Sir Chandrasekhara Venkata Raman, discovered on 28 February 1928, that when a beam of coloured light entered a liquid, a fraction of the light scattered was of a different color, dependent on material property. This radiation effect of molecular scattering of light bears the name of ‘Raman Effect’, from which many applications in photonic communications and spectroscopy evolved. The Raman Effect is the process of scattering light particles by molecules of a medium.

The image formed by a plane mirror (also known as a flat mirror) is called a "virtual image." A virtual image is an image that is not real but appears as if it were. It is formed behind the mirror, and it appears to be the same size as the object being reflected. This image is upright (erect) and reversed from left to right, but it is not a tangible object; it exists as a result of the way light rays reflect off the mirror's surface.