R. S. Krishnan

Rappal Sangameswaraier Krishnan (1911–1999) was an Indian scientist and researcher.

After obtaining a M.A. and a D.Sc. from the University of Madras, Krishnan became a researcher at Cavendish Laboratory of Cambridge University. He played a vital role in developing the 37’ Cyclotron, and was later in charge of the instrument and its maintenance. There, Krishnan observed the deuteron-induced fission in uranium and thorium. In 1941, he was awarded a Ph.D. by Cambridge University.

On his return to India, Krishnan was appointed in the Physics Department of the Indian Institute of Sciences, Bangalore and worked under Dr. C. V. Raman. He is well known for the new effects that he discovered in colloid optics. He discovered the reciprocity relations between the intensity of the horizontally polarised incident light getting scattered with horizontal polarization irrespective of the colloidal particles. This is known as Krishnan (reciprocity) Effect.^[1] His work on the Second Order Raman Spectra in diamond and in alkali halide crystals has also gained worldwide recognition. In 1948 when Dr. Raman retired, Krishnan became the Head of the Department of Physics.

Krishnan represented India in several international conferences and seminars like the 2nd International Conference on Crystallography, Stockholm,Sweden (1951), the International Science Conference at Edinburgh, Scotland, the 5th Australian Spectroscopic Conference, and the 1st International Conference on ‘Raman Spectra on Crystals’ in Paris (1965). He guided more than 60 students in their doctoral studies and published more than 500 research articles in various international journals. Krishnan was a member of the Indian Academy of Sciences, the London Institute of Science, and the American Physical Society. He was a visiting professor to many universities in Europe and the United States of America. After his retirement from the Indian Institute of Sciences in 1972, Krishnan was appointed as the Vice-Chancellor of the University of Kerala, 1973-1977. After his retirement, he returned to Bangalore and spent the remaining period of his life compiling the research publications related with Raman Effect and authoring some scientific works. He died on October 2, 1999.

References

• Obituary at the Wayback Machine (archived August 14, 2004) in Current Science 77 (1999) 1552