Cloak of Invisibility Coming Soon?

Chris writes "The idea of an "invisibility cloak" has made the leap from science fiction books to an international patent application. The "three dimensional cloaking process and apparatus" for concealing objects and people (WO 02/067196) employs photodetectors on the rear surface which are used to record the intensity and color of a source of illumination behind the object. Light emitters on the front surface then generate light beams that exactly mimic the same measured intensity, color and trajectory. The result is that an observer looking at the front of the object appears to see straight through it."

Comments

Practicality?

[nuggz]

There are many angles crossing an object, although this may work for simple front to back (as the article states)
I don't think it is that workable for all directions, or even more then a few.

Re:Practicality?

[N3WBI3]

This would be pretty good camo though. you would see only a distortion from a distance. One could take this a step further and make polygon dectectors / projectors giving you sides. I know it would not be perfect but you just want to make youself hard to see in combat.

Re:Practicality?

[lars_stefan_axelsson]

I don't think it is that workable for all directions, or even more then a few.

Well, that depends on what you mean by workable.

Just getting the hue and intensity right (and being able to vary those) will go a very long way. It's not for nothing that English fishermen weren't allowed to paint their hulls white in days of yore, or that Mountbatten had his fleet painted pink. (The sky is brigther than the ocean at dusk/night and hence a light hull blends in. And pink works better agains the redder skies of asian waters).

The US Army even conducted trials with lamps on tanks to make them harder to spot as silouettes against the sky on a ridge line for example.

Now, the light trick is unworkable for other reasons (you have to be quick on the switch) should you drive in front of a dark object. So if this process could be automated there's much to be gained.

Now, of course if your main objection that this is far from a cloak of invisibility, that's for certain. But it could be quite useful camouflage.

And kids remember the old adage "A running soldier in a camoflague uniform, looks just like a running soldier in a camoflague uniform." Camouflage is still very much a stationary art. I doubt that tricks like these would change that much.

Re:Practicality?

[Anonymous Coward]

My feeling is that this guy knows he doesn't have a chance of making a practical "cloaking device." I think he's just claiming the patent on the idea before anyone else does. Then, when someone else in the future figures out how to make a bona-fide cloaking device (complete with that awesome Romulan warbird cloaking sound), he'll charge them a licensing fee for their design because he already patented the basic idea. Sure, to be granted a patent, he has to have built a cloaking device already. But what if it's only, say, 10% functional? Not at all useful, but he would still claim prior art on the thing.

It's like trawling through science fiction, picking out all of the interesting (but currently unworkable) design ideas, making crude mock-ups of how they might work, and patening them.

Re:Practicality?

[WickedChicken]

Think of a hologram. Depending on your viewing angle the lightwaves bring out a different patten from the interference stored in the hologram. That is how holograms can make 3D images - because both of your eyes see two slightly different images and can calculate distance. I'm sure it wouldn't be too hard to convert a hologram to use LEDs so that depending on what angle you view you get a corresponding image.

Re:Practicality?

[Xaoswolf]

Remember watching the movie "The Predator"? When the hunter sat in a tree, you couldn't see him unless you knew where to look, or already had three dots on your fore head. He was basicly invisible at that time. But when he moved, you got to see all the distortion and weird angles produced by his camoflage. That is basicly what this armor will produce, it will keep tanks hidden better than large cammo netting, snipers will be able to sit invisible for hours in almost plain sight.
You just can't let them get too close or you're screwed.

Looking behind it

[SWroclawski]

The problem with this device as it's designed so far is that it only works when looking straight at the object.

In addition, I have serious questions about the resolution of the device (how many sensors and how many light emitters). Will the person look "pixelated" and or will there be some other problem.

Lastly, such a device is not useful in combat situations as many soldiers in such a ground war situation will be outfitted with infr-red detectors, which will probably be able to detect the human behind the suit.

Good idea but has a lot of practical problems (we haven't even discussed the power source).

I can see it ... no pun intended.

[Scholasticus]

I can see this happening, with a lot more refinement. You'd need gobs of processing power, hosts of tiny photodetectors and projectors, and a very small but reliable and long-lasting power supply (as somebody else already noted). With today's tech, this idea is pretty useless. The engineering obstacles could be overcome in the future. On the other hand, it would be pretty easy to come up with effective countermeasures. Wouldn't this thing radiate like hell in the infrared?

Re:moving "eyes" can pick it up?

[trix_e]

My completely uneducated guess is that the object will appear a lot like those "magic eyes" pictures that were all the rage a few years ago...

i.e. when you move from side to side (or up/down) the object will shift at a slightly different rate than the background, and your senses will detect something. you may not be able to tell what it is, but something will feel "off". I'm sure at greater distances the effect will be less, and therefore the technique will be more useful.

Reminds me of Predator, and the way that it shimmered when it moved. My guess is that they used the same thought when they made that movie.

Very cool.

Better applications

[Twylite]

The article very definately uses the words "detect" (light behind) and "generate" (image in front). This implies it is not some passthrough technology (fiber, etc), but an electronic record and recreation.

If this "clock" could live up to its claims, there are three (possibly more) far more interesting applications that must be considered:

• Holographic photography: the photoreceptors on the back can apparently sense the intensity, colour and trajectory. They can also do this without a lens. Impressive.
• Holographic projection / 3D TV: the light emitters on the front can recreate the image behind the object. In order to do this with enough accuracy to clock an object, they have to recreate the trajectory of the light; failing this they have a 2D image which will be noticable as soon as the viewer moves.
• Realistic looking TV: apart from the 2D/3D problem, TV just doesn't look real because it is poor at depecting matt textures. A glowing, glossy area within your field of vision would certainly attract your attention, even if it fitted into the background.

Given that researchers would be coining it from more down-to-earth inventions like these, I can't really see that the technology - as described - exists or is being developed.

Good camoflage though ...

[Titusdot Groan]

Because of angles of viewing etc. this wouldn't make you invisible -- this would be great camoflage though -- you'd match the color and light of the background almost perfectly.

The most important part of camoflage is making recognizable features hard to see -- hands, faces, etc -- things our visual system is hardwired to pickup out of the background. This invisibility cloak would do that.

I imagine it looking like the Alien in that Arnold movie, hard to see unless it's moving and then the distortions give it away.

Of course is this a really old idea -- heck it a similiar idea was in comics in the 1970s (some super heros club house had this kind of device to hide it from view).

Re:Prior Art?

[Alranor]

Again, IANAL, but I don't think it needs to have been built, just described accurately enough that it's not a new insight for the person actually building it

IIRC nobody could patent geostationary satellites when they were first built because a certain well known sci-fi author had described the concepts previously.

Or I could be talking crap, that happens too.

Perfect bad patent

[RichMan]

This is a pretty near perfect example of a bad patent.
1) the idea is pretty obvious (as well as many references in common SF literature)
2) the actual implementation with current tech will be pretty miserable. Put big bright light behind object, make object shine big bright light at viewer. Viewer is blinded by both and as object is indistinquishable the technique is easily demonstrated to the patent requirement level.
3) it serves as a patent stake. Further research into a better/improved technology will have to deal with this patent.

This is a near perfect bad patent that grants the patent holder a big stake in the ground for actually showing very little. And any future work that will actually improve the technique is going to have to deal with the patent.

Still More Limitations

[swb]

It also doesn't do much for your heat signiture. Since so much military surveillance is done with IR, you'd think that the extra heat generated by the thing being cloacked and the cloaking mechanism that it'd glow like a light bulb under IR.

Re:You're not an engineer, are you?

[SWroclawski]

Everything is solveable.

The idea in the patent is old. So we only care about the implemtnation, and the implementation looks full of problems.

When it's better and practical- then we should care.

Nope

[DahGhostfacedFiddlah]

The Mona Lisa blocks light on the wall behind it. You'd see a black patch on the wall, because there'd be no light. To get this to work, you'd have to mimic light going in both directions, so that the lights in the room would "pass through" the cloak and hit the wall behind it, then bounce off and "pass through" the cloak again.

Re:The biggest question of course...

[smead]

The really big question is will it cause you to embark on an epic quest to destroy it and ultimately lead you to having your finger bit off on the edge of a volcano, all while trying to avoid the temptation to use it?

Re:It's only a patent???

[Tenebrious1]

Only a patent

Haven't you been reading any other articles lately? Only a patent? You mean like Amazon's "one click" patent? Like BT's patent of hyperlinks? Compuserve GIFS? A laser pointer as an exercise device for a cat? The patent on a swing?

No, it's not a new idea. The military has been playing with it for years. Deep sea fish do it naturally with bioluminesence. If they get a working model, then ok, give them a patent. But I'd hate to see another ridiculous patent granted on an idea that's been around for decades.