Raman, Sir Chandrasekhara Venkata

Indian physicist (1888–1970)

Raman was born at Trichinopoly (now Tiruchirappalli) in India and educated at the University of Madras. However, although he revealed considerable talent, he was unable to pursue his education overseas because of ill health. Instead, he chose to enter the civil service where he worked as an auditor for ten years while continuing with his own private research. In 1917 he took up an appointment as professor of physics at the University of Calcutta. In 1933 he moved to Bangalore where he first headed the physics department at the Indian Institute of Science and later, in 1948, became founding director of the Raman Institute.

In 1928 he discovered a spectral effect for which, in 1930, he was awarded the Nobel Prize for physics, thus becoming not only the first Indian but the first Asian to be so honored. The Raman effect (as it is now known) occurs when visible radiation is scattered by the molecules in the medium. Not only will the original frequency of the incident light be found but in addition specific new-frequency lines will be detected as a result of the interaction of photons with the molecules. From these new lines in the spectrum (Raman lines) information can be deduced about the molecular structure. The effect is similar to that found by Arthur Compton for x-rays and had in fact been predicted by Werner Heisenberg some years earlier.

The Indian physicist Sir Chandrasekhar Venkata Raman (1888-1970) was awarded the Nobel Prize in 1930 for his work on the scattering of light and the discovery of the Raman effect, which has to do with changes in the wavelength of light scattered by molecules.

On Nov. 7, 1888, C. V. Raman was born at Trichinopoly, Madras, where his father taught physics in a church college. A few years later the family moved to Vizagapatam, when the father was appointed as lecturer in the local college. Raman received his early education there until he entered Presidency College in Madras in 1902. He graduated with a bachelor's degree in 1904, standing first in his class and winning the Gold Medal in physics. By the time he completed his master's degree in physics in 1907, he had already done original work in optics and acoustics, but since at that time there was little scope for scientific research in India, he took the competitive examination for a post in the Finance Department of the government of India. Again he won first place and as a result was appointed assistant accountant general in the central government offices in Calcutta.

During the next 10 years, while working in the Finance Department, Raman continued his scientific researches on his own in the laboratory of the Indian Association for the Cultivation of Science. The importance of his work was recognized by his appointment in 1917 to the first endowed chair in physics at Calcutta University. He kept this post until 1933.

Raman's years at Calcutta University were marked by great creativity and intellectual excitement, although by Western standards his laboratory facilities were meager. Many honors came to him as the significance of his work was acknowledged in India and abroad, as in 1929, when he was invited to do research at the California Institute of Technology. The most tangible evidence of this recognition came in 1927, when the British government conferred a knighthood on him, and in 1930, when he was awarded the Nobel Prize.

Raman Effect

Raman's early scientific interests were centered on phenomena associated with the scattering of light, the most familiar example of which is the effect created when light enters a darkened room through a small hole. The beam of light is then clearly seen because the light is scattered by the particles of dust in the air. That scattered light contained wavelengths in different proportions from the wavelengths of the main beam of light had been known since Tyndall's experiments in 1868, but a fully satisfactory analysis of the phenomenon had not been made.

It was this and related problems that Raman was studying at Calcutta when he discovered that when an intense light was passed through a liquid and was scattered by the molecules in the liquid, the spectrum of the scattered light showed lines not in the spectrum of the incident light. This discovery was the Raman effect, which had such great influence on later work on molecular structure and radiation that Raman was recognized as one of the truly seminal minds in the history of modern physics.

After Raman retired from Calcutta University, he became director of the Indian Institute of Science in Bangalore, where he remained until 1948, when he became head of the new Raman Research Institute in the same city. Here he continued to guide research and to inspire his students and coworkers. They spoke of his intense enthusiasm and volcanic energy and of his great generosity in acknowledging the contribution of others. According to one former student, he would "give away whole lines of research which lesser men would be tempted to keep for themselves."

Raman's attractiveness as a person was rooted in his esthetic approach to science, with his choice of subjects for investigation reflecting his love of music, color, harmony, and pattern. He told how his great discovery of the Raman effect was stimulated during a voyage to Europe in 1921, when he saw for the first time "the wonderful blue opalescence of the Mediterranean Sea" and began to think that the phenomenon was due to the scattering of sunlight by the molecules of water.

Raman influenced Indian scientific development through the Indian Journal of Physics, which he helped found and which he edited. He was also a gifted popularizer of modern scientific ideas, and he lectured widely to lay audiences. He died in Bangalore on Nov. 21, 1970.

Further Reading

Raman sets forth his own views on modern science in an attractive way in his The New Physics (1951). Some biographical details and a brief account of his scientific work are in Niels H. de V. Heathcote, Nobel Prize Winners in Physics, 1901-1950 (1953). A more technical discussion is S. Bhagavantam, Scattering of Light and the Raman Effect (1940). A consideration of Raman's many-sided contribution to science is made by his students and colleagues in Proceedings of the Indian Academy of Sciences, vol. 28 (1949).

For more information on Sir Chandrasekhara Venkata Raman, visit Britannica.com.

Raman, Sir Chandrasekhara Venkata (chŭn'drəsĕkärə vĕng'kətə rä'mən) , 1888–1970, Indian physicist. He was professor of physics at Calcutta Univ. from 1917 to 1933. In Bangalore (Bengaluru) he directed the Indian Institute of Science and, from 1946, the Raman Institute. For his research on the diffusion of light and for his discovery of the Raman effect, he received the 1930 Nobel Prize in Physics. He is noted also for his studies of diamonds. In 1929 he was knighted.