Chandrasekhara Venkata Raman ( RAH-muhn; IAST: Candraśēkhara Veṅkaṭarāmaṉ; 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. This phenomenon, a hitherto unknown type of scattering of light they called modified scattering, was subsequently termed the Raman effect or Raman scattering. In 1930, Raman received the Nobel Prize in Physics "for his work on the scattering of light and for the discovery of the effect named after him" and became the first Asian and non-White person to receive a Nobel Prize in Physics.
Born in the Indian state of Tamil Nadu, Raman was a precocious child, completing his secondary and higher secondary education from St Aloysius' Anglo-Indian High School at the ages 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 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 incorrect. He founded the Indian Journal of Physics in 1926. He moved to Bengaluru in 1933 to become the first Indian director of the Indian Institute of Science. He founded the Indian Academy of Sciences the year. In 1948, he established the Raman Research Institute, where he worked to his last days. He was the uncle of Nobel laureate Subrahmanyan Chandrasekhar.
The Raman effect was discovered on 28 February 1928. The day is celebrated annually by the Government of India as the National Science Day.
Chandrasekhara Venkata Raman was born on 7 November 1888 in Tiruchirappalli, India. His parents were R. Chandrasekhar Iyer and Parvathi Ammal. He was the second of eight of their children. 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 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. 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. 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 C. Subrahmanya Ayyar had joined the prestigious Indian government service, Indian Finance Service (now Indian Audit and Accounts Service). 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.
He was highly impressed by the Indian Association for the Cultivation of Science (IACS), Calcutta, the first research institute founded in India in 1876. He immediately befriended Asutosh Dey (who would eventually become his lifelong collaborator), Amrita Lal Sircar (the founder Mahendralal Sircar's son and then secretary of IACS), and Ashutosh Mukherjee (then executive member of the IACS 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, Krishnath 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: