C.V. Raman

Sir Chandrasekhara Venkata Raman (1888–1970) was an eminent Indian physicist renowned for his pioneering work in the field of light scattering, which led to the discovery of the Raman Effect. His research revolutionised the understanding of molecular and atomic interactions with light and earned him the Nobel Prize in Physics in 1930, making him the first Asian and non-white recipient of a Nobel Prize in any branch of science. Raman’s contributions laid the foundation for modern spectroscopy and established India’s early scientific reputation on the global stage.

Early Life and Education

C. V. Raman was born on 7 November 1888 in Tiruchirappalli, Tamil Nadu, into a scholarly South Indian Brahmin family. His father, Chandrasekhara Ramanathan Iyer, was a lecturer in mathematics and physics, which exposed young Raman to scientific curiosity at an early age. Raman excelled academically, completing his schooling at St. Aloysius’ Anglo-Indian High School and later attending Presidency College, Madras (now Chennai).
In 1904, he graduated with a B.A. in Physics securing first rank and a gold medal, followed by an M.A. in 1907. His early research papers, published while he was still a student, demonstrated his strong experimental and theoretical aptitude. Despite winning a scholarship for higher studies in England, he joined the Indian Finance Service in Kolkata due to health concerns, a decision that incidentally brought him close to the Indian Association for the Cultivation of Science (IACS).

Scientific Career and Discovery of the Raman Effect

Raman’s scientific career flourished during his association with the IACS, where he conducted experiments in his spare time. His fascination with the behaviour of light led him to investigate optical phenomena, including the scattering and polarisation of light.
In 1928, while studying the diffusion of light in liquids, Raman and his student K. S. Krishnan observed a new type of scattering, where the wavelength of scattered light differed from that of the incident light. This phenomenon, later known as the Raman Effect, demonstrated that light interacts with the molecular vibrations of the medium through which it passes. The change in wavelength served as a molecular fingerprint, providing a new analytical method to study material composition.
Raman announced his discovery in February 1928, and subsequent verification by European scientists established its universal significance. For this groundbreaking work, Raman received the Nobel Prize in Physics in 1930, and the effect was named after him.

The Raman Effect and Its Applications

The Raman Effect occurs when light interacts with molecular vibrations, causing a change in energy and frequency of the scattered photons. It forms the basis of Raman spectroscopy, a non-destructive analytical technique used extensively in modern science and industry.
Applications of Raman spectroscopy include:

• Chemical analysis of compounds through molecular fingerprinting.
• Material science for identifying crystalline structures and stress patterns.
• Medical diagnostics, particularly in identifying cancerous cells.
• Forensic science for detecting trace evidence.
• Astronomy, in studying planetary atmospheres.

This discovery marked a turning point in both theoretical and applied physics, bridging optics, molecular chemistry, and spectroscopy.

Academic and Institutional Contributions

In 1917, Raman was appointed Professor of Physics at the University of Calcutta, where he established a strong research tradition. Later, he served as the Director of the Indian Institute of Science (IISc), Bangalore from 1933 to 1948, where he inspired and trained a generation of Indian scientists, including S. Bhagavantam and G. N. Ramachandran.
In 1948, Raman founded the Raman Research Institute (RRI) in Bangalore, dedicating it to advanced research in physics. The institute became a leading centre for optical, molecular, and acoustic studies. His emphasis on indigenous scientific development and independent research was instrumental in nurturing India’s scientific autonomy post-independence.

Other Scientific Works

Beyond light scattering, Raman made significant contributions to acoustics, crystal dynamics, and optics. His research on the mechanics of violin strings, acoustics of tabla and mridangam, and the colours of the sea and sky revealed his broad scientific curiosity.
Notable areas of his study include:

• Optical properties of crystals and the transmission of light in diamond and quartz.
• Sound propagation in solids and liquids.
• Molecular diffraction of light and its relation to temperature and pressure.
• Nature of musical instruments and their resonance behaviour.

His work on the spectral analysis of light from minerals and organic compounds further expanded the understanding of molecular structures.

Recognition and Honours

Sir C. V. Raman’s contributions were widely recognised both in India and abroad. Apart from the Nobel Prize, his honours include:

• Fellow of the Royal Society (FRS), 1924.
• Knight Bachelor, conferred by the British Government in 1929.
• Bharat Ratna, India’s highest civilian award, in 1954.
• Lenin Peace Prize, 1957.
• Numerous honorary doctorates from Indian and international universities.

His birthday, 7 November, is celebrated annually as National Science Day in India, commemorating the discovery of the Raman Effect.

Legacy and Influence

Raman’s work reshaped the trajectory of Indian science during the colonial and post-independence eras. His insistence on original experimental research, even with limited resources, became a model for scientific self-reliance. He was deeply committed to promoting the spirit of inquiry among students and often emphasised observation and experimentation over rote learning.
Raman’s legacy endures through:

• The Raman Research Institute in Bengaluru.
• Numerous scholarships and awards in his name.
• The inclusion of the Raman Effect in school and university curricula worldwide.
• The continuing use of Raman spectroscopy across physics, chemistry, biology, and engineering.