National Science Day 2022


    In Context 

    • India is celebrating National Science Day on February 28 


    • National Science Day, observed on February 28, marks the discovery of the Raman Effect, in the year 1928.
      • The Government of India designated 28 February as National Science Day (NSD) in 1986. 
    • On this day,In the year 1928, CV Raman discovered the Raman Effect or Raman Scattering which defines the inelastic scattering of photons by the matter which means there is an exchange of energy and change in light’s direction.
      •  In 1930, the scientist won a Nobel Prize for his discovery. 
    • Across the country, people celebrate this day by arranging events, science fairs, quiz competitions, Science model exhibitions and speech competitions.
    • Theme:  Integrated Approach in science and technology for Sustainable Future. 
    • Purpose of the Celebration:
      • To widely spread a message about the significance of scientific applications in the daily life of the people,
      • To display all the activities, efforts and achievements in the field of science for welfare of human being,
      •  To discuss all the issues and implement new technologies for the development of the science,
      • To give an opportunity to the scientific minded citizens in the country,
      • To encourage the people as well as popularise Science and Technology.

    Raman Effect

    • Raman Effect is a change in the wavelength of light that occurs when a light beam is deflected by molecules. 
    • When a beam of light traverses a dust-free, transparent sample of a chemical compound, a small fraction of the light emerges in directions other than that of the incident (incoming) beam. 
    • Most of this scattered light is of unchanged wavelength. A small part, however, has wavelengths different from that of the incident light; its presence is a result of the Raman Effect.
    • Background 
      • Raman Effect is a phenomenon in spectroscopy discovered by the eminent physicist Sir Chandrasekhara Venkata Raman in 1928.  
      • He first observed the phenomenon in 1921 during a trip to Europe.
        • Noticing the blue colour of the Mediterranean Sea and icebergs, he wanted to understand the reason behind the striking phenomenon. 
        • He began conducting experiments with transparent ice blocks and the light of a mercury arc lamp. He recorded the change in wavelength after shining the light through ice cubes.
        • Although not the first person to observe the phenomenon, Raman was the first to publish the observations in 1928. 
          • Russian physicists Grigory Landsberg and Leonid Mandelstam first observed the effect just a week before Raman. However, they published their results months after Raman.
        • This was an important discovery that paved the way for several future scientific developments.