- Person
- Leo Szilard
- Lived
- 1898–1964
- Field
- Nuclear physics
- From
- Hungarian-American
The story
Leo Szilard was born Leó Spitz in Budapest in 1898 to a middle-class Jewish family; the family changed its name to Szilárd, meaning solid, when he was two. After studying physics in Berlin, where he attended lectures by Albert Einstein and Max Planck, he became a gifted inventor, filing early patent applications for the electron microscope and the cyclotron. When Hitler took power in January 1933, Szilard urged family and friends to flee and moved to England himself.
In London he did not only look after himself. He helped found the Academic Assistance Council to find jobs for refugee scholars driven out of Germany, persuaded the Royal Society to give it rooms and recruited leading academics to help. By 1939 it had found places for more than 2,500 refugee scholars.
On the morning of 12 September 1933, Szilard read a report in The Times of a speech by Ernest Rutherford dismissing the idea of extracting useful energy from atoms as moonshine. Annoyed, he found his answer that same day. Waiting for the light to change where Southampton Row passes Russell Square, near the British Museum, he conceived the nuclear chain reaction: if a reaction triggered by a neutron also released more neutrons, it could sustain itself and release enormous energy. He filed a patent in 1934 and assigned it to the British Admiralty to keep it secret.
In the United States, after fission was discovered, he and Walter Zinn showed in 1939 that uranium released extra neutrons, proving a chain reaction might be possible. That year he drafted the letter Einstein signed warning President Roosevelt, which led to the Manhattan Project. He suggested graphite as a moderator, insisted on boron-free graphite, and worked with Enrico Fermi on the first nuclear reactor, which achieved a chain reaction in Chicago on 2 December 1942. The two later received a joint patent for the neutronic reactor.
In 1945 he wrote a petition urging President Truman not to use the atomic bomb on Japan without warning, and after the war he campaigned for civilian control of atomic energy and for arms control. He received the Atoms for Peace Award in 1959.
Why it matters
Szilard's chain reaction is the principle behind nuclear power, and the refugee council he helped found rescued the careers of thousands of scholars.
About Leo Szilard
Physicist who conceived the nuclear chain reaction in 1933, drafted Einstein’s letter to Roosevelt, co-built the first reactor, then campaigned for the rest of his life against nuclear war.
More about Leo Szilard
- Szilard's advice helped clone the first human cellLeo Szilard gave essential advice that, according to Theodore Puck and Philip Marcus, made their 1955 cloning of a human cell a reality.
- Szilard found a way to make medical isotopesIn 1934 at St Bartholomew's Hospital, Leo Szilard and Thomas Chalmers discovered the Szilard–Chalmers effect, widely used to prepare medical isotopes.
- Szilard co-invented the chemostat for growing microbesAfter the war Leo Szilard and Aaron Novick invented the chemostat for growing microbes and discovered feedback inhibition, a key way cells control their chemistry.
- Szilard first proposed the cyclotron and electron microscopeLeo Szilard filed the earliest known patent applications for the electron microscope (1928) and the cyclotron (1929), and one for the linear accelerator (1928).
- Szilard and Einstein invented a silent refrigeratorBetween 1926 and 1930 Leo Szilard worked with Albert Einstein on a refrigerator with no moving parts, patented in the United States in 1930.
- Leo Szilard linked information and thermodynamicsIn his Berlin research of the 1920s, Leo Szilard showed a deep connection between information and entropy, making him a founding figure of information theory.
- Szilard petitioned Truman not to bomb without warningIn July 1945 Leo Szilard drafted a petition, signed by about 70 Manhattan Project scientists, urging President Truman not to use the atomic bomb on Japan without warning.
- Szilard fought for civilian control of the atomAfter the war Leo Szilard lobbied for changes to the Atomic Energy Act of 1946 that placed American nuclear energy under civilian rather than military control.
- Leo Szilard helped rescue 2,500 refugee scholarsIn 1933 Leo Szilard helped found the Academic Assistance Council in Britain, which by 1939 had found places for more than 2,500 refugee scholars.
Sources
- Leo Szilard Wikipedia
- Leo Szilard Atomic Heritage Foundation, National Museum of Nuclear Science & History
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.