Leó Szilárd (Hungarian: Szilárd Leó; German: Leo Spitz until age 2; February 11, 1898 – May 30, 1964) was a Hungarian-American physicist and inventor. He conceived the nuclear chain reaction in 1933, patented the idea of a nuclear reactor with Enrico Fermi, and in late 1939 wrote the letter for Albert Einstein's signature that resulted in the Manhattan Project that built the atomic bomb. He also conceived the electron microscope, the linear accelerator (1928, not knowing Gustav Ising's 1924 journal article and Rolf Widerøe's operational device) and the cyclotron. Szilárd himself did not build all of these devices, or publish these ideas in scientific journals, and so credit for them often went to others. As a result, Szilárd never received the Nobel Prize, but others were awarded the Prize as a result of their work on two of his inventions. He was born in Budapest in the Kingdom of Hungary, and died in La Jolla, California.
As a survivor of the political and economic devastation in Hungary following World War I, which had been eviscerated by the Treaty of Trianon, Szilárd developed an enduring passion for the preservation of human life and freedom, especially freedom to communicate ideas.
He hoped that the U.S. government would not use nuclear weapons because of their potential for use against civilian populations. Szilárd hoped that the mere threat of such weapons would force Germany and/or Japan to surrender. He also worried about the long-term implications of the usage of nuclear weapons, predicting that their usage by the United States would start a nuclear arms race with Russia. He drafted the Szilárd petition advocating demonstration of the atomic bomb. However with the European war concluded and the U.S. suffering many casualties in the Pacific Ocean region, the new U.S. President Harry Truman agreed with advisers and chose to use atomic bombs against Hiroshima and Nagasaki over the protestations of Szilárd and other scientists.
John Barbeen