Biography of Enrico Fermi

How the Physicist Changed What We Know About Atoms

Italian physicist Enrico Fermi
Italian physicist Enrico Fermi, who was the winner of a Nobel Prize in 1938 and exiled by Mussolini, ca 1945. He became a US citizen and worked on developing the atom bomb. (Photo by PhotoQuest/Getty Images)

Enrico Fermi was a physicist whose important discoveries about the atom led to the splitting of the atom (atomic bombs) and the harnessing of its heat into an energy source (nuclear energy).

Dates: September 29, 1901 -- November 29, 1954

Also Known As: Architect of the Nuclear Age

Enrico Fermi Discovers His Passion

Enrico Fermi was born in Rome at the very beginning of the 20th century. At the time, no one could have imagined the impact his scientific discoveries would have on the world.

Interestingly, Fermi didn't get interested in physics until after his brother died unexpectedly during a minor surgery. Fermi was only 14 and the loss of his brother devastated him. Looking for an escape from reality, Fermi happened upon two physics books from 1840 and read them from cover to cover, fixing some of the mathematical errors as he read. He claims he didn't realize at the time that the books were written in Latin.

His passion was born. By the time he was just 17, Fermi's scientific ideas and concepts were so advanced he was able to head directly to graduate school. After four years studying at the University of Pisa, he was awarded his doctorate in physics in 1922.

Experimenting With Atoms

For the next several years, Fermi worked with some of the greatest physicists in Europe, including Max Born and Paul Ehrenfest, while also teaching at the University of Florence and then at the University of Rome.

At the University of Rome, Fermi conducted experiments that progressed atomic science. After James Chadwick discovered the third part of atoms, neutrons, in 1932, scientists worked diligently to discover more about the interior of atoms.

Before Fermi began his experiments, other scientists had already used helium nuclei as projectiles to disrupt an atom's nucleus.

However, since the helium nuclei were positively charged, they could not be successfully used on the heavier elements.

In 1934, Fermi came up with the idea to use neutrons, which have no charge, as projectiles. Fermi would shoot a neutron like an arrow into an atom's nucleus. Many of these nuclei absorbed the extra neutron during this process, creating isotopes for every element. Quite a discovery in and of itself; however, Fermi made another interesting discovery.

Slowing Down the Neutron

Though it doesn't seem to make sense, Fermi found that by slowing down the neutron, it often had a larger impact on the nucleus. He found that the speed at which the neutron was most impacted differed for every element.

For these two discoveries about atoms, Fermi was awarded the Nobel Prize for Physics in 1938.

Fermi Emigrates

The timing was just right for the Nobel Prize. Antisemitism was strengthening within Italy at this time and though Fermi was not Jewish, his wife was.

Fermi accepted the Nobel Prize in Stockholm and then immediately emigrated to the United States. He arrived in the U.S. in 1939 and began working at Columbia University in New York City as a professor of physics.

Nuclear Chain Reactions

Fermi continued his research at Columbia University.

Though Fermi had unknowingly split a nucleus during his earlier experiments, credit for splitting an atom (fission) was given to Otto Hahn and Fritz Strassmann in 1939.

Fermi, however, quickly realized that if you split an atom's nucleus, that atom's neutrons could be used as projectiles to split another atom's nuclei, causing a nuclear chain reaction. Each time a nucleus was split, an enormous amount of energy was released.

Fermi's discovery of the nuclear chain reaction and then his discovery of a way to control this reaction led to both the construction of atomic bombs and of nuclear power.

The Manhattan Project

During World War II, Fermi worked diligently on the Manhattan Project to create an atomic bomb. After the war, however, he believed the human toll from these bombs was too large.

In 1946, Fermi worked as a professor at the University of Chicago's Institute of Nuclear Studies.

In 1949, Fermi argued against the development of a hydrogen bomb. It was built anyway.

On November 29, 1954, Enrico Fermi succumbed to stomach cancer at the age of 53.