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Yuri Yappa
, image = Yappa78.jpg , image_size = 200px , caption = Yuri Yappa (photo of 1978) , birth_date = , birth_place = Leningrad, Russian SFSR, Soviet Union , death_date = , death_place = Saint Petersburg, Russian Federation , field = física teórica , work_institutions = Saint Petersburg State University; JINR , alma_mater = Leningrad University , doctoral_advisor = , doctoral_students = , influences = Vladimir Fock , prizes = Medal "For the Defence of Leningrad" Yuri Andreevich Yappa (russian: Юрий Андреевич Яппа) (September 21, 1927 – August 19, 1998) was a Soviet and Russian theoretical physicist. He is known for publications on particle physics, quantum field theory, General Relativity, philosophy of science, and for his graduate texts on classical electrodynamics and theory of spinors. Biography Yuri Yappa was born in Leningrad, USSR in the family of doctor Andrei Yappa (german: Andreas Jappa, russian: Андрей Яппа). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leningrad
Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), is the second-largest city in Russia. It is situated on the Neva River, at the head of the Gulf of Finland on the Baltic Sea, with a population of roughly 5.4 million residents. Saint Petersburg is the fourth-most populous city in Europe after Istanbul, Moscow and London, the most populous city on the Baltic Sea, and the world's northernmost city of more than 1 million residents. As Russia's Imperial capital, and a historically strategic port, it is governed as a federal city. The city was founded by Tsar Peter the Great on 27 May 1703 on the site of a captured Swedish fortress, and was named after apostle Saint Peter. In Russia, Saint Petersburg is historically and culturally associated with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinor
In geometry and physics, spinors are elements of a complex vector space that can be associated with Euclidean space. Like geometric vectors and more general tensors, spinors transform linearly when the Euclidean space is subjected to a slight (infinitesimal) rotation. Unlike vectors and tensors, a spinor transforms to its negative when the space is continuously rotated through a complete turn from 0° to 360° (see picture). This property characterizes spinors: spinors can be viewed as the "square roots" of vectors (although this is inaccurate and may be misleading; they are better viewed as "square roots" of sections of vector bundles – in the case of the exterior algebra bundle of the cotangent bundle, they thus become "square roots" of differential forms). It is also possible to associate a substantially similar notion of spinor to Minkowski space, in which case the Lorentz transformations of special relativity play the role of rotations. Spinors were introduced in geome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton
A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ratio). Protons and neutrons, each with masses of approximately one atomic mass unit, are jointly referred to as "nucleons" (particles present in atomic nuclei). One or more protons are present in the nucleus of every atom. They provide the attractive electrostatic central force which binds the atomic electrons. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol ''Z''). Since each element has a unique number of protons, each element has its own unique atomic number, which determines the number of atomic electrons and consequently the chemical characteristics of the element. The word ''proton'' is Greek for "first", and this name was given to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elementary Particles
In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. Particles currently thought to be elementary include electrons, the fundamental fermions (quarks, leptons, antiquarks, and antileptons, which generally are matter particles and antimatter particles), as well as the fundamental bosons (gauge bosons and the Higgs boson), which generally are force particles that mediate interactions among fermions. A particle containing two or more elementary particles is a composite particle. Ordinary matter is composed of atoms, once presumed to be elementary particles – ''atomos'' meaning "unable to be cut" in Greek – although the atom's existence remained controversial until about 1905, as some leading physicists regarded molecules as mathematical illusions, and matter as ultimately composed of energy. Subatomic constituents of the atom were first identified in the early 1930s; the electron and the proton, alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moscow Region
Moscow Oblast ( rus, Моско́вская о́бласть, r=Moskovskaya oblast', p=mɐˈskofskəjə ˈobləsʲtʲ), or Podmoskovye ( rus, Подмоско́вье, p=pədmɐˈskovʲjə, literally "under Moscow"), is a federal subject of Russia (an oblast). With a population of 7,095,120 ( 2010 Census) living in an area of , it is one of the most densely populated regions in the country and is the second most populous federal subject. The oblast has no official administrative center; its public authorities are located in Moscow and Krasnogorsk (Moscow Oblast Duma and government), and also across other locations in the oblast.According to Article 24 of the Charter of Moscow Oblast, the government bodies of the oblast are located in the city of Moscow and throughout the territory of Moscow Oblast. However, Moscow is not named the official administrative center of the oblast. Located in European Russia between latitudes 54° and 57° N and longitudes 35° and 41° E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dubna
Dubna ( rus, Дубна́, p=dʊbˈna) is a town in Moscow Oblast, Russia. It has a status of ''naukograd'' (i.e. town of science), being home to the Joint Institute for Nuclear Research, an international nuclear physics research center and one of the largest scientific foundations in the country. It is also home to MKB Raduga, a defense aerospace company specializing in design and production of missile systems, as well as to the Russia's largest satellite communications center owned by Russian Satellite Communications Company. The modern town was developed in the middle of the 20th century and town status was granted to it in 1956. Population: Geography The town is above sea level, situated approximately north of Moscow, on the Volga River, just downstream from the Ivankovo Reservoir. The reservoir is formed by a hydroelectric dam across the Volga situated within the town borders. The town lies on both banks of the Volga. The western boundary of the town is defined by the M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soviet Academy Of Sciences
The Academy of Sciences of the Soviet Union was the highest scientific institution of the Soviet Union from 1925 to 1991, uniting the country's leading scientists, subordinated directly to the Council of Ministers of the Soviet Union (until 1946 – to the Council of People's Commissars of the Soviet Union). In 1991, by the decree of the President of the Russian Soviet Federative Socialist Republic, the Russian Academy of Sciences was established on the basis of the Academy of Sciences of the Soviet Union. History Creation of the Academy of Sciences of the Soviet Union The Academy of Sciences of the Soviet Union was formed by a resolution of the Central Executive Committee and the Council of People's Commissars of the Soviet Union dated July 27, 1925 on the basis of the Russian Academy of Sciences (before the February Revolution – the Imperial Saint Petersburg Academy of Sciences). In the first years of Soviet Russia, the Institute of the Academy of Sciences was perceived rath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Physics
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experimental tools to probe these phenomena. The advancement of science generally depends on the interplay between experimental studies and theory. In some cases, theoretical physics adheres to standards of mathematical rigour while giving little weight to experiments and observations.There is some debate as to whether or not theoretical physics uses mathematics to build intuition and illustrativeness to extract physical insight (especially when normal experience fails), rather than as a tool in formalizing theories. This links to the question of it using mathematics in a less formally rigorous, and more intuitive or heuristic way than, say, mathematical physics. For example, while developing special relativity, Albert Einstein was concerned wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Physics
Molecular physics is the study of the physical properties of molecules and molecular dynamics. The field overlaps significantly with physical chemistry, chemical physics, and quantum chemistry. It is often considered as a sub-field of atomic, molecular, and optical physics. Research groups studying molecular physics are typically designated as one of these other fields. Molecular physics addresses phenomena due to both molecular structure and individual atomic processes within molecules. Like atomic physics, it relies on a combination of classical and quantum mechanics to describe interactions between electromagnetic radiation and matter. Experiments in the field often rely heavily on techniques borrowed from atomic physics, such as spectroscopy and scattering. Molecular Structure In a molecule, both the electrons and nuclei experience similar-scale forces from the Coulomb interaction. However, the nuclei remain at nearly fixed locations in the molecule while the electrons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medal "For The Defence Of Leningrad"
The Medal "For the Defence of Leningrad" (russian: Медаль «За оборону Ленинграда») was a World War II campaign medal of the Soviet Union established on December 22, 1942 by decree of the Presidium of the Supreme Soviet of the USSR to recognise the valour and hard work of the Soviet Union, Soviet civilian and military defenders of Leningrad during the 872-day Siege of Leningrad, siege of the city by the German armed forces between September 8, 1941 and January 27, 1944. The medal's statute was later amended by Resolution of the Presidium of the Supreme Soviet on March 8, 1945. and again one last time on July 18, 1980 by decree of the Presidium of the Supreme Soviet of the USSR № 2523-X. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siege Of Leningrad
The siege of Leningrad (russian: links=no, translit=Blokada Leningrada, Блокада Ленинграда; german: links=no, Leningrader Blockade; ) was a prolonged military blockade undertaken by the Axis powers against the Soviet city of Leningrad (present-day Saint Petersburg) on the Eastern Front of World War II. Germany's Army Group North advanced from the south, while the German-allied Finnish army invaded from the north and completed the ring around the city. The siege began on 8 September 1941, when the Wehrmacht severed the last road to the city. Although Soviet forces managed to open a narrow land corridor to the city on 18 January 1943, the Red Army did not lift the siege until 27 January 1944, 872 days after it began. The blockade became one of the longest and most destructive sieges in history, and it was possibly the costliest siege in history due to the number of casualties which were suffered throughout its duration. While not classed as a war crime at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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