India, Aug. 30 -- Physicist and the country's pre-eminent math historian, PP Divakaran, who died recently in Kochi, was a cherished friend of mine for over six decades. We first met at the Tata Institute of Fundamental Research (TIFR) and immediately fell into a discussion about the ground breaking work on parity violation by TD Lee and CN Yang, a topic that had captivated physicists worldwide, and for which they won the Nobel Prize in 1957. What immediately struck me was the remarkable clarity with which Divakaran, or PPD, as his friends called him, explained the intricate details of their research. His ability to distil complex ideas into understandable points was extraordinary, and would be the hallmark of his eventual work. The second...