Leo Szilard

A Hungarian-American physicist, Leo Szilard was the proponent of the nuclear chain reaction back in 1933. He also established the relationship between the transfer of information and entropy which was what lead to being able to develop the means to separate radioactive elements as well as isotopes. He was also one of the first scientists who recognized the significance of nuclear fission which was the key element behind the development of atomic weapons used by the United States.


Early Life and Educational Background

Born in 1989, on the eleventh day of February, he was the son of an engineer and a member of one of the more affluent Jewish families back then. His name had originally been Leo Spitz, but it was changed to Szilard in the year 1900.

As a child, his interest in Physics came at an early age of just 13 years old—considering how advanced his interests were for his age. He was attending the public school of Budapest before he was drafted to become one of the members of the 1917 Austro-Hungarian army.

While he was in the army, he had been sent to the officer’s training school but was spared of having to engage in active duty because he had influenza. When the war ended, he stayed in Budapest but this set up didn’t last long because of political unrest in the area as well as lack of better educational opportunities. Because of these reasons, he went to Berlin in 1919.

During his time in Berlin, he took engineering courses in the Technische Hochschule or the Institute of Technology. His main interest had still been physics and he had been drawn to the works of the great minds of physics such as Albert Einstein, Erwin Schroedinger, Max Von Laue, Fritz Haber, Walter Nernst, and Max Planck. Most of these physicists had also been teaching in Berlin during those days.

Szilard later on gave up his courses in engineering in the year 1921, and studied physics in the University of Berlin where he was one of the students of renowned physicist Max von Laue. A year later, Szilard earned his cum laude doctorate after his submission of his dissertation called “Uber die thermodynamischen Schwankungserscheinungen” where he discussed the Second Law of Thermodynamics and how it affected not just mean values but the fluctuating values as well. The ideas from his dissertation are now the bases of modern theories.


After he completed his doctorate, he worked at the Kaiser Wilhelm Institute in Berlin along with Hermann Mark, a chemist who is well known for his contributions for the progress of polymer science. During this time, the studies conducted by Szilard focused on how X-rays scattered in crystals as well as the polarization of the same rays when reflected by crystals.

During the years 1925-1933, he had been working with none other than Albert Einstein and together they applied for numerous patents for their collaborative work. One of their more famous patents had been the refrigeration system which they based on pumping metals through a moving magnetic field. Their interest during that time was to catch the attention of A.E.G.—a company which is also known as the German General Electric company, and they hoped that the company would produce a refrigerator to be based on the patent they had. While this refrigerator was never really produced the same refrigeration system they created was used in 1942 to come up with an atomic reactor.

Szilard transferred to England in 1933—the same time when Adolf Hitler also rose to power. There, he had his collaborations with T.A. Chalmers where they came up with the Szilard-Chalmers process. This is the technique where stable isotopes and radioactive elements were separated. Most of his activities during his stay in London had been to have patents for his inventions, as these patents help improve his income through the help of the firm named Claremont, Haynes, and Company. During that time, he was able to influence Sir William Beveridge to establish the Academic Assistance Council, which aimed to help the prosecuted scientists to leave then Nazi Germany. From 1935 to 1937, Szilard had been one of the research physicists of the Clarendon Laboratory in the Oxford University.

The Nuclear Chain Reaction

During his time in London, he first attempted to create the nuclear chain reaction by using indium and beryllium which did not achieve the desired effects. The patent for his nuclear chain reaction was assigned to the British Admiralty with the idea of keeping it secret in mind. Along with Enrico Fermi, Szilard also co-held the patent for the nuclear reactor.

After that time, he moved to Manhattan for research to be done at the Columbia University and shortly after, Fermi went to join him in 1938. In 1939, Szilard along with other scientists namely Fermi, Otto Frisch, Lise Meitner, Fritz Strassman, and Otto Hahn, they were able to conclude how uranium can sustain the chemical reaction they were looking for. With Fermi, Szilard was able to deduce how uranium can be used to sustain chain reactions and that it can be used for nuclear weapons. When they realized this, Szilard also understood what their discovery implied—that it could cause much grief for the world when used in the wrong ways.

Szilard’s Ideas and Views Concerning Nuclear Weapons

He read H.G. Wells’ The World Set Free—a novel which had made a great impact on his thoughts. As a man of science, it was also Szilard who first conceived the possibility of having a device which uses the nuclear chain reaction to come up with a bomb. However, since he was a survivor of economic and political strife in Hungary, he had developed an unending passion for preserving the human life as well as maintaining freedom—even for communicating ideas.

He had advocated not using atomic bombs, knowing how it would also affect not just those considered as “enemies” but civilians and innocents. He had hoped that the mere thought of such a weapon could make Japan and Germany surrender. However, the atomic bombs used in Nagasaki and Hiroshima were still used despite the protests from Szilard as well as other scientists who grasped the complete idea of how it would affect the people in the area where the bombs eventually fell.