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🔗 Mathematics 🔗 Physics 🔗 Lists 🔗 Anthroponymy

Carl Friedrich Gauss (1777–1855) is the eponym of all of the topics listed below. There are over 100 topics all named after this German mathematician and scientist, all in the fields of mathematics, physics, and astronomy. The English eponymous adjective Gaussian is pronounced GOWSS-ee-ən.

🔗 Mathematics 🔗 Statistics

In probability theory and intertemporal portfolio choice, the Kelly criterion (or Kelly strategy or Kelly bet), also known as the scientific gambling method, is a formula for bet sizing that leads almost surely to higher wealth compared to any other strategy in the long run (i.e. approaching the limit as the number of bets goes to infinity). The Kelly bet size is found by maximizing the expected value of the logarithm of wealth, which is equivalent to maximizing the expected geometric growth rate. The Kelly Criterion is to bet a predetermined fraction of assets, and it can seem counterintuitive. It was described by J. L. Kelly Jr, a researcher at Bell Labs, in 1956.

For an even money bet, the Kelly criterion computes the wager size percentage by multiplying the percent chance to win by two, then subtracting one-hundred percent. So, for a bet with a 70% chance to win the optimal wager size is 40% of available funds.

The practical use of the formula has been demonstrated for gambling and the same idea was used to explain diversification in investment management. In the 2000s, Kelly-style analysis became a part of mainstream investment theory and the claim has been made that well-known successful investors including Warren Buffett and Bill Gross use Kelly methods. William Poundstone wrote an extensive popular account of the history of Kelly betting.

🔗 Mathematics 🔗 Ancient Egypt 🔗 British Museum

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 18 cm (7.1 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 33 cm (13 in) tall and consists of multiple parts which in total make it over 5 m (16 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, mysteries ... 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 1927–29 which included photographs of the text. A more recent overview of the Rhind Papyrus was published in 1987 by Robins and Shute.

🔗 Australia 🔗 Death 🔗 Australia/Sydney 🔗 Australia/Australian crime

The Bogle–Chandler case refers to the mysterious deaths of Gilbert Bogle and Margaret Chandler on the banks of the Lane Cove River in Sydney, Australia on 1 January 1963. The case became famous because of the circumstances in which the bodies were found and because the cause of death could not be established. In 2006 a filmmaker discovered evidence to suggest the cause of death was hydrogen sulphide gas. In the early hours of 1 January an eruption of gas from the polluted river bed may have occurred, causing the noxious fumes to pool in deadly quantities in the grove.

🔗 Environment 🔗 Marketing & Advertising 🔗 Anthropology 🔗 Environment/Sustainability

The Diderot effect is a social phenomenon related to consumer goods. It is based on two ideas. The first idea is that goods purchased by consumers will align with their sense of identity, and, as a result, will complement one another. The second idea states that the introduction of a new possession that deviates from the consumer's current complementary goods can result in a process of spiraling consumption. The term was coined by anthropologist and scholar of consumption patterns Grant McCracken in 1988, and is named after the French philosopher Denis Diderot (1713–1784), who first described the effect in an essay.

The term has become common in discussions of sustainable consumption and green consumerism, in regard to the process whereby a purchase or gift creates dissatisfaction with existing possessions and environment, provoking a potentially spiraling pattern of consumption with negative environmental, psychological, and social impacts.

🔗 Computer science

In information theory, linguistics and computer science, the Levenshtein distance is a string metric for measuring the difference between two sequences. Informally, the Levenshtein distance between two words is the minimum number of single-character edits (insertions, deletions or substitutions) required to change one word into the other. It is named after the Soviet mathematician Vladimir Levenshtein, who considered this distance in 1965.

Levenshtein distance may also be referred to as edit distance, although that term may also denote a larger family of distance metrics known collectively as edit distance. It is closely related to pairwise string alignments.

🔗 Computing 🔗 Computer science 🔗 Computing/Software 🔗 Computing/Free and open-source software 🔗 Linux

OpenSSI is an open-source single-system image clustering system. It allows a collection of computers to be treated as one large system, allowing applications running on any one machine access to the resources of all the machines in the cluster.

OpenSSI is based on the Linux operating system and was released as an open source project by Compaq in 2001. It is the final stage of a long process of development, stretching back to LOCUS, developed in the early 1980s.

🔗 Germany 🔗 Denmark 🔗 Automobiles

The CityEl is a 3-wheel lightweight electric car originally designed and manufactured in Denmark, but currently made in Germany by Citycom GmbH.

🔗 Aviation 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Aviation/aircraft 🔗 Military history/World War II 🔗 Military history/European military history 🔗 Military history/British military history

A bouncing bomb is a bomb designed to bounce to a target across water in a calculated manner to avoid obstacles such as torpedo nets, and to allow both the bomb's speed on arrival at the target and the timing of its detonation to be pre-determined, in a similar fashion to a regular naval depth charge. The inventor of the first such bomb was the British engineer Barnes Wallis, whose "Upkeep" bouncing bomb was used in the RAF's Operation Chastise of May 1943 to bounce into German dams and explode underwater, with effect similar to the underground detonation of the Grand Slam and Tallboy earthquake bombs, both of which he also invented.

🔗 Languages 🔗 Ottoman Empire 🔗 Western Asia

The language of the court and government of the Ottoman Empire was Ottoman Turkish, but many other languages were in contemporary use in parts of the empire. Although the minorities of the Ottoman Empire were free to use their language amongst themselves, if they needed to communicate with the government they had to use Ottoman Turkish.

The Ottomans had three influential languages: Turkish, spoken by the majority of the people in Anatolia and by the majority of Muslims of the Balkans except in Albania, Bosnia, and various Aegean Sea islands; Persian, initially used by the educated in northern portions of the Ottoman Empire before being displaced by Ottoman Turkish; and Arabic, used in southern portions of the Ottoman Empire; Arabic was spoken mainly in Arabia, North Africa, Mesopotamia and the Levant. Throughout the vast Ottoman bureaucracy Ottoman Turkish language was the official language, a version of Turkish, albeit with a vast mixture of both Arabic and Persian grammar and vocabulary.

Virtually all intellectual and literate pursuits were taken in Turkish language. Some ordinary people had to hire special "request-writers" (arzuhâlcis) to be able to communicate with the government. The ethnic groups continued to speak within their families and neighborhoods (mahalles) with their own languages (e.g., Jews, Greeks, Armenians, etc.) In villages where two or more populations lived together, the inhabitants would often speak each other's language. In cosmopolitan cities, people often spoke their family languages, many non-ethnic Turks spoke Turkish as a second language. Educated Ottoman Turks spoke Arabic and Persian, as these were the main foreign languages in the pre-Tanzimat era, with the former being used for science and the latter for literary affairs.

In the last two centuries, French and English emerged as popular languages, especially among the Christian Levantine communities. The elite learned French at school, and used European products as a fashion statement. The use of Ottoman Turkish for science and literature grew steadily under the Ottomans, while Persian declined in those functions. Ottoman Turkish, during the period, gained many loanwords from Arabic and Persian. Up to 88% of the vocabulary of a particular work would be borrowed from those two languages.

Linguistic groups were varied and overlapping. In the Balkan Peninsula, Slavic, Greek and Albanian speakers were the majority, but there were substantial minorities of Turks and Romance-speaking Vlachs. In most of Anatolia, Turkish was the majority language, but Greek, Armenian and, in the east and southeast, Kurdish were also spoken. In Syria, Iraq, Arabia, Egypt and north Africa, most of the population spoke varieties of Arabic with, above them, a Turkish-speaking elite. However, in no province of the Empire was there a unique language.