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🔗 Computing 🔗 Computer science 🔗 C/C++ 🔗 C/C++/C

In the C programming language, Duff's device is a way of manually implementing loop unrolling by interleaving two syntactic constructs of C: the do-while loop and a switch statement. Its discovery is credited to Tom Duff in November 1983, when Duff was working for Lucasfilm and used it to speed up a real-time animation program.

Loop unrolling attempts to reduce the overhead of conditional branching needed to check whether a loop is done, by executing a batch of loop bodies per iteration. To handle cases where the number of iterations is not divisible by the unrolled-loop increments, a common technique among assembly language programmers is to jump directly into the middle of the unrolled loop body to handle the remainder. Duff implemented this technique in C by using C's case label fall-through feature to jump into the unrolled body.

🔗 Technology 🔗 Internet 🔗 Computing 🔗 Computing/Networking

An email address identifies an email box to which email messages are delivered. A wide variety of formats were used in early email systems, but only a single format is used today, following the specifications developed for Internet mail systems since the 1980s. This article uses the term email address to refer to the addr-spec defined in RFC 5322, not to the address that is commonly used; the difference is that an address may contain a display name, a comment, or both.

An email address such as John.Smith@example.com is made up of a local-part, an @ symbol, then a case-insensitive domain. Although the standard requires the local part to be case-sensitive, it also urges that receiving hosts deliver messages in a case-independent fashion, e.g., that the mail system at example.com treat John.Smith as equivalent to john.smith; some mail systems even treat them as equivalent to johnsmith. Mail systems often limit their users' choice of name to a subset of the technically valid characters, and in some cases also limit which addresses it is possible to send mail to.

With the introduction of internationalized domain names, efforts are progressing to permit non-ASCII characters in email addresses.

🔗 Environment 🔗 Meteorology 🔗 Astronomy 🔗 Middle Ages 🔗 Middle Ages/History 🔗 Geology 🔗 Glaciers 🔗 Solar System

The 774–775 carbon-14 spike is an observed increase of 1.2% in the concentration of carbon-14 isotope in tree rings dated to 774 or 775, which is about 20 times as high as the normal background rate of variation. It was discovered during a study of Japanese cedar trees, with the year of occurrence determined through dendrochronology. A surge in beryllium isotope ¹⁰
Be, detected in Antarctic ice cores, has also been associated with the 774–775 event. It is known as the Miyake event or the Charlemagne event and it produced the largest and most rapid rise in carbon-14 ever recorded.

The event appears to have been global, with the same carbon-14 signal found in tree rings from Germany, Russia, the United States, Finland and New Zealand.

The signal exhibits a sharp increase of around 1.2% followed by a slow decline (see Figure 1), which is typical for an instant production of carbon-14 in the atmosphere, indicating that the event was short in duration. The globally averaged production of carbon-14 for this event is calculated as Q = 1.3×10⁸ ± 0.2×10⁸ atoms/cm².

🔗 Technology 🔗 History 🔗 Medicine 🔗 Religion 🔗 Biology 🔗 Agriculture 🔗 Economics 🔗 Lists 🔗 Skepticism 🔗 Literature 🔗 Psychology 🔗 Astronomy 🔗 History of Science 🔗 Islam 🔗 Food and drink 🔗 Sexology and sexuality 🔗 Judaism 🔗 Christianity 🔗 Popular Culture 🔗 Sports 🔗 Evolutionary biology

This is a list of common misconceptions. Each entry is formatted as a correction; the misconceptions themselves are implied rather than stated. These entries are meant to be concise, but more detail can be found in the main subject articles.

🔗 United States 🔗 Spaceflight 🔗 Philately 🔗 Guild of Copy Editors

The Apollo 15 postal covers incident, a 1972 NASA scandal, involved the astronauts of Apollo 15, who carried about 400 unauthorized postal covers into space and to the Moon's surface on the Lunar Module Falcon. Some of the envelopes were sold at high prices by West German stamp dealer Hermann Sieger, and are known as "Sieger covers". The crew of Apollo 15, David Scott, Alfred Worden and James Irwin, agreed to take payments for carrying the covers; though they returned the money, they were reprimanded by NASA. Amid much press coverage of the incident, the astronauts were called before a closed session of a Senate committee and never flew in space again.

The three astronauts and an acquaintance, Horst Eiermann, had agreed to have the covers made and taken into space. Each astronaut was to receive about $7,000. Scott arranged to have the covers postmarked on the morning of the Apollo 15 launch on July 26, 1971. They were packaged for space and brought to him as he prepared for liftoff. Due to an error, they were not included on the list of the personal items he was taking into space. The covers spent July 30 to August 2 on the Moon inside Falcon. On August 7, the date of splashdown, the covers were postmarked again on the recovery carrier USS Okinawa. One hundred were sent to Eiermann (and passed on to Sieger); the remaining covers were divided among the astronauts.

Worden had agreed to carry 144 additional covers, largely for an acquaintance, F. Herrick Herrick; these had been approved for travel to space. Apollo 15 carried a total of approximately 641 covers. In late 1971, when NASA learned that the Herrick covers were being sold, the astronauts' supervisor, Deke Slayton, warned Worden to avoid further commercialization of what he had been allowed to take into space. After Slayton heard of the Sieger arrangement, he removed the three as backup crew members for Apollo 17, though the astronauts had by then refused compensation from Sieger and Eiermann. The Sieger matter became generally known in the newspapers in June 1972. There was widespread coverage; some said astronauts should not be allowed to reap personal profits from NASA missions.

By 1977, all three former astronauts had left NASA. In 1983, Worden sued, and the covers were returned to them. One of the postal covers given to Sieger sold for over $50,000 in 2014.

🔗 California 🔗 Organizations 🔗 Scientology 🔗 California/Inland Empire

The Sea Organization (also known as the Sea Org) is a Scientology organization, which the Church of Scientology describes as a "fraternal religious order, comprising the church's most dedicated members". All Scientology management organizations are controlled exclusively by members of the Sea Org. David Miscavige, the de facto leader of Scientology, is the highest-ranking Sea Org officer, holding the rank of captain.

The Sea Org has been described as a paramilitary organization and as a private naval force, having operated several vessels in its past and displaying a maritime tradition. Some ex-members and scholars have described the Sea Org as a totalitarian organization marked by intensive surveillance and a lack of freedom. The Sea Org has also been compared to a monastic organization.

In a 1992 memorandum by the Church of Scientology International, the following information was provided to the Internal Revenue Service with regards to nature of the Sea Org:

[the Sea Org] does not have an ecclesiastical organizing board or command channels chart or secular existence such as an incorporated or unincorporated association. ... Although there is no such "organization" as the Sea Organization, the term Sea Org has a colloquial usage which implies that there is. There are general recruitment posters and literature for "The Sea Org" which implies that people will be employed by the Sea Org when in reality they will join, making the billion year commitment, at some church that is staffed by Sea Org members and become employees of that church corporation. ... The Sea Org exists as a spiritual commitment that is factually beyond the full understanding of the Service or any other but a trained and audited Scientologist.

The Sea Org was established on August 12, 1967, by L. Ron Hubbard, the founder of Dianetics and Scientology, initially on board three ships, the Diana, the Athena, and the Apollo, with the latter serving as flagship.

In 1971, the Sea Org assumed responsibility for the church's ecclesiastical development, and in particular the delivery of the upper levels of its auditing and training, known as the Operating Thetan or "OT" levels. In 1981, under the aegis of the Commodore's Messenger Organization led by David Miscavige, the Sea Org dissolved the Guardian's Office (GO) and assumed full responsibility for the church's international management, later reassigning the GO's duties to the Office of Special Affairs in 1983 during the corporate restructuring of the Church.

It moved to land-based organizations in 1975, though maritime customs persist, with many members wearing naval-style uniforms and addressing both male and female officers as "sir." In 1985, the church purchased a 440-foot (130 m) motor vessel, the Freewinds, which docks in Curaçao in the southern Caribbean and is used as a religious retreat and training center, staffed entirely by Sea Org members. Sea Org members make a lifetime commitment to Scientology by signing a billion-year contract officially described as a symbolic pledge. In exchange, members are given free room and board, as well as a small weekly allowance. Sea Org members agree to strict codes of discipline, such as disavowing premarital sex, working long hours (on average at least 100 hours per week) and living in communal housing called "berthings." They are allowed to marry, but must relinquish their membership if they have or want to raise children.

🔗 Books 🔗 Business 🔗 Comics 🔗 Comics/Comic strips

The Dilbert principle is a concept in management developed by Scott Adams, creator of the comic strip Dilbert, which states that companies tend to systematically promote incompetent employees to management to get them out of the workflow. The Dilbert principle is inspired by the Peter principle, which holds that employees are promoted based on success in their current position until they reach their "level of incompetence" and are no longer promoted. Under the Dilbert principle, employees who were never competent are promoted to management to limit the damage they can do. Adams first explained the principle in a 1995 Wall Street Journal article, and expanded upon it in his 1996 business book The Dilbert Principle.

🔗 Economics 🔗 Transport

The Downs–Thomson paradox (named after Anthony Downs and John Michael Thomson), also known as the Pigou–Knight–Downs paradox (after Arthur Cecil Pigou and Frank Knight), states that the equilibrium speed of car traffic on a road network is determined by the average door-to-door speed of equivalent journeys taken by public transport.

It is a paradox in that improvements in the road network will not reduce traffic congestion. Improvements in the road network can make congestion worse if the improvements make public transport more inconvenient or if it shifts investment, causing disinvestment in the public transport system.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Food and drink 🔗 Military history/Russian, Soviet and CIS military history 🔗 Food and drink/Beverages

White Coke (Russian: Бесцветная кока-кола, tr. Bestsvetnaya koka-kola, lit. "colorless Coca-Cola") is a nickname for a clear variant of Coca-Cola produced in the 1940s at the request of Marshal of the Soviet Union Georgy Zhukov. Like other clear colas, it was of the same original flavor, virtually unchanged by the absence of caramel coloring.

🔗 Computer Security 🔗 Computer Security/Computing 🔗 Microsoft Windows 🔗 Microsoft Windows/Computing 🔗 Cryptography 🔗 Cryptography/Computer science

_NSAKEY was a variable name discovered in an operating system from Microsoft in 1999. The variable contained a 1024-bit public key; such keys are used in cryptography for encryption and authentication. Due to the name it was speculated that the key was owned by the United States National Security Agency (the NSA) which would allow the intelligence agency to subvert any Windows user's security. Microsoft denied the speculation and said that the key's name came from the NSA being the technical review authority for U.S. cryptography export controls.

The key was discovered in a Windows NT 4 Service Pack 5 (which had been released unstripped of its symbolic debugging data) in August 1999 by Andrew D. Fernandes of Cryptonym Corporation.