Tuesday, 27 February 2018

Raman Effect - National science day

sir cv raman

About Chandrasekhara Venkata Raman (1888-1970)

C.V. Raman was born on Nov.7, 1888 in Trichiopoly (Tiruchirapalli). The Raman's family lived on a low income when Raman was born.  C.V. Raman was awarded both Bachelor and Master's degree before Raman turned 20.

Why National Science Day is celebrated on Feb.28th?

In India, National science day was celebrated first on Feb.28, 1987.  Then onwards we are celebrating National Science Day on Feb.28, this is to mark the discovery on the "Raman Effect" by Indian Physicist, sir C.V. Raman on 28 Feb. 1928.

What is Raman Effect?

While C.V. Raman travelling to Europe in the early 1920s, he noticed that the sea water is in blue color.  This leads to the discovery of the Raman Effect.


I. Change in the wavelength of light that occurs when a light beam is deflected by molecules.

II. Certain molecules cause waves radiation to scatter differently than the other molecules.

III. Raman effect is an inelastic scattering of photon.  Change in the wavelength of light that occurs when a light beam is deflected by molecules.  During  scattering, a very few photons undergo a change in behaviour.
Experiment: When there is an interaction between the particles of  the liquid and the photons to be responsible for the change in the behaviour of the photons.

Why National science day is celebrated on Feb.28?

In India, the first National science day was celebrated on Feb. 28, 1987, then onwards continuously celebrating National science day.  The reason behind it is that to mark the discovery of the "Raman Effect" by Indian physicist sir C.V. Raman on 28 Feb. 1928.

Applications of Raman Effect:

Scientists using the raman effect for analysing the atomic structures of the particles without causing any destruction to the substance.

II. Raman effect - Raman spectroscopy is being used to study the properties of different materials.

III. The chemical constitution of the substances also can be analysed by Raman effect.


Why the sky is blue?

As we all know that when light travels in a straight light, and something gets in its path - that may reflect the light, bend it, or scatter it.  By using these known properties we can explain it.

When sunlight passes through the atmosphere, due to the gases & particles present in air, the light is scattered in all the directions.  Sunlight is combination of seven colors, among them, blue is scattered more than the other colors because it travels as shorter and smaller waves.  Blue color is reached to our eyes from all the directions, that is most of the time we see a blue sky. 


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