Phyllis Nicolson

Phyllis Nicolson, born Phyllis Lockett in Macclesfield, was a British mathematician and physicist, born on 21 September 1917 and died on 6 October 1968, best known for her work on the Crank-Nicolson method together with John Crank. She took a B.Sc. in 1938 and an M.Sc. in 1939 at Manchester University and a Ph.D. in 1946 on three problems in theoretical physics, which began with cosmic ray research under Lajos Janossy. From 1940 to 1945 she worked in Douglas Hartree's research group on defence problems, becoming a proficient numerical analyst and an expert user of the differential analyser. Her wartime study of heat conduction, with John Crank on the numerical stability of solution techniques for the heat equation, led to the algorithm published in 1947. She was a research fellow of Girton College, Cambridge, from 1946 to 1949, and after her first husband Malcolm Nicolson died in a train accident in 1951 she took over his lectureship in physics at Leeds.