Invisibility Cloaking Device


Senior Member
Invisibility Cloaking Device

I found this article on current efforts to develop a cloaking device that would make objsts invisible by not reflecting or scattering light that hits it. It's still in the development stage but some success in "plasmonics" have been had. I'll bet the military will be all over this one. Any thoughts?


Scientific wizards find real cloak of invisibility


? ? 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

Key quote
\"The concept is an interesting one. It could find uses in stealth technology and camouflage\" - Dr John Pendry, physicist, Imperial College London

Story in full 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.

A report in the journal Nature reveals that the new system is far more ambitious, being both self-contained and reducing visibility from all angles. In this sense it would be more like the shields used by the Romulans in the Star Trek episode Balance of Terror which hid their spaceship at the touch of a button.

Dr John Pendry, a physicist at Imperial College London, said: \"The concept is an interesting one. It could find uses in stealth technology and camouflage.\"

According to Dr Andrea Alu and Dr Nader Engheta, the engineers behind the project, the key is to reduce light scattering.

Objects are visible because light bounces off them; if this can be prevented and if the objects did not reflect any light, they would become invisible. The \"plasmonic screen\" achieves this by resonating in tune with the illuminating light.

\"Plasmons\" are created when the electrons on the surface of a metallic material move in rhythm. The developers claim a shell of this material will reduce light-scatter to the extent that an object will become invisible, if the light?s frequency is close to the resonant frequency of these \"plasmons\". In this way, the scattering from the shell effectively cancels out the scattering from the object.

Experiments have shown that spherical or cylindrical objects coated with such shields do produce very little light scattering, which renders them nearly invisible. However, the cloak would have to be delicately tuned to suit each object it hides. Also, a specific shield may only work for one wavelength of light, rendering it invisible in, say, red light, but not in multi-wavelength daylight.

Another problem which has to be solved is that the effect would only work in daylight when the wavelength of the light being scattered is the same size as the object - meaning only tiny things can so far be hidden.



Senior Member
Re: Invisibility Cloaking Device

I can just picture the very first 'Field Test', involving the military of course. Out in the middle of no where, at a four corners junction, a very loud sound, not unlike the sound of two trains hitting head on in the wee hours of the morning, a monstrous cloud of dust appears like magic.

Battalion A neglected to syncronize watches with Battalion B with the result that over two thousand men and their equipment received a sound lesson in Physics in regards to objects occupying the same spot at the same time. It is also noted with interest, the theory that invisible objects become skinny has been abandoned with great haste for some strange reason.


Active Member
Re: Invisibility Cloaking Device

Good point, I'd suggest cloaking the tank only after it has stopped moving.


Re: Invisibility Cloaking Device

Invisibility Cloak...

This is kinda a neat idea. It's also Real!!


Stu Dogg

New Member
Re: Invisibility Cloaking Device

this maybe a real photo but it is just that. it is made to look transparnt though the use of many cameras. would never really work in the real world mabe save it for the arts


New Member
Re: Invisibility Cloaking Device

the cloak's purpose is to absorb and mirror light as it is hit, the body doesn't make it's own light.. therefore.. transparency.
Wait until it comes into style, a green transparency coat puts us halfway to making ourselves the invisible entities some wish they were. Nevertheless quite an accomplishment by our Eastern kin.. But aren't we as usual approaching the same idea in scattered ways? Or could that be the hint of diversity not so diverse. *grins*