CODEX Entry 5802: Rudolf Peierls
A German Jew from Berlin, he elected to stay in Britain when Hitler came to power. In 1940 he wrote the Frisch–Peierls memorandum with another exiled Austrian Jew, Otto Robert Frisch. This set out how one might build an atomic bomb in a practical form, using very small amounts of uranium 235. They joined the Manhattan Project as part of the British delegation in charge of uranium enrichment.