Sir C.V. Raman (1888-1970) is known to have placed India on the world Science map. He was the first person from Asia to be awarded a Nobel Prize in any field of science.
How Raman Effect was discovered? A glass of water has no colour. But a deep sea with the same water is a brilliant blue. Why is this so? This was the question that C.V. Raman asked himself in 1921 on seeing the colour of the Mediterranean sea from a ship. He immediately began to conduct experiments on board the ship using some simple instruments he had with him. At that time, scientists believed the sea was blue because it reflected the colour of the sky, but Raman found that it was the water itself that caused blue light to scatter more than other colours in light.
After returning from Europe, he started experiments to study how light behaved when it passed through various substances.
On February 28, 1928, one of the experiments gave a clear result. Light of only one colour was passed through a liquid, but the light that emerged had small traces of another colour. This meant that the molecules in the liquid were changing the colour of some of the light passing through it. The discovery created a sensation around the world and was named the Raman Effect.
In 1930, C.V. Raman became the first person from Asia to be awarded a Nobel Prize in any field of science. The date of the discovery, February 28, is now celebrated as National Science Day in India.
Applications of Raman Effect
The Raman effect has been very useful in many areas of science. It was found that when light was passed through a substance, a series of colours were seen that could be thought of as a fingerprint of the substance. This idea has been used in chemistry, medicine, biology and many other areas of science to find out what a substance is made of.
Raman spectroscopy is commonly used in chemistry, since vibrational information is specific to the chemical bonds and symmetry of molecules. Therefore, it provides a fingerprint by which the molecule can be identified. Raman Scanner can be pointed at a substance to tell what it is. Police have begun to use this scanner to find out if people are carrying any banned substances.
The Indian Academy of Sciences, Bangalore was founded by Sir C. V. Raman in 1934. Professor Raman was elected the first president of the academy. To commemorate the memory of the academy’s founder, Government of India instituted the Raman Chair in 1972. Eminent scientists are invited by the Council of the Academy to occupy the Chair, for periods of between six weeks and six months.