C. V. Raman facts for kids
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C. V. Raman
Raman in 1930
Chandrasekhara Venkata Raman
7 November 1888
|Died||21 November 1970
Bangalore, Mysore, India
|Alma mater||University of Madras (B.A., M.A.)|
|Known for||Raman effect|
|Children||2, including Venkatraman Radhakrishnan|
|Other notable students||
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."
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. 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. 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.
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).
When he reached Calcutta, he asked his student K. R. Ramanathan, who was from the University of Rangoon, to conduct further research at IACS. 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.
Raman's second important discovery on the scattering of light was a new type of radiation, an eponymous phenomenon called the Raman effect. After discovering the nature of light scattering that caused blue colour of water, he focused on the principle behind the phenomenon. His experiments in 1923 showed the possibility of other light rays formed in addition to incident ray when sunlight was filtered through a violet glass in certain liquids and solids. Ramanathan believed that this was a case of a "trace of fluorescence." In 1925, K. S. Krishnan, a new Research Associate, noted the theoretical background for the existence of an additional scattering line beside the usual polarised elastic scattering when light scatters through liquid. He referred to the phenomenon as "feeble fluorescence." But the theoretical attempts to justify the phenomenon were quite futile for the next two years.
The major impetus was the discovery of Compton effect. Arthur Compton at Washington University in St. Louis had found evidence in 1923 that electromagnetic waves can also be described as particles. By 1927, the phenomenon was widely accepted by scientists, including Raman. But the origin of the inspiration went further. As Compton later recollected "that it was probably the Toronto debate that led him to discover the Raman effect two years later." The Toronto debate was about the discussion on the existence of light quantum at the British Association for the Advancement of Science meeting held at Toronto in 1924. There Compton presented his experimental findings, which William Duane of Harvard University argued with his own with evidence that light was a wave. Raman took Duane's side and said, "Compton, you're a very good debater, but the truth isn't in you."
The scattering experiments
Krishnan started the experiment in the beginning of January 1928. On 7 January, he discovered that no matter what kind of pure liquid he used, it always produced polarised fluorescence within the visible spectrum of light. As Raman saw the result, he was astonished why he never observed such phenomenon all those years. That night he and Krishnan named the new phenomenon as "modified scattering" with reference to the Compton effect as an unmodified scattering. On 16 February, they sent a manuscript to Nature titled "A new type of secondary radiation", which was published on 31 March.
On 28 February 1928, they obtained spectra of the modified scattering separate from the incident light. Due to difficulty in measuring the wavelengths of light, they had been relying on visual observation of the colour produced from sunlight through prism. Raman had invented a type of spectrograph for detecting and measuring electromagnetic waves. Referring to the invention, Raman later remarked, "When I got my Nobel Prize, I had spent hardly 200 rupees on my equipment," although it was obvious that his total expenditure for the entire experiment was much more than that. From that moment they could 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 before the press. The Associated Press of India reported it the next day, on 29 February, as "New theory of radiation: Prof. Raman's Discovery." The news was reproduced by The Statesman on 1 March under the headline "Scattering of Light by Atoms – New Phenomenon – Calcutta Professor's Discovery." Raman submitted a three-paragraph report of the discovery on 8 March to Nature and was published on 21 April. The actual data was sent to the same journal on 22 March and was published on 5 May. Raman presented the formal and detailed description as "A new radiation" at the meeting of the South Indian Science Association in Bangalore on 16 March. His lecture was published in the Indian Journal of Physics on 31 March. A thousand copies of the paper reprint were sent to scientists in different countries on that day.
Raman had association 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.
With Suri Bhagavantam, he determined the spin of photons in 1932, which further confirmed the quantum nature of light. With another student, Nagendra Nath, he 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.
Other investigations he carried out included 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 which were published between 1935 and 1942.
In 1948, through studying the spectroscopic behaviour of crystals, he approached the fundamental problems of crystal dynamics in a new manner. He dealt with the structure and properties of diamond from 1944 to 1968, the structure and optical behaviour of numerous iridescent substances including labradorite, pearly feldspar, agate, quartz, opal, and pearl in the early 1950s. Among his other interests were the optics of colloids, and electrical and magnetic anisotropy. His last interests in the 1960s were on biological properties such as the colours of flowers and the physiology of human vision.
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 jokingly recounted 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." The extra allowance refers to an additional INR 150 for married officers at the time. Soon after they moved to Calcutta in 1907, the couple were accused of converting to Christianity. It was because they frequently visited St. John's Church, Kolkata as Lokasundari was fascinated with the church music and Raman with the acoustics.
Throughout his life, Raman developed an extensive personal collection of stones, minerals, and materials with interesting light-scattering properties, which he obtained from his world travels and as gifts. He often carried a small, handheld spectroscope to study specimens. These, along with his spectrograph, are on display at IISc.
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.
Raman had a sense of obsession with the Nobel Prize. In a speech at the University of Calcutta, he said, "I'm not flattered by the honour [Fellowship to the Royal Society in 1924] done to me. This is a small achievement. If there is anything that I aspire for, it is the Nobel Prize. You will find that I get that in five years." He knew that if he were to receive the Nobel Prize, he could not wait for the announcement of the Nobel Committee normally made towards the end of the year considering the time required to reach Sweden by sea route. With confidence, he booked two tickets, one for his wife, for a steamship to Stockholm in July 1930. Soon after he received the Nobel Prize, he was asked in an interview the possible consequences if he had discovered the Raman effect earlier, which he replied, "Then I should have shared the Nobel Prize with Compton and I should not have liked that; I would rather receive the whole of it."
Although Raman hardly talked about religion, he was openly an agnostic, but objected to being labelled atheist. His agnosticism was largely influenced by that of his father who adhered to the philosophies of Herbert Spencer, Charles Bradlaugh, and Robert G. Ingersoll. He resented Hindu traditional rituals but did not give them up in family circles. He was also influenced by the philosophy of Advaita Vedanta. 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 friendly meeting with Mahatma Gandhi and Gilbert Rahm, a German zoologist, the conversation turned to religion. On his deathbed, he said to his wife, "I believe only in the Spirit of Man," and asked for his funeral, "Just a clean and simple cremation for me, no mumbo-jumbo please."
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.
Honours and awards
Raman was honoured with many honorary doctorates and memberships of scientific societies. Within India, apart from being the founder and President of the Indian Academy of Sciences (FASc), he was a Fellow of the Asiatic Society of Bengal (FASB), and from 1943, a Foundation Fellow of the Indian Association for the Cultivation of Science (FIAS). In 1935, he was appointed a Foundation Fellow of the National Institute of Sciences of India (FNI, now the Indian National Science Academy. He was a member of the Deutsche Akademie of Munich, the Swiss Physical Society of Zürich, the Royal Philosophical Society of Glasgow, the Royal Irish Academy, the Hungarian Academy of Sciences, the Academy of Sciences of the USSR, the Optical Society of America, the Mineralogical Society of America, the Romanian Academy of Sciences, the Catgut Acoustical Society of America and the Czechoslovak Academy of Sciences.
In 1924, he was elected a Fellow of the Royal Society. However, he resigned from the fellowship in 1968 for unrecorded reasons, 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 until his death. He was member of the Pontifical Academy of Sciences in 1961.
- In 1912, Raman received the Curzon Research Award, while still working in the Indian Finance Service.
- In 1913, he received the Woodburn Research Medal, while still working in the Indian Finance Service.
- In 1928, he received the Matteucci Medal from the Accademia Nazionale delle Scienze in Rome.
- In 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 a Knight Bachelor in a special ceremony at the Viceroy's House (now Rashtrapati Bhavan) in New Delhi.
- In 1930, he won the Nobel Prize in Physics "for his work on the scattering of light and for the discovery of the effect named after him." He was 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.
- In 1930, he received the Hughes Medal of the Royal Society.
- In 1941, he was awarded the Franklin Medal by the Franklin Institute in Philadelphia.
- In 1954, he was awarded the Bharat Ratna (along with politician and former Governor-General of India C. Rajagopalachari and philosopher Sir Sarvepalli Radhakrishnan).
- In 1957, he was awarded the Lenin Peace Prize.
In Spanish: Chandrasekhara Raman para niños
- Coherent anti-Stokes Raman spectroscopy
- Inverse Raman effect
- Journal of Raman Spectroscopy
- Raman amplification
- Raman laser
- Raman microscope
- Raman optical activity
- Resonance Raman spectroscopy
- Rotating-polarization coherent anti-Stokes Raman spectroscopy
- SHERLOC, a UV Raman spectrometer designed for Mars exploration
- Spatially offset Raman spectroscopy
- Stimulated Raman adiabatic passage
- Surface-enhanced Raman spectroscopy
- Tip-enhanced Raman spectroscopy
- Transmission Raman spectroscopy
- X-ray Raman scattering
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