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๐Ÿ”— Poincarรฉ Recurrence Theorem

๐Ÿ”— Physics ๐Ÿ”— Systems ๐Ÿ”— Systems/Dynamical systems

In mathematics and physics, the Poincarรฉ recurrence theorem states that certain dynamical systems will, after a sufficiently long but finite time, return to a state arbitrarily close to (for continuous state systems), or exactly the same as (for discrete state systems), their initial state.

The Poincarรฉ recurrence time is the length of time elapsed until the recurrence. This time may vary greatly depending on the exact initial state and required degree of closeness. The result applies to isolated mechanical systems subject to some constraints, e.g., all particles must be bound to a finite volume. The theorem is commonly discussed in the context of ergodic theory, dynamical systems and statistical mechanics. Systems to which the Poincarรฉ recurrence theorem applies are called conservative systems.

The theorem is named after Henri Poincarรฉ, who discussed it in 1890 and proved by Constantin Carathรฉodory using measure theory in 1919.

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๐Ÿ”— Olympic medalists in art competitions

๐Ÿ”— Olympics ๐Ÿ”— Lists ๐Ÿ”— Arts

There were 146 medalists in the art competitions that were part of the Olympic Games from 1912 until 1948. These art competitions were considered an integral part of the movement by International Olympic Committee (IOC) founder Pierre de Coubertin and necessary to recapture the complete essence of the Ancient Olympic Games. Their absence before the 1912 Summer Olympics, according to journalism professor Richard Stanton, stems from Coubertin "not wanting to fragment the focus of his new and fragile movement". Art competitions were originally planned for inclusion in the 1908 Summer Olympics but were delayed after that edition's change in venue from Rome to London following the 1906 eruption of Mount Vesuvius. By the 1924 Summer Olympics they had grown to be considered internationally relevant and potentially "a milestone in advancing public awareness of art as a whole".

During their first three appearances, the art competitions were grouped into five broad categories: architecture, literature, music, painting, and sculpture. The Dutch Organizing Committee for the 1928 Summer Olympics split these into subcategories in the hopes of increasing participation. Although it was a successful strategy, the 1932 Summer Olympics eliminated several of these subcategories, which led to fewer entries in the broader categories. For the 1936 Summer Olympics, the German government proposed the addition of a film contest to the program, which was rejected.

Following a final appearance at the 1948 Summer Olympics, art competitions were removed from the Olympic program. Planners of the 1952 Summer Olympics opposed their inclusion on logistical grounds, claiming that the lack of an international association for the event meant that the entire onus of facilitation was placed on the local organizing committee. Concerns were also raised about the professionalism of the event, since only amateurs were allowed to participate in the sporting tournaments, and the growing commercialization of the competitions, as artists had been permitted to sell their submissions during the course of the Games since 1928. In 1952 an art festival and exhibition was held concurrent with the Games, a tradition that has been maintained in all subsequent Summer Olympics.

The IOC does not track medalists in Olympic art competitions in its database and thus the prize winners are only officially recorded in the original Olympic reports. Judges were not required to distribute first, second, and third place awards for every category, and thus certain events lack medalists in these placements. Since participants were allowed multiple submissions, it was also possible for artists to win more than one in a single event, as Alex Diggelmann of Switzerland did in the graphic arts category of the 1948 edition. Diggelmann is tied with Denmark's Josef Petersen, who won second prize three times in literature, for the number of medals captured in the art competitions. Luxembourg's Jean Jacoby is the only individual to win two gold medals, doing so in painting in 1924 and 1928. Of the 146 medalists, 11 were women and only Finnish author Aale Tynni was awarded gold. Germany was the most successful nation, with eight gold, seven silver, and nine bronze medals, although one was won by Coubertin himself, a Frenchman. He submitted his poem Ode to Sport under the pseudonyms Georges Hohrod and Martin Eschbach, as if it were a joint-entry, and won first prize in the 1912 literature category. The original report credits this medal to Germany. Two individuals, Walter W. Winans and Alfrรฉd Hajรณs, won medals in both athletic and art competitions.

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๐Ÿ”— BBS Door

๐Ÿ”— Software ๐Ÿ”— Software/Computing

A door in a bulletin board system (BBS) is an interface between the BBS software and an external application. The term is also used to refer to the external application, a computer program that runs outside of the main bulletin board program. Sometimes called external programs, doors are the most common way to add games, utilities, and other extensions to BBSes. Because BBSes typically depended on the telephone system, BBSes and door programs tended to be local in nature, unlike modern Internet games and applications.

From the 1990s on, most BBS software had the capability to "drop to" doors. Several standards were developed for passing connection and user information to doors; this was usually done with "dropfiles", small binary or text files dropped into known locations in the BBS's file system. Most doors were responsible for operating the serial port or other communications device directly until returning control to the BBS. Later development of FOSSIL drivers have allowed both BBSes and their doors to communicate without being responsible for direct operation of the communications hardware.

๐Ÿ”— Inverted totalitarianism

๐Ÿ”— United States ๐Ÿ”— Politics

The political philosopher Sheldon Wolin coined the term inverted totalitarianism in 2003 to describe what he saw as the emerging form of government of the United States. Wolin analysed the United States as increasingly turning into a managed democracy (similar to an illiberal democracy). He uses the term "inverted totalitarianism" to draw attention to the totalitarian aspects of the American political system while emphasizing its differences from proper totalitarianism, such as Nazi and Stalinist regimes.

The book Days of Destruction, Days of Revolt (2012) by Chris Hedges and Joe Sacco portrays inverted totalitarianism as a system where corporations have corrupted and subverted democracy and where economics bests politics. Every natural resource and living being is commodified and exploited by large corporations to the point of collapse as excess consumerism and sensationalism lull and manipulate the citizenry into surrendering their liberties and their participation in government.

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๐Ÿ”— Ben Franklin effect

๐Ÿ”— Psychology

The Ben Franklin effect is a proposed psychological phenomenon: a person who has already performed a favor for another is more likely to do another favor for the other than if they had received a favor from that person. An explanation for this is cognitive dissonance. People reason that they help others because they like them, even if they do not, because their minds struggle to maintain logical consistency between their actions and perceptions.

The Benjamin Franklin effect, in other words, is the result of one's concept of self coming under attack. Every person develops a persona, and that persona persists because inconsistencies in one's personal narrative get rewritten, redacted, and misinterpreted.

๐Ÿ”— Battle of Alesia

๐Ÿ”— Military history ๐Ÿ”— Classical Greece and Rome ๐Ÿ”— Military history/French military history ๐Ÿ”— Military history/Roman and Byzantine military history ๐Ÿ”— Military history/Classical warfare ๐Ÿ”— Celts ๐Ÿ”— Military history/European military history

The Battle of Alesia or Siege of Alesia was a military engagement in the Gallic Wars that took place in September, 52ย BC, around the Gallic oppidum (fortified settlement) of Alesia, a major centre of the Mandubii tribe. It was fought by the army of Julius Caesar against a confederation of Gallic tribes united under the leadership of Vercingetorix of the Arverni. It was the last major engagement between Gauls and Romans, and is considered one of Caesar's greatest military achievements and a classic example of siege warfare and investment. The battle of Alesia marked the end of Gallic independence in France and Belgium.

The battle site was probably atop Mont Auxois, above modern Alise-Sainte-Reine in France, but this location, some have argued, does not fit Caesar's description of the battle. A number of alternatives have been proposed over time, among which only Chaux-des-Crotenay (in Jura in modern France) remains a challenger today.

At one point in the battle the Romans were outnumbered by the Gauls by four to one. The event is described by several contemporary authors, including Caesar himself in his Commentarii de Bello Gallico. After the Roman victory, Gaul (very roughly modern France) was subdued and became a Roman province. The Roman Senate granted a thanksgiving of 20 days for his victory in the Gallic War.

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๐Ÿ”— 1975 Icelandic Women's Strike

๐Ÿ”— Women's History ๐Ÿ”— Iceland

On 24 October 1975, Icelandic women went on strike for the day to "demonstrate the indispensable work of women for Icelandโ€™s economy and society" and to "protest wage discrepancy and unfair employment practices". It was then publicized domestically as Women's Day Off (Kvennafrรญdagurinn). Participants, led by women's organizations, did not go to their paid jobs and did not do any housework or child-rearing for the whole day. Ninety percent of Iceland's female population participated in the strike. Iceland's parliament passed a law guaranteeing equal pay the following year.

๐Ÿ”— Pangram

๐Ÿ”— Typography

A pangram or holoalphabetic sentence is a sentence using every letter of a given alphabet at least once. Pangrams have been used to display typefaces, test equipment, and develop skills in handwriting, calligraphy, and keyboarding.

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๐Ÿ”— Mellified man

๐Ÿ”— Death ๐Ÿ”— Agriculture ๐Ÿ”— China ๐Ÿ”— Skepticism ๐Ÿ”— Alternative medicine ๐Ÿ”— Arab world ๐Ÿ”— Agriculture/Beekeeping

A mellified man, or a human mummy confection, was a legendary medicinal substance created by steeping a human cadaver in honey. The concoction is detailed in Chinese medical sources, most significantly the Bencao Gangmu of the 16th-century Chinese medical doctor and pharmacologist Li Shizhen. Relying on a second-hand account, Li reports a story that some elderly men in Arabia, nearing the end of their lives, would submit themselves to a process of mummification in honey to create a healing confection.

This process differed from a simple body donation because of the aspect of self-sacrifice; the mellification process would ideally start before death. The donor would stop eating any food other than honey, going as far as to bathe in the substance. Shortly, his feces (and even his sweat, according to legend) would consist of honey. When this diet finally proved fatal, the donor's body would be placed in a stone coffin filled with honey.

After a century or so, the contents would have turned into a sort of confection reputedly capable of healing broken limbs and other ailments. This confection would then be sold in street markets as a hard to find item with a hefty price.

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