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🔗 Internet culture 🔗 Linguistics 🔗 Numismatics 🔗 Cryptocurrency

Hodl ( HOD-əl; often written HODL) is slang in the cryptocurrency community for holding the cryptocurrency rather than selling it. A person who does this is known as a Hodler. It originated in a December 2013 post on the Bitcoin Forum message board by an apparently inebriated user who posted with a typo in the subject, "I AM HODLING." It is often backronymed to "hold on for dear life". In 2017, Quartz listed it as one of the essential slang terms in Bitcoin culture, and described it as a stance, "to stay invested in bitcoin and not to capitulate in the face of plunging prices." TheStreet.com referred to it as the "favorite mantra" of Bitcoin holders. Bloomberg News referred to it as a "mantra" for holders during market routs.

🔗 Socialism 🔗 Urban studies and planning 🔗 New Jersey

The North American Phalanx was a secular utopian socialist commune located in Colts Neck Township, Monmouth County, New Jersey. The community was the longest-lived of about 30 Fourierist Associations in the United States which emerged during a brief burst of popularity during the decade of the 1840s.

The North American Phalanx was established in September 1843 and included the active participation of writer Albert Brisbane and newspaper publisher Horace Greeley, two of the leading figures of the Fourierist movement. The Association was disbanded in January 1856, following a catastrophic fire which destroyed a number of the community's productive enterprises. At the time of its termination it was the last of about 30 Fourierist Associations established during the 1840s still in existence and thus was the longest-lived.

The main residential dwelling of the phalanx, a three-story wooden structure, stood vacant until it was itself destroyed by fire in November 1972.

🔗 Musical Instruments 🔗 Percussion

A lithophone is a musical instrument consisting of a rock or pieces of rock which are struck to produce musical notes. Notes may be sounded in combination (producing harmony) or in succession (melody). The lithophone is an idiophone comparable to instruments such as the glockenspiel, vibraphone, xylophone and marimba.

In the Hornbostel-Sachs classification system, lithophones are designated as '111.22' – directly-struck percussion plaques.

🔗 Biology 🔗 Neuroscience 🔗 Physiology 🔗 Science

A microtome (from the Greek mikros, meaning "small", and temnein, meaning "to cut") is a cutting tool used to produce extremely thin slices of material known as sections, with the process being termed microsectioning. Important in science, microtomes are used in microscopy for the preparation of samples for observation under transmitted light or electron radiation.

Microtomes use steel, glass or diamond blades depending upon the specimen being sliced and the desired thickness of the sections being cut. Steel blades are used to prepare histological sections of animal or plant tissues for light microscopy. Glass knives are used to slice sections for light microscopy and to slice very thin sections for electron microscopy. Industrial grade diamond knives are used to slice hard materials such as bone, teeth and tough plant matter for both light microscopy and for electron microscopy. Gem-quality diamond knives are also used for slicing thin sections for electron microscopy.

Microtomy is a method for the preparation of thin sections for materials such as bones, minerals and teeth, and an alternative to electropolishing and ion milling. Microtome sections can be made thin enough to section a human hair across its breadth, with section thickness between 50 nm and 100 μm.

🔗 Aviation 🔗 Disaster management 🔗 Aviation/Aviation accident 🔗 United Kingdom 🔗 Indonesia

British Airways Flight 9, sometimes referred to by its callsign Speedbird 9 or as the Jakarta incident, was a scheduled British Airways flight from London Heathrow to Auckland, with stops in Bombay, Kuala Lumpur, Perth, and Melbourne.

On 24 June 1982, the route was flown by the City of Edinburgh, a Boeing 747-200. The aircraft flew into a cloud of volcanic ash thrown up by the eruption of Mount Galunggung (approximately 110 miles (180 km) south-east of Jakarta, Indonesia), resulting in the failure of all four engines. The reason for the failure was not immediately apparent to the crew or air traffic control. The aircraft was diverted to Jakarta in the hope that enough engines could be restarted to allow it to land there. The aircraft glided out of the ash cloud, and all engines were restarted (although one failed again soon after), allowing the aircraft to land safely at the Halim Perdanakusuma Airport in Jakarta.

The crew members of the accident segment had boarded the aircraft in Kuala Lumpur, while many of the passengers had been aboard since the flight began in London.

🔗 Biography 🔗 Russia 🔗 Belarus

On 11 March 2022, Mark Izraylevich Bernstein (Russian: Марк Израйлевич Бернштейн), a Belarusian blogger and editor of the Russian-language Wikipedia based in Minsk, was detained by the Belarusian GUBOPiK security force after online accusations of violating the 2022 Russian fake news law for his editing of Wikipedia articles on the topic of the 2022 Russian invasion of Ukraine. He was sentenced to 15 days' administrative arrest under Article 24.3 of the Administrative Code of Belarus (for disobedience to police officers).

🔗 Mathematics

The Banach–Tarski paradox is a theorem in set-theoretic geometry, which states the following: Given a solid ball in 3‑dimensional space, there exists a decomposition of the ball into a finite number of disjoint subsets, which can then be put back together in a different way to yield two identical copies of the original ball. Indeed, the reassembly process involves only moving the pieces around and rotating them without changing their shape. However, the pieces themselves are not "solids" in the usual sense, but infinite scatterings of points. The reconstruction can work with as few as five pieces.

A stronger form of the theorem implies that given any two "reasonable" solid objects (such as a small ball and a huge ball), the cut pieces of either one can be reassembled into the other. This is often stated informally as "a pea can be chopped up and reassembled into the Sun" and called the "pea and the Sun paradox".

The reason the Banach–Tarski theorem is called a paradox is that it contradicts basic geometric intuition. "Doubling the ball" by dividing it into parts and moving them around by rotations and translations, without any stretching, bending, or adding new points, seems to be impossible, since all these operations ought, intuitively speaking, to preserve the volume. The intuition that such operations preserve volumes is not mathematically absurd and it is even included in the formal definition of volumes. However, this is not applicable here because in this case it is impossible to define the volumes of the considered subsets. Reassembling them reproduces a volume, which happens to be different from the volume at the start.

Unlike most theorems in geometry, the proof of this result depends in a critical way on the choice of axioms for set theory. It can be proven using the axiom of choice, which allows for the construction of non-measurable sets, i.e., collections of points that do not have a volume in the ordinary sense, and whose construction requires an uncountable number of choices.

It was shown in 2005 that the pieces in the decomposition can be chosen in such a way that they can be moved continuously into place without running into one another.

🔗 Medicine 🔗 Viruses

Variolation or inoculation was the method first used to immunize an individual against smallpox (Variola) with material taken from a patient or a recently variolated individual, in the hope that a mild, but protective, infection would result. The procedure was most commonly carried out by inserting/rubbing powdered smallpox scabs or fluid from pustules into superficial scratches made in the skin. The patient would develop pustules identical to those caused by naturally occurring smallpox, usually producing a less severe disease than naturally acquired smallpox. Eventually, after about two to four weeks, these symptoms would subside, indicating successful recovery and immunity. The method was first used in China and the Middle East before it was introduced into England and North America in the 1720s in the face of some opposition. The method is no longer used today. It was replaced by smallpox vaccine, a safer alternative. This in turn led to the development of the many vaccines now available against other diseases.

🔗 Human rights 🔗 Soviet Union 🔗 Russia 🔗 Military history 🔗 Crime 🔗 Death 🔗 Socialism 🔗 Poland 🔗 Military history/World War II 🔗 Military history/Russian, Soviet and CIS military history 🔗 Russia/history of Russia 🔗 Military history/Polish military history 🔗 Military history/European military history

The Katyn massacre (Polish: zbrodnia katyńska, "Katyń crime"; Russian: Катынская резня Katynskaya reznya, "Katyn massacre", or Russian: Катынский расстрел, "Katyn execution by shooting") was a series of mass executions of about 22,000 Polish military officers and intelligentsia carried out by the Soviet Union, specifically the NKVD ("People's Commissariat for Internal Affairs", the Soviet secret police) in April and May 1940. Though the killings also occurred in the Kalinin and Kharkiv prisons and elsewhere, the massacre is named after the Katyn Forest, where some of the mass graves were first discovered.

The massacre was initiated in NKVD chief Lavrentiy Beria's proposal of 5 March 1940 to execute all captive members of the Polish officer corps, approved by the Soviet Politburo led by Joseph Stalin. Of the total killed, about 8,000 were officers imprisoned during the 1939 Soviet invasion of Poland, another 6,000 were police officers, and the remaining 8,000 were Polish intelligentsia the Soviets deemed to be "intelligence agents, gendarmes, landowners, saboteurs, factory owners, lawyers, officials, and priests". The Polish Army officer class was representative of the multi-ethnic Polish state; the murdered included ethnic Poles, Polish Ukrainians, Belarusians, and Polish Jews including the Chief Rabbi of the Polish Army, Baruch Steinberg.

The government of Nazi Germany announced the discovery of mass graves in the Katyn Forest in April 1943. Stalin severed diplomatic relations with the London-based Polish government-in-exile when it asked for an investigation by the International Committee of the Red Cross. The USSR claimed the Nazis had killed the victims, and it continued to deny responsibility for the massacres until 1990, when it officially acknowledged and condemned the killings by the NKVD, as well as the subsequent cover-up by the Soviet government.

An investigation conducted by the office of the Prosecutors General of the Soviet Union (1990–1991) and the Russian Federation (1991–2004) confirmed Soviet responsibility for the massacres, but refused to classify this action as a war crime or as an act of mass murder. The investigation was closed on the grounds the perpetrators were dead, and since the Russian government would not classify the dead as victims of the Great Purge, formal posthumous rehabilitation was deemed inapplicable.

In November 2010, the Russian State Duma approved a declaration blaming Stalin and other Soviet officials for ordering the massacre.

🔗 Chemicals

Solanine is a glycoalkaloid poison found in species of the nightshade family within the genus Solanum, such as the potato (Solanum tuberosum), the tomato (Solanum lycopersicum), and the eggplant (Solanum melongena). It can occur naturally in any part of the plant, including the leaves, fruit, and tubers. Solanine has pesticidal properties, and it is one of the plant's natural defenses. Solanine was first isolated in 1820 from the berries of the European black nightshade (Solanum nigrum), after which it was named. It belongs to the chemical family of saponins.