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🔗 Books 🔗 Systems 🔗 Business 🔗 Psychology 🔗 United Kingdom 🔗 Engineering 🔗 Invention 🔗 Systems/Project management 🔗 Method engineering

Six Thinking Hats was written by Dr. Edward de Bono. "Six Thinking Hats" and the associated idea parallel thinking provide a means for groups to plan thinking processes in a detailed and cohesive way, and in doing so to think together more effectively.

In 2005, the tool found some use in the United Kingdom innovation sector, where it was offered by some facilitation companies and had been trialled within the United Kingdom's civil service.

🔗 Nepal

Nepal Standard Time (NPT) is the time zone for Nepal. With a time offset from Coordinated Universal Time (UTC) of UTC+05:45 all over Nepal, it is one of only three time zones with a 45-minute offset from UTC. (The others are Chatham Island Standard Time, with an offset of UTC+12:45, and the unofficial Australian Central Western Time, with an offset of UTC+08:45.)

NPT is an approximation of Kathmandu mean time, which is 5:41:16 ahead of UTC. The standard meridian passes through the peak of Gaurishankar mountain about 100 kilometres (62 mi) east of Kathmandu.

Nepal used local solar time until 1920, in Kathmandu UTC+05:41:16. In 1920, Nepal adopted Indian Standard Time, UTC+05:30. In 1986 Nepal advanced their clocks by 15 minutes, giving them a time zone of UTC+05:45.

🔗 Spaceflight 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/Maritime warfare 🔗 Moon 🔗 Smithsonian Institution-related 🔗 National Archives

Apollo 11 was the spaceflight that first landed humans on the Moon. Commander Neil Armstrong and lunar module pilot Buzz Aldrin formed the American crew that landed the Apollo Lunar Module Eagle on July 20, 1969, at 20:17 UTC. Armstrong became the first person to step onto the lunar surface six hours and 39 minutes later on July 21 at 02:56 UTC; Aldrin joined him 19 minutes later. They spent about two and a quarter hours together outside the spacecraft, and they collected 47.5 pounds (21.5 kg) of lunar material to bring back to Earth. Command module pilot Michael Collins flew the Command Module Columbia alone in lunar orbit while they were on the Moon's surface. Armstrong and Aldrin spent 21 hours, 36 minutes on the lunar surface at a site they named Tranquility Base before lifting off to rejoin Columbia in lunar orbit.

Apollo 11 was launched by a Saturn V rocket from Kennedy Space Center on Merritt Island, Florida, on July 16 at 13:32 UTC, and it was the fifth crewed mission of NASA's Apollo program. The Apollo spacecraft had three parts: a command module (CM) with a cabin for the three astronauts, the only part that returned to Earth; a service module (SM), which supported the command module with propulsion, electrical power, oxygen, and water; and a lunar module (LM) that had two stages—a descent stage for landing on the Moon and an ascent stage to place the astronauts back into lunar orbit.

After being sent to the Moon by the Saturn V's third stage, the astronauts separated the spacecraft from it and traveled for three days until they entered lunar orbit. Armstrong and Aldrin then moved into Eagle and landed in the Sea of Tranquility on July 20. The astronauts used Eagle's ascent stage to lift off from the lunar surface and rejoin Collins in the command module. They jettisoned Eagle before they performed the maneuvers that propelled Columbia out of the last of its 30 lunar orbits onto a trajectory back to Earth. They returned to Earth and splashed down in the Pacific Ocean on July 24 after more than eight days in space.

Armstrong's first step onto the lunar surface was broadcast on live TV to a worldwide audience. He described the event as "one small step for [a] man, one giant leap for mankind." Apollo 11 effectively ended the Space Race and fulfilled a national goal proposed in 1961 by President John F. Kennedy: "before this decade is out, of landing a man on the Moon and returning him safely to the Earth."

🔗 Fencing

Dueling scars (German: Schmisse) have been seen as a "badge of honour" since as early as 1825. Known variously as "Mensur scars", "the bragging scar", "smite", "Schmitte" or "Renommierschmiss", dueling scars were popular amongst upper-class Austrians and Germans involved in academic fencing at the start of the 20th century. Being a practice amongst university students, it was seen as a mark of their class and honour, due to the status of dueling societies at German and Austrian universities at the time, and is an early example of scarification in European society. The practice of dueling and the associated scars was also present to some extent in the German military.

Foreign tourists visiting Germany in the late 19th century were shocked to see the students, generally with their Studentcorps, at major German universities such as Heidelberg, Bonn, or Jena with facial scars – some older, some more recent, and some still wrapped in bandages.

The sport of academic fencing at the time was very different from modern fencing using specially developed swords. The so-called Mensurschläger (or simply Schläger, "hitter") existed in two versions. The most common weapon is the Korbschläger with a basket-type guard. In some universities in the eastern part of Germany, the so-called Glockenschläger is in use which is equipped with a bell-shaped guard. The individual duels between students, known as Mensuren, were somewhat ritualised. In some cases, protective clothing was worn, including padding on the arm and an eye guard.

The culture of dueling scars was mainly common to Germany and Austria, to a lesser extent some central European countries and briefly at places such as Oxford and some other elite universities. German military laws permitted men to wage duels of honor until World War I. During the Third Reich the Mensur was prohibited at all Universities following the partyline.

Within the duel, it was seen as ideal and a way of showing courage to be able to stand and take the blow, as opposed to inflicting the wound. It was important to show one's dueling prowess, but also that one was capable of taking the wound that was inflicted.

🔗 Spaceflight 🔗 Physics 🔗 Rocketry

The Tsiolkovsky rocket equation, classical rocket equation, or ideal rocket equation is a mathematical equation that describes the motion of vehicles that follow the basic principle of a rocket: a device that can apply acceleration to itself using thrust by expelling part of its mass with high velocity can thereby move due to the conservation of momentum.

${\displaystyle \Delta v=v_{\text{e}}\ln {\frac {m_{0}}{m_{f}}}=I_{\text{sp}}g_{0}\ln {\frac {m_{0}}{m_{f}}}}$

where:

${\displaystyle \Delta v\ }$ is delta-v – the maximum change of velocity of the vehicle (with no external forces acting).

${\displaystyle m_{0}}$ is the initial total mass, including propellant, also known as wet mass.

${\displaystyle m_{f}}$ is the final total mass without propellant, also known as dry mass.

${\displaystyle v_{\text{e}}=I_{\text{sp}}g_{0}}$ is the effective exhaust velocity, where:

${\displaystyle I_{\text{sp}}}$ is the specific impulse in dimension of time.

${\displaystyle g_{0}}$ is standard gravity.

${\displaystyle \ln }$ is the natural logarithm function.

🔗 Aviation 🔗 Aviation/aircraft

A propfan, also called an open rotor engine, or unducted fan, is a type of aircraft engine related in concept to both the turboprop and turbofan, but distinct from both. The design is intended to offer the speed and performance of a turbofan, with the fuel economy of a turboprop. A propfan is typically designed with a large number of short, highly twisted blades, similar to a turbofan's bypass compressor (the fan itself). For this reason, the propfan has been variously described as an "unducted fan" or an "ultra-high-bypass (UHB) turbofan."

🔗 Computing 🔗 Computing/Software 🔗 Computing/Free and open-source software

The Oberon System is a modular, single-user, single-process, multitasking operating system written in the programming language of the same name. It was originally developed in the late 1980s at ETH Zürich. The Oberon System has an unconventional visual text user interface instead of a conventional CLI or GUI. This "TUI" was very innovative in its time and influenced the design of the Acme text editor for the Plan 9 from Bell Labs operating system.

The latest version of the Oberon System, Project Oberon 2013, is still maintained by Niklaus Wirth and a number of collaborators but older ETH versions of the Oberon Systems have been orphaned. The Oberon System also evolved into the multi-process, SMP-capable Bluebottle operating system, with a zooming user interface.

🔗 Chess

Quiescence search is an algorithm typically used to extend search at unstable nodes in minimax game trees in game-playing computer programs. It is an extension of the evaluation function to defer evaluation until the position is stable enough to be evaluated statically, that is, without considering the history of the position or future moves from the position. It mitigates the effect of the horizon problem faced by AI engines for various games like chess and Go.

Human players usually have enough intuition to decide whether to abandon a bad-looking move, or search a promising move to a great depth. A quiescence search attempts to emulate this behavior by instructing a computer to search "volatile" positions to a greater depth than "quiet" ones to make sure there are no hidden traps and to get a better estimate of its value.

Any sensible criterion may be used to distinguish "quiet" positions from "volatile" positions. One common criterion is that moves exist in the position that can dramatically change the valuation of the position, such as captures in chess or Go. As the main motive of quiescence search is to get a stable value out of a static evaluation function, it may also make sense to detect wide fluctuations in values returned by a simple heuristic evaluator over several ply, i.e. a history criterion. The quiescence search continues as along as the position remains volatile according to the criterion. In order to get the quiescence search to terminate, plies are usually restricted to moves that deal directly with the threat, such as moves that capture and recapture (often called a 'capture search') in chess. In highly "unstable" games like Go and reversi, a rather large proportion of computer time may be spent on quiescence searching.

🔗 Computer science

Bead sort, also called gravity sort, is a natural sorting algorithm, developed by Joshua J. Arulanandham, Cristian S. Calude and Michael J. Dinneen in 2002, and published in The Bulletin of the European Association for Theoretical Computer Science. Both digital and analog hardware implementations of bead sort can achieve a sorting time of O(n); however, the implementation of this algorithm tends to be significantly slower in software and can only be used to sort lists of positive integers. Also, it would seem that even in the best case, the algorithm requires O(n²) space.