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."

An interesting concept...

[altgrr]

This has been done before using fibre optics, I believe, so that you would effectively see through the person because they wore an outfit consisting of thin fibre optic wires routeing light straight through them. This was on TV once, although I don't know whether it was the actual suit being shown or merely some special effects to show what it _could_ look like. Either way, it looked obvious that there was someone there - anything longer than a brief glance would be time enough to tell.

old camoflage technique

[Alien54]

I recall this as similar to an old WWII camoflage technique, to make the apparent brightness of an object match the bacjground.

I believe in WWII some submarine hunter aircraft had spotlights on the front to make the apparent brightness of the dark aircraft match the sky. Killed more subs that way.

this technique worked really well for large objects if they were a good distance away, like for a tank of the horizon or an aircraft in the sky. awful for close up work.

I recall a good article on this someplace on the web, but to find it now on short notice .....

Re:Huh?

[Possum Man]

Actually, I'm just listening to CBC (Canadian Broadcasting Corporation) radio, and they are claiming that MIT *did* supply a picture, but there is a scandal over it. Apparently they submitted a picture which was allegedly an original done by the professor's daughter, but which turned out to be swiped from a Montreal-based comic book; not a look alike, but a cut and past of an actual drawing. MIT lawyers are claiming they had every right to do that, while the comics-author is claiming this is blatant plagiarization. MIT has removed the drawing, and was not available for comment on CBC.

I'll post a link if I find one. Or if anyone else finds a link first, please post it.

Text of Patent Application (Claims)

[WEFUNK]

Based on a real quick search of the USPTO website, Ray Alden has at least two directly related public applications, Three-dimensional receiving and displaying process and apparatus with military application [uspto.gov] and Multi-perspective background simulation cloaking process and apparatus [uspto.gov]. He also has at least one other application [uspto.gov] in process, and at least one existing patent [uspto.gov] that I found. From what I can tell, the first two applications have the broadest, most ridiculous claims I have ever seen (except perhaps by those on slashdot who claim patents on patenting). At first glance, his other two appear to be more specific and possibly more technically substantive.

Here are his three claims from the first patent application above. As you can see, there are no technological advancements or details claimed or even described. While the embodiment of a working invisibility device would almost certainly contain patentable features, he is essentially trying to patent invisibility itself (at least, short of magic, the obvious way just about every kid and sci-fi author has ever assumed it would be accomplished). The first claim is so silly it would actually cover the use of a camera and video mounted on opposite sides of wall. The brief text of the application is hardly more descriptive, although he makes it clear that the "means" could be use electronics or fiber optics.

"I claim:

1. A means for receiving a light beam on a first side of an object and for generating a corresponding light beam on a second side of said object, wherein said corresponding light beam is intended to resemble the received light beam in trajectory, color and intensity.

2. An array of lenses for receiving light from at least two trajectories and a second array of lenses for emitting light in at least two trajectories; wherein the receiving light trajectories are equivalent to the emitting light trajectories.

3. A means for receiving a light beam on a first side of an object at a first trajectory and for channeling it to a second side of said object, where it is released at the same said trajectory."

Yes, that's it. Thankfully, it's just an application.

Re:Nope

[sallen]

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.

I don't see it being patented, as the thought of an image being, essentially, transfered from what is behind something to in front of an object has been discussed for eon's (or at least years). The process, however, is a lot more difficult than at least mentioned in the small news clip. You're right about blocking light behind it, in relation to the Mona Lisa.
But I believe there's a third item which comes into play. For us to see something, there are three variables involved. The source (and intensity) of the light, the object itself (and how it reflects the light) and our eyes, upon which the light falls, for us to see the image. The 'image' or the object we all see, varies to a degree based upon there we stand. To 'cloak' simply using the process mentioned cannot overcome the fact that we all observe the object differently if we're each standing in a different place, and that doesn't seem to be taken into consideration. The simpliest part of the viewers position (though there are many), is the part of depth perception. If we're three feet from the wall behind the object, and two feet from the Mona Lisa, then 'cloaking' the Mona Lisa has a 'wall', a portion which is displaced from the real one, 'appear' other than in the same plane as the real wall. Part will look further away then the part of the wall that is closer (the cloaked Mona Lisa), because the light will be generated/reflected from a different distance from the 'real' wall. One MIGHT be able to compensate that difference by altering the output and seemingly making the object, but hues/density, etc, seem elsewhere... exactly where the real wall is located. But that works one person standing in exactly the same spot for which the compensation is calculated. A person 10 degrees offset sees a different perception...I don't see how one compensates for that.

If the object is an extreme distance where depth perception is essentially nil or in a dim setting there depth is also less acute, then it is more 'believed' by the viewer. Otherwise, as long as one has two eyes, I see a problem.

Re:Still More Limitations

[Anonymous Coward]

I think you mean thermal imaging. Infrared really has nothing to do with heat as far as detection goes, just light spectrums. And as someone who spent 8 years in the US Marine Corps as a infantryman, I can tell you we typically used light gather night vision gear, nothing heat related (which is less useful during the daytime, regardless). So this has plenty of pratical application.