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๐ Holon
A holon (Greek: แฝ ฮปฮฟฮฝ, from แฝ ฮปฮฟฯ, holos, 'whole' and -ฮฟฮฝ, -on, 'part') is something that is simultaneously a whole in and of itself, as well as a part of a larger whole. In other words, holons can be understood as the constituent partโwholes of a hierarchy.
The holon represents a way to overcome the dichotomy between parts and wholes, as well as a way to account for both the self-assertive and the integrative tendencies of organisms. The term was coined by Arthur Koestler in The Ghost in the Machine (1967). In Koestler's formulations, a holon is something that has integrity and identity while simultaneously being a part of a larger system; it is a subsystem of a greater system.
Holons are sometimes discussed in the context of self-organizing holarchic open (SOHO) systems.
๐ User: Junnn11
Arthropod enthusiast, mainly focus on Panarthropod head problem, phylogeny across arthropod subphyla and stem lineage, basal chelicerates, dinocaridids and lobopodians. Sometime drawing stuff, not so well in english, mainly active at Japanese Wikipedia.
Japanese: ๅฉ็จ่ :Junnn11
Commons: User:Junnn11
Twitter: ni075
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- "User: Junnn11" | 2023-04-19 | 747 Upvotes 101 Comments
๐ False Vacuum
In quantum field theory, a false vacuum is a hypothetical vacuum that is relatively stable, but not in the most stable state possible. In this condition it is called metastable. It may last for a very long time in this state, but could eventually decay to the more stable one, an event known as false vacuum decay. The most common suggestion of how such a decay might happen in our universe is called bubble nucleation โ if a small region of the universe by chance reached a more stable vacuum, this "bubble" (also called "bounce") would spread.
A false vacuum exists at a local minimum of energy and is therefore not completely stable, in contrast to a true vacuum, which exists at a global minimum and is stable.
๐ Speed Tape
Speed tape is an aluminium pressure-sensitive tape used to perform minor repairs on aircraft and racing cars. It is used as a temporary repair material until a more permanent repair can be carried out. It has an appearance similar to duct tape, for which it is sometimes mistaken, but its adhesive is capable of sticking on an airplane fuselage or wing at high speeds, hence the name.
๐ James-Lange Theory
The JamesโLange theory is a hypothesis on the origin and nature of emotions and is one of the earliest theories of emotion within modern psychology. It was developed by philosopher John Dewey and named for two 19th-century scholars, William James and Carl Lange (see modern criticism for more on the theory's origin). The basic premise of the theory is that physiological arousal instigates the experience of emotion. Previously people considered emotions as reactions to some significant events or their features, i.e. events come first, and then there is an emotional response. James-Lange theory proposed that the state of the body can induce emotions or emotional dispositions. In other words, this theory suggests that when we feel teary, it generates a disposition for sad emotions; when our heartbeat is out of normality, it makes us feel anxiety. Instead of feeling an emotion and subsequent physiological (bodily) response, the theory proposes that the physiological change is primary, and emotion is then experienced when the brain reacts to the information received via the body's nervous system. It proposes that each specific category of emotion is attached to a unique and different pattern of physiological arousal and emotional behaviour in reaction due to an exciting stimulus.
The theory has been criticized and modified over the course of time, as one of several competing theories of emotion. Modern theorists have built on its ideas by proposing that the experience of emotion is modulated by both physiological feedback and other information, rather than consisting solely of bodily changes, as James suggested. Psychologist Tim Dalgleish states that most modern affective neuroscientists would support such a viewpoint. In 2002, a research paper on the autonomic nervous system stated that the theory has been "hard to disprove".
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- "James-Lange Theory" | 2023-12-01 | 38 Upvotes 12 Comments
๐ AlchianโAllen effect
The AlchianโAllen effect was described in 1964 by Armen Alchian and William R Allen in the book University Economics (now called Exchange and Production). It states that when the prices of two substitute goods, such as high and low grades of the same product, are both increased by a fixed per-unit amount such as a transportation cost or a lump-sum tax, consumption will shift toward the higher-grade product. This is because the added per-unit amount decreases the relative price of the higher-grade product.
Suppose, for example, that high-grade coffee beans are $3/pound and low-grade beans $1.50/pound; in this example, high-grade beans cost twice as much as low-grade beans. Now add a per-pound international shipping cost of $1. The effective prices are now $4 and $2.50; high-grade beans now cost only 1.6 times as much as low-grade beans. This reduced ratio of difference will induce distant coffee-buyers to now choose a higher ratio of high-to-low grade beans than local coffee-buyers.
The effect has been studied as it applies to illegal drugs and it has been shown that the potency of marijuana increased in response to higher enforcement budgets, and there was a similar effect for alcohol in the U.S. during Prohibition. This effect is called iron law of prohibition.
Another example is that Australians drink higher-quality Californian wine than Californians, and vice versa, because it is only worth the transportation costs for the most expensive wine.
Colloquially, the AlchianโAllen theorem is also known as the โshipping the good apples outโ theorem (Thomas Borcherding), or as the โthird law of demand.โ
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- "AlchianโAllen effect" | 2018-11-12 | 122 Upvotes 53 Comments
๐ Krukenberg procedure
The Krukenberg procedure, also known as the Krukenberg operation, is a surgical technique that converts a forearm stump into a pincer. It was first described in 1917 by the German army surgeon Hermann Krukenberg. It remains in use today for certain special cases but is considered controversial and some surgeons refuse to perform it.
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- "Krukenberg procedure" | 2018-09-10 | 56 Upvotes 11 Comments
๐ Pumped-storage hydroelectricity
Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational potential energy of water, pumped from a lower elevation reservoir to a higher elevation. Low-cost surplus off-peak electric power is typically used to run the pumps. During periods of high electrical demand, the stored water is released through turbines to produce electric power.
Pumped-storage hydroelectricity allows energy from intermittent sources (such as solar, wind) and other renewables, or excess electricity from continuous base-load sources (such as coal or nuclear) to be saved for periods of higher demand. The reservoirs used with pumped storage can be quite small when contrasted with the lakes of conventional hydroelectric plants of similar power capacity, and generating periods are often less than half a day.
The round-trip efficiency of PSH generally varies between 70%โ80%. Although the losses of the pumping process make the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest. If the upper lake collects significant rainfall or is fed by a river then the plant may be a net energy producer in the manner of a traditional hydroelectric plant.
Pumped storage is by far the largest-capacity form of grid energy storage available, and, as of 2020, PSH accounts for around 95% of all active storage installations worldwide, with a total installed throughput capacity of over 181ย GW and a total installed storage capacity of over 1.6ย TWh.
The main requirement for PSH is hilly country. The global greenfield pumped hydro atlas lists more than 600,000 potential sites around the world, which is about 100 times more than needed to support 100% renewable electricity. Most are closed-loop systems away from rivers. Areas of natural beauty and new dams on rivers can be avoided because of the very large number of potential sites. Some projects utilise existing reservoirs (dubbed "bluefield") such as the 350 Gigawatt-hour Snowy 2.0 scheme under construction in Australia. Some recently proposed projects propose to take advantage of "brownfield" locations such as disused mines such as the Kidston project under construction in Australia.
Water requirements for PSH are small: about 1 gigalitre of initial fill water per gigawatt-hour of storage. This water is recycled uphill and back downhill between the two reservoirs for many decades, but evaporation losses (beyond what rainfall and any inflow from local waterways provide) must be replaced. Land requirements are also small: about 10 hectares per gigawatt-hour of storage, which is much smaller than the land occupied by the solar and windfarms that the storage might support. Closed loop (off-river) pumped hydro storage has the smallest carbon emissions per unit of storage of all candidates for large-scale energy storage.
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- "Pumped-storage hydroelectricity" | 2024-06-30 | 92 Upvotes 130 Comments
๐ Jeffrey Hudson the Court Dwarf of the English Queen Henrietta Maria of France
Jeffrey Hudson (1619 โ c.โ1682) was a court dwarf of the English queen Henrietta Maria of France. He was famous as the "Queen's dwarf" and "Lord Minimus" and was considered one of the "wonders of the age" because of his extreme but well-proportioned smallness. He fought with the Royalists in the English Civil War and fled with the Queen to France but was expelled from her court when he killed a man in a duel. He was captured by Barbary pirates and spent 25 years enslaved in North Africa before being ransomed back to England.
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- "Jeffrey Hudson the Court Dwarf of the English Queen Henrietta Maria of France" | 2025-10-07 | 49 Upvotes 18 Comments
๐ Phone Cloning
Phone cloning is the copying of identity from one cellular device to another.
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- "Phone Cloning" | 2020-04-18 | 35 Upvotes 18 Comments