Leó Szilárd (February 11, 1898 – May 30, 1964) was a Hungarian American physicist and inventor who 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 their credit 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.
1.) Genius in the shadows: a biography of Leo Szilard: the man behind the bomb. C. Scribner's Sons. 1992. p. 167. ISBN 9780684190112. "He is what he seems to be: an idealist devoted to the task. As his consciousness, however, is materialistic, leaning to experimenting, and agnostic, he fails to understand himself, same as the world..."
2.) Nina Byers. "Fermi and Szilard". Retrieved 25 July 2012. "Both Enrico and Leo were agnostics."