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🔗 Computing 🔗 Mathematics

In mathematical logic and type theory, the λ-cube is a framework introduced by Henk Barendregt to investigate the different dimensions in which the calculus of constructions is a generalization of the simply typed λ-calculus. Each dimension of the cube corresponds to a new kind of dependency between terms and types. Here, "dependency" refers to the capacity of a term or type to bind a term or type. The respective dimensions of the λ-cube correspond to:

• y-axis (${\displaystyle \uparrow }$): terms that can bind types, corresponding to polymorphism.
• x-axis (${\displaystyle \rightarrow }$): types that can bind terms, corresponding to dependent types.
• z-axis (${\displaystyle \nearrow }$): types that can bind types, corresponding to (binding) type operators.

The different ways to combine these three dimension yield the 8 vertices of the cube, each corresponding to a different kind of typed system. The λ-cube can be generalized into the concept of a pure type system.

🔗 Medicine 🔗 Biology

Closed-eye hallucinations and closed-eye visualizations (CEV) are a distinct class of hallucination. These types of hallucinations generally only occur when one's eyes are closed or when one is in a darkened room. They can be a form of phosphene. Some people report closed-eye hallucinations under the influence of psychedelics. These are reportedly of a different nature than the "open-eye" hallucinations of the same compounds. Similar hallucinations that occur due to loss of vision are called visual release hallucinations.

🔗 Germany

The Bielefeld conspiracy (German: Bielefeldverschwörung or Bielefeld-Verschwörung, pronounced [ˈbiːləfɛltfɛɐ̯ˌʃvøːʁʊŋ]) is a satire of conspiracy theories that claims that the city of Bielefeld, Germany, does not exist, but is an illusion propagated by various forces. First posted on the German Usenet in 1994, the conspiracy has since been mentioned in the city's marketing, and referenced by Chancellor Angela Merkel.

🔗 Physics

Wigner's friend is a thought experiment in theoretical quantum physics, first conceived by the physicist Eugene Wigner in 1961., and developed into a thought experiment by David Deutsch in 1985. The scenario involves an indirect observation of a quantum measurement: An observer W observes another observer F who performs a quantum measurement on a physical system. The two observers then formulate a statement about the physical system's state after the measurement according to the laws of quantum theory. However, in most of the interpretations of quantum theory, the resulting statements of the two observers contradict each other. This reflects a seeming incompatibility of two laws in quantum theory: the deterministic and continuous time evolution of the state of a closed system and the probabilistic, discontinuous collapse of the state of a system upon measurement. Wigner's friend is therefore directly linked to the measurement problem in quantum mechanics with its famous Schrödinger's cat paradox.

🔗 Novels 🔗 Slovenia

Alamut is a novel by Vladimir Bartol, first published in 1938 in Slovenian, dealing with the story of Hassan-i Sabbah and the Hashshashin, and named after their Alamut fortress. The maxim of the novel is "Nothing is an absolute reality; all is permitted". This book was one of the inspirations for the video game series Assassin's Creed.

Bartol first started to conceive the novel in the early 1930s, when he lived in Paris. In the French capital, he met with the Slovene literary critic Josip Vidmar, who introduced him to the story of Hassan-i Sabbah. A further stimulation for the novel came from the assassination of Alexander I of Yugoslavia perpetrated by Croatian and Bulgarian radical nationalists, on the alleged commission of the Italian fascist government. When it was originally published, the novel was sarcastically dedicated to Benito Mussolini.

🔗 Lists 🔗 Brands

The following three lists of generic and genericized trademarks are:

• marks which were originally legally protected trademarks, but have been genericized and have lost their legal status due to becoming generic terms,
• marks which have been abandoned and are now generic terms
• marks which are still legally protected as trademarks, at least in some jurisdictions

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Classical Greece and Rome 🔗 Military history/Classical warfare

Polybolos, meaning "multi thrower" in Greek, was an ancient Greek repeating ballista reputedly invented by Dionysius of Alexandria, a 3rd-century BC Greek engineer at the Rhodes arsenal, and used in antiquity.

Philo of Byzantium encountered and described a weapon similar to the polybolos, a catapult that like a modern machine gun could fire again and again without a need to reload. Philo left a detailed description of the gears that powered its chain drive, the oldest known application of such a mechanism, and that placed bolt after bolt into its firing slot.

🔗 Espionage 🔗 Companies 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Business 🔗 Military history/Maritime warfare 🔗 Military history/European military history 🔗 Military history/British military history 🔗 Military history/Military historiography

Jane's Information Group, now styled Janes, is a global open-source intelligence company specialising in military, national security, aerospace and transport topics, whose name derives from British author Fred T. Jane.

🔗 Radio Stations

United Biscuits Network (UBN) was an internal radio station serving the factories of United Biscuits (UB) in Britain that operated from 1970 to 1979.

In 1970 the BBC had a monopoly on radio broadcasting in Britain, although there were a few offshore pirate radio broadcasters, such as Radio Caroline. At one time factories had sought to avoid unnecessary background sound, but during the Second World War psychologists found that light background music (muzak) increased productivity at times it was low, a trend that continued after the war. But as jobs became deskilled and ever more monotonous, muzak became less effective, and staff turnover increased. United Biscuits was affected by this trend; Hector Laing, the managing director in the 1960s, needed to reduce the costs of high staff turnover. Inspired by the success of the pirate stations, Laing hired suitable staff, bought state-of-the-art broadcasting equipment, and set up UBN at UB headquarters in Osterley, west London (later the headquarters of broadcaster Sky UK).

🔗 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.