the Rayleigh’s law of scattering states that the amount of scattering is inversely proportional to the fourth power of the wavelength (λ) of the wave. Thus,
$\text{extent of scattering = }\dfrac{1}{{{\lambda }^{4}}}$
So, light of shorter wavelength gets scattered more and vice versa. This primarily is the reason for the sky being blue in colour and the sun looking red at sunrise and sunset.
During the day, the light from the sun is scattered by the particles in the sky. Since the colour blue has a shorter wavelength in the visible region (actually violet and indigo have shorter wavelengths, but our eyes are adapted to detect blue better). So, it gets scattered more and the scattered blue light reaches our eyes. Thus, the sky looks blue.
At sunrise and sunset, the sun is near the horizon and light from the sun has to travel a longer distance. So, all other colours of light get scattered on the way. But, red having a larger wavelength gets scattered less (according to Rayleigh’s law of scattering) and thus the red light reaches our eyes. So, the sun looks red during sunrise and sunset.

Note: Students should not memorize the definition of scattering of light but should understand the concept by keeping in mind the real-life examples given above and also try to find out other instances of scattering in day to day life.