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johannessimon81

"Natural Light Cloaking for Aquatic and Terrestrial Creatures" - 3 views

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    Cheap and scalable invisibility cloaks being developed. The setup is so trivial that I would almost call it a "trick" (as in "Magicians trick"): 6 prisms of n=1.78 glass. Nontheless, it does the job of cloaking an object at visible wavelengths and from several directions.
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    can we build one?
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    Yes, I just did :-) It is on my desk
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    New video here (smaller file than previous): "https://dl.dropboxusercontent.com/u/58527156/20130613_101701.mp4" Note how close to the center of the field of view the hidden objects are. I am quite surprised that such poor lenses create such a sharp focus.
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    Well.. I would say that it is not "fully cloaking", as the image behind is mirrored as well
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    That just means that you have to double the setup, i.e., put 4 glasses in a row. Of course the obvious drawback is that you can only look at this cloak from one direction.
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    Is this really new? I don't know, but I know that the original idea of cloaking was pretty different. When cloaking as an application of transformation optics became popular people tried to make devices that work for any incidence angle, any polarization and in full wave optics (not just ray approximation). This is really hard to achieve and I guess that the people that tried to make such devices knew exactly that the task becomes almost trivial by dropping at least two of the three conditions above.
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    I think it is very easy to call something trivial when you're not the one who invested considerable time (5 min in my case) to design a cloaking device and fill the coffee mugs with water... Also, I did not really violate that many conditions: true I reduced the number of dimensions in which the device works to 1 (as opposed to the 2 dimensions of many metamaterial cloaks). However the polarization should not be affected in my setup as well as the wave phase and wave vector (so it works in full wave optics) - apart maybe from the imperfect lens distortion, but hey I was improvising.
Dario Izzo

Heml.is - The Beautiful & Secure Messenger - 3 views

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    And thats the answer to NSA form Pirate Bay .... not as soon as I expected, but still fast :)
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