New theory of radiation: Prof Raman’s discovery

In 1930, Dr Chandrashekhara Venkata Raman was awarded The Nobel prize for “his work on the scattering of light and for the discovery of the effect named after him”. The Raman scattering effect was discovered on 28th of February 1928, and was announced to the world through newspaper with headline “New theory of radiation: Prof Raman’s discovery”.

The idea that lead to this discovery came to him at a very unsuspecting place, the deck of a ship. While returning from europe he wondered if, like air, water also scattered light cauing blue waters. Thus he began experimenting with various liquids with his student Srinivasa Krishnan and by 1924, he had experimented with 60 fluids for light scattering. In all of the liquids, he discovered a peculiar phenomenon, of the total light that went through the liquid, a part of it was scattered in reverse. This, they thought, was maybe because of trace of “something”.

This “something” that was named weak fluorescence by srinivas gave Raman many restless nights but one day, idea struck him, what if this something was residual light waves never observed before, a new type of radiation emitted by the light. Along with Srinivas, Raman tested 80 liquids for this type of scattering using a heliostat and a blue-violet filter and found the same in each one of them.

He had discovered a new type of scattering and propelled Indian science forward, inspiring and mentoring many future Indian scientists like Vikram Sarabhai, Homi J Bhabha, and many. Every year on 28th February, the day of the discovery, National science day is celebrated in India.