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Siegfried Adolf Wouthuysen
Siegfried Adolf Wouthuysen (17 August 1916 – 14 July 1996) was a Dutch physicist who made contributions to quantum mechanics. Early life Wouthuysen was born in Amsterdam in 1916. He obtained his bachelor's degree in Chemistry at Ghent University in 1936 and his master's degree in Mathematics and Physics at Leiden University in 1939. Research Wouthuysen gained his Ph.D. from the University of California, Berkeley, 1948 with a dissertation on ''self-energy and relativistic covariance in field theory'', under his advisor J. Robert Oppenheimer. In 1949 he became assistant professor and in 1955 full professor of Physics at the University of Amsterdam, which position he held until his retirement in 1984. He collaborated with Leslie Lawrence Foldy to develop the Foldy–Wouthuysen transformation, and with George B. Field to develop the Wouthuysen–Field coupling Wouthuysen–Field coupling, or the Wouthuysen–Field effect, is a mechanism that couples the excitation temperature, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutch People
The Dutch (Dutch: ) are an ethnic group and nation native to the Netherlands. They share a common history and culture and speak the Dutch language. Dutch people and their descendants are found in migrant communities worldwide, notably in Aruba, Suriname, Guyana, Curaçao, Argentina, Brazil, Canada,Based on Statistics Canada, Canada 2001 Censusbr>Linkto Canadian statistics. Australia, South Africa, New Zealand and the United States.According tFactfinder.census.gov The Low Countries were situated around the border of France and the Holy Roman Empire, forming a part of their respective peripheries and the various territories of which they consisted had become virtually autonomous by the 13th century. Under the Habsburgs, the Netherlands were organised into a single administrative unit, and in the 16th and 17th centuries the Northern Netherlands gained independence from Spain as the Dutch Republic. The high degree of urbanization characteristic of Dutch society was attained at a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foldy–Wouthuysen Transformation
The Foldy–Wouthuysen transformation was historically significant and was formulated by Leslie Lawrance Foldy and Siegfried Adolf Wouthuysen in 1949 to understand the nonrelativistic limit of the Dirac equation, the equation for spin-½ particles. A detailed general discussion of the Foldy–Wouthuysen-type transformations in particle interpretation of relativistic wave equations is in Acharya and Sudarshan (1960). Its utility in high energy physics is now limited due to the primary applications being in the ultra-relativistic domain where the Dirac field is treated as a quantised field. A canonical transform The FW transformation is a unitary transformation of the orthonormal basis in which both the Hamiltonian and the state are represented. The eigenvalues do not change under such a unitary transformation, that is, the physics does not change under such a unitary basis transformation. Therefore, such a unitary transformation can always be applied: in particular a unitary bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ghent University Alumni
Ghent ( nl, Gent ; french: Gand ; traditional English: Gaunt) is a city and a municipality in the Flemish Region of Belgium. It is the capital and largest city of the East Flanders province, and the third largest in the country, exceeded in size only by Brussels and Antwerp. It is a port and university city. The city originally started as a settlement at the confluence of the Rivers Scheldt and Leie and in the Late Middle Ages became one of the largest and richest cities of northern Europe, with some 50,000 people in 1300. The municipality comprises the city of Ghent proper and the surrounding suburbs of Afsnee, Desteldonk, Drongen, Gentbrugge, Ledeberg, Mariakerke, Mendonk, Oostakker, Sint-Amandsberg, Sint-Denijs-Westrem, Sint-Kruis-Winkel, Wondelgem and Zwijnaarde. With 262,219 inhabitants at the beginning of 2019, Ghent is Belgium's second largest municipality by number of inhabitants. The metropolitan area, including the outer commuter zone, covers an area of and had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of The University Of Amsterdam
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive grove, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessions into a method of teaching philosophy and in 387 BC, established what is known today as the Old Academy. By extension, ''academia'' has come to mean the accumulation, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientists From Amsterdam
A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophical study of nature called natural philosophy, a precursor of natural science. Though Thales (circa 624-545 BC) was arguably the first scientist for describing how cosmic events may be seen as natural, not necessarily caused by gods,Frank N. Magill''The Ancient World: Dictionary of World Biography'', Volume 1 Routledge, 2003 it was not until the 19th century that the term ''scientist'' came into regular use after it was coined by the theologian, philosopher, and historian of science William Whewell in 1833. In modern times, many scientists have advanced degrees in an area of science and pursue careers in various sectors of the economy such as academia, industry, government, and nonprofit environments.'''' History The roles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Physicists
In physics, a quantum (plural quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a physical property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum. For example, a photon is a single quantum of light (or of any other form of electromagnetic radiation). Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain discrete values. (Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom.) Quantization is one of the foundations of the much broader physics of quantum mechanics. Quantization of energy and its influence on how energy and matter interact (quantum electrodynamics) is part of the fundamental framework for understanding and describing nature. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1996 Deaths
File:1996 Events Collage.png, From left, clockwise: A bomb explodes at Centennial Olympic Park in Atlanta, set off by a radical anti-abortionist; The center fuel tank explodes on TWA Flight 800, causing the plane to crash and killing everyone on board; Eight people die in a blizzard on Mount Everest; Dolly the Sheep becomes the first mammal to have been cloned from an adult somatic cell; The Port Arthur Massacre occurs on Tasmania, and leads to major changes in Australia's gun laws; Macarena, sung by Los del Río and remixed by The Bayside Boys, becomes a major dance craze and cultural phenomenon; Ethiopian Airlines Flight 961 crash-ditches off of the Comoros Islands after the plane was hijacked; the 1996 Summer Olympics are held in Atlanta, marking the Centennial (100th Anniversary) of the modern Olympic Games., 300x300px, thumb rect 0 0 200 200 Centennial Olympic Park bombing rect 200 0 400 200 TWA FLight 800 rect 400 0 600 200 1996 Mount Everest disaster rect 0 200 30 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1916 Births
Events Below, the events of the First World War have the "WWI" prefix. January * January 1 – The British Empire, British Royal Army Medical Corps carries out the first successful blood transfusion, using blood that had been stored and cooled. * January 9 – WWI: Gallipoli Campaign: The last British troops are evacuated from Gallipoli, as the Ottoman Empire prevails over a joint British and French operation to capture Constantinople. * January 10 – WWI: Erzurum Offensive: Russia defeats the Ottoman Empire. * January 12 – The Gilbert and Ellice Islands Colony, part of the British Empire, is established in present-day Tuvalu and Kiribati. * January 13 – WWI: Battle of Wadi (1916), Battle of Wadi: Ottoman Empire forces defeat the British, during the Mesopotamian campaign in modern-day Iraq. * January 29 – WWI: Paris is bombed by German Empire, German zeppelins. * January 31 – WWI: An attack is planned on Verdun, France. February * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wouthuysen–Field Coupling
Wouthuysen–Field coupling, or the Wouthuysen–Field effect, is a mechanism that couples the excitation temperature, also called the spin temperature, of neutral hydrogen to Lyman-alpha radiation. This coupling plays a role in producing a difference in the temperature of neutral hydrogen and the cosmic microwave background at the end of the Dark Ages and the beginning of the epoch of reionization. It is named for Siegfried Adolf Wouthuysen and George B. Field. Background The period after recombination occurred and before stars and galaxies formed is known as the "dark ages". During this time, the majority of matter in the universe is neutral hydrogen. This hydrogen has yet to be observed, but there are experiments underway to detect the hydrogen line produced during this era. The hydrogen line is produced when an electron in a neutral hydrogen atom is excited to the triplet spin state, or de-excited as the electron and proton spins go to the singlet state. The energy diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George B
George may refer to: People * George (given name) * George (surname) * George (singer), American-Canadian singer George Nozuka, known by the mononym George * George Washington, First President of the United States * George W. Bush, 43rd President of the United States * George H. W. Bush, 41st President of the United States * George V, King of Great Britain, Ireland, the British Dominions and Emperor of India from 1910-1936 * George VI, King of Great Britain, Ireland, the British Dominions and Emperor of India from 1936-1952 * Prince George of Wales * George Papagheorghe also known as Jorge / GEØRGE * George, stage name of Giorgio Moroder * George Harrison, an English musician and singer-songwriter Places South Africa * George, Western Cape ** George Airport United States * George, Iowa * George, Missouri * George, Washington * George County, Mississippi * George Air Force Base, a former U.S. Air Force base located in California Characters * George (Peppa Pig), a 2-year-old pig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leslie Lawrence Foldy
Leslie Lawrance Foldy (1919–2001) was a theoretical physicist, who made contributions to condensed matter physics and quantum mechanics. Early life Foldy was born in Sabinov, Czechoslovakia, on October 26, 1919. His parents were of Hungarian origin, and named their son László Földi. In 1920, the family moved to the USA due to the invasions of Czechoslovakia by Hungary around that time, and there he was known as Leslie Foldy. Education His high school education was in Cleveland, Ohio, and at that time he called his middle name "Lawrance", upon noticing he hadn't a middle name while the other students had. While at high school, he picked up an interest in physics. In 1941, Foldy graduated with a B.S. degree in physics from the Case School of Applied Science (now renamed to the ''Case School of Engineering''), his senior thesis was on crystal lattice vibrations. Research He started his PHD in 1945 at the University of California in Berkeley, in J. Robert Oppenheimer's grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
