Cloak of Invisibility

[Munkay]

Parallax should have no effect on the technology described in the original post that began this thread--that is if it can indeed be made to work.

Agreed, with negative refraction it's a different ballgame.

But this part of the thread is a reply to the "sensor + video" technology that already exists. That will suffer from parallax, since it can't project a true 360 degree image. You can even see the start of shifting from the slight viewer angle in the video.

Hope that clears things up Alram :)

Cheers,

Munk

Edit: After re-reading my posts, I realized my post may be a little misleading, if not viewed directly in threaded mode. When I replied to Doc, I should have said "[this is a] real problem for the sensor + video technology now and into the future".

[Munkay]

I remember reading they wanted to start trying it out on some tanks and armored rigs. Planes flying overhead would only see the ground and not the rig.
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Another use for this technology is to make "virtual windows". In order to increase productivity in the workplace, they hope to one day use the technology to create a virtual window on cubical walls and windowless building walls.

But the most interesting one I've heard about is using the technology in planes. By creating virtual windows, airline pilots on large planes could see "through" the floor, thus helping them taxi through runways etc. Same goes with blindspots in cars (though I personally have a few reservations about this one).

The possibilities are nearly endless. But until (1) the technology is refined and (2) the cost is dirt cheap, it will make more sense to just use a video camera and LCD screen for these applications.

Cheers,

Munk

[Occhidiangela]

Parallax should have no effect on the technology described in the original post that began this thread--that is if it can indeed be made to work.
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Military Application issue: Infrared sensors.

Infrared is within the broad category of wave emissions. I'd guess an IR sensor could be tuned, or manually adjusted, to mitigate the effects of a superlens operation in that frequency spectrum, if IR wasn't beyond the capability of a superlens to mask in the first place. (My gut feeling says IR emissions would not be masked by this.) I'd have to read the paper and se if they bounded the problem in the "visible light" range, or if it was approached across a broader spectrum of wavelengths.

Occhi

[Munkay]

Military Application issue:  Infrared sensors. 

Infrared is within the broad category of wave emissions.  I'd guess an IR sensor could be tuned, or manually adjusted, to mitigate the effects of a superlens operation in that frequency spectrum, if IR wasn't beyond the capability of a superlens to mask in the first place.  (My gut feeling says IR emissions would not be masked by this.)  I'd have to read the paper and se if they bounded the problem in the "visible light" range, or if it was approached across a broader spectrum of wavelengths.

Occhi

I'll readily admit there is a lot about optics that I do not know about. Occhi, do you mind expanding your post a bit more, to help me fill in the gap?

My understand of a superlens is that it is a lens made with a negative refraction rating (or one that approaches a near zero refraction index). By cutting down on defraction of light, they can be used in applications like microscopes to see at higher magnifications than previously possible due to the "more pure" source of light.

Are you using the term "superlens" to describe anything (other than a lens) which has the capability of a negative refraction index?

Cheers,

Munk

[Occhidiangela]

I'll readily admit there is a lot about optics that I do not know about.  Occhi, do you mind expanding your post a bit more, to help me fill in the gap?

My understand of a superlens is that it is a lens made with a negative refraction rating (or one that approaches a near zero refraction index).  By cutting down on defraction of light, they can be used in applications like microscopes to see at higher magnifications than previously possible due to the "more pure" source of light.

Are you using the term "superlens" to describe anything (other than a lens) which has the capability of a negative refraction index?

Cheers,

Munk
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I used the term "superlens" due to its use in the original Guardian article. I don't understand the arcane optical details well enough to go much further, Optics was not my specialty. I'd really need to read the paper to get a clue about what the mathematicians were proposing without the filter of a news reporter's summary.

EDIT: It would cost me 37 dollars(US) to get the article from the Royal Society.

From the Abstract
a polarizable line dipole located less than a distance d/2 from the lens, where d is the thickness of the lens, will be cloaked due to the presence of a resonant field in front of the lens. Also a polarizable point dipole near a slab lens will be cloaked in the quasistatic limit.

Occhi

[Zarathustra]

Actually, they have had a working invisibility cloak now for a couple of years at least.
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I was under the impression that

a) It's actually an image projected onto the fabric.
b) It only works for a single point of view, and any other angle from which one might view the "cloak" would give the person away.



Seems a novelty and nothing more.

Edit: Upon digging up a bit more information (and remembering an old video of the same technology), it is in fact a projected image that requires an apparatus to be between the viewer and the "cloak", projecting the image onto the cloak of what's on the other side. So you'd see the slight shimmer... and a bulky piece of tech on either side of the "hidden" person.

[Doc]

I was under the impression that

a)  It's actually an image projected onto the fabric.
B)  It only works for a single point of view, and any other angle from which one might view the "cloak" would give the person away.
Seems a novelty and nothing more.

Edit:  Upon digging up a bit more information (and remembering an old video of the same technology), it is in fact a projected image that requires an apparatus to be between the viewer and the "cloak", projecting the image onto the cloak of what's on the other side.  So you'd see the slight shimmer... and a bulky piece of tech on either side of the "hidden" person.
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Not quite. At least from what I read.

It uses software for a pass through technology. The "cloak" goes around the whole body. Images captured from the front view are displayed on the rear LCDs, and images captured from the rear are displayed on the forward LCDs. It offers the illusion that you can see though whatever is standing there. Images captured from the sides are displayed on the other side. When totally still, the image displayed is nearly perfect. I saw some great photos, and trust me, you couldn't hardly see these guys.

The downside was if you were moving, generating and rendering the images bogged down the system. It produced a shimmering effect, just like in the Predator movies. Hundreds of thousands of tiny sequin sized LCDs and cameras takes a lot of processing power I guess. Something they will likely be able to remedy in the future.

I do remember reading that the larger the object is, the easier it should be to cloak. Human beings can only carry so much weight, and the cloth and the CPU combined are quite heavy. On a much larger object, like, a tank or a humvee, you could haul as much CPU power as you needed and the extra weight of the cloaking system wouldn't be as much of an issue. Even mentioned was the ability to cloak Naval ships. I read that and thought "invisible air craft carriers" to my self.

The cat is out of the bag. Cloaking is in it's infancy, and there are a lot of problems with it now, but I think those problems will be hammered out quickly and even in my own lifetime, I believe we will see a Romulan style cloaking device.

[Occhidiangela]

I was under the impression that

a)  It's actually an image projected onto the fabric.
B)  It only works for a single point of view, and any other angle from which one might view the "cloak" would give the person away.
Seems a novelty and nothing more.

Edit:  Upon digging up a bit more information (and remembering an old video of the same technology), it is in fact a projected image that requires an apparatus to be between the viewer and the "cloak", projecting the image onto the cloak of what's on the other side.  So you'd see the slight shimmer... and a bulky piece of tech on either side of the "hidden" person.
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Doc, you might want to re-read the words I underlined from the abstract's excerpt. The thickness of the lens, divided by two, has to be bigger than the object to be masked. An aircraft carrier is a few hundred feet wide, and about eleven hundred feet long, and a roughly 200' masthead height. USS Abraham Lincoln, CVN 72, a modest example

The Lens' effective thickness must thus be about 2200 feet, and I am guessing it's height at about 400' And it needs to be portable. The engineering solution to that is probably not to manufacture wonderful 2000 foot thick glass or plastic lenses, which have their own considerable visual signature, but to be able to emulate/synthesize that lens effect with other materials, and or electromagnetic fields.

Cloaking an aircraft carrier using this theoretically possible method has the thorny problem of non homogeneous color (wavelength variation of reflected and absorbed light) given the variety of things on the visible portions of the typical aircraft carrier. I suspect that the Navy's answer to that corner of the design challende is "We'll, paint it all gray." That wasn't an uncommon philosophy on some of the ships I served on, so the cultural / behavioral obstacle to narrow bands of visible light should be overcome with relative ease.

The hard part, the tech side, is another matter.

Occhi

[Doc]

Doc, you might want to re-read the words I underlined from the abstract's excerpt.  The thickness of the lens, divided by two, has to be bigger than the object to be masked.  An aircraft carrier is a few hundred feet wide, and about eleven hundred feet long, and a roughly 200' masthead height.  USS Abraham Lincoln, CVN 72, a modest example

The Lens' effective thickness must thus be about 2200 feet, and I am guessing it's height at about 400'  And it needs to be portable.  The engineering solution to that is probably not to manufacture wonderful 2000 foot thick glass or plastic lenses, which have their own considerable visual signature, but to be able to emulate/synthesize that lens effect with other materials, and or electromagnetic fields.

Cloaking an aircraft carrier using this theoretically possible method has the thorny problem of non homogeneous color (wavelength variation of reflected and absorbed light) given the variety of things on the visible portions of the typical aircraft carrier.  I suspect that the Navy's answer to that corner of the design challende is "We'll, paint it all gray."  That wasn't an uncommon philosophy on some of the ships I served on, so the cultural / behavioral obstacle to narrow bands of visible light should be overcome with relative ease.

The hard part, the tech side, is another matter.

Occhi
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I believe we are talking about two different systems being used to cloak an object. The stuff I read about a while ago is a bit different than the technology mentioned that started this thread.

[Rhydderch Hael]

Hrmm, I thought in the original series the cloaking device was used by the Romulans, not the Klingons.

-V
Cloak Room Attendant
The Forsaken Inn
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Correct. The Klingons acquired cloaking technology from the Romulans, and the Romulans acquired advanced warship designs from the Klingons.

[Munkay]

Cloaking an aircraft carrier using this theoretically possible method has the thorny problem of non homogeneous color (wavelength variation of reflected and absorbed light)

I recall reading an article on engadget.com about a week ago, though after some searching I can't seem to come up with it. The long story short, is that they believe they have created the first 100% transparent material. By making a grid with small spirals of gold and silver, they are able to create a transparent material that does not suffer from bending light as it flows through it.

Granted, its a technological pipe dream, but maybe the technology for materials like this can be used to make negative refraction material paper thin.

I'll check back in about 400 years or so. Till then I'll keep dreaming ;)

Cheers,

Munk

[Griselda]

I recall reading an article on engadget.com about a week ago, though after some searching I can't seem to come up with it.  The long story short, is that they believe they have created the first 100% transparent material.  By making a grid with small spirals of gold and silver, they are able to create a transparent material that does not suffer from bending light as it flows through it.

Granted, its a technological pipe dream, but maybe the technology for materials like this can be used to make negative refraction material paper thin.

I'll check back in about 400 years or so.  Till then I'll keep dreaming ;)

Cheers,

Munk
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Let's try it on the Emperor first!

[GriffonSpade]

Hi,
Doesn't work.  Consider a simple case: one person wearing that suit, a barren plane (think semi desert) with one tree, and two observers.  One observer, the person wearing the suit, and the tree are in a direct line.  The other person is a few degrees off this line. The observer on the direct line would get the desired effect, but the other observe would see two trees, the real one, and the one projected from the suit at a small angle.  It's just a simple case of parallax, and the further from the background, the worse it gets.

--Pete
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Yes, well it obviously would need some skill to use too. Reduce the number of perspectives people can spot you from(such as getting on the ground or standing against a wall) would reduce this, and people also tend to have the problem of things that are farther away getting smaller and blurrier in their vision, so as long as they dont have some optical aids...

Some advancements would be useful too, like compensating for whatever surface youre close to, like while laying on the ground it would be nigh perfect from above, you'd be more conspicuous if someone was looking straight at you on the ground, if there are any nearby abnormalities in the terrain, such as your foot cameras taking half an off color rock and putting it on your scalp, would instead look right below your face and transfer that to your scalp instead.

Easy to use, hard as Hell to master.

[--Pete]

Hi,

Yes, well it obviously would need some skill to use too.
. . .
Easy to use, hard as Hell to master.
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No. Think it through. You're laying on the ground next to a wall (to combine two of your suggestions). The part of your 'see through' suit that is opposite the edge of the wall and the ground is where the ground/wall image is broadcast from. So, the person looking for you sees a nice ground/wall edge running along the ground, hopping up about 8 inches (20 cm) for about 6 feet (1.8 meters) and then dropping back to ground level. Nothing suspicious about that at all -- bah!.

And yes, it does work well if the person is too far away to see you -- but then, they are probably too far away to shoot you.

And controlling who is looking at you and at what angle in combat is a good trick. If you could do that, you wouldn't need some super suit. Cover and concealment would be enough.

--Pete

[Occhidiangela]

Hi,

And controlling who is looking at you and at what angle in combat is a good trick. 

--Pete
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That situation, as you know, isn't combat. It is a military exercise aimed at proving a weapons system, often an expensive one. ;)

When GS wrote this,

Easy to use, hard as Hell to master

All I could think of was "putter."

OT: Been hoping for rain all week, our precip level is inches below annual average. This morning, when I had planned to golf, we got it.

Occhi

[Drasca]

Let's try it on the Emperor first!
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To old or too cold for the old college try yourself Gris? :D Or has roleplaying the happy-dancing BNM fallen out of fashion this spring?

[Alram]

Nanotechnology now. I want one when they are perfected.

[Nystul]

I see where this is going. The World's Largest Invisible Bass Drum is soon to be a reality!

[Alrin]

The cat is out of the bag. Cloaking is in it's infancy, and there are a lot of problems with it now, but I think those problems will be hammered out quickly and even in my own lifetime, I believe we will see a Romulan style cloaking device.

Yes, anything that helps humans to kill other humans a little bit more quickly and effectively is definately getting a frontseat in the Research & Development labs.
God I hate our species.

[Occhidiangela]

Yes, anything that helps humans to kill other humans a little bit more quickly and effectively is definately getting a frontseat in the Research & Development labs.
God I hate our species.

I read a recent Sci Am article about Plasmons, and the potential for using plasmonics for light bending.

Interesting stuff.

Occhi