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Alfred Bucherer
Alfred Heinrich Bucherer (* 9 July 1863 in Cologne; † 16 April 1927 in Bonn) was a German physicist, who is known for his experiments on relativistic mass. He also was the first who used the phrase "theory of relativity" for Einstein's theory of special relativity. Education He studied from 1884 until 1899 at the University of Hannover, the Johns Hopkins University, the University of Strassburg, the University of Leipzig, and the University of Bonn. In Bonn he habilitated in 1899 and taught there until 1923. In 1903 Bucherer published the first German-language book to be completely based on vector calculus. Theory of relativity Like Henri Poincaré (1895, 1900), Bucherer (1903b) believed in the validity of the Principle of relativity, i.e. that all descriptions of electrodynamic effects should only contain the relative motion of bodies, not of the aether. However, he went a step further and even assumed the physical non-existence of the aether. Based on those ideas he develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Bucherer
Alfred Heinrich Bucherer (* 9 July 1863 in Cologne; † 16 April 1927 in Bonn) was a German physicist, who is known for his experiments on relativistic mass. He also was the first who used the phrase "theory of relativity" for Einstein's theory of special relativity. Education He studied from 1884 until 1899 at the University of Hannover, the Johns Hopkins University, the University of Strassburg, the University of Leipzig, and the University of Bonn. In Bonn he habilitated in 1899 and taught there until 1923. In 1903 Bucherer published the first German-language book to be completely based on vector calculus. Theory of relativity Like Henri Poincaré (1895, 1900), Bucherer (1903b) believed in the validity of the Principle of relativity, i.e. that all descriptions of electrodynamic effects should only contain the relative motion of bodies, not of the aether. However, he went a step further and even assumed the physical non-existence of the aether. Based on those ideas he develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walther Ritz
Walther Heinrich Wilhelm Ritz (22 February 1878 – 7 July 1909) was a Swiss theoretical physicist. He is most famous for his work with Johannes Rydberg on the Rydberg–Ritz combination principle. Ritz is also known for the variational method named after him, the Ritz method. Life Walter Ritz's father Raphael Ritz was born in Valais and was a well-known painter. His mother, born Nördlinger, was the daughter of an engineer from Tübingen. Ritz was a particularly gifted student and attended the municipal lyceum in Sion. In 1897, he entered the polytechnic school in Zurich, where he studied engineering. Soon, he found out that he could not live with the approximations and compromises associated with engineering, and so he switched to the more mathematically accurate physical sciences. In 1900, Ritz contracted tuberculosis, possibly also pleurisy, which he later died from. In 1901 he moved to Göttingen for health reasons. There he was influenced by Woldemar Voigt and David Hil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the ' is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of second order partial differential equations. Newton's law of universal gravitation, which describes classical gravity, can be seen as a prediction of general relativity for the almost flat spacetime geometry around stationary mass distributions. Some predictions of general relativity, however, are beyond Newton's law of universal gravitat ... [...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 Plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tests Of Relativistic Energy And Momentum
Tests of relativistic energy and momentum are aimed at measuring the relativistic expressions for energy, momentum, and mass. According to special relativity, the properties of particles moving approximately at the speed of light significantly deviate from the predictions of Newtonian mechanics. For instance, the speed of light cannot be reached by massive particles. Today, those relativistic expressions for particles close to the speed of light are routinely confirmed in undergraduate laboratories, and necessary in the design and theoretical evaluation of collision experiments in particle accelerators. See also Tests of special relativity for a general overview. Overview In classical mechanics, kinetic energy and momentum are expressed as :E_=\tfracmv^ ,\quad p=mv . \, On the other hand, special relativity predicts that the speed of light is constant in all inertial frames of references. The relativistic energy–momentum relation reads: :E^-(pc)^=(mc^)^ \,, from which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaufmann–Bucherer–Neumann Experiments
The Kaufmann–Bucherer–Neumann experiments measured the dependence of the inertial mass (or momentum) of an object on its velocity. The historical importance of this series of experiments performed by various physicists between 1901 and 1915 is due to the results being used to test the predictions of special relativity. The developing precision and data analysis of these experiments and the resulting influence on theoretical physics during those years is still a topic of active historical discussion, since the early experimental results at first contradicted Einstein's then newly published theory (1905), but later versions of this experiment confirmed it. For modern experiments of that kind, see Tests of relativistic energy and momentum, for general information see Tests of special relativity. Historical context In 1896, Henri Becquerel discovered radioactive decay in a variety of chemical elements. Subsequently, the beta radiation from these decays was discovered to be the emiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adolf Bestelmeyer
Adolf (Christoph Wilhelm) Bestelmeyer (21 December 1875 – 21 November 1957) was a German experimental physicist. Life and work Bestelmeyer studied mathematics and physics at the Technical University of Berlin, the Technical University of Munich and the University of Munich. After his promotion, he worked in 1904 as an assistant at the University of Göttingen. In World War I he was active in torpedo research, and afterwards he was professor of physics at the University of Greifswald from 1917 to 1921. He then served until the end of World War II as a laboratory manager in various companies (like Askania), especially in the area of torpedo construction. Meyer, Helmut: ''Geschichte der Kaiser-Wilhelm-Gesellschaft im Nationalsozialismus''. 16, Wallstein, pp. 122-123, 2007, In 1907, Bestelmeyer questioned the accuracy of the measurements by Walter Kaufmann regarding the speed dependence of the electromagnetic mass. Bestelmeyer used a velocity filter for his own experiments on cath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Kaufmann (physicist)
Walter Kaufmann (June 5, 1871 – January 1, 1947) was a German physicist. He is best known for the first experimental proof of the velocity dependence of mass, which was an important contribution to the development of modern physics, including special relativity. Life Of Jewish descent, in 1890/91 Kaufmann studied mechanical engineering at the technical universities of Berlin and Munich. From 1892 he studied physics at the Universities of Berlin and Munich, attaining a doctorate in 1894. From 1896 he was an assistant at the physical institutes of the Universities of Berlin and Göttingen. Kaufmann habilitated in 1899 and became a professor extraordinarius of physics in at the University of Bonn. After further work at the Berliner Physikalisches Institut he became professor ordinarius for experimental physics and leader of the physical institute at the Albertina in Königsberg, where he taught until he retired in 1935. Later, he was guest lecturer at the University of Freiburg. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Of Light
The speed of light in vacuum, commonly denoted , is a universal physical constant that is important in many areas of physics. The speed of light is exactly equal to ). According to the special theory of relativity, is the upper limit for the speed at which conventional matter or energy (and thus any signal carrying information) can travel through 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 very sensitive measurements, their finite speed has noticeable effects. Starlight viewed on Earth left the stars many years ago, allowing humans to study the history of the universe by viewing distant objects. When communicating with distant space probes, it can take minutes to hours for signals to travel from Earth to the spacecraft and vice versa. In computing, the speed of light fixes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Abraham
Max Abraham (; 26 March 1875 – 16 November 1922) was a German physicist known for his work on electromagnetism and his opposition to the theory of relativity. Biography Abraham was born in Danzig, Imperial Germany (now Gdańsk in Poland) to a family of Jewish merchants. His father was Moritz Abraham and his mother was Selma Moritzsohn. Attending the University of Berlin, he studied under Max Planck. He graduated in 1897. For the next three years, Abraham worked as Planck's assistant. From 1900 to 1909, Abraham worked at Göttingen as a privatdozent, an unpaid lecturing position. Abraham developed his theory of the electron in 1902, in which he hypothesized that the electron was a perfect sphere with a charge divided evenly around its surface. Abraham's model was competing with that developed by Hendrik Lorentz (1899, 1904) and Albert Einstein (1905) which seem to have become more widely accepted; nevertheless, Abraham never gave up his model, since he considered it was bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Length Contraction
Length contraction is the phenomenon that a moving object's length is measured to be shorter than its proper length, which is the length as measured in the object's own rest frame. It is also known as Lorentz contraction or Lorentz–FitzGerald contraction (after Hendrik Lorentz and George Francis FitzGerald) and is usually only noticeable at a substantial fraction of the speed of light. Length contraction is only in the direction in which the body is travelling. For standard objects, this effect is negligible at everyday speeds, and can be ignored for all regular purposes, only becoming significant as the object approaches the speed of light relative to the observer. History Length contraction was postulated by George FitzGerald (1889) and Hendrik Antoon Lorentz (1892) to explain the negative outcome of the Michelson–Morley experiment and to rescue the hypothesis of the stationary aether ( Lorentz–FitzGerald contraction hypothesis). Although both FitzGerald and Lorentz a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hendrik Lorentz
Hendrik Antoon Lorentz (; 18 July 1853 – 4 February 1928) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. He also derived the Lorentz transformation underpinning Albert Einstein's special theory of relativity, as well as the Lorentz force, which describes the combined electric and magnetic forces acting on a charged particle in an electromagnetic field. Lorentz was also responsible for the Lorentz oscillator model, a classical model used to describe the anomalous dispersion observed in dielectric materials when the driving frequency of the electric field was near the resonant frequency, resulting in abnormal refractive indices. According to the biography published by the Nobel Foundation, "It may well be said that Lorentz was regarded by all theoretical physicists as the world's leading spirit, who completed what was left unfinished by his predecessors and prepared t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
