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Sommerfeld
Arnold Johannes Wilhelm Sommerfeld (; 5 December 1868 – 26 April 1951) was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and mentored many students for the new era of theoretical physics. He served as doctoral advisor and postdoc advisor to seven Nobel Prize winners and supervised at least 30 other famous physicists and chemists. Only J. J. Thomson's record of mentorship offers a comparable list of high-achieving students. He introduced the second quantum number, azimuthal quantum number, and the third quantum number, magnetic quantum number. He also introduced the fine-structure constant and pioneered X-ray wave theory. Early life and education Sommerfeld was born in 1868 to a family with deep ancestral roots in Prussia. His mother Cäcilie Matthias (1839–1902) was the daughter of a Potsdam builder. His father Franz Sommerfeld (1820–1906) was a physician from a leading family in Königsberg, where Arnold's g ...
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Fine-structure Constant
In physics, the fine-structure constant, also known as the Sommerfeld constant, commonly denoted by (the Alpha, Greek letter ''alpha''), is a Dimensionless physical constant, fundamental physical constant that quantifies the strength of the electromagnetic interaction between elementary charged particles. It is a dimensionless quantity (dimensionless physical constant), independent of the system of units used, which is related to the strength of the coupling of an elementary charge ''e'' with the electromagnetic field, by the formula . Its numerical value is approximately , with a relative uncertainty of The constant was named by Arnold Sommerfeld, who introduced it in 1916 Equation 12a, ''"rund 7·" (about ...)'' when extending the Bohr model of the atom. quantified the gap in the fine structure of the spectral lines of the hydrogen atom, which had been measured precisely by Albert A. Michelson, Michelson and Edward W. Morley, Morley in 1887. Why the constant should have t ...
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Free Electron Model
In solid-state physics, the free electron model is a quantum mechanical model for the behaviour of charge carriers in a metallic solid. It was developed in 1927, principally by Arnold Sommerfeld, who combined the classical Drude model with quantum mechanical Fermi–Dirac statistics and hence it is also known as the Drude–Sommerfeld model. Given its simplicity, it is surprisingly successful in explaining many experimental phenomena, especially * the Wiedemann–Franz law which relates electrical conductivity and thermal conductivity; * the temperature dependence of the electron heat capacity; * the shape of the electronic density of states; * the range of binding energy values; * electrical conductivities; * the Seebeck coefficient of the thermoelectric effect; * thermal electron emission and field electron emission from bulk metals. The free electron model solved many of the inconsistencies related to the Drude model and gave insight into several other properties of me ...
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Rudolf Seeliger
Rudolf Seeliger (12 November 1886 – 20 January 1965) was a German physicist who specialized in electric discharges in gases and plasma physics. From 1906 to 1909, Seeliger studied at the University of Tübingen and the University of Heidelberg. He then became a student of Arnold Sommerfeld at the University of Munich, where he got his doctorate in 1910. The topic of his thesis, the physics of electrical currents in gas, set the theme for his life’s field of research. He then went to conduct postgraduate research, on the same topic, at the Physikalisch-Technische Reichsanstalt (PTR) in Berlin. In 1915, he was also a Privatdozent at the University of Berlin. In 1918, he was called by Johannes Stark, Director of the Institute of Physics at the University of Greifswald, to be extraordinarius professor there. In 1921, Seeliger took the position of ordinarius professor for theoretical physics at the University. He became Director of the Institute of Physics in 1940, and was ...
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Ludwig Hopf
Ludwig Hopf (23 October 1884 in Nürnberg, Germany – 23 December 1939 in Dublin) was a German-Jewish theoretical physicist who made contributions to mathematics, special relativity, hydrodynamics, and aerodynamics. Early in his career he was the assistant to and a collaborator and co-author with Albert Einstein. Biography Hopf was born into a family of prominent hops merchants and municipal counselors in Nürnberg, Germany, the son of Elise (née Josephthal) and Hans Hopf. From 1902-1909 he studied math and physics at the Universities of Munich and Berlin. Hopf studied under Arnold Sommerfeld at the University of Munich, where he received his Ph.D. in 1909, on the topic of hydrodynamics. Shortly after this, Sommerfeld introduced Hopf to Albert Einstein at a physics conference in Salzburg. Later that year, Einstein, needing an assistant at the University of Zurich, hired Hopf; it was an added bonus that Hopf was a talented pianist, since Einstein played the violin and ...
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Peter Debye
Peter Joseph William Debye ( ; born Petrus Josephus Wilhelmus Debije, ; March 24, 1884 – November 2, 1966) was a Dutch-American physicist and physical chemist, and Nobel laureate in Chemistry. Biography Early life Born in Maastricht, Netherlands, Debye enrolled in the Aachen University of Technology in 1901. In 1905, he completed his first degree in electrical engineering. He published his first paper, a mathematically elegant solution of a problem involving eddy currents, in 1907. At Aachen, he studied under the theoretical physicist Arnold Sommerfeld, who later claimed that his most important discovery was Peter Debye. In 1906, Sommerfeld received an appointment at Munich, Bavaria, and took Debye with him as his assistant. Debye got his Ph.D. with a dissertation on radiation pressure in 1908. In 1910, he derived the Planck radiation formula using a method which Max Planck agreed was simpler than his own. In 1911, when Albert Einstein took an appointment as a profes ...
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Sommerfeld–Kossel Displacement Law
The Sommerfeld–Kossel displacement law states that the first spark (singly ionized) spectrum of an element is similar in all details to the arc (neutral) spectrum of the element preceding it in the periodic table. Likewise, the second (doubly ionized) spark spectrum of an element is similar in all details to the first (singly ionized) spark spectrum of the element preceding it, or to the arc (neutral) spectrum of the element with atomic number two less, and so forth.Herzberg, 1945, p. 81. Hence, the spectra of C I (neutral carbon), N II (singly ionized nitrogen), and O III (doubly ionized oxygen) atoms are similar, apart from shifts of the spectra to shorter wavelengths. C I, N II, and O III all have the same number of electrons, six, and the same ground-state electron configuration: :1s^2\, 2s^2\, 2p^2\, ^3P_0\,. The law was discovered by and named after Arnold Sommerfeld and Walther Kossel Walther Ludwig Julius Kossel (; 4 January 1888 – 22 May 1956) was a German chemist ...
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Azimuthal Quantum Number
In quantum mechanics, the azimuthal quantum number is a quantum number for an atomic orbital that determines its angular momentum operator, orbital angular momentum and describes aspects of the angular shape of the orbital. The azimuthal quantum number is the second of a set of quantum numbers that describe the unique quantum state of an electron (the others being the principal quantum number , the magnetic quantum number , and the spin quantum number ). For a given value of the principal quantum number (''electron shell''), the possible values of are the integers from 0 to . For instance, the  shell has only orbitals with \ell=0, and the  shell has only orbitals with \ell=0, and \ell=1. For a given value of the azimuthal quantum number , the possible values of the magnetic quantum number are the integers from to , including 0. In addition, the spin quantum number can take two distinct values. The set of orbitals associated with a particular value of  are som ...
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Oersted Medal
The Oersted Medal recognizes notable contributions to the teaching of physics. Established in 1936, it is awarded by the American Association of Physics Teachers. The award is named for Hans Christian Ørsted. It is the Association's most prestigious award. Hans Christian Ørsted Well-known recipients include Nobel laureates Robert Andrews Millikan, Edward M. Purcell, Richard Feynman, Isidor I. Rabi, Norman F. Ramsey, Hans Bethe, and Carl Wieman; as well as Arnold Sommerfeld, George Uhlenbeck, Jerrold Zacharias, Philip Morrison, Melba Phillips, Victor Weisskopf, Gerald Holton, John A. Wheeler, Frank Oppenheimer, Robert Resnick, Carl Sagan, Freeman Dyson, Daniel Kleppner, and Lawrence Krauss, and Anthony French, David Hestenes, Robert Karplus, Robert Pohl, and Francis Sears. The 2008 medalist, Mildred S. Dresselhaus, is the third woman to win the award in its 70-plus-year history. Medalists Source: * William Suddards Franklin – 1936 * Edwin Herbert ...
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Quantum Mechanics
Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is the foundation of all quantum physics, which includes quantum chemistry, quantum field theory, quantum technology, and quantum information science. Quantum mechanics can describe many systems that classical physics cannot. Classical physics can describe many aspects of nature at an ordinary (macroscopic and Microscopic scale, (optical) microscopic) scale, but is not sufficient for describing them at very small submicroscopic (atomic and subatomic) scales. Classical mechanics can be derived from quantum mechanics as an approximation that is valid at ordinary scales. Quantum systems have Bound state, bound states that are Quantization (physics), quantized to Discrete mathematics, discrete values of energy, momentum, angular momentum, and ot ...
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Felix Klein
Felix Christian Klein (; ; 25 April 1849 – 22 June 1925) was a German mathematician and Mathematics education, mathematics educator, known for his work in group theory, complex analysis, non-Euclidean geometry, and the associations between geometry and group theory. His 1872 Erlangen program classified geometries by their basic symmetry groups and was an influential synthesis of much of the mathematics of the time. During his tenure at the University of Göttingen, Klein was able to turn it into a center for mathematical and scientific research through the establishment of new lectures, professorships, and institutes. His Felix Klein Protocols, seminars covered most areas of mathematics then known as well as their applications. Klein also devoted considerable time to mathematical instruction and promoted mathematics education reform at all grade levels in Germany and abroad. He became the first president of the International Commission on Mathematical Instruction in 1908 ...
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Ferdinand Von Lindemann
Carl Louis Ferdinand von Lindemann (12 April 1852 – 6 March 1939) was a German mathematician, noted for his proof, published in 1882, that (pi) is a transcendental number, meaning it is not a root of any polynomial with rational coefficients. Life and education Lindemann was born in Hanover, the capital of the Kingdom of Hanover. His father, Ferdinand Lindemann, taught modern languages at a Gymnasium in Hanover. His mother, Emilie Crusius, was the daughter of the Gymnasium's headmaster. The family later moved to Schwerin, where young Ferdinand attended school. He studied mathematics at Göttingen, Erlangen, and Munich. At Erlangen he received a doctorate, supervised by Felix Klein, on non-Euclidean geometry. Lindemann subsequently taught in Würzburg and at the University of Freiburg. During his time in Freiburg, Lindemann devised his proof that is a transcendental number (see Lindemann–Weierstrass theorem). After his time in Freiburg, Lindemann transferred to the U ...
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Clausthal University Of Technology
The Clausthal University of Technology (, also referred to as TU Clausthal or TUC) is an institute of technology ('' Technische Universität'') in Clausthal-Zellerfeld, Lower Saxony, Germany. The small public university is regularly ranked among the Top German universities in engineering by CHE University Rankings. More than 30% of students and 20% of academic staff come from abroad, making it one of the most international universities in Germany. The university is best known for the prominent corporate leaders among its former students. History The academy of the local Hanoverian mining authority was established in 1775 at Clausthal in the Harz mountain range with its centuries-long history of mining in the Upper Harz (most notably at the Rammelsberg). Initially a school for pitmen and smelter workers, it was raised to the status of a mining college by the Westphalian minister Count Hans von Bülow in 1810. In 1864, at the behest of King George V of Hanover, the spin-off of ...
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