Leo Szilard
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[citation needed]. He conceived the linear accelerator (1928, not knowing of Gustav Ising's prior 1924 journal article and Rolf Widerøe's operational device), and also 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.