GFHund · CC BY 3.0

Co-authored the 1940 Frisch-Peierls memorandum, the first paper to show that an atomic bomb could be built from a small, practically obtainable quantity of uranium-235 — a calculation that jump-started Britain's nuclear weapons program and fed directly into the Manhattan Project. He had chosen not to return to Germany after Hitler's rise in 1933 because of his Jewish background, building his career in Britain instead, where he was later knighted.