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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] |
Germans
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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 electromagnetic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1957 Deaths
1957 (Roman numerals, MCMLVII) was a Common year starting on Wednesday, common year starting on Tuesday of the Gregorian calendar, the 1957th year of the Common Era (CE) and ''Anno Domini'' (AD) designations, the 957th year of the 2nd millennium, the 57th year of the 20th century, and the 8th year of the 1950s decade. Events January * January 1 – The Saarland joins West Germany. * January 3 – Hamilton Watch Company introduces the first electric watch. * January 5 – South African player Russell Endean becomes the first batsman to be Dismissal (cricket), dismissed for having ''handled the ball'', in Test cricket. * January 9 – British Prime Minister Anthony Eden resigns. * January 10 – Harold Macmillan becomes Prime Minister of the United Kingdom. * January 11 – The African Convention is founded in Dakar. * January 14 – Kripalu Maharaj is named fifth Jagadguru (world teacher), after giving seven days of speeches before 500 Hindu scholars. * January 15 – The film ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1875 Births
Events January–March * January 1 – The Midland Railway of England abolishes the Second Class passenger category, leaving First Class and Third Class. Other British railway companies follow Midland's lead during the rest of the year (Third Class is renamed Second Class in 1956). * January 5 – The Palais Garnier, one of the most famous opera houses in the world, is inaugurated in Paris. * January 12 – Guangxu Emperor, Guangxu becomes the 11th Qing Dynasty Emperor of China at the age of 3, in succession to his cousin. * January 14 – The newly proclaimed King Alfonso XII of Spain (Queen Isabella II's son) arrives in Spain to restore the monarchy during the Third Carlist War. * February 3 – Third Carlist War – Battle of Lácar: Carlist commander Torcuato Mendiri, Torcuato Mendíri secures a brilliant victory, when he surprises and routs a Government force under General Enrique Bargés at Lácar, east of Estella, nearly capturing newly cr ... [...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] |
Iron Cross
The Iron Cross (german: link=no, Eisernes Kreuz, , abbreviated EK) was a military decoration in the Kingdom of Prussia, and later in the German Empire (1871–1918) and Nazi Germany (1933–1945). King Frederick William III of Prussia established it on 17 March 1813 during the Napoleonic Wars (EK 1813). The award was backdated to the birthday (10 March) of his late wife, Queen Louise. Louise was the first person to receive this decoration (posthumously). Recommissioned Iron Cross was also awarded during the Franco-Prussian War (EK 1870), World War I (EK 1914), and World War II (EK 1939). During the 1930s and World War II, the Nazi regime superimposed a swastika on the traditional medal. The Iron Cross was usually a military decoration only, though there were instances awarded to civilians for performing military functions, including Hanna Reitsch, who received the Iron Cross, 2nd class, and Iron Cross, 1st Class, and Melitta Schenk Gräfin von Stauffenberg, who received ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Special Relativity
In physics, the special theory of relativity, or special relativity for short, is a scientific theory regarding the relationship between space and time. In Albert Einstein's original treatment, the theory is based on two postulates: # The laws of physics are invariant (that is, identical) in all inertial frames of reference (that is, frames of reference with no acceleration). # The speed of light in vacuum is the same for all observers, regardless of the motion of the light source or the observer. Origins and significance Special relativity was originally proposed by Albert Einstein in a paper published on 26 September 1905 titled "On the Electrodynamics of Moving Bodies".Albert Einstein (1905)''Zur Elektrodynamik bewegter Körper'', ''Annalen der Physik'' 17: 891; English translatioOn the Electrodynamics of Moving Bodiesby George Barker Jeffery and Wilfrid Perrett (1923); Another English translation On the Electrodynamics of Moving Bodies by Megh Nad Saha (1920). The incompa ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode Ray
Cathode rays or electron beam (e-beam) are streams of electrons observed in discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to electrons emitted from the cathode (the electrode connected to the negative terminal of the voltage supply). They were first observed in 1859 by German physicist Julius Plücker and Johann Wilhelm Hittorf, and were named in 1876 by Eugen Goldstein ''Kathodenstrahlen'', or cathode rays. In 1897, British physicist J. J. Thomson showed that cathode rays were composed of a previously unknown negatively charged particle, which was later named the ''electron''. Cathode-ray tubes (CRTs) use a focused beam of electrons deflected by electric or magnetic fields to render an image on a screen. Description Cathode rays are so named because they are emitted by the negative electrode, or cathode, in a vacuum tube. To release electrons into the tube, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wien Filter
A Wien filter also known as velocity selector is a device consisting of perpendicular electric and magnetic fields that can be used as a velocity filter for charged particles, for example in electron microscopes and spectrometers. It is used in accelerator mass spectrometry to select particles based on their speed. The device is composed of orthogonal electric and magnetic fields, such that particles with the correct speed will be unaffected while other particles will be deflected. It is named for Wilhelm Wien who developed it in 1898 for the study of anode rays. It can be configured as a charged particle energy analyzer, monochromator, or mass spectrometer. Theory Any charged particle in an electric field will feel a force proportional to the charge and field strength such that \vec = q \vec, where ''F'' is force, ''q'' is charge, and ''E'' is electric field strength. Similarly, any particle moving in a magnetic field will feel a force proportional to the velocity and charge of ... [...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] |
