Invisible Cloaks, Translucent Walls

jd writes "The University of Tokyo has developed the illusion of invisibility, under the name of 'Optical Camouflage.' The system is remarkably simple - you have a mix of light-sensitive and light-emitting devices attached to an adapted reflective surface. The devices are hooked to a computer, which simply projects on each side whatever is on the opposite side. The result is more of a translucent look, than real invisibility, but the potential is there. The inventer's next objective is to make walls that are invisible, using the same technology. Project a real outside image onto an interior wall without windows. This almost sounds more frightening than the cloak, since there's no reason why the sensors would have to be placed outside. Imagine a world where PHBs can turn their office wall into a window onto any cube. Zero privacy. The technology is great, but the potential for abuse is definitely there." Update: 06/15 00:20 GMT by T : You may remember we mentioned this project when it was cloak-only.

Comments

No. not really

[moosesocks]

This works great until you get into three dimensions at which point it all goes sour.

Because light's reflecting off of the coat itself. Plus, the shape of the cloak is not symetrical. I just don't see how it even works. Sure, I could imagine something like a sheet of paper partially working.

As for see-thru wall, it's probably a lot easier then this guy wants it to be...

Just make the wall itself clear. Then use an lcd-like mechanism to act as a 'shutter', allowing the outside light in. Note that each 'pixel' could be quite large (several inches).

In other words, when the wall's off, it's opaque. When current's applied to a section, the liquid inside the wall becomes clear and the wall is see-through. Not sure if the technology's there yet, though....

Line The Interrior Blind-Spots in Cars

[gdavidp]

Interesting, this stuff belongs in the internal areas of cars in the so-called blind spots. Probably needs to improve upon the resolution a bit though. Kind of like wearing a digital CCD/CMOS.

Re:Future of armed infantry

[EvilTwinSkippy]

Well, no, you can't run with this stuff on. You would blur just like the Preditor. Probably worse than blur, as there is a transform equation that is run. You have to potential to flare out into interesting color patterns until it settles into a solid state if you step between two radically different backgrounds. (Red to Blue might accidentally take you through green, or flourescent purple.)

The IR thing is more of a problem. Heck, we already have an excellent visible light stealth system. It's called DARK. All night vision systems track IR since it's generally around in abundence at night.

You are also still a target on Radar, and probably Lidar as the system still reflects or absorbs high amplitude pulses of light differently that the background.

You also run into interesting problems with lighting. If someone shines a spotlight on you, your shadow would still be dark, so you would stand out as a dark spot.

There are undoubtedly computational ways around all that, but after a while your number cruncher is going to be more of an emmission signature than whatever you are hiding.

Re:Future of armed infantry

[localman]

True, in it's current form it's merely a cool demo. But I imagine one could design an LCD that projected a different image depending on the angle you viewed it from. Kind of like those ribbed plastics (can it, beavis) that show different parts of the image depending on the angle... and thus alow simple animation and 3-d looking objects through small movements.

Of course, the image would also have to be grabbed from different angles... so we're talking a load of optics and processing and projecting. But I imagine it could be done in the next 25 years if someone wanted it badly enough.

Cheers.