The physicist Leo Szilard was born on Feb. 11, 1898 in Hungary.

Szilard was probably the first scientist to conceive of how an atomic bomb might work. He later wrote that the concept of a nuclear chain reaction "suddenly occurred to me" in Sept. 1933 while taking a walk thru the streets of London (Leo Szilard: His Version of the Facts, edited by Spencer Weart and Gertrud Weiss Szilard, pg. 17). For the next six years Szilard tried to keep this concept a secret, since he knew what Hitler could do with such a bomb.

But other scientists came to understand the nuclear chain reaction concept. In Dec. 1938 German scientists split the uranium atom, German aggression increased in Europe, and in Sept. 1939 Germany invaded Poland. By now Szilard believed the race was on for the atomic bomb. He had moved to the United States, and he felt the U.S. must build the a-bomb before the Nazis got it. But how could he make this happen? He was an unknown who had no influence in high places.

In Aug. 1939 Szilard wrote a letter to President Franklin Roosevelt pointing out the danger that would arise if Germany made the first a-bomb. To make the letter more influential, it was signed not by Szilard but by his old colleague, Albert Einstein. The result was the slow beginnings of the U.S. atomic bomb project (Genius in the Shadows: A Biography of Leo Szilard, by William Lanouette, pg. 198-212).

One of Szilard's greatest contributions to the work on the a-bomb was his and Enrico Fermi's creation of the first controlled nuclear chain reaction. This was done at the University of Chicago in Dec. 1942.

Were it not for his genius, Szilard would have been fired from the Manhattan Project, for he was outspoken in his criticism of how the project was run. The general in charge of the project, Leslie Groves, emphasized secrecy so strongly that he wanted each scientist to only know about their piece of the project. Szilard felt this restriction on the sharing and development of ideas was slowing down the project. This policy was soon adjusted so that the Manhattan Project scientists could discuss more of their ideas with each other.

Szilard described one of his hobbies as "the baiting of brass hats" (such as Groves). Groves wanted to have Szilard "interned for the duration of the war" as "an enemy alien".

As the defeat of Germany approached in the Spring of 1945, Szilard began to question the need to use the atomic bomb. Until then, he had been driven by the fear of what might happen if Germany got the a-bomb before the Allies could get one in self-defense. Now most of the work for the Chicago scientists was done, and there was more time to think about the consequences of what they had worked on. And no one thought longer or harder about that than Leo Szilard.

Using another letter from Einstein, Szilard scheduled a meeting with Eleanor Roosevelt for May 8. He planned to give her information that would caution President Roosevelt about the danger of a nuclear arms race if the a-bomb was used before an international control agreement could be discussed with the Soviets. But on April 12, President Roosevelt died.

An attempt to meet with President Truman led instead to a May 28, 1945 meeting with James Byrnes, who would soon become Sec. of State. But Byrnes thoroughly disagreed with Szilard's views.

Szilard was one of the main authors of the Franck Report in June, 1945. This report warned that even if the a-bomb helped save lives in this war, the a-bomb's use could lead to a nuclear arms race and, possibly, a nuclear war that would take far more lives than however many might be saved in the current war.

After World War II, Szilard continued his efforts to bring nuclear weapons under control. He also founded the Council for a Livable World, which continues to work for peace to this day.

- Doug Long

For further information:

Spencer Weart & Gertrud Weiss Szilard, editors, Leo Szilard: His Version of the Facts

William Lanouette, Genius in the Shadows: A Biography of Leo Szilard

The Leo Szilard web site

Council For a Livable World web site

Photo courtesy of Argonne National Laboratory

