February 28 is Science Day in India, commemorating the discovery of the Raman Effect by Indian physicist Sir C. V. Raman on 28 February 1928 for which he was awarded the Nobel Prize for Physics in 1930.
Raman Scattering or the Raman Effect is the inelastic scattering of photons by matter. That is, there is an exchange of energy and a change in the light’s direction. The effect is exploited by chemists and physicists to gain information about materials for a variety of purposes by performing various forms of Raman spectroscopy.
Raman spectroscopy provides a structural fingerprint by which molecules can be identified. It is the effect that makes for a spectrometer and for delightful forensic scenes like this.