Fermi gas
A Fermi gas is an ensemble of a large number of fermions. Fermions, named after Enrico Fermi, are particles that obey Fermi–Dirac statistics. These statistics determine the energy distribution of fermions in a Fermi gas in thermal equilibrium, and is characterized by their number density, temperature, and the set of available energy states.
By the Pauli exclusion principle, no quantum state can be occupied by more than one fermion with an identical set of quantum numbers. Thus a noninteracting Fermi gas, unlike a Bose gas, is prohibited from condensing into a Bose–Einstein condensate, although interacting Fermi gases might. The total energy of the Fermi gas at absolute zero is larger than the sum of the single-particle ground states because the Pauli principle implies a sort of interaction or pressure that keeps fermions separated and moving. For this reason, the pressure of a Fermi gas is non-zero even at zero temperature, in contrast to that of a classical ideal gas. This so-called degeneracy pressure stabilizes a neutron star (a Fermi gas of neutrons) or a white dwarf star (a Fermi gas of electrons) against the inward pull of gravity, which would ostensibly collapse the star into a black hole. Only when a star is sufficiently massive to overcome the degeneracy pressure can it collapse into a singularity.
Gas
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or compound molecules made from a variety of atoms (e.g. carbon dioxide). A gas mixture would contain a variety of pure gases much like the air. What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colorless gas invisible to the human observer. The interaction of gas particles in the presence of electric and gravitational fields are considered negligible as indicated by the constant velocity vectors in the image. One type of commonly known gas is steam.
The gaseous state of matter is found between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention. High-density atomic gases super cooled to incredibly low temperatures are classified by their statistical behavior as either a Bose gas or a Fermi gas. For a comprehensive listing of these exotic states of matter see list of states of matter.
Gas (musician)
Gas is a music project of Wolfgang Voigt (born 1961), a Cologne, Germany-based electronic musician. Voigt cites his youthful LSD experiences in the Königsforst, a German forest situated near his hometown of Köln, as the inspiration behind his work under the name Gas. He has claimed that the intention of the project is to "bring the forest to the disco, or vice-versa".
Aliases and projects
Voigt is known for his numerous, nearly inexhaustible list of one-off projects and aliases. Of these, his best known is arguably Gas, a project that saw the marriage of ambient music and 4/4 techno.
Other names under which Voigt has released music include, but are not limited to, All, Auftrieb, Brom, C.K. Decker, Centrifugal Force, Crocker, Dextro NRG, Dieter Gorny, Digital, Dom, Doppel, Filter, Freiland, Fuchsbau, Gelb, Grungerman, Kafkatrax, Love Inc., M:I:5, Mike Ink, Mint, Panthel, Popacid, Riss, RX7, Split Inc., Strass, Studio 1, Tal, Vinyl Countdown, W.V., Wassermann, and X-Lvis.
Characteristics
Gas (1981 film)
(not to be confused with a similar sounding 1970 film Gas-s-s-s)
Gas is a 1981 Canadian comedy film released by Paramount Pictures, the plot of which was inspired by the 1979 energy crisis.
Plot summary
A small Midwestern town is thrown into chaos when the local oil tycoon (Sterling Hayden) orchestrates a phony oil shortage in order to increase profits. A news reporter (Susan Anspach) tries to uncover the plot, and a radio DJ in a helicopter (Donald Sutherland) reports on the craziness caused by the gasoline shortage.
Cast
Fermi (disambiguation)
Enrico Fermi (1901–1954) was an Italian physicist who created the world's first nuclear reactor.
Fermi may also refer to:
Physics
Technology and engineering
Nuclear reactors
Mathematics
Fermi (crater)
Fermi is a large lunar crater of the category named a walled plain. It lies on the far side of the Moon and can not be viewed from the Earth. Thus this feature must be viewed from an orbiting spacecraft.
The most notable aspect of Fermi is that the large and prominent crater Tsiolkovskiy intrudes into its southeastern rim. Unlike Tsiolkovskiy, however, the interior of Fermi is not covered by dark basaltic lava, and so it is barely distinguishable from the surrounding rugged and battered terrain. If it were located on the near side of the Moon, however, this would be one of the largest visible craters, with a dimension roughly equal to the crater Humboldt, lying several hundred kilometers to the west-southwest.
This formation has been significantly eroded and damaged by subsequent impacts, and several notable craters lie across the rim and within the basin. Delporte is the most notable of these, lying across the northwest rim. Just to the east and inside the northern rim of Fermi is Litke. The smaller crater Xenophon is centered across the southern rim. In the southern half of the floor are the craters Diderot and Babakin.
Femtometre
The femtometre (American spelling femtometer, symbol fmAncient Greek: μέτρον, metrοn, "unit of measurement") is an SI unit of length equal to 10−15metres. This distance can also be called fermi and was so named in honour of physicist Enrico Fermi, as it is a typical length-scale of nuclear physics.
Definition and equivalents
1000 attometres = 1 femtometre = 1 fermi = 0.001 picometre = 1.0 × 10−15metres
1,000,000 femtometres = 10 Ångström = 1 nanometre.
For example, the charge radius of a proton is approximately 0.84–0.87 femtometres while the radius of a gold nucleus is approximately 8.45 femtometres.
1 barn = 100 fm2
History
The femtometre was adopted by the 11th Conférence Générale des Poids et Mesures, and added to SI in 1964.
The fermi is named after the Italian physicist Enrico Fermi (1901–1954), one of the founders of nuclear physics. The term was coined by Robert Hofstadter in a 1956 paper published in Reviews of Modern Physics entitled "Electron Scattering and Nuclear Structure". The term is widely used by nuclear and particle physicists. When Hofstadter was awarded the 1961 Nobel Prize in Physics, it subsequently appears in the text of his 1961 Nobel Lecture, "The electron-scattering method and its application to the structure of nuclei and nucleons" (December 11, 1961).
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