During World War II, Kurti worked on the Manhattan project, returning to Oxford in 1945. In 1955 he won the Fernand Holweck Medal and Prize. In 1956, Simon and Kurti built a laboratory experiment that reached a temperature of one microkelvin. This work attracted worldwide attention, and Kurti was elected a Fellow of the Royal Society. He later became the society's Vice-President from 1965 to 1967.