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Ludvig Lorenz
Ludvig Valentin Lorenz (; 18 January 1829 – 9 June 1891) was a Danish physicist and mathematician. He developed mathematical formulae to describe phenomena such as the relation between the refraction of light and the density of a pure transparent substance, and the relation between a metal's electrical and thermal conductivity and temperature ( Wiedemann–Franz–Lorenz law). Biography Lorenz was born in Helsingør and studied at the Technical University in Copenhagen. He became professor at the Military Academy in Copenhagen 1876. From 1887, his research was funded by the Carlsberg Foundation. He investigated the mathematical description for light propagation through a single homogeneous medium and described the passage of light between different media. The formula for the mathematical relationship between the refractive index and the density of a medium was published by Lorenz in 1869 and by Hendrik Lorentz (who discovered it independently) in 1878 and is therefore called t ...
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Helsingør
Helsingør ( , ; sv, Helsingör), classically known in English as Elsinore ( ), is a city in eastern Denmark. Helsingør Municipality had a population of 62,686 on 1 January 2018. Helsingør and Helsingborg in Sweden together form the northern reaches of the Øresund Region, centered on Copenhagen and Malmö. The HH Ferry route connects Helsingør with Helsingborg, 4 km (2.5 miles) across the Øresund. It is known for its castle Kronborg, which William Shakespeare presumably had in mind for his play ''Hamlet.'' History The name ''Helsingør'' has been believed to be derived from the word ''hals'' meaning "neck" or "narrow strait," referring to the narrowest point of the ''Øresund'' (Øre Sound) between what is now Helsingør and Helsingborg, Sweden. The people were mentioned as ''Helsinger'' (which may mean "the people of the strait") for the first time in King Valdemar the Victorious's ''Liber Census Daniæ'' from 1231 (not to be confused with the Helsings of Hä ...
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Hendrik Lorentz
Hendrik Antoon Lorentz (; 18 July 1853 – 4 February 1928) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. He also derived the Lorentz transformation underpinning Albert Einstein's special theory of relativity, as well as the Lorentz force, which describes the combined electric and magnetic forces acting on a charged particle in an electromagnetic field. Lorentz was also responsible for the Lorentz oscillator model, a classical model used to describe the anomalous dispersion observed in dielectric materials when the driving frequency of the electric field was near the resonant frequency, resulting in abnormal refractive indices. According to the biography published by the Nobel Foundation, "It may well be said that Lorentz was regarded by all theoretical physicists as the world's leading spirit, who completed what was left unfinished by his predecessors and prepared t ...
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19th-century Danish Mathematicians
The 19th (nineteenth) century began on 1 January 1801 ( MDCCCI), and ended on 31 December 1900 ( MCM). The 19th century was the ninth century of the 2nd millennium. The 19th century was characterized by vast social upheaval. Slavery was abolished in much of Europe and the Americas. The First Industrial Revolution, though it began in the late 18th century, expanding beyond its British homeland for the first time during this century, particularly remaking the economies and societies of the Low Countries, the Rhineland, Northern Italy, and the Northeastern United States. A few decades later, the Second Industrial Revolution led to ever more massive urbanization and much higher levels of productivity, profit, and prosperity, a pattern that continued into the 20th century. The Islamic gunpowder empires fell into decline and European imperialism brought much of South Asia, Southeast Asia, and almost all of Africa under colonial rule. It was also marked by the collapse of the large S ...
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People From Helsingør
A person ( : people) is a being that has certain capacities or attributes such as reason, morality, consciousness or self-consciousness, and being a part of a culturally established form of social relations such as kinship, ownership of property, or legal responsibility. The defining features of personhood and, consequently, what makes a person count as a person, differ widely among cultures and contexts. In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as they were or will be at another time despite any intervening changes. The plural form "people" is often used to refer to an entire nation or ethnic group (as in "a people"), and this was the original meaning of the word; it subsequently acquired its use as a plural form of ...
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1891 Deaths
Events January–March * January 1 ** Paying of old age pensions begins in Germany. ** A strike of 500 Hungarian steel workers occurs; 3,000 men are out of work as a consequence. **Germany takes formal possession of its new African territories. * January 2 – A. L. Drummond of New York is appointed Chief of the Treasury Secret Service. * January 4 – The Earl of Zetland issues a declaration regarding the famine in the western counties of Ireland. * January 5 **The Australian shearers' strike, that leads indirectly to the foundation of the Australian Labor Party, begins. **A fight between the United States and Indians breaks out near Pine Ridge agency. ** Henry B. Brown, of Michigan, is sworn in as an Associate Justice of the Supreme Court. **A fight between railway strikers and police breaks out at Motherwell, Scotland. * January 6 – Encounters continue, between strikers and the authorities at Glasgow. * January 7 ** General Miles' force ...
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1829 Births
Eighteen or 18 may refer to: * 18 (number), the natural number following 17 and preceding 19 * one of the years 18 BC, AD 18, 1918, 2018 Film, television and entertainment * ''18'' (film), a 1993 Taiwanese experimental film based on the short story ''God's Dice'' * ''Eighteen'' (film), a 2005 Canadian dramatic feature film * 18 (British Board of Film Classification), a film rating in the United Kingdom, also used in Ireland by the Irish Film Classification Office * 18 (''Dragon Ball''), a character in the ''Dragon Ball'' franchise * "Eighteen", a 2006 episode of the animated television series ''12 oz. Mouse'' Music Albums * ''18'' (Moby album), 2002 * ''18'' (Nana Kitade album), 2005 * '' 18...'', 2009 debut album by G.E.M. Songs * "18" (5 Seconds of Summer song), from their 2014 eponymous debut album * "18" (One Direction song), from their 2014 studio album ''Four'' * "18", by Anarbor from their 2013 studio album '' Burnout'' * "I'm Eighteen", by Alice Cooper common ...
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Refraction
In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenomenon, but other waves such as sound waves and water waves also experience refraction. How much a wave is refracted is determined by the change in wave speed and the initial direction of wave propagation relative to the direction of change in speed. For light, refraction follows Snell's law, which states that, for a given pair of media, the ratio of the sines of the angle of incidence ''θ1'' and angle of refraction ''θ2'' is equal to the ratio of phase velocities (''v''1 / ''v''2) in the two media, or equivalently, to the refractive indices (''n''2 / ''n''1) of the two media. :\frac =\frac=\frac Optical prisms and lenses use refraction to redirect light, as does the human eye. The refractive index of materials varies with the wavelengt ...
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Augustin-Jean Fresnel
Augustin-Jean Fresnel (10 May 1788 – 14 July 1827) was a French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light, excluding any remnant of Isaac Newton, Newton's corpuscular theory of light, corpuscular theory, from the late 1830s until the end of the 19th century. He is perhaps better known for inventing the Catadioptric system, catadioptric (reflective/refractive) Fresnel lens and for pioneering the use of "stepped" lenses to extend the visibility of lighthouses, saving countless lives at sea. The simpler Dioptrics, dioptric (purely refractive) stepped lens, first proposed by Georges-Louis Leclerc, Comte de Buffon, Count Buffon and independently reinvented by Fresnel, is used in screen magnifying glass, magnifiers and in condenser lenses for overhead projectors. By expressing Christiaan Huygens, Huygens's principle of secondary waves and Thomas Young (scientist), Young's principle of interference ( ...
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Ellipsometry
Ellipsometry is an optical technique for investigating the dielectric properties (complex refractive index or dielectric function) of thin films. Ellipsometry measures the change of Polarization (waves), polarization upon reflection or transmission and compares it to a model. It can be used to characterize Materials science, composition, Surface roughness, roughness, thickness (depth), Crystalline, crystalline nature, Doping (semiconductor), doping concentration, electrical conductivity and other material properties. It is very sensitive to the change in the optical response of incident radiation that interacts with the material being investigated. A spectroscopic ellipsometer can be found in most thin film analytical labs. Ellipsometry is also becoming more interesting to researchers in other disciplines such as biology and medicine. These areas pose new challenges to the technique, such as measurements on unstable liquid surfaces and microscopic imaging. Etymology The name "el ...
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Gustav Mie
Gustav Adolf Feodor Wilhelm Ludwig Mie (; 29 September 1868 – 13 February 1957) was a German physicist. Life Mie was born in Rostock, Mecklenburg-Schwerin, Germany in 1868. From 1886 he studied mathematics and physics at the University of Rostock. In addition to his major subjects, he also attended lectures in chemistry, zoology, geology, mineralogy and astronomy, as well as logic and metaphysics. In 1889 he continued his studies at the University of Heidelberg and received a doctoral degree in mathematics at the age of 22. In 1897 he got his habilitation at the University of Göttingen in theoretical physics and in 1902 became extraordinary professor for theoretical physics at the University of Greifswald. In 1917 he became full professor for experimental physics at Martin Luther University of Halle-Wittenberg. In 1924 he became professor at the University of Freiburg, where he worked up to his retirement in 1935. In Freiburg, during the Nazi dictatorship, Mie was member ...
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Electromagnetism
In physics, electromagnetism is an interaction that occurs between particles with electric charge. It is the second-strongest of the four fundamental interactions, after the strong force, and it is the dominant force in the interactions of atoms and molecules. Electromagnetism can be thought of as a combination of electricity and magnetism, two distinct but closely intertwined phenomena. In essence, electric forces occur between any two charged particles, causing an attraction between particles with opposite charges and repulsion between particles with the same charge, while magnetism is an interaction that occurs exclusively between ''moving'' charged particles. These two effects combine to create electromagnetic fields in the vicinity of charge particles, which can exert influence on other particles via the Lorentz force. At high energy, the weak force and electromagnetic force are unified as a single electroweak force. The electromagnetic force is responsible for many o ...
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Carlsberg Foundation
Carlsberg Foundation ( da, Carlsbergfondet) was founded by J. C. Jacobsen in 1876, by allocating some of his shares in the Carlsberg Brewery to fund and operate the Carlsberg Laboratory and the Museum of National History at Frederiksborg Palace. The foundation has since expanded to fund scientific research, to manage the Ny Carlsberg Glyptotek, and via the Tuborg Foundation to fund social works. it owned 30.3% of the shares in Carlsberg Group and controlled 74.2% of the voting power. History The foundation was started to run Carlsberg Laboratory. To finance its works the foundation received a portion of shares in Carlsberg Brewery. J.C. Jacobsen's wish was to create a foundation with firm obligations to the natural sciences and direct responsibility for the running of a corporate enterprise. In 1878 the foundation started to manage and fund the Museum of National History at Frederiksborg Palace. In 1882 after the death of J. C. Jacobsen the foundation inherited the remaining sh ...
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