Albert Einstein
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- Bu səhifədəki naviqasiya:
- Einstein–Podolsky–Rosen paradox
- Political views
- Theory of relativity
- [ edit ] Two theory view
- [ edit ] Special relativity
- [ edit ] General relativity
Bohr versus Einstein See also: Bohr–Einstein debates 
Einstein and Niels Bohr In the 1920s, quantum mechanics developed into a more complete theory. Einstein was unhappy with the Copenhagen interpretation of quantum theory developed by Niels Bohr and Werner Heisenberg, both in its outcomes and its instrumentalist methodology, Einstein being a scientific realist. In this interpretation, quantum phenomena are inherently probabilistic, with definite states resulting only upon interaction with classical systems. A public debate between Einstein and Bohr followed, lasting on and off for many years (including during the Solvay Conferences). Einstein formulated thought experiments against the Copenhagen interpretation, which were all rebutted by Bohr. In a 1926 letter to Max Born, Einstein wrote: "I, at any rate, am convinced that He [God] does not throw dice." [95] Einstein was never satisfied by what he perceived to be quantum theory's intrinsically incomplete description of nature, and in 1935 he further explored the issue in collaboration with Boris Podolsky and Nathan Rosen, noting that the theory seems to require non-local interactions; this is known as the EPR paradox.[96] The EPR experiment has since been performed, with results confirming quantum theory's predictions.[97] Repercussions of the Einstein–Bohr debate have found their way into philosophical discourse. Einstein–Podolsky–Rosen paradox Main article: EPR paradox In 1935, Einstein returned to the question of quantum mechanics. He considered how a measurement on one of two entangled particles would affect the other. He noted, along with his collaborators, that by performing different measurements on the distant particle, either of position or momentum, different properties of the entangled partner could be discovered without disturbing it in any way. He then used a hypothesis of local realism to conclude that the other particle had these properties already determined. The principle he proposed is that if it is possible to determine what the answer to a position or momentum measurement would be, without in any way disturbing the particle, then the particle actually has values of position or momentum. This principle distilled the essence of Einstein's objection to quantum mechanics. As a physical principle, it has since been shown to be incompatible with experiments.
Main article: Albert Einstein's political views 
Albert Einstein, seen here with his wife Elsa Einstein and Zionist leaders, including future President of Israel Chaim Weizmann, his wife Dr. Vera Weizmann, Menahem Ussishkin, and Ben-Zion Mossinson on arrival in New York City in 1921. Einstein flouted the ascendant Nazi movement and later tried to be a voice of moderation in the tumultuous formation of the State of Israel.[98] Fred Jerome in his Einstein on Israel and Zionism: His Provocative Ideas About the Middle East argues that Einstein was a Cultural Zionist who supported the idea of a Jewish homeland but opposed the establishment of a Jewish state in Palestine “with borders, an army, and a measure of temporal power.” Instead, he preferred a bi-national state with “continuously functioning, mixed, administrative, economic, and social organizations.”[99][100].However Ami Isseroff in his article Was Einstein a Zionist, argues that Einstein supported the recognition of the State of Israel and declared it "the fulfillment of our dream" when President Harry Truman recognize Israel in May 1948 and in presidential election 1948 Einstein supported Henry A. Wallace’s Progressive Party which advocate pro-Soviet and pro-Israel foreign policy.[101][102]. Throughout the November Revolution in Germany Einstein signed an appeal for the foundation of a nationwide liberal and democratic party,[103][104] which was published in the Berliner Tageblatt on 16 November 1918,[105] and became a member of the German Democratic Party.[106] In his article Why Socialism?,[107] published in 1949 in the Monthly Review, Einstein described a chaotic capitalist society, a source of evil to be overcome, as the "predatory phase of human development". He came to the following conclusion: I am convinced there is only one way to eliminate these grave evils [capitalism], namely through the establishment of a socialist economy, accompanied by an educational system which would be oriented toward social goals. In such an economy, the means of production are owned by society itself and are utilized in a planned fashion. A planned economy, which adjusts production to the needs of the community, would distribute the work to be done among all those able to work and would guarantee a livelihood to every man, woman, and child. The education of the individual, in addition to promoting his own innate abilities, would attempt to develop in him a sense of responsibility for his fellow men in place of the glorification of power and success in our present society.[107] He braved anti-communist politics and resistance to the civil rights movement in the United States. On the floor of the US Congress, Einstein was accused by John E. Rankin of Mississippi of being a "foreign-born agitator" who sought "to further the spread of Communism throughout the world".[108] He also participated in the 1927 congress of the League against Imperialism in Brussels.[109] After World War II, as enmity between the former allies became a serious issue, Einstein wrote, "I do not know how the third World War will be fought, but I can tell you what they will use in the Fourth – rocks!"[110] (Einstein 1949) With Albert Schweitzer and Bertrand Russell, Einstein lobbied to stop nuclear testing and future bombs. Days before his death, Einstein signed the Russell–Einstein Manifesto, which led to the Pugwash Conferences on Science and World Affairs.[111] Einstein was a member of several civil rights groups, including the Princeton chapter of the NAACP. When the aged W. E. B. Du Bois was accused of being a Communist spy, Einstein volunteered as a character witness, and the case was dismissed shortly afterward. Einstein's friendship with activist Paul Robeson, with whom he served as co-chair of the American Crusade to End Lynching, lasted twenty years.[112] Einstein said "Politics is for the moment, equation for the eternity."[113] He declined the presidency of Israel in 1952.[114] Theory of relativity From Wikipedia, the free encyclopedia Jump to: navigation, search This article is about the scientific concept. For philosophical or sociological theories about relativity, see Relativism. For the silent film, see The Einstein Theory of Relativity. 
Two-dimensional projection of a three-dimensional analogy of space-time curvature described in General Relativity. The theory of relativity, or simply relativity, encompasses two theories of Albert Einstein: special relativity and general relativity.[1] However, the word "relativity" is sometimes used in reference to Galilean invariance. The term "theory of relativity" was based on the expression "relative theory" (German: Relativtheorie) used by Max Planck in 1906, who emphasized how the theory uses the principle of relativity. In the discussion section of the same paper Alfred Bucherer used for the first time the expression "theory of relativity" (German: Relativitätstheorie).[2][3]
The theory of relativity enriched physics and astronomy during the 20th century. When first published, relativity superseded a 200-year-old theory of mechanics elucidated by Isaac Newton. It changed perceptions.[4][5][6] For example, it overturned the concept of motion from Newton's day, into all motion is relative. Time was no longer uniform and absolute, as related to everyday experience. Furthermore, no longer could physics be understood as space by itself, and time by itself. Instead, an added dimension had to be taken into account with curved space-time. Time now depended on velocity, and contraction became a fundamental consequence at appropriate speeds.[4][5][6] In the field of microscopic physics, relativity catalyzed and added an essential depth of knowledge to the science of elementary particles and their fundamental interactions, along with introducing the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves.[4][5][6] [edit] Two theory view The theory of relativity was representative of more than a single new physical theory. It affected the theories and methodologies across all the physical sciences. However, as stated above, this is more likely perceived as two separate theories. There are some related explanations for this. First, special relativity was published in 1905, and the final form of general relativity was published in 1916.[4] Second, special relativity fits with and solves for elementary particles and their interactions, whereas general relativity solves for the cosmological and astrophysical realm (including astronomy).[4] Third, special relativity was widely accepted in the physics community by 1920. This theory rapidly became a notable and necessary tool for theorists and experimentalists in the new fields of atomic physics, nuclear physics, and quantum mechanics. Conversely, general relativity did not appear to be as useful. There appeared to be little applicability for experimentalists as most applications were for astronomical scales. It seemed limited to only making minor corrections to predictions of Newtonian gravitation theory. Its impact was not apparent until the 1930s.[4] Finally, the mathematics of general relativity appeared to be incomprehensibly dense. Consequently, only a small number of people in the world, at that time, could fully understand the theory in detail. This remained the case for the next 40 years. Then, at around 1960 a critical resurgence in interest occurred which has resulted in making general relativity central to physics and astronomy. New mathematical techniques applicable to the study of general relativity substantially streamlined calculations. From this, physically discernible concepts were isolated from the mathematical complexity. Also, the discovery of exotic astronomical phenomena in which general relativity was crucially relevant, helped to catalyze this resurgence. The astronomical phenomena included quasars (1963), the 3-kelvin microwave background radiation (1965), pulsars (1967), and the discovery of the first black hole candidates (1971).[4]
Main article: Special relativity 
USSR stamp dedicated to Albert Einstein Special relativity is a theory of the structure of spacetime. It was introduced in Albert Einstein's 1905 paper "On the Electrodynamics of Moving Bodies" (for the contributions of many other physicists see History of special relativity). Special relativity is based on two postulates which are contradictory in classical mechanics:
The resultant theory agrees with experiment better than classical mechanics, e.g. in the Michelson-Morley experiment that supports postulate 2, but also has many surprising consequences. Some of these are:
The defining feature of special relativity is the replacement of the Galilean transformations of classical mechanics by the Lorentz transformations. (See Maxwell's equations of electromagnetism and introduction to special relativity). [edit] General relativity Main article: General relativity General relativity is a theory of gravitation developed by Einstein in the years 1907–1915. The development of general relativity began with the equivalence principle, under which the states of accelerated motion and being at rest in a gravitational field (for example when standing on the surface of the Earth) are physically identical. The upshot of this is that free fall is inertial motion; an object in free fall is falling because that is how objects move when there is no force being exerted on them, instead of this being due to the force of gravity as is the case in classical mechanics. This is incompatible with classical mechanics and special relativity because in those theories inertially moving objects cannot accelerate with respect to each other, but objects in free fall do so. To resolve this difficulty Einstein first proposed that spacetime is curved. In 1915, he devised the Einstein field equations which relate the curvature of spacetime with the mass, energy, and momentum within it. Some of the consequences of general relativity are:
Technically, general relativity is a metric theory of gravitation whose defining feature is its use of the Einstein field equations. The solutions of the field equations are metric tensors which define the topology of the spacetime and how objects move inertially.  Yüklə 279,66 Kb. Dostları ilə paylaş:
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