The Raman effect and Krishnan's diary

Abstract

K.S. Krishnan, F.R.S. (1898-1961) is one of the most distinguished Indian scientists of this century. His collaboration with Sir C.V. Raman on the scattering of light by liquids--a collaboration which Raman described as 'a partnership in scientific research of the Bowen-Millikan type'--led to the discovery of the effect that bears Raman's name. Krishnan recorded the events leading to this discovery in the form of a diary, extracts from which have often appeared in the past, although the diary itself has never been published before. Later, as a Reader in Physics at the University of Dacca and then as the first Mahendra Lal Sircar Professor of Physics at the Indian Association for the Cultivation of Science in Calcutta, Krishnan made seminal studies on crystal magnetism. These studies established him as one of the leading physicists working in this area and brought him international recognition, eventually winning him, in 1940, the Fellowship of the Royal Society. Krishnan was born a little over a hundred years ago; in a centenary tribute to him, I recall here his early work and the nature of his collaboration with Sir C.V. Raman, which produced the most spectacular scientific discovery in India to date. With the consent of the members of his family, I also transcribe in full the Krishnan Diary.