National Science Day is observed every year in India on 28th February with an objective to spread message of importance of science and its application among the people. This year theme of National Science Day is ‘Science for people and people for science’.
Significance of Day
It is observed to mark discovery of Raman effect (inelastic scattering of light) by Physicist CV Raman on 28th February, 1928. For this discovery, he was awarded Nobel Prize in Physics in 1930 (second Indian after Rabindranath Tagore, who was awarded Nobel Prize in Literature in 1930).
National Science Day
It was instituted by Central Government in 1986 based on demand of National Council for Science and Technology Communication. It was observed for first time on 28 February 1987.
Purpose: (i) Spread message about importance of science used in daily life of people and popularise science and technology. (ii) Provide opportunity to scientific-minded citizens in country to showcase their work in organized shows.
It is change in wavelength of light that occurs when light beam is deflected by molecules after passing through transparent medium. The wavelength of these scattered rays is different from that of incident rays of light. It is caused by inelastic scattering of photon (with energy proportional to frequency) by molecules which are excited to higher vibrational or rotational energy levels. It forms basis for Raman spectroscopy which is used by chemists and physicists to gain information about materials.