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Cloaking Devices
A cloaking device is a hypothetical or fictional stealth technology that can cause objects, such as spaceships or individuals, to be partially or wholly invisible to parts of the electromagnetic (EM) spectrum. Fictional cloaking devices have been used as plot devices in various media for many years. Developments in scientific research show that real-world cloaking devices can obscure objects from at least one wavelength of EM emissions. Scientists already use artificial materials called metamaterials to bend light around an object. However, over the entire spectrum, a cloaked object scatters more than an uncloaked object. Fictional origins Cloaks with magical powers of invisibility appear from the earliest days of story-telling. Since the advent of modern Science fiction, many variations on the theme with proposed basis in reality have been imagined. ''Star Trek'' screenwriter Paul Schneider, inspired in part by the 1958 film '' Run Silent, Run Deep,'' and in part by ''The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stealth Technology
Stealth technology, also termed low observable technology (LO technology), is a sub-discipline of military tactics and passive and active electronic countermeasures. The term covers a range of military technology, methods used to make personnel, Stealth aircraft, aircraft, Stealth ship, ships, submarines, missiles, satellites, and Stealth ground vehicle, ground vehicles less visible (ideally invisible) to radar, Thermographic camera, infrared, sonar and other detection methods. It corresponds to military camouflage for these parts of the electromagnetic spectrum (i.e., multi-spectral camouflage). Development of modern stealth technologies in the United States began in 1958, where earlier attempts to prevent radar tracking of its Lockheed U-2, U-2 spy planes during the Cold War by the Soviet Union had been unsuccessful. Designers turned to developing a specific shape for planes that tended to reduce detection by redirecting electromagnetic radiation waves from radars. Radiation-a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shields (Star Trek)
In the ''Star Trek'' fictional universe, shields refer to a 23rd and 24th century technology that provides starships, space stations, and entire planets with limited protection against damage. They are sometimes referred to as ''deflectors'', '' deflector shields'', or (in '' Star Trek: The Original Series'') ''screens''. Types of shields include ''navigational deflectors''. History The term 'shields' first appears in the ''Star Trek'' episode "Balance of Terror", in which they were deployed, albeit to little effect, by a Federation outpost under attack from a Romulan Warbird. The first depicted use by a starship was in the ''Star Trek'' episode "Arena", in which the USS ''Enterprise'' raises its 'screens' after being attacked by an alien warship although the term 'shields' is not used in this episode. Shields are not mentioned during the earlier seasons of the '' Star Trek: Enterprise'' series, starships instead using "polarized hull plating" to make their hull more resista ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Camouflage
Active camouflage or adaptive camouflage is camouflage that adapts, often rapidly, to the surroundings of an object such as an animal or military vehicle. In theory, active camouflage could provide perfect concealment from visual detection. Active camouflage occurs in several groups of animals, including reptiles on land, and cephalopod molluscs and flatfish in the sea. Animals achieve active camouflage both by Camouflage#Changeable skin coloration, color change and (among marine animals such as squid) by counter-illumination, with the use of bioluminescence. Military counter-illumination camouflage was first investigated during World War II for marine use. More recent research has aimed to achieve crypsis by using cameras to sense the visible background, and by controlling systems that can vary their appearance, such as coatings, or variable temperature infrared panels using the Peltier effect. In animals Active camouflage is used in several groups of animals including ceph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theories Of Cloaking
Theories of cloaking discusses various theories based on science and research, for producing an electromagnetic cloaking device. Theories presented employ transformation optics, event cloaking, dipolar scattering cancellation, tunneling light transmittance, sensors and active sources, and acoustic cloaking. A cloaking device is one where the purpose of the transformation is to hide something, so that a defined region of space is invisibly isolated from passing electromagnetic fields (see Metamaterial cloaking) or sound waves. Objects in the defined location are still present, but incident waves are guided around them without being affected by the object itself. Along with this basic " cloaking device", other related concepts have been proposed in peer reviewed, scientific articles, and are discussed here. Naturally, some of the theories discussed here also employ metamaterials, either electromagnetic or acoustic, although often in a different manner than the original demonstr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamaterials
A metamaterial (from the Greek word μετά ''meta'', meaning "beyond" or "after", and the Latin word ''materia'', meaning "matter" or "material") is a type of material engineered to have a property, typically rarely observed in naturally occurring materials, that is derived not from the properties of the base materials but from their newly designed structures. Metamaterials are usually fashioned from multiple materials, such as metals and plastics, and are usually arranged in repeating patterns, at scales that are smaller than the wavelengths of the phenomena they influence. Their precise shape, geometry, size, orientation, and arrangement give them their "smart" properties of manipulating electromagnetic, acoustic, or even seismic waves: by blocking, absorbing, enhancing, or bending waves, to achieve benefits that go beyond what is possible with conventional materials. Appropriately designed metamaterials can affect waves of electromagnetic radiation or sound in a manner not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Journal Of Physics
''New Journal of Physics'' is an online-only, Open access (publishing), open-access, peer review, peer-reviewed scientific journal covering research in all aspects of physics, as well as interdisciplinarity, interdisciplinary topics where physics forms the central theme. The journal was established in 1998 and is a joint publication of the Institute of Physics and the Deutsche Physikalische Gesellschaft. It is published by IOP Publishing. The editor-in-chief is Andreas Buchleitner (Albert Ludwigs University). ''New Journal of Physics'' is part of the SCOAP3, SCOAP3 initiative. In April 2023, on occasion of the World Quantum Day, IOP Publishing has launched a special collection of its most important articles published in the field of quantum research. The articles will be extracted from ''Materials for Quantum Technology'', ''Quantum Science and Technology'', ''New Journal of Physics'' and ''Reports on Progress in Physics''. Abstracting and indexing The journal is abstracted and ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformation Optics
Transformation optics is a branch of optics which applies metamaterials to produce spatial variations, derived from coordinate transformations, which can direct chosen bandwidths of electromagnetic radiation. This can allow for the construction of new composite artificial devices, which probably could not exist without metamaterials and coordinate transformation. Computing power that became available in the late 1990s enables prescribed quantitative values for the permittivity and permeability, the constitutive parameters, which produce localized spatial variations. The aggregate value of all the constitutive parameters produces an effective value, which yields the intended or desired results. Hence, complex artificial materials, known as metamaterials, are used to produce transformations in optical space. The mathematics underpinning transformation optics is similar to the equations that describe how gravity warps space and time, in general relativity. However, instead of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Camouflage
Active camouflage or adaptive camouflage is camouflage that adapts, often rapidly, to the surroundings of an object such as an animal or military vehicle. In theory, active camouflage could provide perfect concealment from visual detection. Active camouflage occurs in several groups of animals, including reptiles on land, and cephalopod molluscs and flatfish in the sea. Animals achieve active camouflage both by Camouflage#Changeable skin coloration, color change and (among marine animals such as squid) by counter-illumination, with the use of bioluminescence. Military counter-illumination camouflage was first investigated during World War II for marine use. More recent research has aimed to achieve crypsis by using cameras to sense the visible background, and by controlling systems that can vary their appearance, such as coatings, or variable temperature infrared panels using the Peltier effect. In animals Active camouflage is used in several groups of animals including ceph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around to . IR is commonly divided between longer-wavelength thermal IR, emitted from terrestrial sources, and shorter-wavelength IR or near-IR, part of the solar spectrum. Longer IR wavelengths (30–100 μm) are sometimes included as part of the terahertz radiation band. Almost all black-body radiation from objects near room temperature is in the IR band. As a form of EMR, IR carries energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-fiction
Non-fiction (or nonfiction) is any document or content (media), media content that attempts, in good faith, to convey information only about the real life, real world, rather than being grounded in imagination. Non-fiction typically aims to present topics Objectivity (philosophy), objectively based on historical, scientific, and empirical information. However, some non-fiction ranges into more subjective territory, including sincerely held opinions on real-world topics. Often referring specifically to prose writing, non-fiction is one of the two fundamental approaches to narrative, story and storytelling, in contrast to narrative fiction, which is largely populated by imaginary characters and events. Non-fiction writers can show the reasons and consequences of events, they can compare, contrast, classify, categorise and summarise information, put the facts in a logical or chronological order, infer and reach conclusions about facts, etc. They can use graphic, structural and prin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stargate
''Stargate'' is a military science fiction media franchise owned by Amazon MGM Studios. It is based on Stargate (film), the film directed by Roland Emmerich, which he co-wrote with producer Dean Devlin; production company StudioCanal owns the rights to the original film. The franchise is based on the idea of an alien wormhole (specifically an Einstein–Rosen bridge) device (the Stargate (device), Stargate) that enables nearly teleportation, instantaneous travel across the cosmos. The franchise began with the film Stargate (film), ''Stargate'', released on October 28, 1994, by Metro-Goldwyn-Mayer and Carolco, which grossed United States dollar, US$197million worldwide. In 1997, Brad Wright and Jonathan Glassner created a television series titled ''Stargate SG-1'' as a sequel to the film. This show was joined by ''Stargate Atlantis'' in 2004, ''Stargate Universe'' in 2009, and a prequel web series, ''Stargate Origins'', in 2018. Also consistent with the same story are a variety o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
