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Felix Bloch
Felix Bloch (23 October 1905 – 10 September 1983) was a Swiss-American physicist and Nobel physics laureate who worked mainly in the U.S. He and Edward Mills Purcell were awarded the 1952 Nobel Prize for Physics for "their development of new ways and methods for nuclear magnetic precision measurements."Sohlman, M (Ed.) ''Nobel Foundation directory 2003.'' Vastervik, Sweden: AB CO Ekblad; 2003. In 1954–1955, he served for one year as the first Director-General of CERN. Felix Bloch made fundamental theoretical contributions to the understanding of ferromagnetism and electron behavior in crystal lattices. He is also considered one of the developers of nuclear magnetic resonance. Biography Early life, education, and family Bloch was born in Zürich, Switzerland to Jewish parents Gustav and Agnes Bloch. Gustav Bloch, his father, was financially unable to attend University and worked as a wholesale grain dealer in Zürich. Gustav moved to Zürich in 1890 to become a Swiss c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zürich
Zürich () is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zürich. It is located in north-central Switzerland, at the northwestern tip of Lake Zürich. As of January 2020, the municipality has 434,335 inhabitants, the Urban agglomeration, urban area 1.315 million (2009), and the Zürich metropolitan area 1.83 million (2011). Zürich is a hub for railways, roads, and air traffic. Both Zurich Airport and Zürich Hauptbahnhof, Zürich's main railway station are the largest and busiest in the country. Permanently settled for over 2,000 years, Zürich was founded by the Roman Empire, Romans, who called it '. However, early settlements have been found dating back more than 6,400 years (although this only indicates human presence in the area and not the presence of a town that early). During the Middle Ages, Zürich gained the independent and privileged status of imperial immediacy and, in 1519, became a primary centre of the Protestant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloch Wall
A domain wall is a term used in physics which can have similar meanings in magnetism, optics, or string theory. These phenomena can all be generically described as topological solitons which occur whenever a discrete symmetry is spontaneously broken. Magnetism In magnetism, a domain wall is an interface separating magnetic domains. It is a transition between different magnetic moments and usually undergoes an angular displacement of 90° or 180°. A domain wall is a gradual reorientation of individual moments across a finite distance. The domain wall thickness depends on the anisotropy of the material, but on average spans across around 100–150 atoms. The energy of a domain wall is simply the difference between the magnetic moments before and after the domain wall was created. This value is usually expressed as energy per unit wall area. The width of the domain wall varies due to the two opposing energies that create it: the magnetocrystalline anisotropy energy and the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swiss People
The Swiss people (german: die Schweizer, french: les Suisses, it, gli Svizzeri, rm, ils Svizzers) are the citizens of Switzerland or people of Swiss abroad, Swiss ancestry. The number of Swiss nationality law, Swiss nationals has grown from 1.7 million in 1815 to 8.7 million in 2020. More than 1.5 million Swiss citizens hold multiple citizenship. About 11% of citizens Swiss abroad, live abroad (0.8 million, of whom 0.6 million hold multiple citizenship). About 60% of those living abroad reside in the European Union (0.46 million). The largest groups of Swiss descendants and nationals outside Europe are found in the Swiss Americans, United States, Brazil and Swiss Canadian, Canada. Although the Switzerland as a federal state, modern state of Switzerland originated in 1848, the period of romantic nationalism, it is not a nation-state, and the Swiss are not a single ethnic group, but rather are a Confederation, confederacy (') or ' ("nation of will", "nation by choice", tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nobel Prize For Physics
) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then "MDCCCXXXIII" above, followed by (smaller) "OB•" then "MDCCCXCVI" below. , awarded_for = Outstanding contributions for humankind in the field of Physics , presenter = Royal Swedish Academy of Sciences , location = Stockholm, Sweden , date = , reward = 9 million Swedish kronor (2017) , year = 1901 , holder_label = Most recently awarded to , holder = Alain Aspect, John Clauser, and Anton Zeilinger , most_awards = John Bardeen (2) , website nobelprize.org, previous = 2021 , year2=2022, main=2022, next=2023 The Nobel Prize in Physics is a yearly award given by the Royal Swedish Academy of Sciences for those who have made the most outstanding contributions for humankind in the field of physics. It i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Guggenheim Fellowships Awarded In 1959
{{incomplete list, date=January 2020 The following is a list of Guggenheim Fellowships awarded in 1959: 1959 U.S. and Canadian Fellows * Ansel Adams, Photography (also awarded Fellowships in 1946 and 1948) * Kinsey A. Anderson, Astronomy-Astrophysics * Francis M. Bator, Economics * Stephen B. Baxter, British History (also awarded a Fellowship in 1973) * Robert A. Becker, Physics (also awarded a Fellowship in 1958) * Lipman Bers, Mathematics (also awarded a Fellowship in 1978) * Elias J. Bickerman, Classics (also awarded a Fellowship in 1949) * Gordon W. Binkerd, Music Composition * Allan Birnbaum, Statistics * Doris Taylor Bishop, Classics * Felix Bloch, Physics * Allan B. Burdick, Genetics * Dennis Byng, Fine Arts (also awarded a Fellowship in 1958) * Louis Calabro, Music Composition (also awarded a Fellowship in 1954) * Gerald M. Capers, U.S. History * Richard Raymond Carlson, Physics * Wen-chung Chou, Music Composition (also awarded a Fellowship in 1957) * Arthur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fritz London Memorial Lectures
The Fritz London Memorial Lectures at Duke University invites scientists who impinge at one or more points upon the various fields of physics and chemistry to which Fritz London contributed. The series is partially supported by an endowment fund established by John Bardeen "to perpetuate the memory of Fritz London, distinguished scientist and member of the Duke faculty from 1939 to the time of his death in 1954, and to promote research and understanding of Physics at Duke University and in the wider scientific community. " List of lecturers * 1956 Lothar Wolfgang Nordheim * 1957 James Franck * 1958 Hendrik Casimir * 1959 Felix Bloch * 1960 Cornelis J. Gorter * 1962 Linus C. Pauling * 1963 Peter J.W. Debye * 1964 John Bardeen * 1965 William M. Fairbank * 1966 Chen Ning Yang * 1968 Walter Thirring * 1969 Eugene P. Wigner * 1971 Lars Onsager * 1972 Jesse Beams * 1973 David Pines * 1974 J. Robert Schrieffer * 1975 Michael Fisher * 1976 Hans Bethe * 1977 Victor Weisskopf * 1978 Philip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Recipients Of The Pour Le Mérite For Sciences And Arts
This is a list of recipients of the Pour le Mérite for Sciences and Arts (german: Pour le Mérite für Wissenschaften und Künste), a German and formerly Prussian honor given since 1842 for achievement in the humanities, sciences, or arts. Bibliography * External linksPour le Mérite für Wissenschaften und Künste website(in German) {{DEFAULTSORT:List of recipients of the Pour le Merite for Sciences and Arts Science and technology award winners Pour le Mérite for Sciences and Arts Pour may refer to these people: * Kour Pour (born 1987), British artist of part-Iranian descent * Mehdi Niyayesh Pour (born 1992), Iranian footballer * Mojtaba Mobini Pour (born 1991), Iranian footballer * Pouya Jalili Pour (born 1976), Iranian si ... Lists of German award winners ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bethe–Bloch Formula
The Bethe formula or Bethe-Bloch formula describes the mean energy loss per distance travelled of swift charged particles (protons, alpha particles, atomic ions) traversing matter (or alternatively the stopping power of the material). For electrons the energy loss is slightly different due to their small mass (requiring relativistic corrections) and their indistinguishability, and since they suffer much larger losses by Bremsstrahlung, terms must be added to account for this. Fast charged particles moving through matter interact with the electrons of atoms in the material. The interaction excites or ionizes the atoms, leading to an energy loss of the traveling particle. The non-relativistic version was found by Hans Bethe in 1930; the relativistic version (shown below) was found by him in 1932.Sigmund, Peter ''Particle Penetration and Radiation Effects. Springer Series in Solid State Sciences, 151.'' Berlin Heidelberg: Springer-Verlag. (2006) The most probable energy loss differs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloch–Siegert Shift
The Bloch–Siegert shift is a phenomenon in quantum physics that becomes important for driven two-level systems when the driving gets strong (e.g. atoms driven by a strong laser drive or nuclear spins in NMR, driven by a strong oscillating magnetic field). When the rotating wave approximation (RWA) is invoked, the resonance between the driving field and a pseudospin occurs when the field frequency \omega is identical to the spin's transition frequency \omega_0. The RWA is, however, an approximation. In 1940 Felix Bloch and Arnold Siegert showed that the dropped parts oscillating rapidly can give rise to a shift in the true resonance frequency of the dipoles. Rotating wave approximation In RWA, when the perturbation to the two level system is H_ = \frac \cos, a linearly polarized field is considered as a superposition of two circularly polarized fields of the same amplitude rotating in opposite directions with frequencies \omega, -\omega. Then, in the rotating frame(\omega), we c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinoshita–Lee–Nauenberg Theorem
The Kinoshita–Lee–Nauenberg theorem or KLN theorem states that perturbatively the standard model as a whole is infrared (IR) finite. That is, the infrared divergences coming from loop integrals are canceled by IR divergences coming from phase space integrals. It was introduced independently by and . An analogous result for quantum electrodynamics alone is known as Bloch–Nordsieck theorem. Ultraviolet divergences in perturbative quantum field theory are dealt with in renormalization. References * * * *Taizo Muta, Foundations of Quantum Chromodynamics: An Introduction to Perturbative Methods in Gauge Theories, World Scientific Publishing Company; 3 edition (September 30, 2009) Standard Model Quantum field theory Theorems in quantum mechanics {{quantum-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloch–Grüneisen Temperature
For typical three-dimensional metals, the temperature-dependence of the electrical resistivity ''ρ(T)'' due to the scattering of electrons by acoustic phonons changes from a high-temperature regime in which ''ρ ∝ T'' to a low-temperature regime in which ''ρ ∝ T''5 at a characteristic temperature known as the Debye temperature. For low density electron systems, however, the Fermi surface can be substantially smaller than the size of the Brillouin zone, and only a small fraction of acoustic phonons can scatter off electrons. This results in a new characteristic temperature known as the Bloch–Grüneisen temperature that is lower than the Debye temperature. The Bloch–Grüneisen temperature is defined as ''2ħv''s''k''F''/k''B, where ''ħ'' is the Planck constant, ''v''s is the velocity of sound, ''ħk''F is the Fermi momentum, and ''k''B is the Boltzmann constant. When the temperature is lower than the Bloch–Grüneisen temperature, the most energetic thermal phonons have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spontaneous Magnetization
Spontaneous magnetization is the appearance of an ordered spin state (magnetization) at zero applied magnetic field in a ferromagnetic or ferrimagnetic material below a critical point called the Curie temperature or . Overview Heated to temperatures above , ferromagnetic materials become paramagnetic and their magnetic behavior is dominated by spin waves or magnons, which are boson collective excitations with energies in the meV range. The magnetization that occurs below is an example of the "spontaneous" breaking of a global symmetry, a phenomenon that is described by Goldstone's theorem. The term "symmetry breaking" refers to the choice of a magnetization direction by the spins, which have spherical symmetry above , but a preferred axis (the magnetization direction) below . Temperature dependence To a first order approximation, the temperature dependence of spontaneous magnetization at low temperatures is given by the Bloch T3/2 law: :M(T) = M(0)\left(1-(T/T_c\right)^), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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