National Science Day

National Science Day

Subject: Science and Technology

Context: On the occasion of National Science day on 28^th February, the Science and Technology minister said that the fundamental and translatory science is important, but it has to be solution-based and people-centric.

Concept:

• It is celebrated in India on 28 February each year to mark the discovery of the Raman effect by Indian physicist Sir C. V. Raman on 28 February 1928.
• the theme of NSD, 2021 was “Future of STI: Impacts on Education, Skills, and Work”.
• For this discovery he received Nobel prize in Physics in 1930.
• It was the first Nobel in Physics for a non-white person, and for an Indian scientist.

About Raman Effect:

• It is the process of scattering of light particles by molecules of a medium. Ex- Scattering of light by sea and oceans. The scattering occurs due to a change in the wavelength of light as it enters the medium. When a beam of light travels through a dust-free, transparent chemical, a small fraction of the light emerges in directions other than where it should.
• Light consists of particles called photons; whose energy is directly proportional to the frequency with which they travel. When they strike molecules in a medium at high speeds, they bounce back and scatter in different directions depending on the angle with which they hit the molecules.
• Most of these scatterings are elastic — the photons retain their energy and are deflected with the same speed as they were traveling with.
• However, once in a while, the molecules of the medium, light passes through absorb or give energy to photons that strike them. The light particles then bounce with decreased or increased energy, and thus, frequency.

Application

• It laid to Raman Spectroscopy which has extensive applications around the globe, and across fields.
• It can help in determining chemical bonding structures, characterise materials, determine temperature, find out crystalline orientation, identify pharmaceutical chemicals, discover counterfeit drugs, identify pigments in old paintings and historical documents, and detect explosives using lasers from a distance