Cloaking device
Encyclopedia
Cloaking devices are advanced stealth technologies
still in development that will 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 device
s in various media for many years, but 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 metamaterial
s to bend light around an object.
, Star Trek
screenwriter Paul Schneider
imagined cloaking as a space-travel analog of a submarine submerging, and employed it in the 1966 episode "Balance of Terror
". Another Star Trek screenwriter, D.C. Fontana, coined the term cloaking device for the 1968 episode "The Enterprise Incident".
Writers and game designers have since incorporated cloaking devices into many other science-fiction narratives, including Doctor Who
, Star Wars
, Stargate
, Predator
, Metal Gear Solid
, Halo: Combat Evolved
, and StarCraft
.
al cloaking device might be an extension of the basic technologies used by stealth aircraft, such as radar-absorbing dark paint, optical camouflage, cooling the outer surface to minimize electromagnetic emissions (usually infrared
), or other techniques to minimize other EM emissions, and to minimize particle emissions from the object. The use of certain devices to jam and confuse remote sensing devices would greatly aid in this process, but are more properly referred to as "active camouflage
". Alternatively, metamaterials provide the theoretical possibility of making electromagnetic radiation appear to pass freely through the 'cloaked' object.
s have featured in several recent proposals for invisibility schemes. "Metamaterials" refers to materials that owe their refractive properties to the way they are structured, rather than the substances that compose them. Using transformation optics
it is possible to design the optical parameters of a "cloak" so that it guides light around some region, rendering it invisible over a certain band of wavelengths. These spatially varying optical parameters do not correspond to any natural material, but may be implemented using metamaterials. There several theories of cloaking, giving rise to different types of invisibility.
(or adaptive camouflage) is a group of camouflage
technologies which would allow an object (usually military
in nature) to blend into its surroundings by use of panels or coatings capable of changing color or luminosity. Active camouflage can be seen as having the potential to become the perfection of the art of camouflaging things from visual detection.
Optical camouflage is a kind of active camouflage in which one wears a fabric which has an image of the scene directly behind the wearer projected onto it, so that the wearer appears invisible. The drawback to this system is that, when the cloaked wearer moves, a visible distortion is often generated as the 'fabric' catches up with the object's motion. The concept exists for now only in theory and in proof-of-concept prototypes, although many experts consider it technically feasible.
It has been reported that the British Army has tested an invisible tank.
at certain density ranges absorbs certain bandwidths of broadband waves, potentially rendering an object invisible. However, generating plasma in air is too expensive and a feasible alternative is generating plasma between thin membranes instead. The Defense Technical Information Center
is also following up research on plasma reducing RCS
technologies. IEEE had also looked into the possibility of this device. A plasma cloaking device was patented in 1991.
Stealth technology
Stealth technology also termed LO technology is a sub-discipline of military tactics and passive electronic countermeasures, which cover a range of techniques used with personnel, aircraft, ships, submarines, and missiles, to make them less visible to radar, infrared, sonar and other detection...
still in development that will cause objects, such as spaceships
Spacecraft
A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
or individuals, to be partially or wholly invisible
Invisibility
Invisibility is the state of an object that cannot be seen. An object in this state is said to be invisible . The term is usually used as a fantasy/science fiction term, where objects are literally made unseeable by magical or technological means; however, its effects can also be seen in the real...
to parts of the electromagnetic (EM) spectrum
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
. Fictional cloaking devices have been used as plot device
Plot device
A plot device is an object or character in a story whose sole purpose is to advance the plot of the story, or alternatively to overcome some difficulty in the plot....
s in various media for many years, but developments in scientific research show that real-world cloaking devices can obscure objects from at least one wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
of EM emissions. Scientists already use artificial materials called metamaterial
Metamaterial
Metamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition, using small inhomogeneities to create effective macroscopic behavior....
s to bend light around an object.
Conceptual origins
Inspired in part by the 1958 film Run Silent, Run DeepRun Silent, Run Deep
Run Silent, Run Deep is a novel published first in 1955 by then-Commander Edward L. Beach, Jr.. The name refers to "silent running", a submarine stealth tactic. It is also the name of a 1958 movie based on the same novel...
, Star Trek
Star Trek: The Original Series
Star Trek is an American science fiction television series created by Gene Roddenberry, produced by Desilu Productions . Star Trek was telecast on NBC from September 8, 1966, through June 3, 1969...
screenwriter Paul Schneider
Paul Schneider (writer)
Paul Schneider was a screenwriter who wrote two episodes of Star Trek: The Original Series: "Balance of Terror" and "The Squire of Gothos". He also wrote the episode "The Terratin Incident" for Star Trek: The Animated Series....
imagined cloaking as a space-travel analog of a submarine submerging, and employed it in the 1966 episode "Balance of Terror
Balance of terror
The phrase "balance of terror" is usually used in reference to the nuclear arms race between the United States and the Soviet Union during the Cold War....
". Another Star Trek screenwriter, D.C. Fontana, coined the term cloaking device for the 1968 episode "The Enterprise Incident".
Writers and game designers have since incorporated cloaking devices into many other science-fiction narratives, including Doctor Who
Doctor Who
Doctor Who is a British science fiction television programme produced by the BBC. The programme depicts the adventures of a time-travelling humanoid alien known as the Doctor who explores the universe in a sentient time machine called the TARDIS that flies through time and space, whose exterior...
, Star Wars
Star Wars
Star Wars is an American epic space opera film series created by George Lucas. The first film in the series was originally released on May 25, 1977, under the title Star Wars, by 20th Century Fox, and became a worldwide pop culture phenomenon, followed by two sequels, released at three-year...
, Stargate
Stargate
Stargate is a adventure military science fiction franchise, initially conceived by Roland Emmerich and Dean Devlin. The first film in the franchise was simply titled Stargate. It was originally released on October 28, 1994, by Metro-Goldwyn-Mayer and Carolco, and became a hit, grossing nearly...
, Predator
Predator (film)
Predator is a 1987 American science fiction action film directed by John McTiernan, starring Arnold Schwarzenegger, Carl Weathers, Jesse Ventura, and Kevin Peter Hall. It was distributed by 20th Century Fox....
, Metal Gear Solid
Metal Gear Solid
is a videogame by Hideo Kojima. The game was developed by Konami Computer Entertainment Japan and first published by Konami in 1998 for the PlayStation video game console. It is the sequel to Kojimas early MSX2 computer games Metal Gear and Metal Gear 2: Solid Snake...
, Halo: Combat Evolved
Halo: Combat Evolved
Halo: Combat Evolved, frequently referred to as Halo: CE, or Halo 1, is a first-person shooter video game developed by Bungie and published by Microsoft Game Studios. The first game of the Halo franchise, it was released on November 15, 2001 as a launch title for the Xbox gaming system, and is...
, and StarCraft
StarCraft
StarCraft is a military science fiction real-time strategy video game developed by Blizzard Entertainment. The first game of the StarCraft series was released for Microsoft Windows on 31 March 1998. With more than 11 million copies sold worldwide as of February 2009, it is one of the best-selling...
.
Scientific experimentation
An operational, non-fictionNon-fiction
Non-fiction is the form of any narrative, account, or other communicative work whose assertions and descriptions are understood to be fact...
al cloaking device might be an extension of the basic technologies used by stealth aircraft, such as radar-absorbing dark paint, optical camouflage, cooling the outer surface to minimize electromagnetic emissions (usually infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
), or other techniques to minimize other EM emissions, and to minimize particle emissions from the object. The use of certain devices to jam and confuse remote sensing devices would greatly aid in this process, but are more properly referred to as "active camouflage
Active camouflage
Active camouflage or adaptive camouflage, is a group of camouflage technologies which allow an object to blend into its surroundings by use of panels or coatings capable of altering their appearance, color, luminance and reflective properties...
". Alternatively, metamaterials provide the theoretical possibility of making electromagnetic radiation appear to pass freely through the 'cloaked' object.
Metamaterial research
Optical metamaterialMetamaterial
Metamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition, using small inhomogeneities to create effective macroscopic behavior....
s have featured in several recent proposals for invisibility schemes. "Metamaterials" refers to materials that owe their refractive properties to the way they are structured, rather than the substances that compose them. Using transformation optics
Transformation optics
Transformation optics represents an advancement in the design of optical devices. It is the basis for conceptualizing complex tools in the electromagnetic regime which allows for novel control of light, also known as electromagnetic waves. The mathematics underpinning transformation optics is...
it is possible to design the optical parameters of a "cloak" so that it guides light around some region, rendering it invisible over a certain band of wavelengths. These spatially varying optical parameters do not correspond to any natural material, but may be implemented using metamaterials. There several theories of cloaking, giving rise to different types of invisibility.
Active camouflage
Active camouflageActive camouflage
Active camouflage or adaptive camouflage, is a group of camouflage technologies which allow an object to blend into its surroundings by use of panels or coatings capable of altering their appearance, color, luminance and reflective properties...
(or adaptive camouflage) is a group of camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
technologies which would allow an object (usually military
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...
in nature) to blend into its surroundings by use of panels or coatings capable of changing color or luminosity. Active camouflage can be seen as having the potential to become the perfection of the art of camouflaging things from visual detection.
Optical camouflage is a kind of active camouflage in which one wears a fabric which has an image of the scene directly behind the wearer projected onto it, so that the wearer appears invisible. The drawback to this system is that, when the cloaked wearer moves, a visible distortion is often generated as the 'fabric' catches up with the object's motion. The concept exists for now only in theory and in proof-of-concept prototypes, although many experts consider it technically feasible.
It has been reported that the British Army has tested an invisible tank.
Plasma stealth
PlasmaPlasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
at certain density ranges absorbs certain bandwidths of broadband waves, potentially rendering an object invisible. However, generating plasma in air is too expensive and a feasible alternative is generating plasma between thin membranes instead. The Defense Technical Information Center
Defense Technical Information Center
The Defense Technical Information Center is the premier repository for research and engineering information for the United States Department of Defense. DTIC's Suite of Services is available to DoD personnel, defense contractors, potential defense contractors, federal government personnel and...
is also following up research on plasma reducing RCS
RCS
RCS may refer to:Clubs and societies*Racing Club de Strasbourg*Radcliffe Choral Society*Royal College of Science*Royal College of Surgeons*Royal Commonwealth SocietyTechnology*Radar cross-section*Radio Computing Services*Reaction control system...
technologies. IEEE had also looked into the possibility of this device. A plasma cloaking device was patented in 1991.
See also
- InvisibilityInvisibilityInvisibility is the state of an object that cannot be seen. An object in this state is said to be invisible . The term is usually used as a fantasy/science fiction term, where objects are literally made unseeable by magical or technological means; however, its effects can also be seen in the real...
- Cloak of invisibilityCloak of invisibilityA cloak of invisibility is a theme that has occurred in fiction, and is a device which is under some scientific inquiry.-Cloaks of invisibility in fiction:...
- MetamaterialMetamaterialMetamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition, using small inhomogeneities to create effective macroscopic behavior....
- Philadelphia Project
- Physics and Star TrekPhysics and Star TrekThe science-fiction media franchise Star Trek has borrowed freely from the scientific world to provide storylines. Episodes are replete with references to tachyon beams, baryon sweeps, quantum fluctuations and event horizons...
- Physics and Star WarsPhysics and Star WarsThe science fantasy interstellar epic Star Wars uses science and technology in its settings and storylines, although it is not considered "hard" science fiction. The series has showcased many technological concepts, both in the movies and in the "Expanded Universe" of novels and comics...