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🔗 Mathematics

In mathematics, Young's lattice is a partially ordered set and a lattice that is formed by all integer partitions. It is named after Alfred Young, who, in a series of papers On quantitative substitutional analysis, developed representation theory of the symmetric group. In Young's theory, the objects now called Young diagrams and the partial order on them played a key, even decisive, role. Young's lattice prominently figures in algebraic combinatorics, forming the simplest example of a differential poset in the sense of Stanley (1988). It is also closely connected with the crystal bases for affine Lie algebras.

🔗 Disaster management 🔗 Economics 🔗 Urban studies and planning

The great horse manure crisis of 1894 refers to the idea that the greatest obstacle to urban development at the turn of the century was the difficulty of removing horse manure from the streets. More broadly, it is an analogy for supposedly insuperable extrapolated problems being rendered moot by the introduction of new technologies. The phrase originates from a 2004 article by Stephen Davies entitled "The Great Horse-Manure Crisis of 1894".

The supposed problem of excessive horse-manure collecting in the streets was solved by the proliferation of cars, buses and electrified trams which replaced horses as the means of transportation in big cities. The term great horse manure crisis of 1894 is often used to denote a problem which seems to be impossible to solve because it is being looked at from the wrong direction.

The name refers to a supposed 1894 publication in The Times, which said "In 50 years, every street in London will be buried under nine feet of manure". The reasoning was that more horses are needed to remove the manure, and these horses produce more manure. An urban planning conference in 1898 supposedly broke up before its scheduled end due to a failure to find an answer to this problem. No such statement in the Times, nor conference result, is known, but in 1893 London there was a complaint that horse manure, formerly an economic good that could be sold, had become a disposal problem, an economic bad.

The supposed crisis has since taken on life as a useful analogy.

🔗 Lists 🔗 Transport 🔗 Transport/Maritime

Fifty-eight selected navigational stars are given a special status in the field of celestial navigation. Of the approximately 6,000 stars visible to the naked eye under optimal conditions, the selected stars are among the brightest and span 38 constellations of the celestial sphere from the declination of −70° to +89°. Many of the selected stars were named in antiquity by the Babylonians, Greeks, Romans, and Arabs.

The star Polaris, often called the "North Star", is treated specially due to its proximity to the north celestial pole. When navigating in the Northern Hemisphere, special techniques can be used with Polaris to determine latitude or gyrocompass error. The other 57 selected stars have daily positions given in nautical almanacs, aiding the navigator in efficiently performing observations on them. A second group of 115 "tabulated stars" can also be used for celestial navigation, but are often less familiar to the navigator and require extra calculations.

For purposes of identification, the positions of navigational stars — expressed as declination and sidereal hour angle — are often rounded to the nearest degree. In addition to tables, star charts provide an aid to the navigator in identifying the navigational stars, showing constellations, relative positions, and brightness.

🔗 Mathematics 🔗 Physics

The finite element method (FEM) is the most widely used method for solving problems of engineering and mathematical models. Typical problem areas of interest include the traditional fields of structural analysis, heat transfer, fluid flow, mass transport, and electromagnetic potential. The FEM is a particular numerical method for solving partial differential equations in two or three space variables (i.e., some boundary value problems). To solve a problem, the FEM subdivides a large system into smaller, simpler parts that are called finite elements. This is achieved by a particular space discretisation in the space dimensions, which is implemented by the construction of a mesh of the object: the numerical domain for the solution, which has a finite number of points. The finite element method formulation of a boundary value problem finally results in a system of algebraic equations. The method approximates the unknown function over the domain. The simple equations that model these finite elements are then assembled into a larger system of equations that models the entire problem. The FEM then uses variational methods from the calculus of variations to approximate a solution by minimizing an associated error function.

Studying or analyzing a phenomenon with FEM is often referred to as finite element analysis (FEA).

🔗 Espionage 🔗 Germany 🔗 Politics 🔗 Psychology 🔗 Socialism 🔗 Germany/GDR

Zersetzung (pronounced [t͡sɛɐ̯ˈzɛt͡sʊŋ] , German for "decomposition" and "disruption") was a psychological warfare technique used by the Ministry for State Security (Stasi) to repress political opponents in East Germany during the 1970s and 1980s. Zersetzung served to combat alleged and actual dissidents through covert means, using secret methods of abusive control and psychological manipulation to prevent anti-government activities. Among the defining features of it was the widespread use of offensive counterespionage methods as a means of repression. People were commonly targeted on a pre-emptive and preventive basis, to limit or stop activities of political dissent and cultural incorrectness that they may have gone on to perform, and not on the basis of crimes they had actually committed. Zersetzung methods were designed to break down, undermine, and paralyze people behind "a facade of social normality" in a form of "silent repression".

Erich Honecker's succession to Walter Ulbricht as First Secretary of the Socialist Unity Party of Germany (SED) in May 1971 saw an evolution of "operational procedures" (Operative Vorgänge) conducted by Stasi away from the overt terror of the Ulbricht era towards what came to be known as Zersetzung ("Anwendung von Maßnahmen der Zersetzung"), which was formalized by Directive No. 1/76 on the Development and Revision of Operational Procedures in January 1976. The Stasi used operational psychology and its extensive network of between 170,000 and over 500,000 informal collaborators (inoffizielle Mitarbeiter) to launch personalized psychological attacks against targets to damage their mental health and lower chances of a "hostile action" against the state. Among the collaborators were youths as young as 14 years of age.

The use of Zersetzung is well documented due to Stasi files published after the Berlin Wall fell, with several thousands or up to 10,000 individuals estimated to have become victims, 5,000 of whom sustained irreversible damage. Special pensions for restitution have been created for Zersetzung victims.

🔗 Biography 🔗 Economics 🔗 Biography/science and academia 🔗 United Kingdom 🔗 Virginia 🔗 Chicago 🔗 Virginia/Albemarle County

Ronald Harry Coase (; 29 December 1910 – 2 September 2013) was a British economist and author. He was the Clifton R. Musser Professor of Economics at the University of Chicago Law School, where he arrived in 1964 and remained for the rest of his life. He received the Nobel Memorial Prize in Economic Sciences in 1991.

Coase, who believed economists should study real markets and not theoretical ones, established the case for the corporation as a means to pay the costs of operating a marketplace. Coase is best known for two articles in particular: "The Nature of the Firm" (1937), which introduces the concept of transaction costs to explain the nature and limits of firms; and "The Problem of Social Cost" (1960), which suggests that well-defined property rights could overcome the problems of externalities (see Coase theorem). Additionally, Coase's transaction costs approach is currently influential in modern organizational economics, where it was reintroduced by Oliver E. Williamson.

🔗 United States 🔗 Biography 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Science Fiction 🔗 Biography/science and academia 🔗 Military history/Military biography 🔗 Biography/military biography 🔗 Biography/arts and entertainment 🔗 Chicago 🔗 United States/Massachusetts - Cape Cod and the Islands 🔗 United States/Indiana - Indianapolis

Kurt Vonnegut Jr. (; November 11, 1922 – April 11, 2007) was an American writer. In a career spanning over 50 years, Vonnegut published fourteen novels, three short story collections, five plays, and five works of non-fiction, with further collections being published after his death. He is most famous for his darkly satirical, best-selling novel Slaughterhouse-Five (1969).

Born and raised in Indianapolis, Indiana, Vonnegut attended Cornell University but dropped out in January 1943 and enlisted in the United States Army. As part of his training, he studied mechanical engineering at Carnegie Institute of Technology (now Carnegie Mellon University) and the University of Tennessee. He was then deployed to Europe to fight in World War II and was captured by the Germans during the Battle of the Bulge. He was interned in Dresden and survived the Allied bombing of the city by taking refuge in a meat locker of the slaughterhouse where he was imprisoned. After the war, Vonnegut married Jane Marie Cox, with whom he had three children. He later adopted his sister's three sons, after she died of cancer and her husband was killed in a train accident.

Vonnegut published his first novel, Player Piano, in 1952. The novel was reviewed positively but was not commercially successful. In the nearly 20 years that followed, Vonnegut published several novels that were only marginally successful, such as Cat's Cradle (1963) and God Bless You, Mr. Rosewater (1964). Vonnegut's breakthrough was his commercially and critically successful sixth novel, Slaughterhouse-Five. The book's anti-war sentiment resonated with its readers amidst the ongoing Vietnam War and its reviews were generally positive. After its release, Slaughterhouse-Five went to the top of The New York Times Best Seller list, thrusting Vonnegut into fame. He was invited to give speeches, lectures and commencement addresses around the country and received many awards and honors.

Later in his career, Vonnegut published several autobiographical essays and short-story collections, including Fates Worse Than Death (1991), and A Man Without a Country (2005). After his death, he was hailed as a morbidly comical commentator on the society in which he lived and as one of the most important contemporary writers. Vonnegut's son Mark published a compilation of his father's unpublished compositions, titled Armageddon in Retrospect. In 2017, Seven Stories Press published Complete Stories, a collection of Vonnegut's short fiction including five previously unpublished stories. Complete Stories was collected and introduced by Vonnegut friends and scholars Jerome Klinkowitz and Dan Wakefield. Numerous scholarly works have examined Vonnegut's writing and humor.

🔗 Physics 🔗 China 🔗 Astronomy 🔗 History of Science 🔗 Astronomy/Astronomical objects 🔗 Arab world

SN 1006 was a supernova that is likely the brightest observed stellar event in recorded history, reaching an estimated −7.5 visual magnitude, and exceeding roughly sixteen times the brightness of Venus. Appearing between April 30 and May 1, 1006 AD in the constellation of Lupus, this "guest star" was described by observers across the modern day countries of China, Japan, Iraq, Egypt, and the continent of Europe, and possibly recorded in North American petroglyphs. Some reports state it was clearly visible in the daytime. Modern astronomers now consider its distance from Earth to be about 7,200 light-years.

🔗 Physics 🔗 Education 🔗 Toys

The Gilbert U-238 Atomic Energy Lab was a toy lab set designed to allow children to create and watch nuclear and chemical reactions using radioactive material. The Atomic Energy Lab was released by the A. C. Gilbert Company in 1950.