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🔗 Computing 🔗 Classical Greece and Rome 🔗 Greece 🔗 Astronomy 🔗 History of Science 🔗 Alternative Views 🔗 Time

The Antikythera mechanism (, ) is an ancient hand powered Greek analogue computer which has also been described as the first example of such device used to predict astronomical positions and eclipses for calendar and astrological purposes decades in advance. It could also be used to track the four-year cycle of athletic games which was similar to an Olympiad, the cycle of the ancient Olympic Games.

This artefact was retrieved from the sea in 1901, and identified on 17 May 1902 as containing a gear by archaeologist Valerios Stais, among wreckage retrieved from a shipwreck off the coast of the Greek island Antikythera. The instrument is believed to have been designed and constructed by Greek scientists and has been variously dated to about 87 BC, or between 150 and 100 BC, or to 205 BC, or to within a generation before the shipwreck, which has been dated to approximately 70–60 BC.

The device, housed in the remains of a 34 cm × 18 cm × 9 cm (13.4 in × 7.1 in × 3.5 in) wooden box, was found as one lump, later separated into three main fragments which are now divided into 82 separate fragments after conservation efforts. Four of these fragments contain gears, while inscriptions are found on many others. The largest gear is approximately 14 centimetres (5.5 in) in diameter and originally had 223 teeth.

It is a complex clockwork mechanism composed of at least 30 meshing bronze gears. A team led by Mike Edmunds and Tony Freeth at Cardiff University used modern computer x-ray tomography and high resolution surface scanning to image inside fragments of the crust-encased mechanism and read the faintest inscriptions that once covered the outer casing of the machine.

Detailed imaging of the mechanism suggests that it had 37 gear wheels enabling it to follow the movements of the Moon and the Sun through the zodiac, to predict eclipses and even to model the irregular orbit of the Moon, where the Moon's velocity is higher in its perigee than in its apogee. This motion was studied in the 2nd century BC by astronomer Hipparchus of Rhodes, and it is speculated that he may have been consulted in the machine's construction.

The knowledge of this technology was lost at some point in antiquity. Similar technological works later appeared in the medieval Byzantine and Islamic worlds, but works with similar complexity did not appear again until the development of mechanical astronomical clocks in Europe in the fourteenth century. All known fragments of the Antikythera mechanism are now kept at the National Archaeological Museum in Athens, along with a number of artistic reconstructions and replicas of the mechanism to demonstrate how it may have looked and worked.

🔗 Plants 🔗 Psychoactive and Recreational Drugs 🔗 Altered States of Consciousness 🔗 South America

Ayahuasca is a South American (pan-Amazonian) psychoactive brew used both socially and as ceremonial spiritual medicine among the indigenous peoples of the Amazon basin. It is a psychedelic and entheogenic brew commonly made out of the Banisteriopsis caapi vine, the Psychotria viridis shrub or a substitute, and possibly other ingredients. A chemically similar preparation, sometimes called "pharmahuasca", can be prepared using N,N-Dimethyltryptamine (DMT) and a pharmaceutical monoamine oxidase inhibitor (MAOI), such as isocarboxazid. B. caapi contains several alkaloids that act as MAOIs, which are required for DMT to be orally active. Ayahuasca is prepared in a tea that, when consumed, causes an altered state of consciousness or "high", including visual hallucinations and altered perceptions of reality.

The other required ingredient is a plant that contains the primary psychoactive, DMT. This is usually the shrub P. viridis, but Diplopterys cabrerana may be used as a substitute. Other plant ingredients often or occasionally used in the production of ayahuasca include Justicia pectoralis, one of the Brugmansia (especially Brugmansia insignis and Brugmansia versicolor, or a hybrid breed) or Datura species, and mapacho (Nicotiana rustica).

🔗 Economics 🔗 Taxation

A land value tax (LVT) is a levy on the value of land without regard to buildings, personal property and other improvements. It is also known as a location value tax, a site valuation tax, split rate tax, or a site-value rating,

Land value taxes are generally favored by economists as they do not cause economic inefficiency, and reduce inequality. A land value tax is a progressive tax, in that the tax burden falls on land owners, because land ownership is correlated with wealth and income. The land value tax has been referred to as "the perfect tax" and the economic efficiency of a land value tax has been accepted since the eighteenth century. Economists since Adam Smith and David Ricardo have advocated this tax because it does not hurt economic activity or discourage or subsidize development.

LVT is associated with Henry George, whose ideology became known as Georgism. George argued that taxing the land value is most logical source of public revenue because the supply of land is fixed and because public infrastructure improvements would be reflected in (and thus paid for) by increased land values.

Land value taxation is currently implemented throughout Denmark, Estonia, Lithuania, Russia, Singapore, and Taiwan; it has also been applied to lesser extents in parts of Australia, Mexico (Mexicali), and the United States (e.g., Pennsylvania).

🔗 Psychoactive and Recreational Drugs

The Marsh Chapel Experiment, also called the "Good Friday Experiment", was a 1962 experiment conducted on Good Friday at Boston University's Marsh Chapel. Walter N. Pahnke, a graduate student in theology at Harvard Divinity School, designed the experiment under the supervision of Timothy Leary, Richard Alpert, and the Harvard Psilocybin Project. Pahnke's experiment investigated whether psilocybin (the active principle in psilocybin mushrooms) would act as a reliable entheogen in religiously predisposed subjects.

🔗 Aviation 🔗 Disaster management

Crew resource management or cockpit resource management (CRM) is a set of training procedures for use in environments where human error can have devastating effects. Used primarily for improving aviation safety, CRM focuses on interpersonal communication, leadership, and decision making in the cockpit of an airliner. Its pioneer was David Beaty, a former Royal Air Force pilot and later a BOAC pilot who wrote his seminal book The Human Factor in Aircraft Accidents in the late 1950s. Despite the considerable development of electronic aids since then, many principles he developed continue to prove effective today.

Crew resource management formally began with a National Transportation Safety Board (NTSB) recommendation made during their investigation of the 1978 United Airlines Flight 173 crash. The issues surrounding that crash included a DC-8 crew running out of fuel over Portland, Oregon while troubleshooting a landing gear problem.

The term "cockpit resource management" (later generalized to "crew resource management") was coined in 1979 by NASA psychologist John Lauber who had studied communication processes in cockpits for several years. While retaining a command hierarchy, the concept was intended to foster a less authoritarian cockpit culture, where co-pilots were encouraged to question captains if they observed them making mistakes.

Crew resource management grew out of the 1977 Tenerife airport disaster where two Boeing 747 aircraft collided on the runway killing 583 people. A few weeks later, NASA held a workshop on the topic, endorsing this innovative training. United Airlines was the first airline to provide CRM training for its cockpit crews in 1981. By the 1990s, it had become a global standard.

United Airlines additionally trained their flight attendants to use CRM in conjunction with the pilots to provide another layer of enhanced communication and teamwork. Studies have shown that by both work groups using CRM together, communication barriers are reduced and problems can be solved more efficiently, leading to increased safety. CRM training concepts have been modified for application to a wide range of activities where people must make dangerous time-critical decisions. These arenas include air traffic control, ship handling, firefighting, and medical operating rooms.

🔗 Philosophy 🔗 Philosophy/Philosophy of science 🔗 Philosophy/Epistemology

Molyneux's problem is a thought experiment in philosophy concerning immediate recovery from blindness. It was first formulated by William Molyneux, and notably referred to in John Locke's An Essay Concerning Human Understanding (1689). The problem can be stated in brief, "if a man born blind can feel the differences between shapes such as spheres and cubes, could he, if given the ability to see, distinguish those objects by sight alone, in reference to the tactile schemata he already possessed?"

🔗 Politics 🔗 Socialism 🔗 Holidays 🔗 Organized Labour 🔗 Neopaganism

May Day is a public holiday in some regions, usually celebrated on 1 May or the first Monday of May. It is an ancient festival marking the first day of summer, and a current traditional spring holiday in many European cultures. Dances, singing, and cake are usually part of the festivities.

In 1889, May Day was chosen as the date for International Workers' Day by the socialists and communists of the Second International, as well as anarchists, labor activists, and leftists in general around the world, to commemorate the Haymarket affair in Chicago and the struggle for an eight-hour working day. International Workers' Day is also called "May Day", but it is a different celebration from the traditional May Day.

🔗 Russia 🔗 Mathematics 🔗 Russia/science and education in Russia 🔗 Switzerland 🔗 Anthroponymy

In mathematics and physics, many topics are named in honor of Swiss mathematician Leonhard Euler (1707–1783), who made many important discoveries and innovations. Many of these items named after Euler include their own unique function, equation, formula, identity, number (single or sequence), or other mathematical entity. Many of these entities have been given simple and ambiguous names such as Euler's function, Euler's equation, and Euler's formula.

Euler's work touched upon so many fields that he is often the earliest written reference on a given matter. In an effort to avoid naming everything after Euler, some discoveries and theorems are attributed to the first person to have proved them after Euler.

🔗 United States 🔗 Crime 🔗 Television 🔗 Chicago 🔗 Illinois 🔗 United States/American television

A broadcast signal hijacking of two television stations in Chicago, Illinois was carried out on November 22, 1987, in an act of video piracy. The stations' broadcasts were interrupted by a video of an unknown person wearing a Max Headroom mask and costume, accompanied by distorted audio.

The first incident took place for 25 seconds during the sports segment of WGN-TV's 9:00 p.m. news broadcast; the second occurred around two hours later, for about 90 seconds during PBS affiliate WTTW's broadcast of Doctor Who.

The hacker made references to Max Headroom's endorsement of Coca-Cola, the TV series Clutch Cargo, WGN anchor Chuck Swirsky; and "all the greatest world newspaper nerds", a reference to WGN's call letters, which stand for "World's Greatest Newspaper". A corrugated panel swiveled back and forth mimicking Max Headroom's geometric background effect. The video ended with a pair of exposed buttocks being spanked with a flyswatter before normal programming resumed. The culprits were never caught or identified.

🔗 Brands 🔗 Toys

Spirograph is a geometric drawing device that produces mathematical roulette curves of the variety technically known as hypotrochoids and epitrochoids. The well known toy version was developed by British engineer Denys Fisher and first sold in 1965.

The name has been a registered trademark of Hasbro Inc. since 1998 following purchase of the company that had acquired the Denys Fisher company. The Spirograph brand was relaunched worldwide in 2013, with its original product configurations, by Kahootz Toys.