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Unobtainium
Unobtainium (or unobtanium) is a term used in fiction, engineering, and common situations for a material ideal for a particular application but impractically difficult or impossible to obtain. Unobtainium originally referred to materials that do not exist at all, but can also be used to describe real materials that are unavailable due to extreme rarity or cost. Less commonly, it can mean a device with desirable engineering properties for an application that are exceedingly difficult or impossible to achieve. The properties of any particular example of unobtainium depend on the intended use. For example, a pulley made of unobtainium might be massless and frictionless. But for a nuclear propulsion, nuclear rocket, unobtainium might have the needed qualities of lightness, strength at high temperatures, and resistance to radiation damage; a combination of all three qualities is impossible with today's materials. The concept of unobtainium is often applied hand-wavingly, flippantly, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiction
Fiction is any creative work, chiefly any narrative work, portraying character (arts), individuals, events, or setting (narrative), places that are imagination, imaginary or in ways that are imaginary. Fictional portrayals are thus inconsistent with fact, history, or plausibility. In a traditional narrow sense, fiction refers to literature, written narratives in prose often specifically novels, novellas, and short story, short stories. More broadly, however, fiction encompasses imaginary narratives expressed in any Media (communication), medium, including not just writings but also drama, live theatrical performances, films, television programs, radio dramas, comics, role-playing games, and video games. Definition and theory Typically, the fictionality of a work is publicly expressed, so the audience expects a work of fiction to deviate to a greater or lesser degree from the real world, rather than presenting for instance only factually accurate portrayals or character (arts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lockheed Corporation
The Lockheed Corporation was an American aerospace manufacturer. Lockheed was founded in 1926 and merged in 1995 with Martin Marietta to form Lockheed Martin. Its founder, Allan Lockheed, had earlier founded the similarly named but otherwise-unrelated Loughead Aircraft Manufacturing Company, which was operational from 1912 to 1920. History Origins Allan Loughead and his brother Malcolm Loughead had operated an earlier aircraft company, Loughead Aircraft Manufacturing Company, which was operational from 1912 to 1920. The company built and operated aircraft for paying passengers on sightseeing tours in California and had developed a prototype for the civil market, but folded in 1920 due to the flood of surplus aircraft deflating the market after World War I. Allan went into the real estate market while Malcolm had meanwhile formed a successful company marketing brake systems for automobiles. On December 13, 1926, Allan Loughead, Jack Northrop, John Northrop, Kenneth Kay and Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rare-earth Metals
The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare earths have diverse applications in electrical and electronic components, lasers, glass, magnetic materials, and industrial processes. The term "rare-earth" is a misnomer because they are not actually scarce, but historically it took a long time to isolate these elements. They are relatively plentiful in the entire Earth's crust (cerium being the 25th-most-abundant element at 68 parts per million, more abundant than copper), but in practice they are spread thinly as trace impurities, so to obtain rare earths at usable purity requires processing enormous amounts of raw ore at great expense; thus the name "rare" earths. Scandium and yttrium are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WD-11
The WD-11 vacuum tube, a triode, was introduced by the Westinghouse Electric corporation in 1922 for their Aeriola RF model radio and found use in other contemporary regenerative receivers (used as a detector-amplifier) including the Regenoflex and Radiola series. The WD11 and "RCA-11" (and later simply named "11" by RCA and Philips/Miniwatt) have the following characteristics: Drawbacks The design of the WD-11 is somewhat flawed. When the filament burns out, it has a tendency to contact the plate. This feeds high voltages back through the heater circuitry, subsequently burning out the filaments on the remaining tubes. The WD-11 has a unique 4-pin base layout that was unlike any subsequent UV and UX style tube bases. It had 3 "small" pins and one "large" pin. Later UV based tubes relied on an index pin on the side of the tube base and UX tubes had 2 large and 2 small pins to ensure proper indexing. It was replaced a year after its introduction by higher performance tubes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Biking
Mountain biking (MTB) is a sport of riding bicycles off-road, often over rough terrain, usually using specially designed mountain bikes. Mountain bikes share similarities with other bikes but incorporate features designed to enhance durability and performance in rough terrain, such as air or coil-sprung shocks used as suspension, larger and wider wheels and tires, stronger frame materials, and mechanically or hydraulically actuated disc brakes. Mountain biking can generally be broken down into distinct categories: Cross-country cycling, cross country, trail riding#Mountain biking, trail, all mountain, Enduro (mountain biking), enduro, Downhill cycling, downhill and freeride (mountain biking), freeride. About The sport requires endurance, core and back strength, balance, bike handling skills, and self-reliance. Advanced riders pursue both steep technical descents and high-incline climbs. In the case of freeride, downhill, and dirt jumping, aerial maneuvers are performed off bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-end
In economics, a luxury good (or upmarket good) is a good for which demand increases more than what is proportional as income rises, so that expenditures on the good become a more significant proportion of overall spending. Luxury goods are in contrast to necessity goods, where demand increases proportionally less than income. ''Luxury goods'' is often used synonymously with superior goods. Definition and etymology The word "luxury" derives from the Latin verb ''luxor'' meaning to overextend or strain. From this, the noun ''luxuria'' and verb ''luxurio'' developed, "indicating immoderate growth, swelling, ... in persons and animals, willful or unruly behavior, disregard for moral restraints, and licensciousness", and the term has had negative connotations for most of its long history. One definition in the OED is a "thing desirable but not necessary". A luxury good can be identified by comparing the demand for the good at one point in time against the demand for the good at a dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-22 Raptor
The Lockheed Martin/Boeing F-22 Raptor is an American twin-engine, jet-powered, all-weather, supersonic stealth fighter aircraft. As a product of the United States Air Force's Advanced Tactical Fighter (ATF) program, the aircraft was designed as an air superiority fighter, but also incorporates ground attack, electronic warfare, and signals intelligence capabilities. The prime contractor, Lockheed Martin, built most of the F-22 airframe and weapons systems and conducted final assembly, while program partner Boeing provided the wings, aft fuselage, avionics integration, and training systems. First flown in 1997, the F-22 descended from the Lockheed YF-22 and was variously designated F-22 and F/A-22 before it formally entered service in December 2005 as the F-22A. Although the U.S. Air Force (USAF) had originally planned to buy a total of 750 ATFs to replace its F-15 Eagles, it later scaled down to 381, and the program was ultimately cut to 195 aircraft – 187 of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F/A-18 Hornet
The McDonnell Douglas F/A-18 Hornet is an all-weather supersonic, twinjet, twin-engine, carrier-based aircraft, carrier-capable, Multirole combat aircraft, multirole combat aircraft, designed as both a Fighter aircraft, fighter and attack aircraft (hence the F/A 1962 United States Tri-Service aircraft designation system, designation). Designed by McDonnell Douglas and Northrop Corporation, Northrop, the F/A-18 was derived from the latter's YF-17 in the 1970s for use by the United States Navy and United States Marine Corps, Marine Corps. The Hornet is also used by the air forces of several other nations, and formerly by the U.S. Navy's Flight Demonstration Squadron, the Blue Angels. The F/A-18 was designed to be a highly versatile aircraft due to its avionics, glass cockpit, cockpit displays, and excellent aerodynamic characteristics, with the ability to carry a wide variety of weapons. The aircraft can perform escort fighter, fighter escort, fleet air defense, suppression of en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-15 Eagle
The McDonnell Douglas F-15 Eagle is an American twin-engine, all-weather fighter aircraft designed by McDonnell Douglas (now part of Boeing). Following reviews of proposals, the United States Air Force (USAF) selected McDonnell Douglas's design in 1969 to meet the service's need for a dedicated air superiority fighter. The Eagle took its maiden flight in July 1972, and entered service in 1976. It is among the most successful modern fighters, with over 100 victories and no losses in aerial combat, with the majority of the kills by the Israeli Air Force.Spick 2000, p. 127. The Eagle has been exported to many countries, including Israel, Japan, and Saudi Arabia. Although the F-15 was originally envisioned as a pure air superiority fighter, its design included a secondary ground-attack capability that was largely unused. It proved flexible enough that an improved all-weather strike derivative, the F-15E Strike Eagle, was later developed, entered service in 1989 and has been ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B-1 Lancer
The Rockwell B-1 Lancer is a supersonic variable-sweep wing, heavy bomber used by the United States Air Force. It has been nicknamed the "Bone" (from "B-One"). , it is one of the United States Air Force's three strategic bombers, along with the B-2 Spirit and the B-52 Stratofortress. It is a heavy bomber with up to a 75,000-pound (34,000 kg) of payload. The B-1 was first envisioned in the 1960s as a bomber that would combine the Mach 2 speed of the B-58 Hustler with the range and payload of the B-52, ultimately replacing both. After a long series of studies, North American Rockwell (subsequently renamed Rockwell International, B-1 division later acquired by Boeing) won the design contest for what emerged as the B-1A. Prototypes of this version could fly Mach number, Mach 2.2 at high altitude and long distances and at Mach 0.85 at very low altitudes. The program was canceled in 1977 due to its high cost, the introduction of the AGM-86 ALCM, AGM-86 cruise missile that flew t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold War
The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 until the dissolution of the Soviet Union in 1991. The term ''Cold war (term), cold war'' is used because there was no direct fighting between the two superpowers, though each supported opposing sides in regional conflicts known as proxy wars. In addition to the struggle for ideological and economic influence and an arms race in both conventional and Nuclear arms race, nuclear weapons, the Cold War was expressed through technological rivalries such as the Space Race, espionage, propaganda campaigns, Economic sanctions, embargoes, and sports diplomacy. After the end of World War II in 1945, during which the US and USSR had been allies, the USSR installed satellite state, satellite governments in its occupied territories in Eastern Europe and N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
