C. V. Raman

Sir Chandrasekhara Venkata Raman
File:Chandrasekhara Venkata Raman.gif Chandrasekhara Venkata Raman
Born	7 November 1888 Tiruchirapalli, India
Died	29 November, 2001 Bangalore, India
Residence	India
Nationality	Indian
Field	Physics
Institutions	Indian Finance Department Indian Association for the Cultivation of Science Indian Institute of Science
Alma mater	Presidency College
Academic advisor	None
Notable students	G. N. Ramachandran
Known for	Raman effect
Notable prizes	Nobel Prize in Physics Bharat Ratna Lenin Peace Prize

Sir Chandrasekhara Venkata Raman, CBE (Tamil: சந்திரசேகர வெங்கடராமன்) (7 November 1888 – 21 November 1970) was an Indian physicist, who was awarded the 1930 Nobel Prize in Physics for his work on the scattering of light and his discovery of a unique form of scattering known as Raman scattering or the Raman effect.

Biography

Early years

Raman was born in Tiruchirapalli, Tamil Nadu to a Tamil Brahmin family. At an early age, Raman moved to the city of Visakhapatnam, Andhra Pradesh.

Middle years

He completed his BA and MA in Physics from the Presidency College, Madras . He entered Presidency College, Madras, in 1902, and in 1904 passed his B.A. examination, winning the first place and the gold medal in physics; in 1907 he gained his M.A. degree, obtaining the highest distinctions. He joined the Indian Finance Department as an Assistant Accountant General in Calcutta. As the story goes, one evening while returning from work, he spotted the sign of the Indian Association for the Cultivation of Science. He started visiting the laboratory after office hours and did experiments, which culminated with his Nobel Prize winning work.

In 1917, Raman resigned from his government service and took up the newly created Palit Professorship in Physics at the University of Calcutta. Simultaneously, he continued doing research at the IACS, where he became the Honorary Secretary. Raman used to refer to this period as the golden era of his career. Many talented students gathered around him at the IACS and the University of Calcutta. He was president of the 16th session of the Indian Science Congress in 1929.

Raman won the 1930 Nobel Prize in Physics for his work on the scattering of light and for the discovery of the Raman effect. Raman spectroscopy is based on this phenomenon.

Raman also worked on the acoustics of musical instruments. He worked out the theory of transverse vibration of bowed strings, on the basis of superposition velocities. This does a better job in explaining bowed string vibration over Helmholtz's approach. He was also the first to investigate the harmonic nature of the sound of the Indian drums such as the tabla and the mridangam.

In 1934, Raman became the director of the newly established Indian Institute of Science in Bangalore, where two years later he continued as a professor of physics. In 1947, he was appointed as the first National Professor by the new government of Independent India.

He also started a company called Travancore Chemical and Manufacturing Co. Ltd. in 1943, along with Dr. Krishnamurthy. The Company during its 60 year history, established 4 factories in Southern India. [1]

He was knighted in 1929 and awarded the Bharat Ratna in 1954. Raman was also awarded the Lenin Peace Prize (1957).

CV Raman is the uncle of three world renowned Physicists Subrahmanyan Chandrasekhar Nobel laureate, Sivaramakrishna Chandrasekhar FRS, known for Liquid crystal research and Sivaraj Ramaseshan, former director of Indian Institute of Science.

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

Later years

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

Raman scattering

Raman scattering or the Raman effect is the inelastic scattering of a photon.

When light is scattered from an atom or molecule, most photons are elastically scattered (Rayleigh scattering). The scattered photons have the same energy (frequency) and, therefore, wavelength, as the incident photons. However, a small fraction of scattered light (approximately 1 in 10 million photons) is scattered from excitations with optical frequencies different from, and usually lower than, the frequency of the incident photons. In a gas, Raman scattering can occur with a change in vibrational, rotational or electronic energy of a molecule (see energy level). Chemists are concerned primarily with the vibrational Raman effect.

In 1922, Indian physicist Chandrasekhara Venkata Raman published his work on the "Molecular Diffraction of Light," the first of a series of investigations with his collaborators which ultimately led to his discovery (on 28 February 1928) of the radiation effect which bears his name. The Raman effect was first reported by C. V. Raman and K. S. Krishnan, and independently by Grigory Landsberg and Leonid Mandelstam, in 1928. Raman received the Nobel Prize in 1930 for his work on the scattering of light. In 1998 the Raman Effect was designated an ACS National Historical Chemical Landmark in recognition of its significance as a tool for analyzing the composition of liquids, gases, and solids.

The Raman effect differs from the process of fluorescence. For the latter, the incident light is completely absorbed and the system is transferred to an excited state from which it can go to various lower states only after a certain resonance lifetime. The result of both processes is essentially the same: A photon with the frequency different from that of the incident photon is produced and the molecule is brought to a higher or lower energy level. But the major difference is that the Raman effect can take place for any frequency of the incident light. In contrast to the fluorescence effect, the Raman effect is therefore not a resonant effect.

Works

Quotes

When he was offered a toast during the Nobel function: Being a strict teetotaller he responded,

Sir, you have seen the Raman effect on alcohol; please do not try to see the alcohol effect on Raman.

Books

For compact work, see: Scientific Papers of CV Raman, Ed. S Ramaseshan, Indian Academy of Sciences, Bangalore 1988.

• Vol. 1 - Scattering of Light (Ed. S Ramaseshan)
• Vol. 2 - Acoustic
• Vol. 3 - Optica
• Vol. 4 - Optics of Minerals and Diamond
• Vol. 5 - Physics of Crystals
• Vol. 6 - Floral Colours and Visual Perception
• Vol, 7 -

Bibliography

1909

• "The Small Motion at the Nodes of a Vibrating String," Nature, 1909
• "The Maintenance of Forced Oscillations of a New Type," Nature, 1909
• "The Ectara," J. Indian Math. Club, 1909

1910

• "The Maintenance of Forced Oscillations," Nature, 1910
• "Oscillations of the Stretched Strings," J. Indian Math. Club, 1910

1911

• "Photographs of Vibrational Curves," Philos. Mag., 1911
• "Remarks on a Paper by J.S. Stokes on 'Some Curious Phenomena Observed in Connection with Melde's Experiment'," Physics Rev., 1911
• "The Small Motion at the Nodes of a Vibrating String," Phys. Rev., 1911

1912

• "The Maintenance of Forced Oscillations of a New Type," Philos. Mag, 1912
• "Some Remarkable Cases of Resonance," Phys. Rev. 1912
• "Experimental Investigations on the Maintenance of Vibrations," Bull. Indian Assoc. Cultiv. Sci., 1912

1913

• "Some Acoustical Observations," Bull. Indian Assoc. Cultiv. Sci., 1913

1914

• "The Dynamical Theory of the Motion of Bowed Strings," Bull. Indian Assoc. Cultiv. Sci., 1914
• "The Maintenance of Vibrations," Phys. Rev. 1914
• "Dynamical Theory of the Motion of Bowed Strings," Bulletin, Indian Association for the Cultivation of Science, 1914
• "On Motion in a Periodic Field of Force," Bull. Indian Assoc. Cultiv. Sci., 1914

1915

• "On the Maintenance of Combinational Vibrations by Two Simple Harmonic forces," Phys. Rev., 1915
• "On Motion in a Periodic Field of Force," Philos. Mag, 1915

1916

• "On Discontinuous Wave-Motion - Part 1," Philos. Mag, 1916 (with S Appaswamair)
• "On the 'Wolf-Note' of the Violin and Cello," Nature (London). 1916
• "On the 'Wolf-Note' in the Bowed Stringed Instruments," Philos. Mag., 1916

1917

• "The Maintenance of Vibrations in a Periodic Field of Force," Philos. Mag, 1917 (with A. Dey)
• "On Discontinuous Wave-Motion - Part 2," Philos. Mag, 1917 (with A Dey)
• "On Discontinuous Wave-Motion - Part 3," Philos. Mag, 1917 (with A Dey)
• "On the Alterations of Tone Produced by a Violin 'Mute'," Nature (London) 1917

1918

• "On the 'Wolf-Note' in the Bowed Stringed Instruments," Philos. Mag., 1918
• "On the Wolf-Note in Pizzicato Playing," Nature (London), 1918
• "On the Mechanical Theory of the Vibrations of Bowed Strings and of Musical Instruments of the Violin Family, with Experimental Verification of Results - Part 1," Bulletin, Indian Association for the Cultivation of Science, 1918
• "The Theory of the Cyclical Vibrations of a Bowed String," Bulletin, Indian Association for the Cultivation of Science, 1918

1919

• "An Experimental Method for the Production of Vibrations," Phys. Rev., 1919
• "A New Method for the Absolute Determination of Frequency," Proc. R. Soc. London, 1919
• "On the Partial Tones of Bowed Stringed Instruments," Philos. Mag, 1919
• "The Kinematics of Bowed Strings," J. Dept of Sci., Univ. Calcutta, 1919

1920

• "On the Sound of Splashes," Philos. Mag, 1920
• "On a Mechanical Violin-Player for Acoustical Experiments, Philos. Mag., 1920
• "Experiments with Mechanically-Played Violins," Proc. Indian Association for the Cultivation of Science, 1920
• "On Kaufmann's Theory of the Impact of the Pianoforte Hammer," proc. S. Soc. London, 1920 (with B Banerji)
• "Musical Drums with Harmonic Overtones," Nature (London), 1920 (with S. Kumar)

1921

• "Whispering Gallery Phenomena at St. Paul's Cathedral," Nature (London) 1921 (with G.A. Sutherland)
• "The Nature of Vowel Sounds," Nature (London) 1921
• "On the Whispering Gallery Phenomenon," Proc. R. Soc. London, 1922 (with G.A. Sutherland)
• "On Some Indian Stringed Instruments," Proc. Indian Association for the Cultivation of Science, 1921

1922

• "On Whispering Galleries," Indian Assoc. Cultiv. Sci., 1922
• "On the Molecular Scattering of Light in Water and the Colour of the Sea," Proceedings of the Royal Society, 1922
• "The Acoustical Knowledge of the Ancient Hindus," Asutosh Mookerjee Silver Jubilee - Vol 2,

1926

• "The Subjective Analysis of Musical Tones," Nature (London), 1926

1927

• "Musical Instruments and Their Tones"

1928

• "A new type of Secondary Radiation," Nature, 1928
• "A new radiation," Indian Journal of Physics, 1928

1935

• "The Indian Musical Drums," Proc. Indian Acad. Sci., 1935
• "The Diffraction of Light by High Frequency Sound Waves: Part I," Proc. Indian Acad. Sci., 1935 (with N. S. Nagendra Nath)
• "The Diffraction of Light by High Frequency Sound Waves: Part II," Proc. Indian Acad. Sci., 1935 (with N. S. Nagendra Nath)
• "Nature of Thermal Agitation in Liquids," Nature (London), 1935 (with B.V. Raghavendra Rao)

1936

• "The Diffraction of Light by High Frequency Sound Waves: Part III: Doppler Effect and Coherence Phenomena," Proc. Indian Acad. Sci., 1936 (with N. S. Nagendra Nath)
• "The Diffraction of Light by High Frequency Sound Waves: Part IV: Generalised Theory," Proc. Indian Acad. Sci., 1936 (with N. S. Nagendra Nath)
• "The Diffraction of Light by High Frequency Sound Waves: Part V: General Considerations - Oblique Incidence and Amplitude Changes," Proc. Indian Acad. Sci., 1936 (with N. S. Nagendra Nath)
• "Diffraction of Light by Ultrasonic Waves," Nature (London), 1936 (with N. S. Nagendra Nath)

1937

• "Acoustic Spectrum of Liquids," Nature (London), 1937 (with B.V. Raghavendra Rao)

1938

• "Light Scattering and Fluid Viscosity," Nature (London), 1938 (with B.V. Raghavendra Rao)

1948

• Aspects of Science, 1948

1951

• The New Physics: Talks on Aspects of Science, 1951

1959

• Lectures on Physical Optics, 1959

See also

• Light
• Photon
• Raman laser
• Raman scattering
• Raman spectroscopy
• Raman amplification
• Raman optical activity

External links

• The Nobel Prize in Physics 1930 (Nobel Committee)
• Britannica on Raman
• Nobel prize internet archive
• PATH CREATOR-C.V.RAMAN
• Nobel Lecture

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