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π Super-App
A super-app (also written as super app or superapp) is a mobile or web application that can provide multiple services including payment and financial transaction processing, effectively becoming an all-encompassing self-contained commerce and communication online platform that embraces many aspects of personal and commercial life. Notable examples of super-apps include Tencent's WeChat in China, and Grab in Southeast Asia.
π Rhind Mathematical Papyrus
The Rhind Mathematical Papyrus (RMP; also designated as papyrus British Museum 10057 and pBM 10058) is one of the best known examples of ancient Egyptian mathematics. It is named after Alexander Henry Rhind, a Scottish antiquarian, who purchased the papyrus in 1858 in Luxor, Egypt; it was apparently found during illegal excavations in or near the Ramesseum. It dates to around 1550 BC. The British Museum, where the majority of the papyrus is now kept, acquired it in 1865 along with the Egyptian Mathematical Leather Roll, also owned by Henry Rhind. There are a few small fragments held by the Brooklyn Museum in New York City and an 18Β cm (7.1Β in) central section is missing. It is one of the two well-known Mathematical Papyri along with the Moscow Mathematical Papyrus. The Rhind Papyrus is larger than the Moscow Mathematical Papyrus, while the latter is older.
The Rhind Mathematical Papyrus dates to the Second Intermediate Period of Egypt. It was copied by the scribe Ahmes (i.e., Ahmose; Ahmes is an older transcription favoured by historians of mathematics), from a now-lost text from the reign of king Amenemhat III (12th dynasty). Written in the hieratic script, this Egyptian manuscript is 33Β cm (13Β in) tall and consists of multiple parts which in total make it over 5Β m (16Β ft) long. The papyrus began to be transliterated and mathematically translated in the late 19th century. The mathematical translation aspect remains incomplete in several respects. The document is dated to Year 33 of the Hyksos king Apophis and also contains a separate later historical note on its verso likely dating from the period ("Year 11") of his successor, Khamudi.
In the opening paragraphs of the papyrus, Ahmes presents the papyrus as giving "Accurate reckoning for inquiring into things, and the knowledge of all things, mysteriesΒ ... all secrets". He continues with:
This book was copied in regnal year 33, month 4 of Akhet, under the majesty of the King of Upper and Lower Egypt, Awserre, given life, from an ancient copy made in the time of the King of Upper and Lower Egypt Nimaatre. The scribe Ahmose writes this copy.
Several books and articles about the Rhind Mathematical Papyrus have been published, and a handful of these stand out. The Rhind Papyrus was published in 1923 by Peet and contains a discussion of the text that followed Griffith's Book I, II and III outline. Chace published a compendium in 1927β29 which included photographs of the text. A more recent overview of the Rhind Papyrus was published in 1987 by Robins and Shute.
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- "Rhind Mathematical Papyrus" | 2023-04-02 | 42 Upvotes 30 Comments
π Berserker Hypothesis
The berserker hypothesis, also known as the deadly probes scenario, is the idea that humans have not yet detected intelligent alien life in the universe because it has been systematically destroyed by a series of lethal Von Neumann probes. The hypothesis is named after the Berserker series of novels (1963-2005) written by Fred Saberhagen.
The hypothesis has no single known proposer, and instead is thought to have emerged over time in response to the HartβTipler conjecture, or the idea that an absence of detectable Von Neumann probes is contrapositive evidence that no intelligent life exists outside of the Sun's Solar System. According to the berserker hypothesis, an absence of such probes is not evidence of life's absence, since interstellar probes could "go berserk" and destroy other civilizations, before self-destructing.
In his 1983 paper "The Great Silence", astronomer David Brin summarized the frightening implications of the berserker hypothesis: it is entirely compatible with all the facts and logic of the Fermi paradox, but would mean that there exists no intelligent life left to be discovered. In the worst-case scenario, humanity has already alerted others to its existence, and is next in line to be destroyed.
There is no need to struggle to suppress the elements of the Drake equation in order to explain the Great Silence, nor need we suggest that no [intelligent aliens] anywhere would bear the cost of interstellar travel. It need only happen once for the results of this scenario to become the equilibrium conditions in the Galaxy. We would not have detected extra-terrestrial radio traffic β nor would any [intelligent aliens] have ever settled on Earth β because all were killed shortly after discovering radio.
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- "Berserker Hypothesis" | 2023-07-14 | 12 Upvotes 8 Comments
π Solomon Shereshevsky
Solomon Veniaminovich Shereshevsky (Russian: Π‘ΠΎΠ»ΠΎΠΌΠΎΠ½ ΠΠ΅Π½ΠΈΠ°ΠΌΠΈΠ½ΠΎΠ²ΠΈΡ Π¨Π΅ΡΠ΅ΡΠ΅Π²ΡΠΊΠΈΠΉ; 1886 β 1 May 1958), also known simply as 'Π¨' ('Sh'), 'S.', or Luria's S, was a Soviet journalist and mnemonist active in the 1920s. He was the subject of Alexander Luria's case study The Mind of a Mnemonist (1968).
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- "Solomon Shereshevsky" | 2024-01-03 | 77 Upvotes 11 Comments
π Archy
Archy is a software system whose user interface introduced a different approach for interacting with computers with respect to traditional graphical user interfaces. Designed by human-computer interface expert Jef Raskin, it embodies his ideas and established results about human-centered design described in his book The Humane Interface. These ideas include content persistence, modelessness, a nucleus with commands instead of applications, navigation using incremental text search, and a zooming user interface (ZUI). The system was being implemented at the Raskin Center for Humane Interfaces under Raskin's leadership. Since his death in February 2005 the project was continued by his team, which later shifted focus to the Ubiquity extension for the Firefox browser.
Archy in large part builds on Raskin's earlier work with the Apple Macintosh, Canon Cat, SwyftWare, and Ken Perlin's Pad ZUI system. It can be described as a combination of Canon Cat's text processing functions with a modern ZUI. Archy is more radically different from established systems than are Sun Microsystems' Project Looking Glass and Microsoft Research's "Task Gallery" prototype. While these systems build upon the WIMP desktop paradigm, Archy has been compared as similar to the Emacs text editor, although its design begins from a clean slate.
Archy used to be called The Humane Environment ("THE"). On January 1, 2005, Raskin announced the new name, and that Archy would be further developed by the non-profit Raskin Center for Humane Interfaces. The name "Archy" is a play on the Center's acronym, R-CHI. It is also an allusion to Don Marquis' archy and mehitabel poetry. Jef Raskin jokingly stated: "Yes, we named our software after a bug." (a cockroach), further playing with the meaning of bugs in software.
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- "Archy" | 2013-07-09 | 76 Upvotes 35 Comments
π Quadratrix of Hippias
The quadratrix or trisectrix of Hippias (also called the quadratrix of Dinostratus) is a curve which is created by a uniform motion. It is traced out by the crossing point of two lines, one moving by translation at a uniform speed, and the other moving by rotation around one of its points at a uniform speed. An alternative definition as a parametric curve leads to an equivalence between the quadratrix, the image of the Lambert W function, and the graph of the function .
The discovery of this curve is attributed to the Greek sophist Hippias of Elis, around 420 BC. Historians of mathematics have suggested that Hippias used it to solve the angle trisection problem, hence its name as a trisectrix. Later around 350 BC Dinostratus used it to solve the problem of squaring the circle, hence its name as a quadratrix. Dinostratus's theorem, used by Dinostratus to square the circle, relates an endpoint of the curve to the value of Ο. Both angle trisection and squaring the circle can be solved using a compass, a straightedge, and a given copy of this curve; however, they cannot be solved with compass and straightedge alone. Although a dense set of points on the curve can be constructed by compass and straightedge, allowing these problems to be approximated, the whole curve cannot be constructed in this way.
The quadratrix of Hippias is a transcendental curve. It is one of several curves used in Greek mathematics for squaring the circle.
π Kayfabe
In professional wrestling, kayfabe (also called work or worked) is the portrayal of staged events within the industry as "real" or "true", specifically the portrayal of competition, rivalries, and relationships between participants as being genuine and not of a staged or predetermined nature of any kind. The term kayfabe has evolved to also become a code word of sorts for maintaining this "reality" within the direct or indirect presence of the general public.
Kayfabe is often seen as the suspension of disbelief that is used to create the non-wrestling aspects of promotions, such as feuds, angles, and gimmicks in a manner similar to other forms of fictional entertainment. In relative terms, a wrestler breaking kayfabe during a show would be likened to an actor breaking character on-camera. Also, since wrestling is performed in front of a live audience, whose interaction with the show is crucial to its success, kayfabe can be compared to the fourth wall in acting, since hardly any conventional fourth wall exists to begin with. In general, everything in a professional wrestling show is to some extent scripted, or "kayfabe", even though at times it is portrayed as real-life.
Kayfabe was fiercely maintained for decades, but with the advent of the Internet wrestling community, and the sports entertainment movement, the pro wrestling industry has become less concerned with protecting so-called backstage secrets and typically maintains kayfabe only during the shows. Kayfabe is, however, occasionally broken during shows, usually when dealing with genuine injuries during a match or paying tribute to wrestlers.
π Tide-Predicting Machine No. 2
Tide-Predicting Machine No. 2, also known as Old Brass Brains, was a special-purpose mechanical computer that uses gears, pulleys, chains, and other mechanical components to compute the height and time of high and low tides for specific locations. The machine can perform tide calculations much faster than a person could do with pencil and paper. The U.S. Coast and Geodetic Survey put the machine into operation in 1910. It was used until 1965, when it was replaced by an electronic computer.
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- "Tide-Predicting Machine No. 2" | 2018-08-12 | 82 Upvotes 13 Comments
π James-Lange Theory
The JamesβLange theory is a hypothesis on the origin and nature of emotions and is one of the earliest theories of emotion within modern psychology. It was developed by philosopher John Dewey and named for two 19th-century scholars, William James and Carl Lange (see modern criticism for more on the theory's origin). The basic premise of the theory is that physiological arousal instigates the experience of emotion. Previously people considered emotions as reactions to some significant events or their features, i.e. events come first, and then there is an emotional response. James-Lange theory proposed that the state of the body can induce emotions or emotional dispositions. In other words, this theory suggests that when we feel teary, it generates a disposition for sad emotions; when our heartbeat is out of normality, it makes us feel anxiety. Instead of feeling an emotion and subsequent physiological (bodily) response, the theory proposes that the physiological change is primary, and emotion is then experienced when the brain reacts to the information received via the body's nervous system. It proposes that each specific category of emotion is attached to a unique and different pattern of physiological arousal and emotional behaviour in reaction due to an exciting stimulus.
The theory has been criticized and modified over the course of time, as one of several competing theories of emotion. Modern theorists have built on its ideas by proposing that the experience of emotion is modulated by both physiological feedback and other information, rather than consisting solely of bodily changes, as James suggested. Psychologist Tim Dalgleish states that most modern affective neuroscientists would support such a viewpoint. In 2002, a research paper on the autonomic nervous system stated that the theory has been "hard to disprove".
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- "James-Lange Theory" | 2023-12-01 | 38 Upvotes 12 Comments
π The Colditz Glider
The Colditz Cock was a glider built by British prisoners of war for an escape attempt from Oflag IV-C (Colditz Castle) in Germany.
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- "The Colditz Glider" | 2017-07-23 | 47 Upvotes 7 Comments