Enrico Fermi was an Italian
theoretical and
experimental physicist, best known for his work on the development of
Chicago Pile-1, the first
nuclear reactor, and for his contributions to the development of
quantum theory,
nuclear and
particle physics, and
statistical mechanics. Along with
J. Robert Oppenheimer, he is referred to as "the father of the atomic bomb". He held
several patents related to the use of nuclear power, and was awarded the 1938
Nobel Prize in Physics for his work on
induced radioactivity and the discovery of
transuranic elements. Throughout his life Fermi was widely regarded as one of the very few physicists who excelled both theoretically and experimentally. Fermi's first major contribution was to statistical mechanics. After
Wolfgang Pauli announced his
exclusion principle in 1925, Fermi followed with a paper in which he applied the principle to an ideal gas, employing a statistical formulation now known as
Fermi–Dirac statistics. Today, particles that obey the exclusion principle are called "
Fermions". Later Pauli postulated the existence of an invisible particle with no charge that was emitted at the same time an electron was emitted during
beta decay in order to satisfy the law of
conservation of energy. Fermi took up this idea, developing a model that incorporated the postulated particle, which Fermi named the "
neutrino". His theory, later referred to as
Fermi's interaction and still later as the theory of the
weak interaction, described one of the
four forces of nature. Through experiments inducing radioactivity with recently discovered
neutrons, Fermi discovered that
slow neutrons were more easily
captured than fast ones, and developed a
diffusion equation to describe this, which became known as the
Fermi age equation. He bombarded
thorium and
uranium with slow neutrons, and concluded that he had created new elements, for which he was awarded the Nobel Prize, but the new elements were subsequently revealed to be
fission products. Fermi left Italy in 1938 to escape racial laws that affected his Jewish wife Laura, and emigrated to the United States, where he worked on the
Manhattan Project during
World War II. Fermi led the team that designed and built the Chicago Pile-1, and initiated the first artificial self-sustaining
nuclear chain reaction when it went
critical on 2 December 1942. He was on hand when the
X-10 Graphite Reactor at
Oak Ridge, Tennessee, went critical in 1943, and the
B Reactor at the
Hanford Site went critical in 1944. At
Los Alamos he headed F Division, where he worked on the
thermonuclear "Super". He was present at the
Trinity test on 16 July 1945, where he used one of his
Fermi method experiments to estimate the bomb's yield. After the war, Fermi served on the influential General Advisory Committee of the
Atomic Energy Commission, a scientific committee chaired by Robert Oppenheimer which advised the commission on nuclear matters and policy. Following the detonation of
RDS-1 in August 1949, the first Soviet
fission bomb, he wrote a strongly worded report for the committee, opposing the development of a hydrogen bomb on both moral and technical grounds. He was among the scientists who testified on Oppenheimer's behalf at the
Oppenheimer security hearing in 1954 that resulted in denial of Oppenheimer's security clearance. Fermi did important work in particle physics, especially related to
pions and
muons, and he speculated that
cosmic rays arose through material being accelerated by magnetic fields in interstellar space. Many awards, concepts, and institutions are named after Fermi, including the
Enrico Fermi Award, the
Enrico Fermi Institute, the
Fermi National Accelerator Laboratory, the
Fermi Gamma-ray Space Telescope, the
Enrico Fermi Nuclear Generating Station, and the synthetic element
fermium.
The
Isidore H. Heller House is a house located at 5132 Woodlawn Avenue in the
Hyde Park community area of
Chicago in
Cook County,
Illinois,
United States. The house was designed by American
architect Frank Lloyd Wright. The design is credited as one of the turning points in Wright's shift to
geometric,
Prairie School architecture, which is defined by horizontal lines, flat or
hipped roofs with broad overhanging
eaves, windows grouped in horizontal bands, and an integration with the landscape, which is meant to evoke native
Prairie surroundings. The work demonstrates Wright's shift away from emulating the style of his mentor,
Louis Sullivan.
Richard Bock, a Wright collaborator and sculptor, provided some of the ornamentation, including a
plaster frieze. The ownership history of this building demonstrates the property's evolution and development in the framework of surrounding Hyde Park buildings, and the building's location in the current community—near other Prairie School architecture—includes this building into the overall body of Lloyd Wright's work. The Heller House was designated a
Chicago Landmark on September 15, 1971, and added to the
National Register of Historic Places on March 16, 1972. On 18 August 2004, the U.S. Department of the Interior designated the house a
National Historic Landmark.
