Nuclear Physicist. He received recognition as a Hungarian-born American physicist, who is credited with developing the nuclear chain reaction in October of 1933 and patented the idea in 1936. Born Leo Spitz, the son of an engineer in an affluent Jewish family, his family's surname was changed to Szilard in 1900. Near the end of World War I, he was drafted in 1917 into the Austrian-Hungarian Army as an officer, but because he became ill during the influenza epidemic, he did not see combat. After graduating from Budapest University of Technology, he received his PhD cum laud in August of 1922 from the University of Berlin, joining the staff of the Institute of Theoretical Physics at the facility. He did research at the Kaiser Wilhelm Institute until 1925. With improvements in refrigeration, he applied for 29 patents, collaborating at times with Nobel Prize recipient Albert Einstein. For decades, he and Einstein were not only professional colleagues but personal friends. He was known throughout his career for being able to brainstorm ideas but hating to do any paperwork. As the politics of the Nazi Party began to persecute Jews, he escaped to Austria before coming to London, England, by 1933. He helped other Jewish families to escape Germany. In 1935, he held a position at the Clarendon Laboratory at Oxford University. During the mid-1930s, he made several trips to the United States as a lecturer. In 1937, he relocated to New York City and began research at Columbia University. His 1933 discovery of the nuclear chain reaction did not have much importance until December of 1938 when another group of scientists was studying natural uranium in the race with Germany to harness nuclear energy. In early 1942, he went with 1938 Nobel Prize recipient Enrico Fermi to the University of Chicago, and on December 2, 1942, they produced the world's first sustained chain reaction. Although he became a naturalized citizen of the United States in March of 1943, there were a few distrusting professional adversaries who may have blocked his career advancement. During World War II, he participated in the Manhattan Project, helping design the Atomic Bomb, but by 1945, he, along with 68 other scientists, signed a petition not wanting the bomb to be used as a weapon, but this fell on deaf ears and never sent to the White House. He was one of the seven signatories on the Franck Report, wanting the first bomb to be dropped on an unpopulated area. Disillusioned after the use of the atomic bomb, he became a part-time professor of biophysics at the Institute of Radiobiology and Biophysics at the University of Chicago in 1946 while working part-time at the University's Division of Social Sciences as an advisor to the Office of Inquiry into the Social Aspects of Atomic Energy. Promoting nuclear arms control and disarmament for the rest of his life, he was a founding member of the Pugwash Conference on Science and World Affairs related to nuclear arms control in 1957. In 1955, he was granted a U.S. Patent on a nuclear reactor design, jointly with Fermi, and became a professor in 1956 at the Enrico Fermi Institute for Nuclear Studies at the University of Chicago. In July of 1963, he was appointed as a non-resident fellow at the Salk Institute for Biological Studies in California. He relocated to California the following February, dying three months later of a heart attack. While studying in Germany before World War II, he met another student, Gertrude Weiss, who became his devoted friend for decades, with the couple eventually marrying in 1951. For professional reasons, the couple lived apart for a number of years. He admitted that he did not make a good husband. His wife joined him in his move to California. After his remains were cremated, his ashes were divided between three burial sites: Cypress View Mausoleum in San Diego, California; Lake View Cemetery in Ithaca, New York, alongside his wife, Dr. Gertrude Weiss, who died in 1981; and the National Graveyard in Budapest, Hungary. His professional papers are held in the Special Collections and Archives at the University of California at San Diego. He was nominated for the 1947 Nobel Prize in Chemistry and the 1949 Nobel Prize in Physics but did not receive either.