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A Shepard tone, named after Roger Shepard, is a sound consisting of a superposition of sine waves separated by octaves. When played with the bass pitch of the tone moving upward or downward, it is referred to as the Shepard scale. This creates the auditory illusion of a tone that continually ascends or descends in pitch, yet which ultimately seems to get no higher or lower.

Authoritarian capitalism, or illiberal capitalism, is an economic system in which a capitalist market economy exists alongside an authoritarian government. Related to and overlapping with state capitalism, a system in which the state undertakes commercial activity, authoritarian capitalism combines private property and the functioning of market forces with repression of dissent, restrictions on freedom of speech and either a lack of elections or an electoral system with a single dominant political party.

Political scientists disagree on the long-run sustainability of authoritarian capitalism, with arguments both for and against the long-term viability of political repression alongside a free-market capitalist economic system.

Countries commonly referred to as being authoritarian capitalist states include China since the economic reforms, Hungary under Viktor Orbán, Russia under Vladimir Putin, Singapore under Lee Kuan Yew and Turkey under Recep Tayyip Erdoğan as well as fascist regimes and military dictatorships during the Cold War. Nazi Germany has also been described as authoritarian capitalist.

The New Oxford American Dictionary (NOAD) is a single-volume dictionary of American English compiled by American editors at the Oxford University Press.

NOAD is based upon the New Oxford Dictionary of English (NODE), published in the United Kingdom in 1998, although with substantial editing, additional entries, and the inclusion of illustrations. It is based on a corpus linguistics analysis of Oxford's 200 million word database of contemporary American English.

NOAD includes a diacritical respelling scheme to convey pronunciations, as opposed to the Gimson phonemic IPA system that is used in NODE.

A screw drive is a system used to turn a screw. At a minimum, it is a set of shaped cavities and protrusions on the screw head that allows torque to be applied to it. Usually, it also involves a mating tool, such as a screwdriver, that is used to turn it. The following heads are categorized based on commonality, with some of the less-common drives being classified as "tamper-resistant".

Most heads come in a range of sizes, typically distinguished by a number, such as "Phillips #00". These sizes do not necessarily describe a particular dimension of the drive shape, but rather are arbitrary designations.

Lloyd's Coffee House was a significant meeting place in London in the 17th and 18th centuries.

It was opened by Edward Lloyd (c. 1648–15 February 1713) on Tower Street in 1686. The establishment was a popular place for sailors, merchants and shipowners, and Lloyd catered to them by providing reliable shipping news. The shipping industry community frequented the place to discuss maritime insurance, shipbroking and foreign trade. The dealings that took place led to the establishment of the insurance market Lloyd's of London, Lloyd's Register and several related shipping and insurance businesses.

The coffee shop relocated to Lombard Street in December 1691. Lloyd had a pulpit installed in the new premises, from which maritime auction prices and shipping news were announced. Candle auctions were held in the establishment, with lots frequently involving ships and shipping. From 1696–1697 Lloyd also experimented with publishing a newspaper, Lloyd's News, reporting on shipping schedules and insurance agreements reached in the coffee house. In 1713, the year of Edward Lloyd's death, he modified his will to assign the lease of the coffee house to his head waiter, William Newton, who then married one of Lloyd's daughters, Handy. Newton died the following year and Handy subsequently married Samuel Sheppard. She died in 1720 and Sheppard died in 1727, leaving the coffee house to his sister Elizabeth and her husband, Thomas Jemson. Jemson founded the Lloyd's List newspaper in 1734, similar to the previous Lloyd's News. Merchants continued to discuss insurance matters here until 1774, when the participating members of the insurance arrangement formed a committee and moved to the Royal Exchange on Cornhill as the Society of Lloyd's.

Iron gall ink (also known as common ink, standard ink, oak gall ink or iron gall nut ink) is a purple-black or brown-black ink made from iron salts and tannic acids from vegetable sources. It was the standard ink formulation used in Europe for the 1400-year period between the 5th and 19th centuries, remained in widespread use well into the 20th century, and is still sold today.

In the U.S., Federal Communications Commission (FCC) regulations prohibit the use of mobile phones aboard aircraft in flight. Contrary to popular misconception, the Federal Aviation Administration (FAA) does not actually prohibit the use of personal electronic devices (including cell phones) on aircraft. Paragraph (b)(5) of 14 CFR 91.21 leaves it up to the airlines to determine if devices can be used in flight, allowing use of "Any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used."

In Europe, regulations and technology have allowed the limited introduction of the use of passenger mobile phones on some commercial flights, and elsewhere in the world many airlines are moving towards allowing mobile phone use in flight. Many airlines still do not allow the use of mobile phones on aircraft. Those that do often ban the use of mobile phones during take-off and landing.

Many passengers are pressing airlines and their governments to allow and deregulate mobile phone use, while some airlines, under the pressure of competition, are also pushing for deregulation or seeking new technology which could solve the present problems. On the other hand, official aviation agencies and safety boards are resisting any relaxation of the present safety rules unless and until it can be conclusively shown that it would be safe to do so. There are both technical and social factors which make the issues more complex than a simple discussion of safety versus hazard.

In quantum field theory, a false vacuum is a hypothetical vacuum that is relatively stable, but not in the most stable state possible. In this condition it is called metastable. It may last for a very long time in this state, but could eventually decay to the more stable one, an event known as false vacuum decay. The most common suggestion of how such a decay might happen in our universe is called bubble nucleation – if a small region of the universe by chance reached a more stable vacuum, this "bubble" (also called "bounce") would spread.

A false vacuum exists at a local minimum of energy and is therefore not completely stable, in contrast to a true vacuum, which exists at a global minimum and is stable.

Fart lighting also known as pyroflatulence, or flatus ignition is the practice of igniting the gases produced by flatulence. The resulting flame is often of a blue hue hence the act being known colloquially as a "blue angel", "blue dart" or in Australia, a "blue flame". The fact that flatus is flammable and the actual combustion of it through this practice gives rise to much humorous derivation. Other colors of flame such as orange and yellow are possible depending on the mixture of gases formed in the colon.

In 1999 author Jim Dawson observed that fart lighting has been a novelty practice primarily among young men or college students for decades but is discouraged for its potential for causing harm. Such experiments typically occur on camping trips and in same-sex group residences, such as tree-houses, dormitories, or fraternity houses. With the advent of video sharing features online, hundreds of self-produced videos, both documentary as well as spoof, have been posted to sites such as YouTube. The people appearing in the videos are predominantly young teen males. In his book The Curse of the Self: Self-Awareness, Egotism, and the Quality of Human Life author Mark Richard Leary explains how a great deal of unhappiness is due to people's inability to exert control over their thoughts and behavior and that "stupid stunts", including lighting flatulence, were a way to make an impression and be included in group bonding or hazing.

Although there is little scientific discourse on the combustive properties of flatus, there are many anecdotal accounts of flatus ignition and the activity has increasingly found its way into popular culture with references in comic routines, movies, and television; including cartoons. In Electric Don Quixote: The Definitive Story of Frank Zappa author Neil Slaven quotes Frank Zappa for calling fart lighting "The manly art of fart-burning", and another book quotes the musician Kenny Williams for saying that it demonstrates "compression, ignition, combustion and exhaust."

There have been documented cases of flatulence during surgery being inadvertently ignited causing patient injury and the risk of death.

A shaft passer is a hypothetical device that allows a spoked wheel to rotate despite having a shaft (such as the axle of another wheel) passing between its spokes. The device is usually mentioned as a joke between nerds, in the manner of a fool's errand, since there is no evidence of one ever having been constructed until very recently.

One of the earliest printed references to these devices was made by Richard Feynman, who was told by a colleague at Frankford Arsenal in Philadelphia that the cable-passing version of the device had been used during both world wars on German naval mine mooring cables, to prevent the mines from being caught by British cables swept along the sea bottom.

The device was supposed to work using a spoked, rimless wheel that allows cables to pass through as it rotates. The ends of the spokes are widened, and the cable is held together by a short curved sleeve through which these spoke ends slide.