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Mu B
In atomic physics, the Bohr magneton (symbol ) is a physical constant and the natural unit for expressing the magnetic moment of an electron caused by its orbital or spin angular momentum. In SI units, the Bohr magneton is defined as \mu_\mathrm = \frac and in the Gaussian CGS units as \mu_\mathrm = \frac , where * is the elementary charge, * is the reduced Planck constant, * is the electron mass, * is the speed of light. History The idea of elementary magnets is due to Walther Ritz (1907) and Pierre Weiss. Already before the Rutherford model of atomic structure, several theorists commented that the magneton should involve the Planck constant ''h''. By postulating that the ratio of electron kinetic energy to orbital frequency should be equal to ''h'', Richard Gans computed a value that was twice as large as the Bohr magneton in September 1911. At the First Solvay Conference in November that year, Paul Langevin obtained a value of ''eħ''/(2''m''e). Langevin assumed tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Of Units
A system of units of measurement, also known as a system of units or system of measurement, is a collection of units of measurement and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of science and wikt:commerce, commerce. Instances in use include the International System of Units or (the modern form of the metric system), the British imperial system, and the United States customary system. History In antiquity, ''systems of measurement'' were defined locally: the different units might be defined independently according to the length of a king's thumb or the size of his foot, the length of stride, the length of arm, or maybe the weight of water in a keg of specific size, perhaps itself defined in ''hands'' and ''knuckles''. The unifying characteristic is that there was some definition based on some standard. Eventually ''cubits'' and ''yard, strides'' gave way to "customary units" to meet the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Of Light
The speed of light in vacuum, commonly denoted , is a universal physical constant exactly equal to ). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time interval of second. The speed of light is invariant (physics), the same for all observers, no matter their relative velocity. It is the upper limit for the speed at which Information#Physics_and_determinacy, information, matter, or energy can travel through Space#Relativity, space. All forms of electromagnetic radiation, including visible light, travel at the speed of light. For many practical purposes, light and other electromagnetic waves will appear to propagate instantaneously, but for long distances and sensitive measurements, their finite speed has noticeable effects. Much starlight viewed on Earth is from the distant past, allowing humans to study the history of the universe by viewing distant objects. When Data communication, comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletin De La Section Scientifique De L'Académie Roumaine
Bulletin or The Bulletin may refer to: Periodicals (newspapers, magazines, journals) * ''Bulletin'' (online newspaper), a Swedish online newspaper * ''The Bulletin'' (Australian periodical), an Australian magazine (1880–2008) ** Bulletin Debate, a famous dispute from 1892 to 1893 between Henry Lawson and Banjo Paterson * ''The Bulletin'' (alternative weekly), an alternative weekly published in Montgomery County, Texas, U.S. * ''The Bulletin'' (Bend), a daily newspaper in Bend, Oregon, U.S. * ''The Bulletin'' (Belgian magazine), a weekly English-language magazine published in Brussels, Belgium * ''The Bulletin'' (Philadelphia newspaper), a newspaper in Philadelphia, Pennsylvania, U.S. (2004–2009) * ''The Bulletin'' (Norwich) * ''London Bulletin'', surrealist monthly magazine (1938–1940) * ''The Morning Bulletin'', a daily newspaper published in Rockhampton, Queensland, Australia since 1861 * ''Philadelphia Bulletin'', a newspaper published in Philadelphia, U.S. (1847†... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annales Scientifiques De L'Université De Jassy
Annals are a concise form of historical writing which record events chronologically, year by year. The equivalent word in Latin and French is ''annales'', which is used untranslated in English in various contexts. List of works with titles containing the word "Annales" * ''Annales'' (Ennius), an epic poem by Quintus Ennius covering Roman history from the fall of Troy down to the censorship of Cato the Elder * Annals (Tacitus) ''Ab excessu divi Augusti'' "Following the death of the divine Augustus" * Annales Alamannici, ed. W. Lendi, Untersuchungen zur frühalemannischen Annalistik. Die Murbacher Annalen, mit Edition (Freiburg, 1971) * Annales Bertiniani, eds. F. , J. Vielliard, S. Clemencet and L. Levillain, Annales de Saint-Bertin (Paris, 1964) * , Paris, France. Published 1802 to 1813, then became the Mémoires then the Nouvelles Annales * Annales Fuldenses, ed. F. Kurze, ''Monumenta Germaniae Historica'' SRG (Hanover, 1891) * ''Annales. Histoire, Sciences Sociales'', a French ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ștefan Procopiu
Ștefan Procopiu (; January 19, 1890 – August 22, 1972) was a Romanian physicist and a titular member of the Romanian Academy. Biography Procopiu was born in 1890 in Bârlad, Romania. His father, Emanoil Procopiu, was employed at the Bârlad courthouse. His mother, Ecaterina Tașcă, was the sister of Gheorghe Tașcă (see Tașcă family). He attended the Gheorghe Roșca Codreanu High School in Bârlad from 1901 to 1908, continuing his studies at the Faculty of Sciences of the University of Iași from 1908 to 1912. After graduation he became assistant to Professor Dragomir Hurmuzescu. In 1919 he obtained a scholarship to continue his studies at the University of Paris, attending courses of famous scientists, such as Gabriel Lippmann, Marie Curie, Paul Langevin, and Aimé Cotton. On 5 March 1924, Procopiu obtained the title of doctor in physics with the thesis "On the electric birefringence of suspensions" presented to a commission including professor Aimé Cotton a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:Category:Romanian Physicists
{{DEFAULTSORT:Romanian physicists Physicists A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ... European physicists Physicists by nationality ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Langevin
Paul Langevin (23 January 1872 – 19 December 1946) was a French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the '' Comité de vigilance des intellectuels antifascistes'', an anti-fascist organization created after the 6 February 1934 far right riots. Being a public opponent of fascism in the 1930s resulted in his arrest and being held under house arrest by the Vichy government for most of World War II. Langevin was also president of the Human Rights League (LDH) from 1944 to 1946, having recently joined the French Communist Party. He was a doctoral student of Pierre Curie and later a lover of widowed Marie Curie. He is also known for his two US patents with Constantin Chilowsky in 1916 and 1917 involving ultrasonic submarine detection. He is entombed at the Panthéon. Life Langevin was born in Paris, and studied at the '' École de Physique et Chimie'' and the ''École Normale Supérieure''. He then went to the Univ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvay Conference
The Solvay Conferences () have been devoted to preeminent unsolved problems in both physics and chemistry. They began with the historic invitation-only 1911 Solvay Conference on Physics, considered a turning point in the world of physics, and are ongoing. Since the success of 1911, they have been organised by the International Solvay Institutes for Physics and Chemistry, founded by the Belgian industrialist Ernest Solvay in 1912 and 1913, and located in Brussels. The institutes coordinate conferences, workshops, seminars, and colloquia. Recent Solvay Conferences entail a three year cycle: the Solvay Conference on Physics followed by a gap year, followed by the Solvay Conference on Chemistry. The 1st Solvay Conference on Biology titled "The organisation and dynamics of biological computation" took place in April 2024. Notable conferences First conference Hendrik Lorentz was chairman of the first Solvay Conference on Physics, held in Brussels from 30 October to 3 November ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Historical Studies In The Physical Sciences
''Historical Studies in the Natural Sciences'' is a peer-reviewed academic journal published by the University of California Press on behalf of the Office for History of Science and Technology (University of California, Berkeley). It was established as '' Chymia'' in 1948, being published under than name until 1967 when it temporarily ceased publication. It resumed under ''Historical Studies in the Physical Sciences'' in 1969, renaming itself ''Historical Studies in the Physical and Biological Sciences'' in 1986 under John L. Heilbron, an acquiring its current name in 2008. It covers the study of the intellectual and social history of the physical sciences (including physics, chemistry, and astronomy) and the biological sciences (including biology, biophysics, and genetics), from the 17th century to the modern era. Russell McCormmach, who edited the first ten annual volumes of ''Historical Studies in the Physical Sciences''. John L. Heilbron took over as editor in 1980 and in 198 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Gans
__NOTOC__ Richard Martin Gans (7 March 1880 – 27 June 1954), German of Jewish origin, born in Hamburg, was the physicist who founded the Physics Institute of the National University of La Plata, Argentina. He was its Director in two different periods. During the first one, starting in 1911, he continued the work started by Emil Bose raising the research level of the institute to international renown. In 1914 he founded the publication of a scientific journal: ''Contribución al estudio de las ciencias fisicomatemáticas,'' with two series: ''matematicofÃsica'' and ''técnica.'' His second period in La Plata was from the late 1940s through the early 1950s, when he played an important role as member of one of the commissions which reviewed Ronald Richter's claims related to the Huemul Project. After leaving La Plata in 1951 he taught theoretical and advanced physics at the University of Buenos Aires. Gans theory is named after Richard Gans. This theory gives the solution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena such as oscillations, waves, or for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Energy
In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Robert and Halliday, David (1960) ''Physics'', Section 7-5, Wiley International Edition The kinetic energy of an object is equal to the work, or force ( F) in the direction of motion times its displacement ( s), needed to accelerate the object from rest to its given speed. The same amount of work is done by the object when decelerating from its current speed to a state of rest. The SI unit of energy is the joule, while the English unit of energy is the foot-pound. In relativistic mechanics, \fracmv^2 is a good approximation of kinetic energy only when ''v'' is much less than the speed of light. History and etymology The adjective ''kinetic'' has its roots in the Greek word κίνησις ''kinesis'', meaning "motion". The dichoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
