Sir Chandrasekhara Venkata Raman FRS (7 November 1888 – 21 November 1970) was an Indian physicist known for his work in the field of light scattering. Using a spectrograph that he developed, he and his student K. S. Krishnan discovered that when light traverses a transparent material, the deflected light changes its wavelength and frequency. This phenomenon, a hitherto unknown type of scattering of light, which they called "modified scattering" was subsequently termed the Raman effect or Raman scattering. Raman received the 1930 Nobel Prize in Physics for the discovery and was the first Asian to receive a Nobel Prize in any branch of science.

Born to Tamil Brahmin parents, Raman was a precocious child, completing his secondary and higher secondary education from St Aloysius' Anglo-Indian High School at the age of 11 and 13, respectively. He topped the bachelor's degree examination of the University of Madras with honours in physics from Presidency College at age 16. His first research paper, on diffraction of light, was published in 1906 while he was still a graduate student. The next year he obtained a master's degree. He joined the Indian Finance Service in Calcutta as Assistant Accountant General at age 19. There he became acquainted with the Indian Association for the Cultivation of Science (IACS), the first research institute in India, which allowed him to carry out independent research and where he made his major contributions in acoustics and optics.

In 1917, he was appointed the first Palit Professor of Physics by Ashutosh Mukherjee at the Rajabazar Science College under the University of Calcutta. On his first trip to Europe, seeing the Mediterranean Sea motivated him to identify the prevailing explanation for the blue colour of the sea at the time, namely the reflected Rayleigh-scattered light from the sky, as being incorrect. He founded the Indian Journal of Physics in 1926. He moved to Bangalore in 1933 to become the first Indian director of the Indian Institute of Science. He founded the Indian Academy of Sciences the same year. He established the Raman Research Institute in 1948 where he worked to his last days.

The Raman effect was discovered on 28 February 1928. The day is celebrated annually by the Government of India as the National Science Day. In 1954, the Government of India honoured him with the first Bharat Ratna, its highest civilian award. He later smashed the medallion in protest against Prime Minister Jawaharlal Nehru's policies on scientific research.

Early life and education

C. V. Raman was born in Tiruchirapalli in the Madras Presidency of British India (now Tiruchirapalli, Tamil Nadu, India) to Tamil Brahmin parents, Chandrasekhara Ramanathan Iyer and Parvathi Ammal.  He was the second of eight siblings. His father was a teacher at a local high school, and earned a modest income. He 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 (then Vishakapatnam, Vizagapatam or Vizag) in Andhra Pradesh as his father was appointed to the faculty of physics at Mrs A.V. Narasimha Rao College.

Raman was educated at the St Aloysius' Anglo-Indian High School, Visakhapatnam. He passed matriculation at age 11 and the First Examination in Arts examination (equivalent to today's intermediate examination, pre-university course) with a scholarship at age 13, securing first position in both under the Andhra Pradesh school board (now Andhra Pradesh Board of Secondary Education) examination.

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 medals in physics and English. At age 18, while still a graduate student, he published his first scientific paper on "Unsymmetrical diffraction bands due to a rectangular aperture" in the British journal Philosophical Magazine in 1906. He earned 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, and from which Lord Rayleigh started to communicate with Raman, courteously addressing him as “Professor.”

Aware of Raman's capacity, his physics teacher Rhishard Llewellyn Jones insisted he continue research in England. Jones arranged for Raman's physical inspection with Colonel (Sir Gerald) Giffard. Raman often had poor health and was considered as a “weakling.” The inspection revealed that he would not withstand the harsh weathers of England, the incident of which he later recalled, and said, “[Giffard] examined me and certified that I was going to die of tuberculosis… if I were to go to England.”

Career

Raman's elder brother Chandrasekhara Subrahmanya Ayyar had joined the Indian Finance Service (now Indian Audit and Accounts Service), the most prestigious government service in India. In no condition to study abroad, Raman followed suit and qualified for the Indian Finance Service achieving first position in the entrance examination in February 1907. He was posted in Calcutta (now Kolkata) 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 their support, he obtained permission to conduct research at IACS in his own time even "at very unusual hours," as Raman later reminisced. Up to that time the institute had not yet recruited regular researchers, or produced any research paper. Raman's article "Newton's rings in polarised light" published in Nature in 1907 became the first from the institute. The work inspired IACS to publish a journal, Bulletin of Indian Association for the Cultivation of Science, in 1909 in which Raman was the major contributor.

In 1909, Raman was transferred to Rangoon, British Burma (now Myanmar), to take up the position of currency officer. After only a few months, he had to return to Madras as his father died from an illness. The subsequent death of his father and funeral rituals compelled him to remain there for the rest of the year. Soon after he resumed office at Rangoon, he was transferred back to India at Nagpur, Maharashtra, in 1910. Even before he served a year in Nagpur, he was promoted to Accountant General in 1911 and again posted to Calcutta.

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), a PhD scholar under Ganesh Prasad, was his first student. From the next year, other universities followed suit including University of Allahabad, Rangoon University, Queen's College Indore, Institute of Science, Nagpur, Krisnath College, and University of Madras. By 1919, Raman had guided more than a dozen students. Following Sircar's death in 1919, Raman received two honorary positions at IACS, Honorary Professor and Honorary Secretary. He referred to this period as the "golden era" of his life.

Raman was chosen by the University of Calcutta to become the Palit Professor of Physics, a position established after the benefactor Sir Taraknath Palit, in 1913. The university senate made the appointment on 30 January 1914, as recorded in the meeting minutes:

The following appointments to the Palit Professorships were made at the meeting of the Senate on 30 January 1914: Dr P C Ray and Mr C.V. Raman, MA... The appointment of each Professor shall be permanent. A Professor shall vacate his office upon completion of sixtieth year of his age.

Prior to 1914, Ashutosh Mukherjee had invited Jagadish Chandra Bose to take up the position, but Bose declined. As a second choice, Raman became the first Palit Professor of Physics but was delayed for taking up the position as World War I broke out. It was only in 1917 when he joined Rajabazar Science College, a campus created by the University of Calcutta in 1914, that he became a full-fledged professor. He reluctantly resigned as a civil servant 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 to his advantage, the terms and conditions as a professor were explicitly indicated in the report of his joining the university, which stated:

Mr C.V. Raman's acceptance of the Sir T N Palit Professorship on condition that he will not be required to go out of India... Reported that Mr C. V. Raman joined his appointment as Palit Professor of Physics from 2.7.17... Mr Raman informed that he will not be required to take any teaching work in MA and MSc classes, to the detriment of his own research or assisting advanced students in their researches.

Raman's appointment as the Palit Professor was strongly objected to by some members of the Senate of the University of Calcutta, especially foreign members, as he 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. The same year he visited Oxford to deliver a lecture at the Congress of Universities of the British Empire. He had earned quite a reputation by then, and his hosts were Nobel laureates J. J. Thomson and Lord Rutherford. Upon his election as Fellow of the Royal Society in 1924, Mukherjee asked him of his future plans, which he replied, saying, “The Nobel Prize of course.” In 1926, he established the Indian Journal of Physics and acted as the first editor. The second volume of the journal published his famous article "A new radiation", reporting the discovery of the Raman effect.

Raman was succeeded by Debendra Mohan Bose as the Palit Professor in 1932. Following his appointment as Director of the Indian Institute of Science (IISc) in Bangalore, he left Calcutta in 1933. Maharaja Krishnaraja Wadiyar IV, the King of Mysore, Jamsetji Tata and Nawab Sir Mir Osman Ali Khan, the Nizam of Hyderabad, had contributed the lands and funds for the Indian Institute of Science in Bangalore. The Viceroy of India, Lord Minto approved the establishment in 1909, and the British government appointed its first director, Morris Travers. Raman became the fourth director and the first Indian director. During his tenure at IISc, he recruited G. N. Ramachandran, who later went on to become a distinguished X-ray crystallographer. He founded the Indian Academy of Sciences in 1934 and started publishing the academy's journal Proceedings of the Indian Academy of Sciences (later split up into Proceedings - Mathematical Sciences, Journal of Chemical Sciences, and Journal of Earth System Science). Around that time the Calcutta Physical Society was established, the concept of which he had initiated early in 1917.

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 organic and inorganic chemical manufacturers in India. In 1947, Raman was appointed the first National Professor by the new government of independent India.

Raman retired from IISC 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.

Scientific contributions

Musical sound

One of Raman's interests was on the scientific basis of musical sounds. He was inspired by Hermann von Helmholtz's The Sensations of Tone, the book he came across when he joined IACS. He published his findings prolifically between 1916 and 1921. He worked out the theory of transverse vibration of bowed string instruments based on superposition of velocities. One of his earliest studies was on the wolf tone in violins and cellos. He studied the acoustics of various violin and related instruments, including Indian stringed instruments, and water splashes. He even performed what he called “Experiments with mechanically-played violins.”

Raman also studied the uniqueness of Indian drums. His analyses of the harmonic nature of the sounds of tabla and mridangam were the first scientific studies on Indian percussions. He wrote a critical research on vibrations of the pianoforte string that was known as Kaufmann's theory. 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.

Blue colour of the sea

Raman, in his broadening venture on optics, started to investigate scattering of light starting in 1919.  His first phenomenal discovery of the physics of light was the blue colour of seawater. During a voyage home from England on board the S.S. Narkunda in September 1921, he contemplated the blue colour of the Mediterranean Sea. Using simple optical equipment, a pocket-sized spectroscope and a Nicol prism in hand, he studied the seawater. Of several hypotheses on the colour of the sea propounded at the time, 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". Rayleigh had correctly described the nature of the blue sky by a phenomenon now known as Rayleigh scattering, the scattering of light and refraction by particles in the atmosphere. His explanation of the blue colour of water was instinctively accepted as correct. Raman could view the water using Nicol prism to avoid the influence of sunlight reflected by the surface. He described how the sea appears even more blue than usual, contradicting Rayleigh.

As soon as the S.S. Narkunda docked in Bombay Harbour (now Mumbai Harbour), Raman finished an article "The colour of the sea" that was published in the November 1921 issue of Nature. He noted that Rayleigh's explanation is "questionable by a simple mode of observation" (using Nicol prism). As he thought:

Looking down into the water with a Nicol in front of the eye to cut off surface reflections, the track of the sun's rays could be seen entering the water and appearing by virtue of perspective to converge to a point at a considerable depth inside it. The question is: What is it that diffracts the light and makes its passage visible? An interesting possibility that should be considered in this connection is that the diffracting particles may, at least in part, be the molecules of the water themselves.

Title page to Raman's Molecular Diffraction of Light (1922)

When he reached Calcutta, he asked his student K. R. Ramanathan, who was from the University of Rangoon, to conduct further research at IACS. By early 1922, Raman came to a conclusion, as he reported in the Proceedings of the Royal Society of London:

It is proposed in this paper to urge an entirely different view, that in this phenomenon, as in the parallel case of the colour of the sky, molecular diffraction determines the observed luminosity and in great measure also its colour. As a necessary preliminary to the discussion, a theoretical calculation and experimental observations of the intensity of molecular scattering in water will be presented.

True to his words, Ramanathan published an elaborate experimental finding in 1923. His subsequent study of the Bay of Bengal in 1924 provided the full evidence. It is now known that the intrinsic colour of water is mainly attributed to the selective absorption of longer wavelengths of light in the red and orange regions of the spectrum, owing to overtones of the infrared absorbing O-H (oxygen and hydrogen combined) stretching modes of water molecules.

Spouse and Children

CV Raman was attracted to a girl called Lokasundari while playing the veena, and he pointed out his intention to marry her. With the family's agreement, he married her on May 6, 1907. He has two sons, Radhakrishnan and Chandrashekhar. His son Radhakrishnan went on to become a well-known astronomer.

Awards

Chandrasekhar Venkata Raman(CV Raman), India's greatest scientist, was also honored with several honors for his significant contributions to science, which we will discuss below:-

1. In 1924, scientist CV Raman was elected as a member of the 'Royal Society of London.
2. On February 28, 1928, CV Raman discovered the 'Raman Effect,' and the Government of India declared that day to be 'National Science Day.
3. CV Raman received several medals, prestigious degrees, and royalty from various institutions in 1929 for his various experiments and achievements.
4. For scientific breakthroughs like dispersion and the 'Raman Effect,' he was given the Nobel Prize in 1930, an excellent and prestigious accolade.
5. He was also given India's highest accolade, the Bharat Ratna, in 1954 for his tremendous contribution to science.

Death

At the end of October 1970, Raman had a cardiac arrest and collapsed in his laboratory. He was moved to the hospital where doctors diagnosed his condition and declared that he would not survive another 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 in his bedroom and discussed with them the fate 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

The Nobel Prize

Independent discovery

In 1928, Grigory Landsberg and Leonid Mandelstam at the Moscow State University independently discovered the Raman effect. They published their findings in July issue of Naturwissenschaften,  and presented their findings at the Sixth Congress of the Russian Association of Physicists held at Saratov between 5 and 16 August. In 1930, they were nominated for the Nobel Prize alongside Raman. According to the Nobel Committee, however: (1) the Russians did not come to an independent interpretation of their discovery as they cited Raman's article; (2) they observed the effect only in crystals, whereas Raman and Krishnan observed it in solids, liquids and gases, and therefore proved the universal nature of the effect; (3) the problems concerning the intensity of Raman and infrared lines in the spectra had been explained during the previous year; (4) the Raman method had been applied with great success in different fields of molecular physics; and (5) the Raman effect had effectively helped to check the symmetry properties of molecules, and thus the problems concerning nuclear spin in atomic physics.

The Nobel Committee proposed only Raman's name to the Royal Swedish Academy of Sciences for the Nobel Prize. Evidence later appeared that the Russians had discovered the phenomenon earlier, a week before Raman and Krishnan's discovery. According to Mandelstam's letter (to Orest Khvolson), the Russian had observed the spectral line on 21 February 1928.

Role of Krishnan

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. Krishnan co-authored all the scientific papers on the discovery in 1928 except two. He alone wrote all the follow-up studies. Krishnan himself never claimed himself worthy of the prize. But Raman admitted later that Krishnan was the co-discoverer. He however remained openly antagonistic towards Krishnan, which the latter 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.”

The Raman–Born controversy

During October 1933 to March 1934, Max Born was employed by IISc as Reader in Theoretical Physics following the invitation by Raman early in 1933. Born at the time was a refugee from Nazi Germany and temporarily employed at St John's College, Cambridge. Since the beginning of the 20th century Born had developed a theory on lattice dynamics based on thermal properties. He presented his theory in one of his lectures at IISc. By then Raman had developed a different theory and claimed that Born's theory contradicted the experimental data. Their debate lasted for decades.

In this dispute, Born received support from most physicists, as his view was proven to be a better explanation. Raman's theory was generally regarded as having a partial relevance. Beyond the intellectual debate, their rivalry extended to personal and social levels. Born later said that Raman probably thought of him as an “enemy.” In spite of the mounting evidence for Born's theory, Raman refused to concede. As the editor of Current Science he rejected articles which supported Born's theory. Born was nominated several times for the Nobel Prize specifically for his contributions to lattice theory, and eventually won it for his statistical works on quantum mechanics in 1954. The account was written as a “belated Nobel Prize.”

Indian authorities

Raman had an 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 his Bharat Ratna medallion to pieces with a hammer, as it was given to him by the Nehru government. He publicly ridiculed Nehru when the latter visited the Raman Research Institute in 1948. There they displayed a piece of gold and copper against an ultraviolet light. Nehru was tricked into believing that copper which glowed more brilliantly than any other metal was gold. Raman was quick to remark, “Mr Prime Minister, everything that glitters is not gold.”

On the same occasion Nehru, 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 such as in the establishment of the Bhabha Atomic Research Centre (BARC), Defense Research and Development Organization (DRDO), and the Council of Scientific and Industrial Research (CSIR). He remained hostile to people associated with these establishments including Homi J. Bhabha, S.S. Bhatnagar, and his once favourite student, Krishnan. He even called such programmes as the “Nehru–Bhatnagar effect.” In 1959, Raman proposed to establish another research institute in Madras. The Government of Madras advised him to apply for funds from the central government. But Raman clearly foresaw, as he replied to C. Subramaniam, then the Minister for Finance Education in Madras, that his proposal to Nehru's government "would be met with a refusal." So ended the plan.

Raman described AICC authorities as "a big tamasha" (drama or spectacle) that just kept on discussing issues without action. As to problems of food resources in India, his advice to the government was, “We must stop breeding like pigs and the matter will solve itself.”

Indian Academy of Sciences

The Indian Academy of Sciences was born out of conflicts during the procedures of proposal for a national scientific organisation in line with the Royal Society. In 1933, the Indian Science Congress Association (ISCA), at the time the largest scientific organisation, planned to establish a national science body, which would be authorised to advise the government on scientific matters. Sir Richard Gregory, then editor of Nature, on his visit to India had suggested Raman, as editor of Current Science, to establish an Indian Academy of Sciences. Raman was of the opinion that it should be an exclusively Indian membership as opposed to the general consensus that British members should be included. He resolved that "How can India Science prosper under the tutelage of an academy which has its own council of 30, 15 of who are Britishers of whom only two or three are fit enough to be its Fellows." On 1 April 1933, he convened a separate meeting of the south Indian scientists. He and Subba Rao officially resigned from ISCA.

Raman registered the new organisation as Indian Academy of Sciences on 24 April to the Registrar of Societies. It was a provisional name to be changed to the Royal Society of India after approval from the Royal Charter. The Government of India did not recognise it as an official national scientific body, as such the ICSA created a separate organisation named the National Institute of Sciences of India on 7 January 1935 (but again changed to the Indian National Science Academy in 1970). INSA had been led by the foremost rivals of Raman including Meghnad Saha, Bhabha, Bhatnagar, and Krishnan.

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 diplomatic personality on other colleagues, which 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. Max 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 even made personal attack on 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.”

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" towards research in 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 inclined to take up the second choice.