C V Raman

Remembering one of India's most distinguished scientists on his birth anniversary:

Chandrasekhara Venkata Raman ( 7 November 1888 – 21 November 1970) was an Indian physicist who made groundbreaking works in the field of light scattering. With his student K. S. Krishnan, he discovered that when light traverses a transparent material, some of the deflected light change wavelength and amplitude. This phenomenon was a new type of scattering of light and was subsequently known as the Raman effect (Raman scattering).  Raman won the 1930 Nobel Prize in Physics and was the first Asian person to receive a Nobel Prize in any branch of science.

Early life

C. V. Raman was born in Trichinopoly, Madras Presidency (now Trichy, Tamil Nadu), to Hindu Tamil parents, Chandrasekhara Ramanathan Iyer and Parvathi Ammal.  His father was a teacher at the local high school, and earned a modest income. Raman recalled: "I was born with a copper spoon in my mouth. At my birth my father was earning the magnificent salary of ten rupees per month!"  In 1892, his family moved to  Visakhapatnam  in Andhra Pradesh as his father was appointed to the faculty of physics at a college there.  Raman was a precocious child, and  compled his secondary and higher secondary education from St Aloysius' Anglo-Indian High School in Vizag at the ages of 11 and 13, respectively.

In 1902, Raman joined Presidency College in Madras (now Chennai) where his father had been transferred to teach mathematics and physics. In 1904, he obtained a B.A. degree from the University of Madras, where he stood first and won the gold medal in physics. 

At age 18, while still a post-graduate student, he published his first scientific paper on diffraction of light in the British journal Philosophical Magazine in 1906. He completed an M.A. degree from the same university with highest distinction in 1907. His second paper published in the same journal that year was on surface tension of liquids. It was alongside Lord Rayleigh's paper on the sensitivity of ear to sound. After this,  Lord Rayleigh started to communicate with Raman, courteously addressing him as "Professor."

Aware of Raman's capacity, his physics teacher Richard Llewellyn Jones insisted that he  continue his  research in England. Jones arranged for Raman's physical examination by  Colonel (Sir Gerald) Giffard. The inspection revealed that Raman would not withstand the harsh weather of England. As Raman later recalled,  "[Giffard] examined me and certified that I was going to die of tuberculosis if I were to go to England." (It is true that many Indians have fallen victim to the harsh British climate, the most notable being the brilliant mathematician Srinivasa Ramanujan.)

Professional Career

In no condition to study abroad, Raman followed in his brother's footsteps  and joined the Indian Finance Service after securing first position in the entrance examination in 1907. He was posted in Calcutta as Assistant Accountant General in June 1907.  

It was there that he became highly impressed with the Indian Association for the Cultivation of Science (IACS), the first research institute founded in India in 1876.  He immediately befriended Asutosh Dey, who would eventually become his lifelong collaborator, Amrita Lal Sircar, founder and secretary of IACS, and Ashutosh Mukherjee, executive member of the institute and Vice Chancellor of the University of Calcutta. 

With such connections, he obtained permission to conduct research in his own time. Up to that time the institute had not yet recruited regular researchers, or produced any research papers. Raman's article "Newton's rings in polarised light" was published in Nature in 1907 from the institute.

From 1915, the University of Calcutta started assigning research scholars under Raman at IACS. Sudhangsu Kumar Banerji (who later become Director General of Observatories of India Meteorological Department),  was his first student. 

In  1917, the University of Calcutta appointed him Professor of Physics at the newly formed  Rajabazar Science College campus of the University. He reluctantly resigned as a civil servant in the Indian Finance Service  after a decade of service, which was described as "supreme sacrifice" since his salary as a professor would be roughly half of his salary at the time. But the advantage was that he could delve into dedicated research, as explicitly indicated in the report of his joining the university, which stated:

"Mr C. V. Raman joined  as Professor of Physics from 2.7.17. Mr Raman was informed that he will not be required to take any teaching work, so that his own of doing research or assisting students in their research  will not be affected."  

The University of Calcutta allotted PhD students to Raman, and other universities followed suit. By 1919, Raman had guided more than a dozen students.  He referred to this period as the "golden era" of his life. He made his major contributions to research  in acoustics and optics.

Raman's appointment as Professor of Physics was strongly objected to by some members of the Senate of the University of Calcutta, especially foreign members, as Raman had no PhD and had never studied abroad. As a kind of rebuttal Mukherjee arranged for an honorary DSc which the University of Calcutta conferred Raman in 1921.

One of Raman's interests was understanding the physics of musical sounds.  He studied and published his findings quite prolifically between 1916 and 1921. He worked out the theory of transverse vibration of string instruments. 

Raman also studied the uniqueness of Indian drums. His analyses of the harmonic nature of the sound of tabla and mridangam were the first scientific studies on Indian percussion. 

In 1921, he visited Oxford to deliver a lecture at the Congress of Universities of the British Empire.  He was by then widely known, and his hosts were J. J. Thomson and Lord Rutherford. He was elected as Fellow of the Royal Society in 1924.

Lord Rutherford was instrumental in some of Raman's most pivotal moments in life. He nominated Raman for the Nobel Prize in Physics in 1930, presented him the Hughes Medal as President of the Royal Society in 1930, and recommended him for the position of Director at IISc in 1932.

During his brief visit of England in 1921, he managed to study how sound travels in the Whispering Gallery of the dome of St Paul's Cathedral in London that produces unusual sound effects. His work on acoustics was an important prelude, both experimentally and conceptually, to his later works on optics and quantum mechanics.

Raman, in his broadening venture on optics, started to investigate scattering of light starting in 1919.  After his first trip to Europe, during the  voyage home from England on board the boat in September 1921, he contemplated the blue colour of the Mediterranean Sea. Using simple optical equipment, a pocket-sized spectroscope and a Nicol prism, he studied the seawater. He deduced that the blue colour of the sea was a phenomenon of diffraction.

Of several hypotheses on the colour of the sea, the best explanation had been that of Lord Rayleigh's in 1910, according to which "The much admired dark blue of the deep sea has nothing to do with the colour of water, but is simply the blue of the sky seen by reflection". 

The Nicol prism allowed Raman to view the water without the influence of sunlight reflected by the surface. He described how the sea appears even more blue than usual, contradicting Rayleigh.

As soon as his ship  docked in Bombay Harbour, Raman finished an article "The colour of the sea" published in the November 1921 issue of Nature. He noted that Rayleigh's explanation is "questionable".

When he reached Calcutta, he and  his student K.R. Ramanathan conducted further research on this topic. His elaborate experimental findings were published  in 1923. 

Raman's second important discovery on the scattering of light was a new type of radiation, an eponymous phenomenon called Raman effect. On Feb 28 1928, he and his student KS  Krishnan, a Research Associate in his laboratory,  discovered  a novel phenomenon of light scattering, which they called "modified scattering," but more famously known as the Raman effect.  He published his famous article "A new radiation" reporting the discovery of the Raman effect in the Indian Journal of Physics, which he had established in 1926. Feb 28 is celebrated by the Government of India as the National Science Day every year, in remembrance of this discovery. 

The major impetus was the discovery of Compton effect. Arthur Compton at the Massachusetts Institute of Technology had found evidence in 1923 that electromagnetic waves such as X-rays  can also be described as particles (photons), as he  observed that they were  scattered by particles like electrons.  By 1927, the phenomenon was widely accepted by scientists, including Raman.  

As the news of Compton's Nobel Prize in Physics was announced in December 1927, Raman ecstatically told Krishnan, "Excellent news. Very nice indeed. But if this is true of X-Rays, it must be true of Light too. I have always thought so. There must be an optical analogue to Compton Effect. We must pursue it. It must and shall be found."

Krishnan started the experiment at the beginning of January 1928. On 7 January Krishnan discovered that no matter what kind of pure liquid he used, it always produced polarised fluorescence within the visible spectrum of light. When Raman saw the result, he named the new phenomenon as "modified scattering" with reference to the Compton effect, which was unmodified scattering. 

On 28 February 1928, Raman and Krishnan obtained spectra of the modified scattering separate from the incident light. Raman had invented an instrument for detecting and measuring electromagnetic waves called a spectrograph. They could then employ the instrument using monochromatic light from a mercury arc lamp which penetrated transparent material and was allowed to fall on a spectrograph to record its spectrum. The lines of scattering could now be measured and photographed.

The same day, Raman made the announcement to the press. The Associated Press of India reported it the next day, on 29 February, as "New theory of radiation: Prof. Raman's Discovery." It ran the story as:

Prof. C. V. Raman, F.R.S., of Calcutta University, has made a discovery which promises to be of fundamental significance to physics. The new phenomenon exhibits features even more startling than those discovered by Prof. Compton with X-rays. The principal feature observed is that when matter is excited by light of one colour, the atoms contained in it emit light of two colours, one of which is different from the exciting colour and is lower down the spectrum. The astonishing thing is that the altered colour is quite independent of the nature of the substance used.

In addition to being a new phenomenon itself, the Raman effect was one of the earliest proofs of the quantum nature of light. Robert W. Wood at the Johns Hopkins University was the first American to confirm the Raman effect in the early 1929. He made a series of experimental verification, after which he commented, saying, "It appears to me that this very beautiful discovery which resulted from Raman's long and patient study of the phenomenon of light scattering is one of the most convincing proofs of the quantum theory".  

The field of Raman spectroscopy came to be based on this phenomenon, and Ernest Rutherford, President of the Royal Society, referred to it in his presentation of the Hughes Medal to Raman in 1930 as "among the best three or four discoveries in experimental physics in the last decade."

In 1933, he left Kolkata to join the Indian Institute of Science in Bangalore as its first Indian director. During his tenure at IISc, he recruited G. N. Ramachandran, who later went on to become a distinguished X-ray crystallographer. In Bangalore,  founded the Indian Academy of Sciences in 1934.

With his former student Panchapakesa Krishnamurti, Raman started a company called Travancore Chemical and Manufacturing Co. Ltd. in 1943.  The company, renamed as TCM Limited in 1996, was one of the first manufacturers of organic and inorganic chemicals in India. 

In 1947, Raman 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 a year later. He served as its director and remained active there until his death in 1970.

Later work

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

Raman was  associated  with the Banaras Hindu University in Varanasi. He attended the foundation ceremony of BHU and delivered lectures on mathematics and "Some new paths in physics" during the lecture series organised at the university from 5 to 8 February 1916. He also held the position of permanent visiting professor at BHU.

Raman and his student, Nagendra Nath, provided the correct theoretical explanation for the light  scattering by sound waves (acousto-optic effect), 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.

Other investigations carried out by Raman were experimental and theoretical studies on the diffraction of light by acoustic waves of ultrasonic  and hypersonic frequencies, and those on the effects produced by X-rays on infrared vibrations in crystals exposed to ordinary light.

In 1948, Raman, through studying the  spectroscopic behaviour of crystals, approached in a new manner fundamental problems of crystal dynamics. He dealt with the structure and properties of diamond, the structure and optical behaviour of numerous iridescent substances including agate, opal, and pearls. Among his other interests were the optics of colloids, electrical and magnetic anisotropy, and the physiology of human vision.

Personal life

Raman married Lokasundari Ammal (1892–1980) on 6 May 1907. It was a self-arranged marriage and his wife was 13 years old. His wife later recounted (apparently jokingly) that their marriage was not so much about her musical prowess (she was playing veena when they first met) as "the extra allowance which the Finance Department gave to its married officers."(Married officers got additional INR 150.) 

They had two sons, Chandrasekhar Raman and radio-astronomer Venkatraman Radhakrishnan. Raman was the paternal uncle of Subrahmanyan Chandrasekhar, recipient of the 1983 Nobel Prize in Physics.

Religious beliefs

Soon after they moved to Calcutta in 1907, the couple were accused of converting to Christianity. It was because they were fascinated by St. John's Church, Kolkata and often visited it, Lokasundari for the music and Raman for the acoustics.

Although Raman hardly talked about religion, he was openly an agnostic, but objected to being labeled atheist.  He however did not give up Hindu traditional rituals. Traditional pagri (Indian turban) with a tuft underneath and a upanayana (Hindu sacred thread) were his signature attire. Though it was not customary to wear turbans in South Indian culture, he explained his habit as, "Oh, if I did not wear one, my head will swell. You all praise me so much and I need a turban to contain my ego." He even attributed his turban for the recognition he received on his first visit to England, particular from J. J. Thomson and Lord Rutherford.  In a public speech, he once said,

There is no Heaven, no Swarga, no Hell, no rebirth, no reincarnation and no immortality. The only thing that is true is that a man is born, he lives and he dies. Therefore, he should live his life properly.

In a friendly meeting with Mahatma Gandhi and Gilbert Rahm, a German zoologist, the conversation turned to religion. Raman said,  "I shall answer your [Rahm's] question. If there is a God we must look for him in the Universe. If he is not there, he is not worth looking for... The growing discoveries in the science of astronomy and physics seem to be further and further revelations of God."

Death

At the end of October 1970, Raman had a cardiac arrest and collapsed in his laboratory. He was moved to the hospital where the doctors diagnosed his condition and declared that Raman would not live more than four hours. He however survived a few days and requested to stay in the gardens of his institute surrounded by his followers.

Two days before Raman died, he told one of his former students, "Do not allow the journals of the Academy to die, for they are the sensitive indicators of the quality of science being done in the country and whether science is taking root in it or not."  That evening, Raman met with the Board of Management of his institute and discussed (from his bed) with them any proceedings of the institute's management.He also willed his wife to perform a simple cremation without any rituals upon his death. He died from natural causes early the next morning on 21 November 1970 at the age of 82.

On the news of Raman's death, Prime Minister Indira Gandhi publicly announced, saying, "The country, the House [of Parliament], and everyone of us will mourn the death of Dr. C. V. Raman. He was the greatest scientist of modern India and one of the greatest intellects our country has produced in its long history. His mind was like the diamond, which he studied and explained. His life's work consisted in throwing light upon the nature of lights, and the world honoured him in many ways for the new knowledge which he won for science."

Controversies

Krishnan

His student Krishnan was not nominated for the Nobel Prize even though he was the main researcher in the discovery of Raman effect. It was he alone who first noted the new scattering. Of about all the scientific papers on the discovery in 1928, Krishnan co-authored all the papers except two. He alone wrote all the follow-up studies. Though  Krishnan himself never claimed himself worthy of the prize,  Raman admitted later that Krishnan was the co-discoverer. Later, however, he however remained openly antagonistic towards Krishnan, which Krishnan described as "the greatest tragedy of my life." After Krishnan's death, Raman said to a correspondent from The Times of India, "Krishnan was the greatest charlatan I have known, and all his life he masqueraded in the cloak of another man's discovery."

Hostility to Indian authorities

Raman had a vicious aversion to the then Prime Minister of India Jawaharlal Nehru and Nehru's policies on science. In one instance he smashed the bust of Nehru on the floor. In another he shattered to pieces with a hammer his Bharat Ratna medallion, as it was given to him by the Nehru government.

Nehru even offered Raman financial assistance to his institute which Raman flatly refused by replying, "I certainly don't want this to become another government laboratory." Raman was particularly against the control of research programmes by the government. Strangely, he opposed  the establishment of government-funded organizations like the Bhabha Atomic Research Centre (BARC),  Defense Research and Development Organisation (DRDO), and the Council of Scientific and Industrial Research (CSIR).

He remained hostile to people associated with these establishments such as Homi J. Bhabha, S.S. Bhatnagar, and his once favourite student, Krishnan. He even called such programmes as the "Nehru–Bhatnagar effect."

Indian Institute of Science

Raman had a great fallout with the authorities at the Indian Institute of Science (IISc). He was accused of biased development in physics, while ignoring other fields. He lacked the diplomatic skills of other colleagues   S. Ramaseshan, his nephew and later Director of IISc, reminisced, saying, "Raman went in there like a bull in a china shop." He wanted research in physics at the level of those of western institutes, but at the expense of other fields of science. Raman had invited Max Born, who later won the Nobel Prize in Physics, to work at the IISc. Born observed, "Raman found a sleepy place where very little work was being done by a number of extremely well paid people." At the Council meeting Kenneth Aston, professor in the Electrical Technology Department, harshly criticised Raman and Raman's recruitment of Born. Raman had every intention of giving full position of professor to Born. Aston  personal attacked  Born by referring to him as someone "who was rejected by his own country, a renegade and therefore a second-rate scientist unfit to be part of the faculty, much less to be the head of the department of physics." (Born was a refugee from Hitler's pogrom against the Jews.)

The Council of IISc constituted a review committee to oversee Raman's conduct in January 1936. The committee, chaired by James Irvine, Principal and Vice Chancellor of the University of St Andrews, reported in March that Raman had misused the funds and entirely shifted the "centre of gravity" in research to physics, and also that the proposal of Born as Professor of Mathematical Physics (which was already approved by the Council in November 1935) was not financially feasible. The Council offered Raman two choices,  either to resign from the institute with effect from 1 April or resign as the Director and continue as Professor of physics. If he did not make the choice, he was to be fired. Raman was compelled to make the second choice.

Honours

Raman was honoured with many honorary doctorates and memberships of scientific societies. He was member of the Deutsche Akademie of Munich, Swiss Physical Society of Zürich, Royal Philosophical Society of Glasgow, Royal Irish Academy, Hungarian Academy of Sciences, Academy of Sciences of the U.S.S.R., Optical Society of America and  Mineralogical Society of America, Romanian Academy of Sciences, Catgut Acoustical Society of America, and Czechoslovak Academy of Sciences.

In 1924, he was elected a Fellow of the Royal Society. However, for reasons that are not clear,  he resigned from the fellowship in 1968, the only Indian FRS ever to do so.

He was the President of the 16th session of the Indian Science Congress in 1929. He was the founder President of the Indian Academy of Sciences from 1933 till his death. He was member of the Pontifical Academy of Sciences in 1961.

Awards

1912 - Curzon Research Award

1913 - Woodburn Research Medal

1928 - Matteucci Medal from the Accademia Nazionale delle Scienze in Rome

1930 - he was knighted. An approval for his inclusion in the 1929 Birthday Honours was delayed, and Lord Irwin, the Viceroy of India, conferred him Knight Bachelor in a special ceremony at the Viceroy's House (now Rashtrapati Bhawan) in New Delhi.

1930 - Nobel Prize in Physics "for his work on the scattering of light and for the discovery of the effect named after him."

1930 - Hughes Medal of the Royal Society 

1941 - Franklin Medal of Franklin Institute in Philadelphia.

1954 - Bharat Ratna 

1957 - Lenin Peace Prize.

Posthumous recognition

India celebrates National Science Day on 28th February of every year to commemorate the discovery of the Raman effect in 1928.

Postal stamps featuring Raman were issued in 1971 and 2009.

A road in India's capital, New Delhi, is named C. V. Raman Marg.

An area in eastern Bangalore is called CV Raman Nagar.

The road running north of the national seminar complex in Bangalore is named C. V. Raman Road.

A building at the Indian Institute of Science in Bangalore is named the Raman Building.

A hospital in eastern Bangalore on 80 Ft. Rd. is named the Sir C. V. Raman Hospital.

There is also CV Raman Nagar in Trichy, his birthplace.

Raman, a lunar crater is named after C. V. Raman.

C. V. Raman Global University was established in 1997.

In 1998, the American Chemical Society and Indian Association for the Cultivation of Science  recognised Raman's discovery as an International Historic Chemical Landmark. The Raman effect  became even more valuable with the advent of modern computers and lasers. Its current uses range from the non-destructive identification of minerals to the early detection of life-threatening diseases.

Dr. C.V. Raman University was established in Chhattisgarh in 2006.

On 7 November 2013, a Google Doodle honoured Raman on the 125th anniversary of his birthday.

Raman Science Centre in Nagpur is named after Sir C. V. Raman.

Dr. C.V. Raman University, Bihar was established in 2018.

Dr. C.V. Raman University, Khandwa was established in 2018.

Raman stands out as a shining example of the fact that  Indians do not need to go abroad to excel in  science. With dedication and zeal, he became a brilliant physicist, and was the first Asian and non-white person to win a Nobel Prize in the sciences.