Advances in invisibility / stealth technology
Just passed by this article about an invisibility shield proposed by two scientists at University of Pennsylvania in Philadelphia.
Previous attempts at invisibility have generally focused around the chameleon principle: a screen is coloured to match its background, so that the screened object is camouflaged. But the invisibility shield proposed by Alù and Engheta is completely different, and more ambitious than previous attempts.
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.
It is a self-contained structure that would reduce visibility from all viewing angles.
I dare say it would be quite a feat if anyone is able to create practical applications of this theoretical work.
via news @ nature.com
Also, via near near future and Boing Boing and Crumb Trail and KurzweilAI.net and Technically Speaking and Marginal Revolution
July 4th, 2005 at 7:07am
Hi, just some thoughts on invisibility. ( more problems )
I’m not a scientist and I only heard Invisibility mentioned on the radio an hour ago, so I decided to look on the web to see what’s out there, and there you were. So far I’ve found nothing but questions, but that’s what I expected.
Firstly, to me, ‘Blending In’, except for Air It’s self is not invisibility. Secondly, simply the scattering of light may not be enough to cause true ‘ Invisibility ’ because the objects ( background ) to whatever is invisible would Probably not be seen unless it ( they) were also reconstructed because the true Light they would reflect would be missing. Invisibility for humans depends on the eyes so I suspect that some ‘trick’ on the Retina would serve a similar purpose.
( Persistence of Vision ). Motion as well as light may be the combination. The eye cannot see, or make sense of what is not clear to it. ( so the props of a plane become a blur. Perhaps the illusion of being slightly ‘ somewhere else ), creating a false image from ourselves could be considered, sending the light from an object somewhere else and removing it from the original. It seems so far that playing with an observers ‘eye’ might be the quickest way to obtain a type of ‘False Invisibility’ in the near future.
The uses for any reasonable degree of success is obvious, however, there would still be the problems of overcoming heat sensors and motion detectors, and detection through other wavelengths, etc. One thing that sprung to mind was the idea of perhaps drawing different shapes, as many as possible and then ‘flipping’ each one to see which has the least Persistence of Vision. I guess the images Flipped would have to be 3D, and then color, and I presume that all images should have the same total area and light, color, etc. I’ve no idea yet. If nothing else, this would be a starting point. I’ll search on the web to see if something like that has already been done to save some bother.
Regards,
Les Kirschner.