CV Raman

Today I am writing about one of the greatest Scientist of our country, and he is

Sir Chandrasekhara Venkata Raman

Popularly known as CV Raman

He was an Indian physicist born in the former Madras Province in India presently the state of Tamil Nadu, who carried out ground-breaking work in the field of light scattering which earned him the 1930 Nobel Prize for Physics. He discovered that when light traverses a transparent material, some of the deflected light changes wavelength. This phenomenon, subsequently known as Raman scattering, results from the Raman effect. In 1954, India honoured him with its highest civilian award, the Bharat Ratna.

At an early age, Raman moved to the city of Visakhapatnam and studied at St. Aloysius Anglo-Indian High School. Raman passed his matriculation examination at the age of 11 and he passed his F.A. examination (equivalent to today’s Intermediate exam or  12/HSc) with a scholarship at the age of 13.

In 1902, Raman joined Presidency College in Madras where his father was a lecturer in mathematics and physics. In 1904 he passed his Bachelor degree exam of University of Madras. He stood first and won the gold medal in physics. In 1907 he gained his Master of sciences degree with the highest distinctions from University of Madras.

In the year 1917, Raman resigned from his government service after he was appointed as the Palit professor at theCalcutta University. At the same time, he continued doing research at the Indian Association for thecultivation of Sciences (IACS), Calcutta, where he became the Honorary Secretary. Raman used to refer to this period as the golden era of his career. Many students gathered around him at the IACS and the University of Calcutta. In 1926 Prof. Raman established the Indian Journal of Physics and he was the first editor. The second volume of the Journal published his famous article “A New Radiation”,reporting the discovery of Raman Effect.

During a voyage to Europe in 1921, Raman noticed the blue colour of glaciers and the Mediterranean sea. He was motivated to discover the reason for the blue colour. Raman carried out experiments regarding the scattering of light by water and transparent blocks of ice which explained the phenomenon.

Raman employed monochromotic light from a mercury arc lamp which penetrated transparent material and was allowed to fall on aspectograph to record its spectrum. He detected lines in the spectrum, which were later called Raman lines. He presented his theory at a meeting of scientists in Bangalore on 16 March 1928, and won the Nobel Prize in Physics in 1930. In Munich, some physicists were initially unable to reproduce Raman’s results, leading to scepticism. However, Peter Pringsheim was the first German to reproduce Raman’s results successfully. He sent spectra to Arnold Sommerfeld. Pringsheim was the first to coin the term “Raman effect” and “Raman lines.”

On 28 February 1928, Raman led experiments at the IACS with collaborators, including KS Krsihnan, on the scattering of light, when he discovered what now is called the Raman effect. A detailed account of this period is reported in the biography by G. Venkatraman. It was instantly clear that this discovery was of huge value. It gave further proof of the quantum nature of light. Raman had a complicated professional relationship with KS krishnan, who surprisingly did not share the award, but is mentioned prominently even in the Nobel lecture.

Raman sectroscopy came to be based on this phenomenon, and Ernest Rutherford referred to it in his presidential address to the Royal Society in 1929. Raman was president of the 16th session of the I S C in 1929. He was conferred a knighthood, and medals and honorary doctorates by various universities. Raman was confident of winning the Nobel Prize in Physics as well but was disappointed when the Nobel Prize went to Owen Richardson in 1928 and to Louis  de Broglie in 1929. He was so confident of winning the prize in 1930 that he booked tickets in July, even though the awards were to be announced in November, and would scan each day’s newspaper for announcement of the prize, tossing it away if it did not carry the news.He did eventually win the 1930 Nobel Prize in Physics “for his work on the scattering of light and for the discovery of the Raman effect”. He is the first Asian and first non-white to receive any Nobel Prize in the sciences. Before him Rabindranath Tagore(also Indian) had received the Nobel Prize for Literature in 1913.

Raman and Suri Bhagavantam discovered the quantum photon spin in 1932, which further confirmed the quantum nature of light.

Raman also worked on the acoustics of musical instruments. He worked out the theory of transverse vibration of bowed strings, on the basis of super position velocities. He was also the first to investigate the harmonic nature of the sound of the Indian drums such as the tabla and the mridingam. He was also interested in the properties of other musical instruments based on forced vibrations such as the violin. He also investigated the propagation of sound in whispering galleries. Raman’s work on acoustics was an important prelude, both experimentally and conceptually, to his later work on optics and quantum mechanics.

Raman and his student, Nagendra Nath, provided the correct theoretical explanation for the acousto-optic effect (light scattering by sound waves), in a series of articles resulting in the celebrated Raman–Nath theory Modulators, and switching systems based on this effect have enabled optical communication components based on laser systems.

Raman was succeeded by Debendra Mohan Bose as the Palit Professor in 1932. In 1933, Raman left IACS to join Indian Institute of Science in Bangalore as its first Indian director. Other investigations carried out by Raman were experimental and theoretical studies on the diffraction of light by acoustic waves of ultrasonic and hypersonic frequencies (published 1934–1942), and those on the effects produced by X-rays on infrared vibrations in crystals exposed to ordinary light.

He also started the company called Travancore Chemical and Manufacturing Co. Ltd. (now known as TCM Ltd.) which manufactured potasium chlorate  for the match industry .in 1943 along with Dr. Krishnamurthy. The Company subsequently established four factories in Southern India. In 1947, he was appointed as the first National Professor by the new government of Independent India.

Raman retired from the Indian Institute of Science in 1948 and established the Raman Research Institute in Bangalore, Karnataka, a year later. He served as its director and remained active there until his death in 1970, in Bangalore, at the age of 82.

He was  in true sense a complete scientist, who devoted his fill life in the field of science only.

Waiting for our comments/feed backs/ views.

Anil Malik

28th Nov,  2018