In 38 Szilard accepted a research position at Columbia in Manhattan and was joined by Fermi. They learned about nuclear fission in 39 and concluded the element uranium could sustain a chain reaction and their experiment validated significant neutron multiplication. They knew they were opening the door to nuclear weapons. Leo saw the flashes after turning the switch, turned it off and went home. "That night ,I knew the world was headed for sorrow."
The Germans were also in the race to produce a nuclear chain reaction. Their attempts to control the reaction using graphite were unsuccessful due to the method of producing graphite
- using boron carbide rods adding impurities into the graphite and disabling the whole operation
- Szilard had graphite manufacturers produce boron free graphite
- On Dec 2,1942, the first human controlled chain reaction occurred.
Szilard started the Manhattan project
- he drafted a confidential letter to FDR explaining the possibility of nuclear weapons
- he warned the Nazis were working on such weapons
- encouraged development of a US program
- In Aug 39, he approached his old friend and collaborator Albert Einstein
- convincing him to sign a joint letter to FDR -The Einstein-Szilárd letter
- Research into nuclear fission by the US government was established and ultimately resulted in the Manhattan Project.
- The letter was handed to General Edwin Watson
- Szilard moved to the University of Chicago to continue work on the project
- Along with Fermi , he constructed the first neutronic reactor- 1942 the first self sustaining nuclear chain reaction
- Szilard was dismayed that scientists were losing control of their research to the military and clashed with Gen Leslie Groves military project head. Szilard resented the US further for its use of the Atomic bomb in Japan.He thought lives could have been spared.
In 1938 Szilárd accepted an offer to conduct research at Columbia University
in Manhattan, and moved to New York, and
was soon joined by Fermi. After learning about nuclear fission in 1939, they
concluded that uranium would be the element
capable of sustaining a chain reaction. Szilárd and Fermi conducted a simple
experiment at Columbia and discovered significant neutron multiplication in
uranium, proving that the chain reaction was possible and opening the way to
nuclear weapons. Szilárd later described the event: "We turned the switch, saw
the flashes, watched for ten minutes, then switched everything off and went
home. That night I knew the world was headed for sorrow".
around that time the Germans and others were in a race to produce a nuclear
chain reaction. German attempts to control the chain reaction sought to do so
using graphite, but these attempts proved unsuccessful. Szilárd realized
graphite was indeed perfect for controlling chain reactions, just as the Germans
had determined, but that the method of producing graphite used boron
carbide rods, and the minute amount of boron impurities in the
manufactured graphite was enough to stop the chain reaction. Szilárd had
graphite manufacturers produce boron-free graphite. As a result, the first
human-controlled chain reaction occurred on 2 December 1942.
The Manhattan Project
Szilárd was directly responsible for the creation of
the Manhattan Project. He
drafted a confidential letter to Franklin D.
Roosevelt explaining the possibility of nuclear weapons, warning of Nazi work on
such weapons and encouraging the development of a program which could lead
to their creation. In August 1939 he approached his old friend and collaborator Albert Einstein and
convinced him to sign the letter, lending the weight of his fame to the
proposal. The Einstein-Szilárd
letter led directly to the establishment of research into nuclear fission by
the U.S. government and ultimately to the creation of the Manhattan Project; FDR
handed the letter off to an aide, General Edwin M. "Pa" Watson
with the instruction: "Pa, this requires action!" Later,
Szilárd moved to the University of
Chicago to continue work on the project. There, along with Fermi, he helped
to construct the first "neutronic reactor", a uranium and graphite "atomic
pile" in which the first self-sustaining nuclear chain reaction was
achieved, in 1942.
As the war continued, Szilárd became increasingly
dismayed that scientists were losing control over their research to the
military, and clashed many times with General Leslie Groves, military
head of the project. His resentment towards the U.S.
government was exacerbated by his failed attempts to avoid the use of the
atomic bomb in war
through having a test organised that could be witnessed by Japanese observers
who would then have the opportunity to surrender and spare lives.
became a naturalized citizen
of the United States in