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🔗 Eleanor Cross

🔗 Death 🔗 England 🔗 Middle Ages 🔗 Middle Ages/History 🔗 Visual arts 🔗 Lincolnshire 🔗 Hertfordshire

The Eleanor crosses were a series of twelve tall and lavishly decorated stone monuments topped with crosses erected in a line down part of the east of England. King Edward I had them built between 1291 and about 1295 in memory of his beloved wife Eleanor of Castile. The King and Queen had been married for 36 years and she stayed by the King’s side through his many travels. While on a royal progress, she died in the East Midlands in November 1290, perhaps due to fever. The crosses, erected in her memory, marked the nightly resting-places along the route taken when her body was transported to Westminster Abbey near London.

The crosses stood at Lincoln, Grantham and Stamford, all in Lincolnshire; Geddington and Hardingstone in Northamptonshire; Stony Stratford in Buckinghamshire; Woburn and Dunstable in Bedfordshire; St Albans and Waltham (now Waltham Cross) in Hertfordshire; Cheapside in London; and Charing (now Charing Cross) in Westminster.

Three of the medieval monuments – those at Geddington, Hardingstone and Waltham Cross – survive more or less intact; but the other nine, other than a few fragments, are lost. The largest and most ornate of the twelve was the Charing Cross. Several memorials and elaborated reproductions of the crosses have been erected, including the Queen Eleanor Memorial Cross at Charing Cross Station (built 1865).

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🔗 Schönhage–Strassen Algorithm

🔗 Computer science

The Schönhage–Strassen algorithm is an asymptotically fast multiplication algorithm for large integers. It was developed by Arnold Schönhage and Volker Strassen in 1971. The run-time bit complexity is, in Big O notation, O ( n log n log log n ) {\displaystyle O(n\cdot \log n\cdot \log \log n)} for two n-digit numbers. The algorithm uses recursive fast Fourier transforms in rings with 2n+1 elements, a specific type of number theoretic transform.

The Schönhage–Strassen algorithm was the asymptotically fastest multiplication method known from 1971 until 2007, when a new method, Fürer's algorithm, was announced with lower asymptotic complexity; however, Fürer's algorithm currently only achieves an advantage for astronomically large values and is used only in Basic Polynomial Algebra Subprograms (BPAS) (see Galactic algorithms).

In practice the Schönhage–Strassen algorithm starts to outperform older methods such as Karatsuba and Toom–Cook multiplication for numbers beyond 2215 to 2217 (10,000 to 40,000 decimal digits). The GNU Multi-Precision Library uses it for values of at least 1728 to 7808 64-bit words (33,000 to 150,000 decimal digits), depending on architecture. There is a Java implementation of Schönhage–Strassen which uses it above 74,000 decimal digits.

Applications of the Schönhage–Strassen algorithm include mathematical empiricism, such as the Great Internet Mersenne Prime Search and computing approximations of π, as well as practical applications such as Kronecker substitution, in which multiplication of polynomials with integer coefficients can be efficiently reduced to large integer multiplication; this is used in practice by GMP-ECM for Lenstra elliptic curve factorization.

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🔗 Lake Agassiz

🔗 Canada 🔗 Geology 🔗 Canada/Ontario 🔗 Canada/Manitoba 🔗 Canada/Geography of Canada 🔗 Lakes 🔗 Canada/Saskatchewan

Lake Agassiz was a very large glacial lake in central North America. Fed by glacial meltwater at the end of the last glacial period, its area was larger than all of the modern Great Lakes combined though its mean depth was not as great as that of many major lakes today.

First postulated in 1823 by William H. Keating, it was named by Warren Upham in 1879 after Louis Agassiz, when Upham recognized that the lake was formed by glacial action.

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🔗 A*

🔗 Computing 🔗 Computer science 🔗 Mathematics

A* (pronounced "A-star") is a graph traversal and path search algorithm, which is often used in computer science due to its completeness, optimality, and optimal efficiency. One major practical drawback is its O ( b d ) {\displaystyle O(b^{d})} space complexity, as it stores all generated nodes in memory. Thus, in practical travel-routing systems, it is generally outperformed by algorithms which can pre-process the graph to attain better performance, as well as memory-bounded approaches; however, A* is still the best solution in many cases.

Peter Hart, Nils Nilsson and Bertram Raphael of Stanford Research Institute (now SRI International) first published the algorithm in 1968. It can be seen as an extension of Edsger Dijkstra's 1959 algorithm. A* achieves better performance by using heuristics to guide its search.

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  • "A*" | 2019-08-10 | 50 Upvotes 6 Comments

🔗 Fan death

🔗 Death 🔗 Korea 🔗 Skepticism 🔗 Alternative Views 🔗 Korea/Korean popular culture working group

Fan death is a widely held belief in Korean culture, where it is thought that running an electric fan in a closed room with unopened or no windows will prove fatal. Despite no concrete evidence to support the concept, belief in fan death persists to this day in Korea, and also to a lesser extent in Japan and Russia.

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🔗 Principle of Least Astonishment

🔗 Computing 🔗 Philosophy

The principle of least astonishment (POLA), also called the principle of least surprise (alternatively a "law" or "rule") applies to user interface and software design. A typical formulation of the principle, from 1984, is: "If a necessary feature has a high astonishment factor, it may be necessary to redesign the feature."

More generally, the principle means that a component of a system should behave in a way that most users will expect it to behave; the behavior should not astonish or surprise users.

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🔗 The knowledge argument

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Philosophy/Philosophy of mind

The knowledge argument (also known as Mary's room or Mary the super-scientist) is a philosophical thought experiment proposed by Frank Jackson in his article "Epiphenomenal Qualia" (1982) and extended in "What Mary Didn't Know" (1986). The experiment is intended to argue against physicalism—the view that the universe, including all that is mental, is entirely physical. The debate that emerged following its publication became the subject of an edited volume—There's Something About Mary (2004)—which includes replies from such philosophers as Daniel Dennett, David Lewis, and Paul Churchland.

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🔗 Gish Gallop

🔗 Skepticism 🔗 Psychology 🔗 Debating

The Gish gallop is a technique used during debating that focuses on overwhelming an opponent with as many arguments as possible, without regard for accuracy or strength of the arguments. The term was coined by Eugenie Scott and named after the creationist Duane Gish, who used the technique frequently against proponents of evolution.

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🔗 Wronger Than Wrong

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Business 🔗 Philosophy/Philosophy of science 🔗 Science

Wronger than wrong is a statement that equates two errors when one of the errors is clearly more wrong than the other. It was described by Michael Shermer as Asimov's axiom. The mistake was discussed in Isaac Asimov's book of essays The Relativity of Wrong as well as in a 1989 article of the same name in the Fall 1989 issue of the Skeptical Inquirer:

When people thought the Earth was flat, they were wrong. When people thought the Earth was spherical, they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together.

Asimov explained that science is both progressive and cumulative. Even though scientific theories are later proven wrong, the degree of their wrongness attenuates with time as they are modified in response to the mistakes of the past. For example, data collected from satellite measurements show, to a high level of precision, how the Earth's shape differs from a perfect sphere or even an oblate spheroid or a geoid.

Shermer stated that being wronger than wrong is actually worse than being not even wrong (that is, being unfalsifiable).

According to John Jenkins, who reviewed The Relativity of Wrong, the title essay of Asimov's book is the one "which I think is important both for understanding Asimov's thinking about science and for arming oneself against the inevitable anti-science attack that one often hears – [that] theories are always preliminary and science really doesn't 'know' anything."

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🔗 Yenish people

🔗 Europe 🔗 Ethnic groups

The Yenish (German: Jenische; French: Yéniche) are an itinerant group in Western Europe who live mostly in Germany, Austria, Switzerland, Luxembourg, Belgium, and parts of France, roughly centred on the Rhineland. A number of theories for the group's origins have been proposed, including that the Yenish descended from members of the marginalized and vagrant poor classes of society of the early modern period, before emerging as a distinct group by the early 19th century. Most of the Yenish became sedentary in the course of the mid-19th to 20th centuries.

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