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🔗 Mathematics

Gödel's completeness theorem is a fundamental theorem in mathematical logic that establishes a correspondence between semantic truth and syntactic provability in first-order logic. It makes a close link between model theory that deals with what is true in different models, and proof theory that studies what can be formally proven in particular formal systems.

It was first proved by Kurt Gödel in 1929. It was then simplified in 1947, when Leon Henkin observed in his Ph.D. thesis that the hard part of the proof can be presented as the Model Existence Theorem (published in 1949). Henkin's proof was simplified by Gisbert Hasenjaeger in 1953.

🔗 Technology 🔗 Engineering

Overengineering (or over-engineering, or over-kill) is the act of designing a product to be more robust or have more features than often necessary for its intended use, or for a process to be unnecessarily complex or inefficient.

Overengineering is often done to increase a factor of safety, add functionality, or overcome perceived design flaws that most users would accept.

Overengineering can be desirable when safety or performance is critical (e.g. in aerospace vehicles and luxury road vehicles), or when extremely broad functionality is required (e.g. diagnostic and medical tools, power users of products), but it is generally criticized in terms of value engineering as wasteful of resources such as materials, time and money.

As a design philosophy, it is the opposite of the minimalist ethos of "less is more" (or: “worse is better”) and a disobedience of the KISS principle.

Overengineering generally occurs in high-end products or specialized markets. In one form, products are overbuilt and have performance far in excess of expected normal operation (a city car that can travel at 300 km/h, or a home video recorder with a projected lifespan of 100 years), and hence are more expensive, bulkier, and heavier than necessary. Alternatively, they may become overcomplicated – the extra functions may be unnecessary, and potentially reduce the usability of the product by overwhelming lesser experienced and technically literate end users, as in feature creep.

Overengineering can decrease the productivity of design teams, because of the need to build and maintain more features than most users need.

A related issue is market segmentation – making different products for different market segments. In this context, a particular product may be more or less suited (and thus considered over- or under-engineered) for a particular market segment.

🔗 Video games 🔗 Marketing & Advertising

A feelie is a physical item included to supplement a video game. Likely deriving their name from the fictional media in Aldous Huxley's 1932 novel Brave New World, feelies were popularized by the American video game company Infocom in the 1980s and subsequently adopted by such companies as Origin Systems and Sierra Entertainment in the United States and Namco and ASCII in Japan. Becoming less prevalent since the rise of digital distribution, feelies are now limited primarily to deluxe editions that are sold at a premium.

Feelies may take various forms, with common ones including reproductions of game objects, printed materials, cosmetics, and figurines. Historically, feelies allowed video game developers to implement copy protection and minimize the amount of digital space used for supplemental materials while simultaneously distinguishing their products from those of competitors. For players, feelies could provide assistance during gameplay, opportunities for continued play elsewhere, and improved immersion. Scholars have explored feelies as paratexts, while video game journalists have recalled them fondly.

🔗 Biography 🔗 Espionage 🔗 Germany 🔗 Military history 🔗 Military history/Military biography 🔗 Biography/military biography 🔗 United Kingdom 🔗 Military history/World War II

Eric Arthur Roberts (18 June 1907 – 17 or 18 December 1972) was an MI5 agent during the Second World War under the alias Jack King. By posing as a Gestapo agent and infiltrating fascist groups in the UK, Roberts was able to prevent secret information finding its way to Germany. Roberts continued to work for the security services after the war, particularly in Vienna, but it was a time of great anxiety in the services because of the suspicions surrounding double agents such as the Cambridge spy ring.

Roberts never felt completely accepted by MI5 because of his social background and a desk role did not suit him as well as his wartime role had. He is the subject of the biography Agent Jack (2018) by Robert Hutton, and his adventures were the inspiration for the novel Our Friends In Berlin by Anthony Quinn and for a major character in the novel Transcription by Kate Atkinson.

🔗 Aviation 🔗 Aviation/airline

Janet, sometimes called Janet Airlines, is the unofficial name given to a highly classified fleet of passenger aircraft operated for the United States Department of the Air Force as an employee shuttle to transport military and contractor employees. The purpose is to pick up the employees at their home airport, and take them to their place of work. Then, in the afternoon, they take the employees back to their home airports. The airline mainly serves the Nevada National Security Site (most notably Area 51 and the Tonopah Test Range), from a private terminal at Las Vegas's McCarran International Airport.

The airline's aircraft are generally unmarked, but do have a red paint strip along the windows of the aircraft, which gives some sort of hint at Janet being the operator.

🔗 Sociology 🔗 Finland

Wiio's laws are humoristically formulated observations about how humans communicate.

Wiio's laws are usually summarized with "Human communications usually fail except by accident", which is the main observation made by Professor Osmo Antero Wiio in 1978.

🔗 Professional sound production 🔗 Stagecraft

The Schaffer–Vega diversity system (SVDS) was a wireless guitar system developed in 1975–76, engineered and prototyped by Ken Schaffer in New York City, and manufactured by the Vega Corporation, El Monte, California. A handheld microphone version was introduced in 1977.

The system was the first cordless system to be adopted by major rock acts because it solved technical problems common to earlier wireless systems. The reliable sound and freedom of movement it provided paved the way for bands to tour with large multi-level stages in arenas. Schaffer-Vegas were used in the late 1970s and early 1980s by many rock bands such as Pink Floyd (namely guitarist David Gilmour), the Rolling Stones, AC/DC and Kiss.

🔗 Technology 🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Military history/Maritime warfare 🔗 Military history/Russian, Soviet and CIS military history

The VA-111 Shkval (from Russian: шквал, squall) torpedo and its descendants are supercavitating torpedoes originally developed by the Soviet Union. They are capable of speeds in excess of 200 knots (370 km/h or 230 miles/h).

🔗 Serbia 🔗 Yugoslavia 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/French military history 🔗 Military history/Balkan military history 🔗 Military history/European military history 🔗 Military history/Post-Cold War 🔗 Kosovo 🔗 NATO 🔗 Serbia/Belgrade

The North Atlantic Treaty Organisation (NATO) carried out an aerial bombing campaign against the Federal Republic of Yugoslavia during the Kosovo War. The air strikes lasted from 24 March 1999 to 10 June 1999. The bombings continued until an agreement was reached that led to the withdrawal of Yugoslav armed forces from Kosovo, and the establishment of the United Nations Interim Administration Mission in Kosovo, a UN peacekeeping mission in Kosovo. The official NATO operation code name was Operation Allied Force whereas the United States called it Operation Noble Anvil; in Yugoslavia the operation was incorrectly called Merciful Angel (Serbian: Милосрдни анђео / Milosrdni anđeo) as a result of a misunderstanding or mistranslation.

NATO's intervention was prompted by Yugoslavia's bloodshed and ethnic cleansing of Albanians, which drove the Albanians into neighbouring countries and had the potential to destabilize the region. Yugoslavia's actions had already provoked condemnation by international organisations and agencies such as the UN, NATO, and various INGOs. Yugoslavia's refusal to sign the Rambouillet Accords was initially offered as justification for NATO's use of force. NATO countries attempted to gain authorisation from the UN Security Council for military action, but were opposed by China and Russia, who indicated that they would veto such a measure. As a result, NATO launched its campaign without the UN's approval, stating that it was a humanitarian intervention. The UN Charter prohibits the use of force except in the case of a decision by the Security Council under Chapter VII, or self-defence against an armed attack – neither of which were present in this case.

By the end of the war, the Yugoslavs had killed 1,500 to 2,131 combatants, while choosing to heavily target Kosovar Albanian civilians, with 8,676 killed or missing and some 848,000 expelled from Kosovo. The NATO bombing killed about 1,000 members of the Yugoslav security forces in addition to between 489 and 528 civilians. It destroyed or damaged bridges, industrial plants, hospitals, schools, cultural monuments, private businesses as well as barracks and military installations. In the days after the Yugoslav army withdrew, over 164,000 Serbs and 24,000 Roma left Kosovo. Many of the remaining non-Albanian civilians (as well as Albanians perceived as collaborators) were victims of abuse which included beatings, abductions, and murders. After Kosovo and other Yugoslav Wars, Serbia became home to the highest number of refugees and IDPs (including Kosovo Serbs) in Europe.

The bombing was NATO's second major combat operation, following the 1995 bombing campaign in Bosnia and Herzegovina. It was the first time that NATO had used military force without the expressed endorsement of the UN Security Council, which triggered debates over the legitimacy of the intervention.

🔗 Military history 🔗 Comedy 🔗 Military history/Maritime warfare 🔗 Military history/European military history 🔗 Military history/British military history

The Dreadnought hoax was a practical joke pulled by Horace de Vere Cole in 1910. Cole tricked the Royal Navy into showing their flagship, the battleship HMS Dreadnought, to a fake delegation of Abyssinian royals. The hoax drew attention in Britain to the emergence of the Bloomsbury Group, among whom some of Cole's collaborators numbered. The hoax was a repeat of a similar impersonation which Cole and Adrian Stephen had organised while they were students at Cambridge in 1905.