|
Richard C. Tolman
Richard Chace Tolman (March 4, 1881 – September 5, 1948) was an American mathematical physicist and physical chemist who made many contributions to statistical mechanics. He also made important contributions to theoretical cosmology in the years soon after Einstein's discovery of general relativity. He was a professor of physical chemistry and mathematical physics at the California Institute of Technology (Caltech). Biography Tolman was born in West Newton, Massachusetts and studied chemical engineering at the Massachusetts Institute of Technology, receiving his bachelor's degree in 1903 and PhD in 1910 under A. A. Noyes. He married Ruth Sherman Tolman in 1924. In 1912, he conceived of the concept of relativistic mass, writing that "the expression m_0 \left(1 - \frac \right)^ is best suited for the mass of a moving body." In a 1916 experiment with Thomas Dale Stewart, Tolman demonstrated that electricity consists of electrons flowing through a metallic conduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allan C
Allan may refer to: People * Allan (name), a given name and surname, including list of people and characters with this name * Allan (footballer, born 1984) (Allan Barreto da Silva), Brazilian football striker * Allan (footballer, born 1989) (Allan dos Santos Natividade), Brazilian football forward * Allan (footballer, born 1991) (Allan Marques Loureiro), Brazilian football midfielder * Allan (footballer, born 1994) (Allan Christian de Almeida), Brazilian football midfielder * Allan (footballer, born 1997) (Allan Rodrigues de Souza), Brazilian football midfielder Places * Allan, Queensland, Australia * Allan, Saskatchewan, Canada * Allan, the Allaine river's lower course, in France * Allan, Drôme, town in France * Allan, Iran (other), places in Iran Other uses * Allan, a Clan Grant split (or sept) * Ahlawat or Allan, an ethnic clan in India * ''Allan'', a 1966 film directed by Donald Shebib * "Allan" (song), a 1988 song recorded by the French artist Mylène Farme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relativistic Mass
The word " mass" has two meanings in special relativity: '' invariant mass'' (also called rest mass) is an invariant quantity which is the same for all observers in all reference frames, while the relativistic mass is dependent on the velocity of the observer. According to the concept of mass–energy equivalence, invariant mass is equivalent to '' rest energy'', while relativistic mass is equivalent to ''relativistic energy'' (also called total energy). The term "relativistic mass" tends not to be used in particle and nuclear physics and is often avoided by writers on special relativity, in favor of referring to the body's relativistic energy. In contrast, "invariant mass" is usually preferred over rest energy. The measurable inertia and the warping of spacetime by a body in a given frame of reference is determined by its relativistic mass, not merely its invariant mass. For example, photons have zero rest mass but contribute to the inertia (and weight in a gravitational field ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arnold Sommerfeld
Arnold Johannes Wilhelm Sommerfeld, (; 5 December 1868 – 26 April 1951) was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and mentored many students for the new era of theoretical physics. He served as doctoral supervisor for many Nobel Prize winners in physics and chemistry (only J. J. Thomson's record of mentorship is comparable to his). He introduced the second quantum number ( azimuthal quantum number) and the third quantum number ( magnetic quantum number). He also introduced the fine-structure constant and pioneered X-ray wave theory. Early life and education Sommerfeld was born in 1868 to a family with deep ancestral roots in Prussia. His mother Cäcilie Matthias (1839–1902) was the daughter of a Potsdam builder. His father Franz Sommerfeld (1820–1906) was a physician from a leading family in Königsberg, where Arnold's grandfather had resettled from the hinterland in 1822 for a career as Court Pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niels Bohr
Niels Henrik David Bohr (; 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research. Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. Although the Bohr model has been supplanted by other models, its underlying principles remain valid. He conceived the principle of complementarity: that items could be separately analysed in terms of contradictory properties, like behaving as a wave or a stream of particles. The notion of complementarity dominated Bohr's thinking in both science and philosophy. Bohr founded the Institute of Theoretical Physics at the University of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Planck
Max Karl Ernst Ludwig Planck (, ; 23 April 1858 – 4 October 1947) was a German theoretical physicist whose discovery of energy quanta won him the Nobel Prize in Physics in 1918. Planck made many substantial contributions to theoretical physics, but his fame as a physicist rests primarily on his role as the originator of quantum theory, which revolutionized human understanding of atomic and subatomic processes. In 1948, the German scientific institution Kaiser Wilhelm Society (of which Planck was twice president) was renamed Max Planck Society (MPG). The MPG now includes 83 institutions representing a wide range of scientific directions. Life and career Planck came from a traditional, intellectual family. His paternal great-grandfather and grandfather were both theology professors in Göttingen; his father was a law professor at the University of Kiel and Munich. One of his uncles was also a judge. Planck was born in 1858 in Kiel, Holstein, to Johann Julius Wilhelm Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Old Quantum Theory
The old quantum theory is a collection of results from the years 1900–1925 which predate modern quantum mechanics. The theory was never complete or self-consistent, but was rather a set of heuristic corrections to classical mechanics. The theory is now understood as the semi-classical approximation to modern quantum mechanics. The main and final accomplishments of the old quantum theory were the determination of the modern form of the periodic table by Edmund Stoner and the Pauli Exclusion Principle which were both premised on the Arnold Sommerfeld enhancements to the Bohr model of the atom. The main tool of the old quantum theory was the Bohr–Sommerfeld quantization condition, a procedure for selecting out certain states of a classical system as allowed states: the system can then only exist in one of the allowed states and not in any other state. History The old quantum theory was instigated by the 1900 work of Max Planck on the emission and absorption of light in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Academy Of Arts And Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other Founding Fathers of the United States. It is headquartered in Cambridge, Massachusetts. Membership in the academy is achieved through a thorough petition, review, and election process. The academy's quarterly journal, '' Dædalus'', is published by MIT Press on behalf of the academy. The academy also conducts multidisciplinary public policy research. History The Academy was established by the Massachusetts legislature on May 4, 1780, charted in order "to cultivate every art and science which may tend to advance the interest, honor, dignity, and happiness of a free, independent, and virtuous people." The sixty-two incorporating fellows represented varying interests and high standing in the political, professional, and commercial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technocracy Movement
The technocracy movement was a social movement active in the United States and Canada in the 1930s which favored technocracy as a system of government over representative democracy and concomitant partisan politics. Historians associate the movement with engineer Howard Scott's Technical Alliance and Technocracy Incorporated, prior to the internal factionalism that dissolved the latter organization during the Second World War. Technocracy was ultimately overshadowed by other proposals for dealing with the crisis of the Great Depression. The technocracy movement proposed replacing partisan politicians and business people with scientists and engineers who had the technical expertise to manage the economy. But the movement did not fully aspire to scientocracy.Peter J. TaylorTechnocratic Optimism, H.T. Odum, and the Partial Transformation of Ecological Metaphor after World War II''Journal of the History of Biology'', Vol. 21, No. 2, June 1988, p. 213. The movement was committed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical Alliance
The Technical Alliance was a group of engineers, scientists, and technicians based in New York City, formed towards the end of 1919 by American engineer Howard Scott. The Alliance started an ''Energy Survey of North America'', aimed at documenting the wastefulness of the capitalist system. The Technical Alliance advocated a more rational and productive society headed by technical experts, but their survey work failed to have a significant impact. Although some waste was documented, the "prosperity and conservatism of the 1920s undermined the political orientation of the Technical Alliance", and it disbanded in 1921, and the energy survey was not completed. Members The Technical Alliance was by no means a mass organization, but it did have some notable members and technical experts. Apart from Scott, other members of the Technical Alliance included: * Frederick L. Ackerman * Carl C. Alsberg * Alice Barrows * Allen Carpenter * Stuart Chase * L.K. Comstock * Bassett Jones * Rob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Mass
The electron mass (symbol: ''m''e) is the mass of a stationary electron, also known as the invariant mass of the electron. It is one of the fundamental constants of physics. It has a value of about or about , which has an energy-equivalent of about or about Terminology The term "rest mass" is sometimes used because in special relativity the mass of an object can be said to increase in a frame of reference that is moving relative to that object (or if the object is moving in a given frame of reference). Most practical measurements are carried out on moving electrons. If the electron is moving at a relativistic velocity, any measurement must use the correct expression for mass. Such correction becomes substantial for electrons accelerated by voltages of over . For example, the relativistic expression for the total energy, ''E'', of an electron moving at speed v is :E = \gamma m_\text c^2 , where the Lorentz factor is \gamma = 1/\sqrt . In this expression ''m''e is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Conductor
In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge (electric current) in one or more directions. Materials made of metal are common electrical conductors. Electric current is generated by the flow of negatively charged electrons, positively charged holes, and positive or negative ions in some cases. In order for current to flow within a closed electrical circuit, it is not necessary for one charged particle to travel from the component producing the current (the current source) to those consuming it (the loads). Instead, the charged particle simply needs to nudge its neighbor a finite amount, who will nudge ''its'' neighbor, and on and on until a particle is nudged into the consumer, thus powering it. Essentially what is occurring is a long chain of momentum transfer between mobile charge carriers; the Drude model of conduction describes this process more rigorously. This momentum transfer model makes metal a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal
A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the ''metallic bond'' between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polythiazyl, polymeric sulfur nitride. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
