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Postulates Of Special Relativity
Albert Einstein derived the theory of special relativity in 1905, from principles now called the postulates of special relativity. Einstein's formulation is said to only require two postulates, though his derivation implies a few more assumptions. The idea that special relativity depended only on two postulates, both of which seemed to follow from the theory and experiment of the day, was one of the most compelling arguments for the correctness of the theory (Einstein 1912: "''This theory is correct to the extent to which the two principles upon which it is based are correct. Since these seem to be correct to a great extent, ...''") Postulates of special relativity 1. First postulate (principle of relativity) : The laws of physics take the same form in all inertial frames of reference. 2. Second postulate (invariance of '' c'') : As measured in any inertial frame of reference, light is always propagated in empty space with a definite velocity ''c'' that is independent of t ... [...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] |
Luminiferous Aether
Luminiferous aether or ether (''luminiferous'' meaning 'light-bearing') was the postulated Transmission medium, medium for the propagation of light. It was invoked to explain the ability of the apparently wave-based light to propagate through empty space (a vacuum), something that waves should not be able to do. The assumption of a spatial plenum (space completely filled with matter) of luminiferous aether, rather than a spatial vacuum, provided the theoretical medium that was required by wave theories of light. The aether hypothesis was the topic of considerable debate throughout its history, as it required the existence of an invisible and infinite material with no interaction with physical objects. As the nature of light was explored, especially in the 19th century, the physical qualities required of an aether became increasingly contradictory. By the late 19th century, the existence of the aether was being questioned, although there was no physical theory to replace it. The ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Rothe
Hermann Rothe (28 December 1882 in Vienna – 18 December 1923 in Vienna) was an Austrian mathematician. Rothe studied at the University of Vienna and the University of Göttingen. He attained the Doctorate in Engineering in 1909 in Vienna. Then he was assistant at the Vienna University of Technology, where he attained the Habilitation in 1910. In 1913 Rothe married and began to teach mathematics at the Vienna University of Technology as Professor extraordinarius, and from 1920 as Professor ordinarius. In 1923 he died after a long disease. Rothe is known for his collaboration (1910–1912) with Philipp Frank on special relativity. Based on group theory, they tried to derive the Lorentz transformation without the postulate of the constancy of the speed of light. In English: Furthermore, Rothe worked — outside his teaching activity — on mathematical problems like Hermann Grassmann's "Ausdehnungslehre" (theory of extension, or exterior algebra). Publications * * See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philipp Frank
Philipp Frank (; March 20, 1884 – July 21, 1966) was an Austrian-American physicist, mathematician and philosopher of the early-to-mid 20th century. He was a logical positivism, logical positivist, and a member of the Vienna Circle. He was influenced by Ernst Mach, Mach and was one of the Machists criticised by Lenin in ''Materialism and Empirio-criticism''. Biography He studied physics at the University of Vienna and graduated in 1907 with a thesis in theoretical physics under the supervision of Ludwig Boltzmann. He joined the faculty there in 1910. Albert Einstein recommended him as his successor for a professorship at the Karl-Ferdinands-Universität, German Charles-Ferdinand University of Prague, a position which he held from 1912 until 1938. Doctoral students included Reinhold Furth and Peter Bergmann. In 1938, he was invited by Harvard University to America as a visiting lecturer on quantum theory and the philosophy of modern physics. The Germans having invaded Czechoslov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vladimir Ignatowski
Vladimir Sergeyevitch Ignatowski, or Waldemar Sergius von Ignatowsky and similar names in other publications (* March 8/20, 1875 in Tbilisi, Georgia; † January 30, 1942 in Leningrad), was a Russian physicist. Life and work Ignatowski graduated in 1906 in Saint Petersburg. 1906-1908 he continued to study at the University of Giessen, with his dissertation in 1909. 1911-1914 he taught at the Higher Technical School in Berlin. Afterwards he worked for different institutions in the Soviet Union. Then he became a corresponding member of the Soviet Academy of Sciences. Aleksandr Solzhenitsyn reported in his book The Gulag Archipelago, that Ignatowski was put under arrest by Soviet officials, who raised absurd allegations against him. It was claimed that Ignatowski was recruited by the German secret service in 1909, not to spy in the next war (World War I), but to spy in the "''war after the next war''" (World War II). So Ignatowski was executed in 1942 in Leningrad.Solschenizyn, 1973 ... [...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 Francis FitzGerald, 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 ether theory#Length contraction, Lorentz–FitzGerald ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michelson–Morley Experiment
The Michelson–Morley experiment was an attempt to measure the motion of the Earth relative to the luminiferous aether, a supposed medium permeating space that was thought to be the carrier of light waves. The experiment was performed between April and July 1887 by American physicists Albert A. Michelson and Edward W. Morley at what is now Case Western Reserve University in Cleveland, Ohio, and published in November of the same year. The experiment compared the speed of light in perpendicular directions in an attempt to detect the relative motion of matter, including their laboratory, through the luminiferous aether, or "aether wind" as it was sometimes called. The result was negative, in that Michelson and Morley found no significant difference between the speed of light in the direction of movement through the presumed aether, and the speed at right angles. This result is generally considered to be the first strong evidence against some aether theories, as well as initiating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Francis FitzGerald
George Francis FitzGerald (3 August 1851 – 21 February 1901) was an Irish physicist known for hypothesising length contraction, which became an integral part of Albert Einstein's special theory of relativity. Life and work in physics FitzGerald was born at No. 19, Lower Mount Street in Dublin on 3 August 1851 to the Reverend William FitzGerald and his wife Anne Frances Stoney (sister of George Johnstone Stoney and Bindon Blood Stoney). Professor of Moral Philosophy in Trinity and vicar of St Anne's, Dawson Street, at the time of his son's birth, William FitzGerald was consecrated Bishop of Cork, Cloyne and Ross in 1857 and translated to Killaloe and Clonfert in 1862. George returned to Dublin and entered Trinity College Dublin as a student at the age of 16, winning a scholarship in 1870 and graduating in 1871 in Mathematics and Experimental Science. He became a Fellow of Trinity in 1877 and spent the rest of his career there, becoming Erasmus Smith's Professor of Natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
