Raman Effect

February 28 is observed as National Science Day in India to commemorate the discovery of the Raman Effect by Sir C.V. Raman in 1928.

• This discovery won him the Nobel Prize in Physics (1930), making him the only Indian scientist to win a science Nobel while working in India.
• National Science Day was designated by the Government of India in 1986 and first celebrated in 1987 to highlight the importance of science and its applications.
• Theme for 2025: ‘Empowering Indian Youth for Global Leadership in Science & Innovation for Viksit Bharat’.
• About Raman Effect: When light strikes a material, it interacts with its molecules and exchanges energy.

o The scattered light contains a portion with a different wavelength and thus a different colour.

• Example: The blue colour of oceans is due to the scattering of sunlight by water molecules.

o The blue colour of the sky is due to the scattering of sunlight by air molecules.

• Applications of the Raman Effect: It helps determine the structure of substances (solid, liquid, or gas) without breaking them apart. The discovery became widely useful with the advent of lasers in the 1960s.
• Key applications:

o Forensic Science: Rapid analysis of illegal drugs without breaking the evidence seal.

o Industrial Chemistry: Monitoring paint drying to understand chemical reactions as it hardens.

o Nuclear Science: Using fiber-optic probes to analyze nuclear waste materials safely.