Rappal Sangameswara Iyer Krishnan (23 September 1911 – 2 October 1999) was an Indian experimental physicist and scientist. He was the Head of the department of Physics at the Indian Institute of Science and the vice chancellor of the University of Kerala. He is known for his pioneering researches on colloid optics and a discovery which is now known as Krishnan Effect. He was a Fellow of the Indian Academy of Sciences, Indian National Science Academy and the Institute of Physics, London and a recipient of the C. V. Raman Prize. Wikipedia