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🔗 Mathematics

In geometry, a ball is a region in a space comprising all points within a fixed distance, called the radius, from a given point; that is, it is the region enclosed by a sphere or hypersphere. An n-ball is a ball in an n-dimensional Euclidean space. The volume of a n-ball is the Lebesgue measure of this ball, which generalizes to any dimension the usual volume of a ball in 3-dimensional space. The volume of a n-ball of radius R is ${\displaystyle R^{n}V_{n},}$ where ${\displaystyle V_{n}}$ is the volume of the unit n-ball, the n-ball of radius 1.

The real number ${\displaystyle V_{n}}$ can be expressed by a expression involving the gamma function. It can be computed with several recurrence relations. It can be expressed in terms of ${\displaystyle A_{n},}$ the area of the unit n-sphere.

🔗 Politics

The Democracy Index is an index compiled by the Economist Intelligence Unit (EIU), a UK-based company. It intends to measure the state of democracy in 167 countries, of which 166 are sovereign states and 164 are UN member states.

The index was first published in 2006, with updates for 2008, 2010 and later years. The index is based on 60 indicators grouped in five different categories, measuring pluralism, civil liberties and political culture. In addition to a numeric score and a ranking, the index categorises each country in one of four regime types: full democracies, flawed democracies, hybrid regimes and authoritarian regimes.

🔗 Classical Greece and Rome

The Seikilos epitaph is the oldest surviving complete musical composition, including musical notation, from anywhere in the world. The epitaph has been variously dated, but seems to be either from the 1st or the 2nd century AD. The song, the melody of which is recorded, alongside its lyrics, in the ancient Greek musical notation, was found engraved on a tombstone (a stele) from the Hellenistic town Tralles near present-day Aydın, Turkey, not far from Ephesus. It is a Hellenistic Ionic song in either the Phrygian octave species or Iastian tonos. While older music with notation exists (for example the Hurrian songs), all of it is in fragments; the Seikilos epitaph is unique in that it is a complete, though short, composition.

🔗 Video games

The Corrupted Blood incident was a virtual pandemic in the MMORPG World of Warcraft, which began on September 13, 2005, and lasted for one week. The epidemic began with the introduction of the new raid Zul'Gurub and its end boss Hakkar the Soulflayer. When confronted and attacked, Hakkar would cast a hit point-draining and highly contagious debuff spell called "Corrupted Blood" on players.

The spell, intended to last only seconds and function only within the new area of Zul'Gurub, soon spread across the virtual world by way of an oversight that allowed pets and minions to take the affliction out of its intended confines. By both accidental and purposeful intent, a pandemic ensued that quickly killed lower-level characters and drastically changed normal gameplay, as players did what they could do to avoid infection. Despite measures such as programmer-imposed quarantines, and the players' abandoning of densely populated cities (or even just not playing the game), it lasted until a combination of patches and resets of the virtual world finally controlled the spread.

The conditions and reactions of the event attracted the attention of epidemiologists for its implications of how human populations could react to a real-world epidemic.

🔗 Film 🔗 Law 🔗 Film/American cinema 🔗 Film/Filmmaking

The Writers Guild of America (WGA) writing credit system for motion pictures and television programs covers all works under the jurisdiction of the Writers Guild of America, East (WGAE) and the Writers Guild of America, West (WGAW). Since 1941, the Screen Writers Guild and then the WGA has been the final arbiter of who receives credit for writing a theatrical, television or new media motion picture written under their jurisdiction. Though the system has been a standard since before the WGA's inception, it has seen criticism.

🔗 Philosophy 🔗 Psychology 🔗 Philosophy/Ancient philosophy 🔗 Philosophy/Ethics

Akrasia (; Greek ἀκρασία, "lacking command" or "weakness", occasionally transliterated as acrasia or Anglicised as acrasy or acracy) is a lack of self-control, or acting against one's better judgment. Beginning with Plato, a variety of philosophers have attempted to determine whether or not akrasia exists and how to best define it.

🔗 Novels 🔗 Science Fiction

Red Star (Russian: Красная звезда) is Alexander Bogdanov's 1908 science fiction novel about a communist society on Mars. The first edition was published in St. Petersburg in 1908, before eventually being republished in Moscow and Petrograd in 1918, and then again in Moscow in 1922. Set in early Russia during the Revolution of 1905 and additionally on a fictional socialist society on Mars, the novel tells the story of Leonid, a Russian scientist-revolutionary who travels to Mars to learn and experience their socialist system and to teach them of his own world. In the process, he becomes enamored of the people and technological efficiency that he encounters in this new world. An English translation by Charles Rougle was published in 1984.

🔗 United States 🔗 Mathematics 🔗 Law 🔗 History of Science 🔗 United States/Indiana

The Indiana Pi Bill is the popular name for bill #246 of the 1897 sitting of the Indiana General Assembly, one of the most notorious attempts to establish mathematical truth by legislative fiat. Despite its name, the main result claimed by the bill is a method to square the circle, rather than to establish a certain value for the mathematical constant π, the ratio of the circumference of a circle to its diameter. The bill, written by the crank Edward J. Goodwin, does imply various incorrect values of π, such as 3.2. The bill never became law, due to the intervention of Professor C. A. Waldo of Purdue University, who happened to be present in the legislature on the day it went up for a vote.

The impossibility of squaring the circle using only compass and straightedge constructions, suspected since ancient times, was rigorously proven in 1882 by Ferdinand von Lindemann. Better approximations of π than those implied by the bill have been known since ancient times.

🔗 United States 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Military history/World War II 🔗 Mammals/Bats

Bat bombs were an experimental World War II weapon developed by the United States. The bomb consisted of a bomb-shaped casing with over a thousand compartments, each containing a hibernating Mexican free-tailed bat with a small, timed incendiary bomb attached. Dropped from a bomber at dawn, the casings would deploy a parachute in mid-flight and open to release the bats, which would then disperse and roost in eaves and attics in a 20–40-mile radius (32–64 km). The incendiaries, which were set on timers, would then ignite and start fires in inaccessible places in the largely wood and paper constructions of the Japanese cities that were the weapon's intended target.