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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 1890/1891, Kaufmann studied mechanical engineering at the Technische Hochschulen in Chalottenburg 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 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 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elberfeld
Elberfeld is a municipal subdivision of the Germany, German city of Wuppertal; it was an independent town until 1929. History The first official mentioning of the geographic area on the banks of today's Wupper River as "''elverfelde''" was in a document of 1161. Etymologically, ''elver'' is derived from the old Low German word for "river." (See etymology of the name of the German Elbe#Etymology, Elbe River; cf. North Germanic languages, North Germanic ''älv''.) Therefore, the original meaning of "elverfelde" can be understood as "field on the river." Elverfelde received its town charter in 1610. In 1726, Elias Eller and a pastor, Daniel Schleyermacher, founded a Philadelphian Society. They later moved to Ronsdorf in the Duchy of Berg, becoming the Zionites (Germany), Zionites, a fringe sect. In 1826 Friedrich Harkort, a famous German industrialist and politician, had a type of suspension railway built as a trial and ran it on the grounds of what is today the tax office at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Professor
Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other tertiary education, post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a 'person who professes'. Professors are usually experts in their field and teachers of the highest rank. In most systems of List of academic ranks, academic ranks, "professor" as an unqualified title refers only to the most senior academic position, sometimes informally known as "full professor". In some countries and institutions, the word ''professor'' is also used in titles of lower ranks such as associate professor and assistant professor; this is particularly the case in the United States, where the unqualified word is also used colloquially to refer to associate and assistant professors as well, and often to instructors or lecturers. Professors often conduct original research and commonly teach undergraduate, Postgraduate educa ... [...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 Technische Hochschulen in Charlottenburg (now Technische Universität Berlin) and in Munich (now 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. Be ... [...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 physics, theoretical physicist whose discovery of energy quantum, 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 mechanics, quantum theory and one of the founders of modern physics, which revolutionized understanding of atomic and Subatomic particle, subatomic processes. He is known for the Planck constant, which is of foundational importance for quantum physics, and which he used to derive a set of Unit of measurement, units, today called Planck units, expressed only in terms of fundamental physical constants. Planck was twice president of the German scientific institution Kaiser Wilhelm Society. In 1948, it was renamed the Max Planck Society (Max-Planck-Gesellschaft) and nowadays includes 83 institutions representing a wide range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle Of Relativity
In physics, the principle of relativity is the requirement that the equations describing the laws of physics have the same form in all admissible frames of reference. For example, in the framework of special relativity, the Maxwell equations have the same form in all inertial frames of reference. In the framework of general relativity, the Maxwell equations or the Einstein field equations have the same form in arbitrary frames of reference. Several principles of relativity have been successfully applied throughout science, whether implicitly (as in Newtonian mechanics) or explicitly (as in Albert Einstein's special relativity and general relativity). Basic concepts Certain principles of relativity have been widely assumed in most scientific disciplines. One of the most widespread is the belief that any law of nature should be the same at all times; and scientific investigations generally assume that laws of nature are the same regardless of the person measuring them. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observational Equivalence
Observational equivalence is the property of two or more underlying entities being indistinguishable on the basis of their observable implications. Thus, for example, two scientific theories are observationally equivalent if all of their empirically testable predictions are identical, in which case empirical evidence cannot be used to distinguish which is closer to being correct; indeed, it may be that they are actually two different perspectives on one underlying theory. In econometrics, two parameter values (or two ''structures,'' from among a class of statistical models) are considered observationally equivalent if they both result in the same probability distribution of observable data. This term often arises in relation to the identification problem. In macroeconomics, it happens when you have multiple structural models, with different interpretation, but indistinguishable empirically. "the mapping between structural parameters and the objective function may not display a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Einstein
Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence formula , which arises from special relativity, has been called "the world's most famous equation". He received the 1921 Nobel Prize in Physics for . Born in the German Empire, Einstein moved to Switzerland in 1895, forsaking his German citizenship (as a subject of the Kingdom of Württemberg) the following year. In 1897, at the age of seventeen, he enrolled in the mathematics and physics teaching diploma program at the Swiss ETH Zurich, federal polytechnic school in Zurich, graduating in 1900. He acquired Swiss citizenship a year later, which he kept for the rest of his life, and afterwards secured a permanent position at the Swiss Patent Office in Bern. In 1905, he submitted a successful PhD dissertation to the University of Zurich. In 19 ... [...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 wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorentz Ether Theory
What is now often called Lorentz ether theory (LET) has its roots in Hendrik Lorentz's "theory of electrons", which marked the end of the development of the classical aether theories at the end of the 19th and at the beginning of the 20th century. Lorentz's initial theory was created between 1892 and 1895 and was based on removing assumptions about aether motion. It explained the failure of the negative aether drift experiments to first order in ''v''/''c'' by introducing an auxiliary variable called "local time" for connecting systems at rest and in motion in the aether. In addition, the negative result of the Michelson–Morley experiment led to the introduction of the hypothesis of length contraction in 1892. However, other experiments also produced negative results and (guided by Henri Poincaré's principle of relativity) Lorentz tried in 1899 and 1904 to expand his theory to all orders in ''v''/''c'' by introducing the Lorentz transformation. In addition, he assumed that non-el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass In Special Relativity
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 Observer (special relativity), 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 of 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) o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Mass
Electromagnetic mass was initially a concept of classical mechanics, denoting as to how much the electromagnetic field, or the self-energy, is contributing to the mass of charged particles. It was first derived by J. J. Thomson in 1881 and was for some time also considered as a dynamical explanation of inertial mass ''per se''. Today, the relation of mass, momentum, velocity, and all forms of energy – including electromagnetic energy – is analyzed on the basis of Albert Einstein's special relativity and mass–energy equivalence. As to the cause of mass of elementary particles, the Higgs mechanism in the framework of the relativistic Standard Model is currently used. However, some problems concerning the electromagnetic mass and self-energy of charged particles are still studied. Charged particles Rest mass and energy It was recognized by J. J. Thomson in 1881 that a charged sphere moving in a space filled with a medium of a specific inductive capacity (the electromagne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Freiburg
The University of Freiburg (colloquially ), officially the Albert Ludwig University of Freiburg (), is a public university, public research university located in Freiburg im Breisgau, Baden-Württemberg, Germany. The university was founded in 1457 by the House of Habsburg, Habsburg dynasty as the second university in Austrian-Habsburg territory after the University of Vienna. Today, Freiburg is the List of universities in Germany#Universities by date of establishment, fifth-oldest university in Germany, with a long tradition of teaching the humanities, social sciences and natural sciences and technology and enjoys a high academic reputation both nationally and internationally. The university is made up of 11 faculty (division), faculties and attracts students from across Germany as well as from over 120 other countries. Foreign students constitute about 18.2% of total student numbers. The University of Freiburg has been associated with figures such as Hannah Arendt, Rudolf Carna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
