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🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Equine 🔗 Military history/Medieval warfare

The Great Stirrup Controversy is the academic debate about the Stirrup Thesis, the theory that feudalism in Europe developed largely as a result of the introduction of the stirrup to cavalry in the 8th century CE. It relates to the hypothesis suggested by Lynn Townsend White Jr. in his 1962 book, Medieval Technology and Social Change. White believed that the stirrup enabled heavy cavalry and shock combat, which in turn prompted the Carolingian dynasty of the 8th and 9th centuries to organize its territory into a vassalage system, rewarding mounted warriors with land grants for their service. White's book has proved very influential, but others have accused him of speculation, oversimplification, and ignoring contradictory evidence on the subject. Scholars have debated whether the stirrup actually provided the impetus for this social change, or whether the rise of heavy cavalry resulted from political changes in Medieval Europe.

🔗 Chess

Kasparov versus the World was a game of chess played in 1999 over the Internet. Conducting the white pieces, Garry Kasparov faced the rest of the world in consultation, with the World Team moves to be decided by plurality vote. Over 50,000 people from more than 75 countries participated in the game.

The host and promoter of the match was the MSN Gaming Zone, with sponsorship from First USA bank. After 62 moves played over four months, Kasparov won the game. Contrary to expectations, the game produced a mixture of deep tactical and strategic ideas, and although Kasparov won, he admitted that he had never expended as much effort on any other game in his life. He later said, "It is the greatest game in the history of chess. The sheer number of ideas, the complexity, and the contribution it has made to chess make it the most important game ever played."

🔗 Technology 🔗 Environment 🔗 Automobiles 🔗 Environment/Green vehicle

A compressed-air car is a compressed-air vehicle powered by pressure vessels filled with compressed air. It is propelled by the release and expansion of the air within a motor adapted to compressed air. The car might be powered solely by air, or combined (as in a hybrid electric vehicle) with other fuels such as gasoline, diesel, or an electric plant with regenerative braking.

Compressed-air cars use a thermodynamic process. Air cools when expanding and heats when compressed. Thermal energy losses in the compressor and tankage reduce the capacity factor of compressed air systems.

This technology might develop into an inexpensive, clean transportation technology. The energy, vehicles and compressors might be produced easily by decentralized methods, even circular industry. Using plastic might permit open source fabrication using numerical control, including additive manufacturing. The compressed air for such vehicles might be produced easily by common types of renewable energy. For example, multistage air compressors and intercoolers or hydraulic pumps might be attached directly to trompes, hydropower, VAWT wind turbines or stirling engines using a solar concentrator. Direct mechanical compression avoids the Carnot inefficiencies of heat engines. Insulated storage of compressed air avoids energy conversion and battery storage. Heat-based systems might use tankage of solar-heated molten salts driving a heat exchanger rather than an onboard heat recovery system. Electric energy, electric grids and their issues might be avoided.

🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/World War II 🔗 Military history/German military history 🔗 Military history/European military history 🔗 Military history/British military history

The Charlie Brown and Franz Stigler incident occurred on 20 December 1943, when, after a successful bomb run on Bremen, 2nd Lt Charles "Charlie" Brown's B-17 Flying Fortress (named "Ye Olde Pub") was severely damaged by German fighters. Luftwaffe pilot Franz Stigler had the opportunity to shoot down the crippled bomber but did not do so. After an extensive search by Brown, the two pilots met each other 50 years later and developed a friendship that lasted until Stigler's death in March 2008.

🔗 Telecommunications 🔗 Radio 🔗 Electronics 🔗 Engineering

In radio communications, an evolved antenna is an antenna designed fully or substantially by an automatic computer design program that uses an evolutionary algorithm that mimics Darwinian evolution. This procedure has been used in recent years to design a few antennas for mission-critical applications involving stringent, conflicting, or unusual design requirements, such as unusual radiation patterns, for which none of the many existing antenna types are adequate.

🔗 Biography 🔗 Australia 🔗 Crime 🔗 Australia/Australian crime 🔗 South Africa 🔗 Zimbabwe

Paul Calder Le Roux (born 24 December 1972) is a former programmer, former criminal cartel boss and informant to the US Drug Enforcement Administration (DEA).

In 1999, he created E4M, a free and open-source disk encryption software program for Microsoft Windows, and is sometimes credited for open-source TrueCrypt, which is based on E4M's code, though he denies involvement with TrueCrypt.

He was arrested on 26 September 2012 for conspiracy to import narcotics into the United States, and agreed to cooperate with authorities in exchange for a lesser sentence and immunity to any crimes he might admit to afterwards. He subsequently admitted to arranging or participating in seven murders, carried out as part of an extensive illegal business empire.

Le Roux was sentenced to 25 years in prison in June 2020.

🔗 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).

🔗 Transport

Smeed's Law, named after R. J. Smeed, who first proposed the relationship in 1949, is a purported empirical rule relating traffic fatalities to traffic congestion as measured by the proxy of motor vehicle registrations and country population. The law proposes that increasing traffic volume (an increase in motor vehicle registrations) leads to an increase in fatalities per capita, but a decrease in fatalities per vehicle.

Smeed also predicted that the average speed of traffic in central London would always be nine miles per hour, because that is the minimum speed that people tolerate. He predicted that any intervention intended to speed traffic would only lead to more people driving at this "tolerable" speed unless there were any other disincentives against doing so.

His hypothesis in relation to road traffic safety has been refuted by several authors, who point out that fatalities per person have decreased in many countries, when the "Law" requires that they should increase as long as the number of vehicles per person continues to rise.

🔗 Astronomy 🔗 Astronomy/Solar System

The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto. They are the most readily visible Solar System objects after Saturn, the dimmest of the classical planets; though their closeness to bright Jupiter makes naked-eye observation very difficult, they are readily seen with common binoculars, even under night sky conditions of high light pollution. The invention of the telescope enabled the discovery of the moons in 1610. Through this, they became the first Solar System objects discovered since humans have started tracking the classical planets, and the first objects to be found to orbit any planet beyond Earth.

They are planetary-mass moons and among the largest objects in the Solar System. All four, along with Titan, Triton, and Earth's Moon, are larger than any of the Solar System's dwarf planets. The largest, Ganymede, is the largest moon in the Solar System and surpasses the planet Mercury in size (though not mass). Callisto is only slightly smaller than Mercury in size; the smaller ones, Io and Europa, are about the size of the Moon. The three inner moons — Io, Europa, and Ganymede — are in a 4:2:1 orbital resonance with each other. While the Galilean moons are spherical, all of Jupiter's remaining moons have irregular forms because they are too small for their self-gravitation to pull them into spheres.

The Galilean moons are named after Galileo Galilei, who observed them in either December 1609 or January 1610, and recognized them as satellites of Jupiter in March 1610; they remained the only known moons of Jupiter until the discovery of the fifth largest moon of Jupiter Amalthea in 1892. Galileo initially named his discovery the Cosmica Sidera ("Cosimo's stars") or Medicean Stars, but the names that eventually prevailed were chosen by Simon Marius. Marius discovered the moons independently at nearly the same time as Galileo, 8 January 1610, and gave them their present individual names, after mythological characters that Zeus seduced or abducted, which were suggested by Johannes Kepler in his Mundus Jovialis, published in 1614. Their discovery showed the importance of the telescope as a tool for astronomers by proving that there were objects in space that cannot be seen by the naked eye. The discovery of celestial bodies orbiting something other than Earth dealt a serious blow to the then-accepted (among educated Europeans) Ptolemaic world system, a geocentric theory in which everything orbits around Earth.