Enrico Fermi was awarded the Nobel Prize in Physics in the year 1938 for his discovery of the existence of new radioactive elements produced by neutron irradiation and also for his discovery of nuclear reactions brought about by slow neutrons. The Nobel Prize in Physics has been awarded annually by the Royal Swedish Academy of Sciences. From 1901 the prizes have been awarded at a formal ceremony held on December 10 at Sweden, Stockholm.

Birth and education

Enrico Fermi was born on September 29, 1901 in Rome, Italy. He was the son of Alberto Fermi and Ida de Gattis. His father was a Chief Inspector in the Ministry of Communications. He studied at a local grammar school. From an early age he showed an aptitude for mathematics and physics. He was greatly encouraged by his father’s colleagues especially A. Amidei. In 1918 as he was an intelligent student he won a fellowship to study at the prestigious Scuola Normale Superiore, Pisa. In 1922 he obtained a doctorate in physics under the guidance of Professor Puccianti from the University of Pisa.

Early career in Italy

In 1923 he was awarded a scholarship by the Italian government and spent a few months under the guidance of Professor Gottingen. In 1924 he was awarded a Rockefeller Fellowship, which enabled him to move to Leyden and work with P. Ehrenfest. Later in the same year he returned to Italy to work as a lecturer in Mathematical Physics and Mechanics at the University of Florence from 1924 to 1926.

It was in 1926 that Fermi discovered the statistical laws governing the particles subject to Pauli’s exclusion principle. These are now called Fermi- Dirac statistics and the particles are called fermions. These particles are an entire class of elementary particles with a half integer spin. They have been named fermions in his honour. They are in contrast to bosons the particles, which obey the Bose-Eintein statistics. Fermions explained diverse phenomena ranging from the thermal conductivity of metals to the structure and stability of dense compact stars like white dwarfs.

In 1927 Fermi became the Professor of Theoretical Physics at the University of Rome and remained there till 1838. Throughout his academic career Fermi was very popular for his lucid teaching.

Initially his research was focused on thermo dynamics and theoretical investigations on spectroscopy. In 1938 he evolved the b decay theory. He coalesced the work previous work on radiation theory with Pauli’s concept of the neutrino. In 1934 Curie and Joliot had discovered artificial radioactivity. Fermi showed that nuclear transformation occurred in almost every element subjected to nuclear bombardment. He showed that in addition to electrons ghostly particles first proposed by Pauli must also be emitted. He named these particles neutrinos. Neutrinos were experimentally detected in 1956. They play a very important role in astrophysics. This work lead to the conclusion of the existence of slow neutrons leading to the discovery of nuclear fission. Fermi’s theory of b decay has played a crucial role in the understanding of weak nuclear reactions for several decades.

Fermi used neutrons as a tool to probe into the secrets held within the atomic nuclei. Several new radioactive elements were obtained by bombarding the naturally occurring nuclei with neutrons and the subsequent beta decay of these nuclei. Thus he produced more than forty different artificial radioisotopes. This resulted in the production of elements that lay beyond what was considered the Periodic Table at that time.

These radioisotopes have found to have many uses. They have been used in medicine, material testing and applications, heart implants, power generation in satellites and in many other diverse applications.

Around this time he also proposed a theory for Lippmann’s colour photographic techniques. He also contributed the “Golden rule “ in quantum mechanics. He wrote a key paper on the quantum theory of electromagnetic interactions.

The Nobel Prize

By 1938 Fermi was the greatest expert on neutrons. In the same year he awarded the Nobel Prize in Physics for his work in experimental nuclear physics. He demonstrated the existence of new radioactive elements produced by neutron radiation. He was also awarded the prize for his related discovery of nuclear reactions brought about by slow neutrons.

Move to the USA

After receiving the Nobel Prize in 1938 he left for New York with his wife and children to escape from the anti- fascist policies prevalent in Italy. His wife Laura was Jewish.

After his arrival in America he was appointed as Professor of Physics from 1939 to 1942 at Columbia University. After Fermi’s successful experiments many scientists tried to identify the products of the neutron bombardment of uranium but were unsuccessful. In December 1938 in Germany Hahn and Strassman had succeeded in splitting an atom of uranium for the first time and show that two products are Barium- 139 and Lanthanum- 140 were produced. Fermi verified the experiment conducted by these scientists. This new discovery made Fermi see the possibility of the emission of secondary neutrons and of a chain reaction.

Einstein’s letter to President Roosevelt spurred the setting up of the Manhattan project culminating in the development of the atomic bomb. In 1939 the Navy awarded Columbia University a grant of $ 6,000 to conduct research in Atomic Energy. Fermi now conducted a series of experiments, which led to the development of the atomic pile, and the first controlled nuclear chain reaction. This major and path breaking event Chicago Pile –1 a massive pile of graphite bricks and uranium fuel went critical on December 2, 1942. It was thus in 1939 that the Italian Enrico Fermi and fellow émigré Hungarian Leo Szilard and others built the first nuclear reactor. Eventually Fermi and Szilard’s work was integrated into the Manhattan Project. He then became one of the leaders of the team of physicists on the Manhattan Project.

In 1944 he became an American citizen. In 1944 he was at Los Alamos in the New Mexican Desert for the test of the bomb in the devastating new weapon of the century in July 1945. When the first nuclear bomb exploded the surrounding desert sand turned to glass for a radius of about one kilometre.

With his characteristic simplicity he estimated its explosive yield. He dropped scraps of paper in the predawn stillness and again when the blast wind arrived and compared the displacement and made his calculations. His simple calculations and fundamental experiments were always a major hallmark of his professional outlook and once again they fetched him the desired outcome.

In 1946 he became a Professor at the Institute for Nuclear Studies, University of Chicago. He held this position till his untimely death. He now focused on high energy physics. He investigated the pion-nucleon reaction. He also explored the mysterious origin of cosmic rays. He developed a theory according to which a universal magnetic field acts as a giant accelerator and accounts for the fantastic energies present in the cosmic ray particles. This is called Fermi acceleration. He also collaborated with S. Chandrasekhar on the origin of the galactic magnetic fields.

In 1949 he had argued against the development of the hydrogen bomb believing it to be a weapon whose practical effect was almost one of genocide. But the discovery on how to release nuclear energy has had long-term beneficial effects. Nuclear energy when harnessed properly is a clean and efficient and comparatively non-polluting source of energy, which has ecological benefits for our world.

Publications

Enrico Fermi has published various important papers in most of the prestigious scientific journals of physics. A Committee under the Chairmanship of his friend and former student Professor Emilio Segre has published his Collected Papers.

Other honours

Fermi was a member of several renowned academies and societies in Italy and all over the world. He was one among the first thirty members of the Royal Academy of Italy. He was the first recipient of a special award of $ 50,000 for work on the atom. The award has now been named in his honour.

Guest lecturer

Fermi was in great demand as a lecturer. He taught courses and gave lectures at the University of Michigan, Ann Arbor and at Stanford University, California. He was very popular with his students for his approach to physics was a simple and fundamental one although he was very capable of handling complex mathematical calculations.

Personal Life

In 1928 Enrico Fermi married Laura Capon. They had one son Giulio and one daughter Nella. Fermi enjoyed walking, mountaineering and winter sports. He had a disarming streak of modesty and an ability to do all kinds of work whether creative or routine. This quality endeared him to Nobel laureate and technicians alike. He was very popular and well liked by people from all strata of society.

Death

Fermi died on the 28th of November 1954 in Chicago. He was only fifty-three years old. He had stomach cancer. He was buried in the Oak Wood Cemetery.

Fermi was regarded as the only physicist of the twentieth century who excelled in both theoretical and experimental physics. His legacy lives on intellectually through the many scientists and physicists he has trained and the many he continues to inspire. There is also a street named after him in Rome. It is called Via Enrico Fermi.