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🔗 Computing

The CueCat, styled :CueCat with a leading colon, is a cat-shaped handheld barcode reader that was given away free to Internet users starting in 2000 by the now-defunct Digital Convergence Corporation. The CueCat was named CUE for the unique bar code which the device scanned and CAT as a play on "Keystroke Automation Technology" and it enabled a user to open a link to an Internet URL by scanning a barcode — called a "cue" by Digital Convergence — appearing in an article or catalog or on some other printed matter. In this way, a user could be directed to a web page containing related information without having to enter a URL. The company asserted that the ability of the device to direct users to a specific URL, rather than a domain name, was valuable. In addition, television broadcasters could use an audio tone in programs or commercials that, if a TV was connected to a computer via an audio cable, acted as a web address shortcut.

The CueCat connected to computers using the PS/2 keyboard port and USB, and communicated to desktop "CRQ" software running on Windows 32-bit and Mac OS 9 operating systems. Users of this software were required to register with their ZIP code, gender, and email address. This registration process enabled the device to deliver relevant content to a single or multiple users in a household.

By year-end 2001, Codes could no longer be generated for the device or scanned with the device. However, third-party software can decode the lightweight encryption in the device.

🔗 Mathematics

The shoelace formula or shoelace algorithm (also known as Gauss's area formula and the surveyor's formula) is a mathematical algorithm to determine the area of a simple polygon whose vertices are described by their Cartesian coordinates in the plane. The user cross-multiplies corresponding coordinates to find the area encompassing the polygon, and subtracts it from the surrounding polygon to find the area of the polygon within. It is called the shoelace formula because of the constant cross-multiplying for the coordinates making up the polygon, like tying shoelaces. It is also sometimes called the shoelace method. It has applications in surveying and forestry, among other areas.

The formula was described by Meister (1724–1788) in 1769 and by Gauss in 1795. It can be verified by dividing the polygon into triangles, and can be considered to be a special case of Green's theorem.

The area formula is derived by taking each edge AB, and calculating the area of triangle ABO with a vertex at the origin O, by taking the cross-product (which gives the area of a parallelogram) and dividing by 2. As one wraps around the polygon, these triangles with positive and negative area will overlap, and the areas between the origin and the polygon will be cancelled out and sum to 0, while only the area inside the reference triangle remains. This is why the formula is called the surveyor's formula, since the "surveyor" is at the origin; if going counterclockwise, positive area is added when going from left to right and negative area is added when going from right to left, from the perspective of the origin.

The area formula can also be applied to self-overlapping polygons since the meaning of area is still clear even though self-overlapping polygons are not generally simple. Furthermore, a self-overlapping polygon can have multiple "interpretations" but the Shoelace formula can be used to show that the polygon's area is the same regardless of the interpretation.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory

The Fulton surface-to-air recovery system (STARS) is a system used by the Central Intelligence Agency (CIA), United States Air Force and United States Navy for retrieving persons on the ground using aircraft such as the MC-130E Combat Talon I and Boeing B-17. It involves using an overall-type harness and a self-inflating balloon with an attached lift line. An MC-130E engages the line with its V-shaped yoke and the person is reeled on board. Red flags on the lift line guide the pilot during daylight recoveries; lights on the lift line are used for night recoveries. Recovery kits were designed for one and two-man retrievals.

This system was developed by inventor Robert Edison Fulton, Jr., for the Central Intelligence Agency in the early 1950s. It was an evolution from a similar system that was used during World War II by American and British forces to retrieve both personnel and downed assault gliders following airborne operations. The earlier system did not use a balloon, but a line stretched between a pair of poles set in the ground on either side of the person to be retrieved. An aircraft, usually a C-47 Skytrain, trailed a grappling hook that engaged the line, which was attached to the person to be retrieved.

🔗 Aviation 🔗 History 🔗 Spaceflight 🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Spaceflight/Timeline of spaceflight working group 🔗 Physics 🔗 Lists 🔗 Military history/World War II 🔗 Military history/Cold War 🔗 Rocketry 🔗 Military history/European military history 🔗 Military history/British military history

Spaceflight as a practical endeavor began during World War II with the development of operational liquid-fueled rockets. Beginning life as a weapon, the V-2 was pressed into peaceful service after the war at the United States' White Sands Missile Range as well as the Soviet Union's Kapustin Yar. This led to a flourishing of missile designs setting the stage for the exploration of space. The small American WAC Corporal rocket was evolved into the Aerobee, a much more powerful sounding rocket. Exploration of space began in earnest in 1947 with the flight of the first Aerobee, 46 of which had flown by the end of 1950. These and other rockets, both Soviet and American, returned the first direct data on air density, temperature, charged particles and magnetic fields in the Earth's upper atmosphere.

By 1948, the United States Navy had evolved the V-2 design into the Viking capable of more than 100 miles (160 km) in altitude. The first Viking to accomplish this feat, number four, did so 10 May 1950. The Soviet Union developed a virtual copy of the V-2 called the R-1, which first flew in 1948. Its longer-ranged successor, the R-2, entered military service in 1950. This event marked the entry of both superpowers into the post-V-2 rocketry era.

🔗 Computing 🔗 Economics 🔗 Apps

A super-app (also written as super app or superapp) is a mobile or web application that can provide multiple services including payment and financial transaction processing, effectively becoming an all-encompassing self-contained commerce and communication online platform that embraces many aspects of personal and commercial life. Notable examples of super-apps include Tencent's WeChat in China, and Grab in Southeast Asia.

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Philosophy/Ethics

The paradox of hedonism, also called the pleasure paradox, refers to the practical difficulties encountered in the pursuit of pleasure. For the hedonist, constant pleasure-seeking may not yield the most actual pleasure or happiness in the long run—or even in the short run, when consciously pursuing pleasure interferes with experiencing it.

The utilitarian philosopher Henry Sidgwick was first to note in The Methods of Ethics that the paradox of hedonism is that pleasure cannot be acquired directly. Variations on this theme appear in the realms of ethics, philosophy, psychology, and economics.

🔗 Languages 🔗 Ottoman Empire 🔗 Western Asia

The language of the court and government of the Ottoman Empire was Ottoman Turkish, but many other languages were in contemporary use in parts of the empire. Although the minorities of the Ottoman Empire were free to use their language amongst themselves, if they needed to communicate with the government they had to use Ottoman Turkish.

The Ottomans had three influential languages: Turkish, spoken by the majority of the people in Anatolia and by the majority of Muslims of the Balkans except in Albania, Bosnia, and various Aegean Sea islands; Persian, initially used by the educated in northern portions of the Ottoman Empire before being displaced by Ottoman Turkish; and Arabic, used in southern portions of the Ottoman Empire; Arabic was spoken mainly in Arabia, North Africa, Mesopotamia and the Levant. Throughout the vast Ottoman bureaucracy Ottoman Turkish language was the official language, a version of Turkish, albeit with a vast mixture of both Arabic and Persian grammar and vocabulary.

Virtually all intellectual and literate pursuits were taken in Turkish language. Some ordinary people had to hire special "request-writers" (arzuhâlcis) to be able to communicate with the government. The ethnic groups continued to speak within their families and neighborhoods (mahalles) with their own languages (e.g., Jews, Greeks, Armenians, etc.) In villages where two or more populations lived together, the inhabitants would often speak each other's language. In cosmopolitan cities, people often spoke their family languages, many non-ethnic Turks spoke Turkish as a second language. Educated Ottoman Turks spoke Arabic and Persian, as these were the main foreign languages in the pre-Tanzimat era, with the former being used for science and the latter for literary affairs.

In the last two centuries, French and English emerged as popular languages, especially among the Christian Levantine communities. The elite learned French at school, and used European products as a fashion statement. The use of Ottoman Turkish for science and literature grew steadily under the Ottomans, while Persian declined in those functions. Ottoman Turkish, during the period, gained many loanwords from Arabic and Persian. Up to 88% of the vocabulary of a particular work would be borrowed from those two languages.

Linguistic groups were varied and overlapping. In the Balkan Peninsula, Slavic, Greek and Albanian speakers were the majority, but there were substantial minorities of Turks and Romance-speaking Vlachs. In most of Anatolia, Turkish was the majority language, but Greek, Armenian and, in the east and southeast, Kurdish were also spoken. In Syria, Iraq, Arabia, Egypt and north Africa, most of the population spoke varieties of Arabic with, above them, a Turkish-speaking elite. However, in no province of the Empire was there a unique language.

🔗 Yugoslavia 🔗 Economics

Despite common origins, the economy of the Socialist Federal Republic of Yugoslavia (SFRY) was significantly different from the economies of the Soviet Union and other Eastern European socialist states, especially after the Yugoslav-Soviet break-up in 1948. The occupation and liberation struggle in World War II left Yugoslavia's infrastructure devastated. Even the most developed parts of the country were largely rural and the little industry of the country was largely damaged or destroyed.

🔗 United States 🔗 Biography 🔗 Mathematics 🔗 United States/Vermont

Zerah Colburn (September 1, 1804 – March 2, 1840) was a child prodigy of the 19th century who gained fame as a mental calculator.