Raman Effect
Early Life: Chandrasekhar Venkata Raman was born on 7 November, 1888 at Tiruchirappally in the Madras Presidency (Tamil Nadu). He was the second child of Parvati Amma and Chandrasekhar Iyer, a lecturer in Physics and Mathematics. Raman was a brilliant student. He completed his BA from Presidency College, Madras at the age of 15. He graduated with honours, winning a gold medal in Physics. He completed his MA with distinction from the same college when he was hardly 18.
Raman topped the Civil Service competitive examination and in 1907, he was posted as Assistant Accountant General in Calcutta.
One day, while travelling to his office by tram, he noticed a signboard on a building that said, ‘Indian Association for Cultivation of Science’ (IACS). It was a private science institute established by Mahendralal Sircar. He got down from the tram and obtained permission to work there. The institute later became the springboard for his groundbreaking research.
The institute had many unused scientific apparatus. Using these instruments, Raman started working on various problems in sound and light without any guidance. He followed a gruelling schedule; he would reach the institute everyday by 5.30 am, work till 9.30 am, go home for a quick meal and then go to his office. He would be back at the institute by 5 pm and return home only by 10. He would spend the entire Sunday at the laboratory. Soon Raman started to publish high-quality research papers in international journals and became famous in the scientific world.
In 1917, Raman resigned from his well paying government job to become the first Palit Professor of Physics (a highly respected teaching post) at the Calcutta University. At the same time, he continued working at IACS. Students flocked to work under him, drawn by his fame and brilliance.
The Blue Sea: In 1921, he sailed to London to represent his university at the Assembly of Universities. While returning by steamer, Raman was fascinated by the deep blue colour of the Mediterranean Sea. Lord Raleigh (a Physics Nobel laureate) had already established that the blue colour of the sky was due to the scattering of light by air and dust molecules in the atmosphere. The blue component of light gets scattered the most, giving the sky its characteristic blue colour. Scientists explained that the blue colour of the sea was simply the reflection of the blue sky in the water.
Raman refused to accept the explanation. He conducted some simple experiments on board using a nicol prism and showed that the blue colour of the sea was caused by the scattering of sunlight by the water molecules.
Effect-ive discovery: Raman continued his light-scattering studies with different liquids using his homemade equipment in the IACS labs. Using optical filters, Raman passed a strong light beam of a single colour through a liquid and observed the light scattered by the liquid through a spectrograph. His studies yielded an unexpected result. A very small portion of the deflected light actually changed colour from the original light. This phenomenon was later named Raman effect. The change in colour of the scattered light was indicative of the molecule which scattered the light and thus became a tool to understand that molecule.
Raman made his discovery on 28 February, 1928. Two years later, he was awarded the Nobel Prize in Physics, making him the first Indian and non-white to receive a Nobel Prize in science.
India observes National Science Day on 28 February to honour Raman’s discovery. Dr. G. Venkataraman’s biography of Sir C. V.Raman is aptly titled Journey into Light.
Raman also studied X-Ray scattering and published papers in the field of musical instruments. Many awards and recognition came his way. He was elected as Fellow of the Royal Society in 1924, knighted in 1929 and was awarded the Franklin medal in 1942.
Raman joined the Indian Institute of Science in Bangalore in 1934 as its first Indian director. In 1949, he established the Raman Research Institute. He continued to teach and mentor students till he passed away in 1970.
When Raman was invited to Rashtrapati Bhavan to receive the Bharat Ratna on 27January, 1955, he wrote to the then Indian President Dr. Rajendra Prasad, expressing his inability to attend the function. He said he was busy supervising the thesis of his student and he thought that the job of mentoring his student was far more important than being present for the award function!
