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Plasmonic Cover - Invisibility Technology
Guys came across this just while surfing the net and sonds pretty intresting.
How many of us have had a dream of being invisible , many of us havent we.
Right from watching old days of ghosts, to current generation Harry Potter using his invibility cloak.
American researchers are working on this and trying to make this possible
read the article to understand the theory put by them and start dreaming
about what will u do after becoming invisible.
-----------------------------------------------------------------------------------------------------
Key points
• American researchers working on 'plasmonic cover' 'cloaking device'
• Invisibility shield would prevent objects reflecting and scattering light
• Device differs from other invisibility research reliant on chameleon principle
-----------------------------------------------------------------------------------------------------
Article I
Plasmonic Cover, May Render Object Invisible
Andrea Alù and Nader Engheta of the University of Pennsylvania in Philadelphia have conceived a technology that may exceed the capabilities of the current sophisticated camouflage systems used today. Their concept involves using Plasmon waves, which will reduce the scattering of light when it strikes an object. That scattering of light is what makes object visible to the eye.
Key Concept
The key to the concept is to reduce light scattering. We see objects because light bounces off them; if this scattering of light could be prevented (and if the objects didn’t absorb any light) they would become invisible. Alù and Engheta’s plasmonic screen suppresses scattering by resonating in tune with the illuminating light.
Plasmons are waves of electron density, caused when the electrons on the surface of a metallic material move in rhythm. The researchers say that a shell of plasmonic material will scatter light negligibly if the light’s frequency is close to the resonant frequency of the plasmons. The scattering from the shell effectively cancels out the scattering from the object.
For visible-light shielding, says Engheta, nature has already provided suitable plasmonic materials: silver and gold. To reduce the scattering of longer-wavelength radiation such as microwaves, one could make the shield from a ‘metamaterial’: a large-scale structure with unusual electromagnetic properties, typically constructed from arrays of wire loops and coils.
Alù and Engheta’s calculations show that spherical or cylindrical objects coated with such plasmonic shields do indeed produce very little light scattering. It is as though, when lit by light of the right wavelength, the objects become extremely small, so small that they cannot be seen.
The idea is still in the theoretical stage but it appears to be sound from a physics standpoint. Also according to theory, the technology will work better on small objects, optimally, it will work best when the wavelength of the light is the same size as the object being shielded, which basically means ‘microscopic’ items. At this point the object can’t be shielded from daylight because it is made up of various light wavelengths, and the Plasmonic cover will work when it is tuned to one specific light frequency. The theory is new and is sure to change when it is understood better. So don’t rule out the possibility of having a cloaking device just yet.
[rank=tonytalkstech.com/2005/03/01/plasmonic-cover-may-render-object-invisible/]Source for Article I[/rank]
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Article II
Invisibility Shields Planned by Engineers
National Geographic News
by James Owen
February 28, 2005
In popular science fiction, the power of invisibility is readily apparent. Star Trek fans, for example, know that the devious Romulans could make their spaceships suddenly disappear.
But is the idea really so implausible? Not according to new findings by scientists who say they have come up with a way to create cloaking device.
Electronic engineers at the University of Pennsylvania in Philadelphia are researching a device they say could make objects "nearly invisible to an observer." The contrivance works by preventing light from bouncing off the surface of an object, causing the object to appear so small it all but disappears.
The concept was reported today by the science news Web site news@nature.com. It says the proposed cloaking device would not require any peripheral attachments (such as antennas or computer networks) and would reduce visibility no matter what angle an object is viewed at.
Sir John Pendry, a physicist at Imperial College, London, said the concept potentially holds several important applications "in stealth technology and camouflage."
While types of invisibility shielding have been developed before, the phenomenon described by Andrea Alú and Nader Engheta sounds like something that might have been witnessed from the bridge of science fiction's starship Enterprise.
The concept is based on a "plasmonic cover," which is a means to prevent light from scattering. (It is light bouncing off an object that makes it visible to an observer).
The cover would stop light from scattering by resonating at the same frequency as the light striking it. If such a device could cope with different wavelengths of electromagnetic radiation (including visible light), in theory, the object would vanish into thin air.
[rank=www.ufoarea.com/technology_invisibility_shields.html]Source for Article II - Read Complete Article[/rank]
-----------------------------------------------------------------------------------------------------
Article III
Widespread Military Applications Seen for Invisibility Technology
(Plasmonic cover cloaking devices)
The Scotsman | March 1, 2005
JAMES REYNOLDS
A CLOAKING device that makes objects invisible is being developed by researchers, bringing the magic of Harry Potter into the world of science fact.
While Harry uses his cloak of invisibility to move about Hogwarts School unseen, electronic engineers at the University of Pennsylvania are working on a real invisibility shield called a "plasmonic cover".
The development, which works by preventing objects from reflecting and scattering light, could have widespread use in the military as it would be more effective than current stealth technology.
Although no final product has been made, the engineers claim their proposal "does not obviously violate any of the laws of physics".
Other types of invisibility cloaks have been developed before, but these mostly use the "chameleon principle" - colouring objects to match their background, enabling them to blend in and become camouflaged.
One such system involved using light detectors and emitters that project a replica of the image appearing behind an object on to its front surface.
Similarly, researchers in Tokyo are developing a camouflage fabric that uses a comparable principle where the background is projected on to light-reflecting beads in the material. Such systems are, however, dependent on the viewer from which the object is being concealed being in the right position.
[rank=www.infowars.com/articles/science/real_cloak_invisibility.htm]Source & Read Complete Article Here[/rank]
Guys came across this just while surfing the net and sonds pretty intresting.
How many of us have had a dream of being invisible , many of us havent we.
Right from watching old days of ghosts, to current generation Harry Potter using his invibility cloak.
American researchers are working on this and trying to make this possible
read the article to understand the theory put by them and start dreaming
about what will u do after becoming invisible.
-----------------------------------------------------------------------------------------------------
Key points
• American researchers working on 'plasmonic cover' 'cloaking device'
• Invisibility shield would prevent objects reflecting and scattering light
• Device differs from other invisibility research reliant on chameleon principle
-----------------------------------------------------------------------------------------------------
Article I
Plasmonic Cover, May Render Object Invisible
Andrea Alù and Nader Engheta of the University of Pennsylvania in Philadelphia have conceived a technology that may exceed the capabilities of the current sophisticated camouflage systems used today. Their concept involves using Plasmon waves, which will reduce the scattering of light when it strikes an object. That scattering of light is what makes object visible to the eye.
Key Concept
The key to the concept is to reduce light scattering. We see objects because light bounces off them; if this scattering of light could be prevented (and if the objects didn’t absorb any light) they would become invisible. Alù and Engheta’s plasmonic screen suppresses scattering by resonating in tune with the illuminating light.
Plasmons are waves of electron density, caused when the electrons on the surface of a metallic material move in rhythm. The researchers say that a shell of plasmonic material will scatter light negligibly if the light’s frequency is close to the resonant frequency of the plasmons. The scattering from the shell effectively cancels out the scattering from the object.
For visible-light shielding, says Engheta, nature has already provided suitable plasmonic materials: silver and gold. To reduce the scattering of longer-wavelength radiation such as microwaves, one could make the shield from a ‘metamaterial’: a large-scale structure with unusual electromagnetic properties, typically constructed from arrays of wire loops and coils.
Alù and Engheta’s calculations show that spherical or cylindrical objects coated with such plasmonic shields do indeed produce very little light scattering. It is as though, when lit by light of the right wavelength, the objects become extremely small, so small that they cannot be seen.
The idea is still in the theoretical stage but it appears to be sound from a physics standpoint. Also according to theory, the technology will work better on small objects, optimally, it will work best when the wavelength of the light is the same size as the object being shielded, which basically means ‘microscopic’ items. At this point the object can’t be shielded from daylight because it is made up of various light wavelengths, and the Plasmonic cover will work when it is tuned to one specific light frequency. The theory is new and is sure to change when it is understood better. So don’t rule out the possibility of having a cloaking device just yet.
[rank=tonytalkstech.com/2005/03/01/plasmonic-cover-may-render-object-invisible/]Source for Article I[/rank]
-----------------------------------------------------------------------------------------------------
Article II
Invisibility Shields Planned by Engineers
National Geographic News
by James Owen
February 28, 2005
In popular science fiction, the power of invisibility is readily apparent. Star Trek fans, for example, know that the devious Romulans could make their spaceships suddenly disappear.
But is the idea really so implausible? Not according to new findings by scientists who say they have come up with a way to create cloaking device.
Electronic engineers at the University of Pennsylvania in Philadelphia are researching a device they say could make objects "nearly invisible to an observer." The contrivance works by preventing light from bouncing off the surface of an object, causing the object to appear so small it all but disappears.
The concept was reported today by the science news Web site news@nature.com. It says the proposed cloaking device would not require any peripheral attachments (such as antennas or computer networks) and would reduce visibility no matter what angle an object is viewed at.
Sir John Pendry, a physicist at Imperial College, London, said the concept potentially holds several important applications "in stealth technology and camouflage."
While types of invisibility shielding have been developed before, the phenomenon described by Andrea Alú and Nader Engheta sounds like something that might have been witnessed from the bridge of science fiction's starship Enterprise.
The concept is based on a "plasmonic cover," which is a means to prevent light from scattering. (It is light bouncing off an object that makes it visible to an observer).
The cover would stop light from scattering by resonating at the same frequency as the light striking it. If such a device could cope with different wavelengths of electromagnetic radiation (including visible light), in theory, the object would vanish into thin air.
[rank=www.ufoarea.com/technology_invisibility_shields.html]Source for Article II - Read Complete Article[/rank]
-----------------------------------------------------------------------------------------------------
Article III
Widespread Military Applications Seen for Invisibility Technology
(Plasmonic cover cloaking devices)
The Scotsman | March 1, 2005
JAMES REYNOLDS
A CLOAKING device that makes objects invisible is being developed by researchers, bringing the magic of Harry Potter into the world of science fact.
While Harry uses his cloak of invisibility to move about Hogwarts School unseen, electronic engineers at the University of Pennsylvania are working on a real invisibility shield called a "plasmonic cover".
The development, which works by preventing objects from reflecting and scattering light, could have widespread use in the military as it would be more effective than current stealth technology.
Although no final product has been made, the engineers claim their proposal "does not obviously violate any of the laws of physics".
Other types of invisibility cloaks have been developed before, but these mostly use the "chameleon principle" - colouring objects to match their background, enabling them to blend in and become camouflaged.
One such system involved using light detectors and emitters that project a replica of the image appearing behind an object on to its front surface.
Similarly, researchers in Tokyo are developing a camouflage fabric that uses a comparable principle where the background is projected on to light-reflecting beads in the material. Such systems are, however, dependent on the viewer from which the object is being concealed being in the right position.
[rank=www.infowars.com/articles/science/real_cloak_invisibility.htm]Source & Read Complete Article Here[/rank]
