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πŸ”— SKI Combinator Calculus

πŸ”— Mathematics

The SKI combinator calculus is a combinatory logic system and a computational system. It can be thought of as a computer programming language, though it is not convenient for writing software. Instead, it is important in the mathematical theory of algorithms because it is an extremely simple Turing complete language. It can be likened to a reduced version of the untyped lambda calculus. It was introduced by Moses SchΓΆnfinkel and Haskell Curry.

All operations in lambda calculus can be encoded via abstraction elimination into the SKI calculus as binary trees whose leaves are one of the three symbols S, K, and I (called combinators).

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πŸ”— Ackermann Steering Geometry

πŸ”— Technology

Ackermann steering geometry is a geometric arrangement of linkages in the steering of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radii.

It was invented by the German carriage builder Georg Lankensperger in Munich in 1817, then patented by his agent in England, Rudolph Ackermann (1764–1834) in 1818 for horse-drawn carriages. Erasmus Darwin may have a prior claim as the inventor dating from 1758.

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πŸ”— Implicate and explicate order

πŸ”— Physics πŸ”— Skepticism

Implicate order and explicate order are ontological concepts for quantum theory coined by theoretical physicist David Bohm during the early 1980s. They are used to describe two different frameworks for understanding the same phenomenon or aspect of reality. In particular, the concepts were developed in order to explain the bizarre behavior of subatomic particles which quantum physics struggles to explain.

In Bohm's Wholeness and the Implicate Order, he used these notions to describe how the appearance of such phenomena might appear differently, or might be characterized by, varying principal factors, depending on contexts such as scales. The implicate (also referred to as the "enfolded") order is seen as a deeper and more fundamental order of reality. In contrast, the explicate or "unfolded" order include the abstractions that humans normally perceive. As he wrote,

In the enfolded [or implicate] order, space and time are no longer the dominant factors determining the relationships of dependence or independence of different elements. Rather, an entirely different sort of basic connection of elements is possible, from which our ordinary notions of space and time, along with those of separately existent material particles, are abstracted as forms derived from the deeper order. These ordinary notions in fact appear in what is called the "explicate" or "unfolded" order, which is a special and distinguished form contained within the general totality of all the implicate orders (Bohm 1980, p.Β xv).

πŸ”— Breeding back

πŸ”— Extinction

Breeding back is a form of artificial selection by the deliberate selective breeding of domestic animals, in an attempt to achieve an animal breed with a phenotype that resembles a wild type ancestor, usually one that has gone extinct. Breeding back is not to be confused with dedomestication.

It must be kept in mind that a breeding-back breed may be very similar to the extinct wild type in phenotype, ecological niche, and to some extent genetics, but the original gene pool of that wild type was eliminated with its extinction. A breeding-back attempt cannot actually recreate the extinct wild type of the breeding target, as an extinct wild type cannot be resurrected through it. Furthermore, even the superficial authenticity of a bred-back animal depends on the quality of the stock used to breed the new lineage. As a result of this, some breeds, like Heck cattle, are at best a vague look-alike of the extinct wild type aurochs, according to the literature.

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πŸ”— Social Facilitation

πŸ”— Philosophy πŸ”— Politics πŸ”— Psychology πŸ”— Marketing & Advertising πŸ”— Philosophy/Philosophy of science πŸ”— Philosophy/Epistemology πŸ”— Sociology πŸ”— Education

Social facilitation is defined as improvement or decrease in individual performance when working with other people rather than alone.

In addition to working together with other people, social facilitation also occurs in the mere presence of other people. Previous research has found that individual performance is improved by coaction, performing a task in the presence of others who are performing a similar task, and having an audience while performing a certain task. An example of coaction triggering social facilitation can be seen in instances where a cyclist's performance is improved when cycling along with other cyclists as compared to cycling alone. An instance where having an audience triggers social facilitation can be observed where a weightlifter lifts heavier weight in the presence of an audience. Social facilitation has occasionally been attributed to the fact that certain people are more susceptible to social influence, with the argument that personality factors can make these people more aware of evaluation.

The Yerkes-Dodson law, when applied to social facilitation, states that "the mere presence of other people will enhance the performance in speed and accuracy of well-practiced tasks, but will degrade in the performance of less familiar tasks." Compared to their performance when alone, when in the presence of others they tend to perform better on simple or well-rehearsed tasks and worse on complex or new ones.

The audience effect attempts to explain psychologically why the presence of an audience leads to people performing tasks better in some cases and worse in others. This idea was further explored when some studies showed that the presence of a passive audience facilitated the better performance of a simple task, while other studies showed that the presence of a passive audience inhibited the performance of a more difficult task or one that was not well practiced, possibly due to psychological pressure or stress. (See Yerkes–Dodson law.)

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πŸ”— Searches for Noah's Ark

πŸ”— Religion πŸ”— Skepticism πŸ”— Bible πŸ”— Islam πŸ”— Judaism πŸ”— Iraq πŸ”— Turkey πŸ”— Mythology

Searches for Noah's Ark have been reported since antiquity, as ancient scholars sought to affirm the historicity of the Genesis flood narrative by citing accounts of relics recovered from the Ark.:β€Š43–47β€Š With the emergence of biblical archaeology in the 19th century, the potential of a formal search attracted interest in alleged discoveries and hoaxes. By the 1940s, expeditions were being organized to follow up on these apparent leads.:β€Š8–9β€Š This modern search movement has been informally called "arkeology".

In 2020, the young Earth creationist group the Institute for Creation Research acknowledged that, despite many expeditions, Noah's Ark had not been found and is unlikely to be found. Many of the supposed findings and methods used in the search are regarded as pseudoscience and pseudoarchaeology by geologists and archaeologists.:β€Š581–582β€Š:β€Š72–75β€Š

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πŸ”— Elwyn Berlekamp has died

πŸ”— United States πŸ”— Biography πŸ”— Biography/science and academia πŸ”— United States/Ohio πŸ”— University of California

Elwyn Ralph Berlekamp (September 6, 1940 – April 9, 2019) was an American mathematician known for his work in computer science, coding theory and combinatorial game theory. He was a professor emeritus of mathematics and EECS at the University of California, Berkeley.

Berlekamp was the inventor of an algorithm to factor polynomials, and was one of the inventors of the Berlekamp–Welch algorithm and the Berlekamp–Massey algorithms, which are used to implement Reed–Solomon error correction.

Berlekamp had also been active in money management. In 1986, he began information-theoretic studies of commodity and financial futures.

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πŸ”— Coffin Texts

πŸ”— Death πŸ”— Ancient Egypt πŸ”— Ancient Egypt/Egyptian religion

The Coffin Texts are a collection of ancient Egyptian funerary spells written on coffins beginning in the First Intermediate Period. They are partially derived from the earlier Pyramid Texts, reserved for royal use only, but contain substantial new material related to everyday desires, indicating a new target audience of common people. Ordinary Egyptians who could afford a coffin had access to these funerary spells and the pharaoh no longer had exclusive rights to an afterlife.

As the modern name of this collection of some 1,185 spells implies, they were mostly inscribed on Middle Kingdom coffins. They were also sometimes written on tomb walls, stelae, canopic chests, papyri and mummy masks. Due to the limited writing surfaces of some of these objects, the spells were often abbreviated, giving rise to long and short versions, some of which were later copied in the Book of the Dead.

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πŸ”— Origins of the β€œOK” Word

πŸ”— Linguistics πŸ”— Linguistics/Etymology

OK (spelling variations include okay, O.K., and ok) is an English word (originally American English) denoting approval, acceptance, agreement, assent, acknowledgment, or a sign of indifference. OK is frequently used as a loanword in other languages. It has been described as the most frequently spoken or written word on the planet. The origins of the word are disputed.

As an adjective, OK principally means "adequate" or "acceptable" as a contrast to "bad" ("The boss approved this, so it is OK to send out"); it can also mean "mediocre" when used in contrast with "good" ("The french fries were great, but the burger was just OK"). It fulfills a similar role as an adverb ("Wow, you did OK for your first time skiing!"). As an interjection, it can denote compliance ("OK, I will do that"), or agreement ("OK, that is fine"). It can mean "assent" when it is used as a noun ("the boss gave her the OK to the purchase") or, more colloquially, as a verb ("the boss OKed the purchase"). OK, as an adjective, can express acknowledgement without approval. As a versatile discourse marker or back-channeling item, it can also be used with appropriate intonation to show doubt or to seek confirmation ("OK?", "Is that OK?").

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πŸ”— Cox-Zucker_machine

πŸ”— Mathematics

The Cox–Zucker machine is an algorithm created by David A. Cox and Steven Zucker. This algorithm determines if a given set of sections provides a basis (up to torsion) for the Mordell–Weil group of an elliptic surface E β†’ S where S is isomorphic to the projective line.

The algorithm was first published in the 1979 paper "Intersection numbers of sections of elliptic surfaces" by Cox and Zucker, and it was later named the "Cox–Zucker machine" by Charles Schwartz in 1984. The name is a homophone for an obscenity, and this was a deliberate move by Cox and Zucker, who conceived of the idea of coauthoring a paper as graduate students at Princeton for the express purpose of enabling this joke, a joke they followed through on while professors at Rutgers five years later. As Cox explained in a memorial tribute to Zucker in Notices of the American Mathematical Society in 2021: "A few weeks after we met, we realized that we had to write a joint paper because the combination of our last names, in the usual alphabetical order, is remarkably obscene."

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