National Science Day: All You need To Know About Raman Effect

National Science Day is celebrated to honour the discovery of a phenomenon of the scattering of photons by Indian scientist CV Raman in 1928, known as 'Raman Effect'.

National Science Day is celebrated every year in India on February 28 to honour the discovery of a phenomenon of the scattering of photons by Indian scientist Chandrasekhara Venkata Raman in 1928. The discovery was later named as 'Raman Effect' after his name. Mr Raman was awarded the Nobel Prize for science in 1930 for the remarkable discovery. On this day, schools, colleges, universities and other academic, scientific, technical, medical and research institutions organise quiz competitions, seminars and other events.

According to the website of the Ministry of Culture, Raman Effect is a phenomenon in spectroscopy, which is defined as the scattering of photons by excited molecules at higher energy levels. In simple terms, it is the change in the wavelength of light that occurs when a light beam is deflected by molecules.

When a beam of light traverses a dust-free, transparent sample of a chemical compound, a small fraction of the light emerges in directions other than those of the incident (incoming) beam. Most of this scattered light is of an unchanged wavelength. A small part, however, has wavelengths different from those of the incident light; its presence is a result of the Raman Effect.