Infeld was interested in the
theory of relativity. He was awarded a doctorate at the
Jagiellonian University (1921), worked as an assistant and a docent at the
University of Lwów (1930–1933) and then as a professor at the
University of Toronto between 1939 and 1950. He collaborated with
Albert Einstein at
Princeton University (1936–1938). The two scientists jointly formulated the equation describing star movements as well as concurrently writing the book
The Evolution of Physics. After the
first use of nuclear weapons in 1945, Infeld, like Einstein, became a
peace activist. Because of his activities, he was unjustly accused of having communist sympathies. In 1950, he and his family left Canada and returned to
communist Poland. He also could not return to the US at that time. In the US, despite having worked previously directly with Einstein, who formally invented nuclear weapons with his famous formula, Infeld risked receiving the death penalty like the
Rosenbergs if accused of spying for the Soviet Union. He felt he had an obligation to help science in Poland recover from the ravages of the
Second World War. He served as president of the
Polish Physical Society between 1955 and 1957. In the staunchly anti-communist climate of the time, many in the Canadian government and media feared that working in a communist country he would betray
nuclear weapons secrets. He was stripped of his
Canadian citizenship and was widely denounced as a traitor. In actuality, Infeld's field was the
theory of relativity—not directly linked to
nuclear weapons research. After Infeld's return to Poland, he requested a leave of absence from the
University of Toronto. His request was denied, and Infeld resigned his post. In 1995 the University of Toronto made amends and granted Infeld the posthumous title of
professor emeritus. Upon his return to
Poland, Infeld became a professor at the
University of Warsaw, a post he held until his death. The
Born–Infeld model was named after
Max Born and Leopold Infeld, who first proposed it. The Infeld-Hull Factorization Method describing general sets of solutions to the
Schrödinger equation. Infeld was one of the 11 signatories to the
Russell–Einstein Manifesto in 1955 and is the only signatory never to receive a
Nobel Prize. In 1964 he was one of the signatories of the so-called
Letter of 34 to Prime Minister
Józef Cyrankiewicz regarding freedom of culture. Infeld is the author of
Quest: An Autobiography and the biography
Whom the Gods Love: The Story of Évariste Galois.
Personal life In New Jersey, on April 12, 1939, he married a mathematician who took the name
Helen Infeld and they had two children, both born in Toronto, Joan M. and Eric (sometimes spelled Eryk). ==Publications==