|
Edmund Stoner
Edmund Clifton Stoner Royal Society, FRS (2 October 1899 – 27 December 1968) was a British theoretical physicist. He is principally known for his work on the origin and nature of itinerant ferromagnetism (the type of ferromagnetic behaviour associated with pure transition metals like cobalt, nickel, and iron), including the collective electron theory of ferromagnetism and the Stoner criterion for ferromagnetism. Stoner made significant contributions to the electron configurations in the periodic table. Biography Stoner was born in Esher, Surrey, the son of cricketer Arthur Stoner, Arthur Hallett Stoner. He won a scholarship to Bolton School (1911–1918) and then attended University of Cambridge in 1918, graduating in 1921. After graduation, he worked at the Cavendish Laboratory on the absorption of X-rays by matter and electron energy levels; his 1924 paper on this subject prefigured the Pauli exclusion principle. Stoner was appointed a Lecturer in the Department of Physics at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surrey
Surrey () is a ceremonial and non-metropolitan county in South East England, bordering Greater London to the south west. Surrey has a large rural area, and several significant urban areas which form part of the Greater London Built-up Area. With a population of approximately 1.2 million people, Surrey is the 12th-most populous county in England. The most populated town in Surrey is Woking, followed by Guildford. The county is divided into eleven districts with borough status. Between 1893 and 2020, Surrey County Council was headquartered at County Hall, Kingston-upon-Thames (now part of Greater London) but is now based at Woodhatch Place, Reigate. In the 20th century several alterations were made to Surrey's borders, with territory ceded to Greater London upon its creation and some gained from the abolition of Middlesex. Surrey is bordered by Greater London to the north east, Kent to the east, Berkshire to the north west, West Sussex to the south, East Sussex to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Stoner
Arthur Stoner (11 May 1870 – 1938) was an English cricketer and umpire. Stoner's batting and bowling styles are unknown. He was born in Streatham, London. He is the father of the condensed matter physicist Edmund Clifton Stoner. Stoner made his first-class debut for Surrey against Cambridge University in 1899. He made five further first-class appearances for Surrey, the last of which came against Leicestershire in the 1900 County Championship. In his six first-class matches, he scored a total of 98 runs at an average of 10.88, with a high score of 61. This score came against Hampshire in 1899. He left Surrey at the end of the 1900 season. Stoner later joined Durham, making his debut for the county in the Minor Counties Championship against the Yorkshire Second XI. He played Minor counties cricket for Durham from 1904 to 1908, making 26 Minor Counties Championship appearances. He later stood as an umpire in 54 first-class matches between 1928 and 1934, as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically, density is defined as mass divided by volume: : \rho = \frac where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate – this quantity is more specifically called specific weight. For a pure substance the density has the same numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium and iridium are the densest known elements at standard conditions for temperature and pressure. To simplify comparisons of density across different s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and even by industry. Further, both spellings are often used ''within'' a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling. is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as of this. Manometric u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ralph H
Ralph (pronounced ; or ,) is a male given name of English, Scottish and Irish origin, derived from the Old English ''Rædwulf'' and Radulf, cognate with the Old Norse ''Raðulfr'' (''rað'' "counsel" and ''ulfr'' "wolf"). The most common forms are: * Ralph, the common variant form in English language, English, which takes either of the given pronunciations. * Rafe (name), Rafe, variant form which is less common; this spelling is always pronounced , as are all other English spellings without "l". * Raife, a very rare variant. * Raif, a very rare variant. Raif Rackstraw from H.M.S. Pinafore * Ralf, the traditional variant form in Dutch language, Dutch, German language, German, Swedish language, Swedish, and Polish language, Polish. * Ralfs (given name), Ralfs, the traditional variant form in Latvian language, Latvian. * Raoul (other), Raoul, the traditional variant form in French language, French. * Raúl, the traditional variant form in Spanish language, Spanish. * Raul, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermi Gas
An ideal Fermi gas is a state of matter which is an ensemble of many non-interacting fermions. Fermions are particles that obey Fermi–Dirac statistics, like electrons, protons, and neutrons, and, in general, particles with half-integer spin. 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. The model is named after the Italian physicist Enrico Fermi. This physical model can be accurately applied to many systems with many fermions. Some key examples are the behaviour of charge carriers in a metal, nucleons in an atomic nucleus, neutrons in a neutron star, and electrons in a white dwarf. Description An ideal Fermi gas or free Fermi gas is a physical model assuming a collection of non-interacting fermions in a constant potential well. Fermions are elementary or composite particles with half-integer spin, thus follow Fermi-Dira ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Anderson
Wilhelm Robert Karl Anderson ( – 26 March 1940) was a Russian-Estonian astrophysicist of Baltic German descent who studied the physical structure of the stars. Life Wilhelm Anderson was born in Minsk (now in Belarus) into a Baltic German family. His younger brothers were the well known mathematician Oskar Anderson (1887–1960) and the folklorist Walter Anderson (1885–1962). Anderson spent some of his youth in Kazan, where his father Nikolai Anderson (1845–1905) was a university professor for Finno-Ugric languages. He studied at the University of Kazan, where he graduated from the department of mathematics and science in 1909. Between 1910 and 1920, he worked as a physics teacher first in Samara and then from 1918 in Minsk. Together with his brother Walter Anderson, he moved to Tartu (Estonia) in 1920. At the University of Tartu, he first gained a Masters degree in Astronomy in 1923 and then a Doctorate in 1927. In 1934 he became a habilitation candidate at the uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Dwarf
A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes from the emission of residual thermal energy; no fusion takes place in a white dwarf. The nearest known white dwarf is at 8.6 light years, the smaller component of the Sirius binary star. There are currently thought to be eight white dwarfs among the hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910. The name ''white dwarf'' was coined by Willem Luyten in 1922. White dwarfs are thought to be the final evolutionary state of stars whose mass is not high enough to become a neutron star or black hole. This includes over 97% of the other stars in the Milky Way. After the hydrogen- fusing period of a main-sequence star of low or medium mass ends, such a star will expand to a red giant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrophysics
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–''what'' they are, rather than ''where'' they are." Among the subjects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, ''astrophysicists'' apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pauli Exclusion Principle
In quantum mechanics, the Pauli exclusion principle states that two or more identical particles with half-integer spins (i.e. fermions) cannot occupy the same quantum state within a quantum system simultaneously. This principle was formulated by Austrian physicist Wolfgang Pauli in 1925 for electrons, and later extended to all fermions with his spin–statistics theorem of 1940. In the case of electrons in atoms, it can be stated as follows: it is impossible for two electrons of a poly-electron atom to have the same values of the four quantum numbers: ''n'', the principal quantum number; ', the azimuthal quantum number; ''m'', the magnetic quantum number; and ''ms'', the spin quantum number. For example, if two electrons reside in the same orbital, then their ''n'', ', and ''m'' values are the same; therefore their ''ms'' must be different, and thus the electrons must have opposite half-integer spin projections of 1/2 and −1/2. Particles with an integer spin, or bosons, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron's mass is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum ( spin) of a half-integer value, expressed in units of the reduced Planck constant, . Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
