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July 6th, 2016 
Awake Goy
Susanne Posel ,Chief Editor Occupy Corporatism | Media Spokesperson, HEALTH MAX Group
Researchers at the University of Texas at Austin (UTA) have finally answered the age of question of whether or not we can ever be invisible.
In the spirit of H.G. Wells and Harry Potter, Andrea Alu, professor of electrical and computer engineering at UTA asked a simple question: “Can we make a passive cloak that makes human-scale objects invisible?”
In short the answer is maybe because of “stringent constraints in coating an object with a passive material and making it look as if the object were not there, for an arbitrary incoming wave and observation point.”
Speaking of passive materials, these “metamaterials… can bend or absorb light without drawing energy from an external power source.”
There are prototypes of “invisiblity cloaks such as one created three years ago at the Department of Electrical and Computer Engineering (DECE) at the University of Toronto (UoT).
This design was thin, scalable and adaptive to various objects and sizes to hide an object to radar detection. And even though the object is still visible to the human eye, this “practical” approach was hailed as a step toward an actual invisibility cloak.
The UoT researchers explained that they devised “a different way of doing it. It’s very simple: instead of surrounding what you’re trying to cloak with a thick metamaterial shell, we surround it with one layer of tiny antennas, and this layer radiates back a field that cancels the reflections from the object.”
Called an active electromagnetic cloak (AEMC), this device “uses an array of elementary sources to cancel the scattered fields created by an object. An active interior cloak does this by placing the sources along the boundary of the object.”
This technology “can be thought of as introducing a discontinuity in the field to cancel out the scattered field by the object.”
And while this prototype is functional, the UTA team have discovered that the actual problem is the size of the object because a bigger object “requires hiding the object from visible light waves, which are much shorter than radio waves” and that means a bigger cloak.
Fundamental limitations in current technological understanding of quantum frameworks and the capabilities of electromagnetics is standing in the way of developing better invisibility cloaks.
Francesco Monticone, graduate student and co-author of the paper said : “We have shown that it will not be possible to drastically suppress the light scattering of a tank or an airplane for visible frequencies with currently available techniques based on passive materials. But for objects comparable in size to the wavelength that excites them (a typical radio-wave antenna, for example, or the tip of some optical microscopy tools), the derived bounds show that you can do something useful, the restrictions become looser, and we can quantify them.”
Monicone continued: “If we want to go beyond the performance of passive cloaks, there are other options. Our group and others have been exploring active and nonlinear cloaking techniques, for which these limits do not apply. Alternatively, we can aim for looser forms of invisibility, as in cloaking devices that introduce phase delays as light is transmitted through, camouflaging techniques, or other optical tricks that give the impression of transparency, without actually reducing the overall scattering of light.”
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