National Science Day: What is the Raman effect that won CV Raman the Nobel

Every year, India celebrates National Science Day on February 28. The day is marked in honour of Indian physicist Sir Chandrasekhara Venkata Raman, or CV Raman, and his Nobel Prize-winning discovery of the Raman Effect.

Raman was a bona fide genius, completing his master's by the age of 19. During a trip back home from the UK, Raman noticed the stark blue colour of the Mediterranean Sea and wondered why it appeared blue instead of green. He hypothesized that the blue colour was due to the scattering of light by the water molecules in the sea, and this idea inspired him to conduct further research on the scattering of light.

Seven years after this trip, Raman along with his student KS Krishnan managed to successfully discover through experiments that when light scatters through a transparent object, its wavelength and frequency change as well. This effect, now known as the Raman effect or Raman scattering, won Krishnan and Raman the Nobel Prize in Physics in 1930. Coincidently, the same effect was noted independently by Soviet scientists Grigory Landsberg and Leonid Mandelstam just a week prior but their research paper came later than Raman’s.