Researchers Develop Purely Optical Cloaking

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Researchers Develop Purely Optical Cloaking

Posted by Soulskill on Saturday September 27, 2014 @10:20AM from the still-cannot-fire-while-cloaked dept.

Rambo Tribble writes: Researchers at the University of Rochester have developed a remarkably effective visual cloak using a relatively simple arrangement of optical lenses. The method is unique in that it uses off-the-shelf components and provides cloaking through the visible spectrum. Also, it works in 3-D. As one researcher put it, "This is the first device that we know of that can do three-dimensional, continuously multidirectional cloaking, which works for transmitting rays in the visible spectrum." Bonus: The article includes instructions to build your own.

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Ob. Klingon by ihtoit · 2014-09-27 10:27 · Score: 1

So' ghuS!

--
Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
Not that new by Anonymous Coward · 2014-09-27 10:34 · Score: 2, Informative

It's interesting, but I can't have been the only kid to have noticed my thumb disappearing between two magnifying glasses decades ago.
1. Re:Not that new by ArmoredDragon · 2014-09-27 10:43 · Score: 2
  
  This. All they're really doing is using four lenses to move the light around the object, but it only really works if the object has to stay within a certain limited area. This technique would never work for something like Predator and certainly not for Romulan Warbirds.
2. Re:Not that new by Oligonicella · 2014-09-27 11:07 · Score: 1
  
  Maybe the really, really huge lenses were out of the camera shot.
3. Re:Not that new by Ken+McE · 2014-09-27 11:12 · Score: 1
  
  This technique would never work for something like Predator
  
  What you would do is mount your lenses on the object you're hiding. They would move along with it.
4. Re:Not that new by ArmoredDragon · 2014-09-27 15:39 · Score: 1
  
  And so instead you see a bunch of lenses moving around which are considerably larger than the object they're trying to conceal, and furthermore would only work if all of them are oriented towards one particular viewer (viewers off to the side wouldn't be subject to this illusion.)
  In other words, the Predator's plan of catching Arnie would fail pretty fast once his rear most lens bangs into a tree, knocking the whole thing out of alignment. Maybe Arnie doesn't see the predator, but he sees a strangely warped tree giving him plenty of warning which direction NOT to travel in in order to get to the choppa.
5. Re:Not that new by brantondaveperson · 2014-09-27 17:49 · Score: 1
  
  If someone invents a device that can transmit information a fraction of a second into the past,
  No. If someone invents a device like that, they will win the Nobel prize and transform our understanding of physics. Their name will go down in history, and perhaps yours too, for predicting it on slashdot. This, though, appears to be four lenses arranged in a slightly nifty way. It's certainly not a 'cloaking device' - although I expect the researchers wouldn't describe it as such anyway.
  The problem here is that science reporting has deteriorated to the point that the journalist has to pretty much make things up to get anybody to read their article.
6. Re:Not that new by Too+Much+Noise · 2014-09-27 19:43 · Score: 1
  
  but it only really works if the object has to stay within a certain limited area
  Actually, it's even more trivial than that. As they explicitly say in the video, the object has to stay out of the central area. Why? because the central area is where you're focusing the light. Now if they would only take those four lenses, put them in a tube and 'cloak' an absorber around the focal point to remove stray light, they would have a marvelous invention. I suggest calling it a telescope.
  Welcome to elementary optics class, now with Harry Potter themed experiments.
7. Re:Not that new by Rockoon · 2014-09-27 21:29 · Score: 1
  
  Now if they would only take those four lenses, put them in a tube and 'cloak' an absorber around the focal point to remove stray light, they would have a marvelous invention. I suggest calling it a telescope.
  It really only requires 2 lenses, but in both a 4-lens (do such refractors exist? seems overly complicated) or 2 lens telescope the "cloaking" is only one direction and relies on the fact that the thing being "cloaked" is out of focus.
  
  Anyone with a big aperture telescope can see this effect quick clearly without any fancy staging/setup at all. Simply look through the telescope at a distant object and then put your finger in front of the objective aperture. The only thing you will see is a very slight dimming as your finger passes in front of the aperture, and this includes the finger being right in the middle.
  
  --
  "His name was James Damore."
8. Re: Not that new by iamhassi · 2014-09-28 06:07 · Score: 1
  
  Who needs lenses? Many micro cameras (like cellphone) and many LCDs would be fine. Hardest part is getting the lighting right, especially during dusk or dawn, because the LCD would need to display what is on the other side without being darker or lighter than the other side. Can't have a bright LCD showing a black image because it's night time.
  
  I'm wondering why someone has not taken a few dozen cellphones and surrounded a sphere just to show a proof of concept.
  
  --
  my karma will be here long after I'm gone
9. Re:Not that new by JakeBurn · 2014-09-28 12:50 · Score: 1
  
  I was just thinking that same thing. A reasonably titled 'cloaking device' would need to actively camouflage an object from detection. Limiting not only the viewing angle but also the viewing distance makes this more like an optical illusion or magic trick than the practically useful device the name cloaking device confers. A board covered in glue, then covered in dirt, being used to cover a hole in the ground could technically be called a cloaking device with such a ridiculously broad definition. Maybe more so as nearly any above ground distance and angle would still result in the cloaked object not being perceived.
10. Re: Not that new by JakeBurn · 2014-09-28 12:52 · Score: 1
  
  That idea has long been an industry proof of concept. Same for using projectors and cameras to display the backing image on the other side of the cloaking material.
I had a similar idea as a kid... by MindPrison · 2014-09-27 10:43 · Score: 1

...many MANY freaking years ago (man, I'm old)...I came up with an idea slightly different from this, I never tried it so maybe some of you have some theories on if this would work or not, but I'll try to describe my Optical Cloak design idea:

You know what an endoscope is, right? If not...google it and then read this again. Now...imagine you have a million strings of fiber and utilizing the same technology as with an endoscope, filling each sides with a lens just like the endoscopes work, you should (at least in theory) have a very effective cloak from a distance.

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What this world is coming to - is for you and me to decide.
1. Re:I had a similar idea as a kid... by Charliemopps · 2014-09-27 10:50 · Score: 1
  
  It would be one directional.
2. Re:I had a similar idea as a kid... by Ken+McE · 2014-09-27 11:15 · Score: 1
  
  It would be one directional.
  
  MindPrision wrote "endoscope", but I believe he meant "fiber optic." Glass optical fibers should work both ways just fine.
3. Re:I had a similar idea as a kid... by Solandri · 2014-09-27 16:21 · Score: 2
  
  Won't work. Well it work in one special case, but not in the general case. Any time the fiber path (defined by the two endpoints of the fiber) isn't parallel to line of sight, the light coming out the end of the fiber won't match what's directly behind that point. So if you place a camera in a specific spot, and you route the fibers from the front to the equivalent position in the back (relative to the camera), then it would work. But the moment you moved the camera, the fibers would then be at an angle instead of parallel to line of sight, and the "background" as seen through the fibers wouldn't align with the actual background. It also fails when there's parallax. Line of sight is diverging rays shooting out from the eye, so the fibers have to be aligned at that exact angle of divergence. If the eye is closer or further, there's parallax, and again the background through the fibers doesn't match the exact background.
  
  Basically, your optical fibers are just mimicking putting a TV in front of the object and displaying an image of the background on the TV. A real cloak can't just take light which strikes a plane (sphere, whatever) on one side and emit the same light on the opposite side. It also needs to preserve the arrival angle of the path that light was taking as it struck one side, and emit it on the other side at the same departure angle it would have taken had the cloaked object not been there. Which this clever arrangement of lenses does (albeit for a very narrow field of view).
4. Re: I had a similar idea as a kid... by O('_')O_Bush · 2014-09-28 01:26 · Score: 1
  
  That is the same idea, but worse, than a large screen panel with a camera facing the other way.
  
  The simple fact is that the surface of a 3D shape can't be made to show the path of light through every part of that shape from every angle simultaneously without bending light.
  
  Either it can only do so from one angle at once, meaning any other angle is inneffective, or it can show all angles through a point, and any other point is inneffective.
  
  --
  while(1) attack(People.Sandy);
It is a simple terrestrial telescope by 140Mandak262Jamuna · 2014-09-27 10:46 · Score: 2

It is a simple terrestrial telescope. Objects on the focal plane, but outside focal point will not be seen.

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sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Amazing amount of cloaking! by 140Mandak262Jamuna · 2014-09-27 11:15 · Score: 1

The professor is just too modest, calling it small amount of cloaking. In fact it is infinite amount of cloaking. Seriously! On the focal plane of the eye-piece there is a small region, what we would call the "aperture". EVERYTHING ELSE on the focal plane is obscured!!. Not only that your regular camera has been using it all along! In your SLR camera, there are mechanisms that control the aperture, making it bigger or smaller. There are motors and gears in the compound zoom lens. You might even have your fingers wrapped around the cylinder of the zoom lens. It is all cloaked from the image sensor! What a technology! The good professor should sue all the zoom lens manufacturers for pre-stealing his invention before he invented it.

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sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
This is beyond sad by cosmin_c · 2014-09-27 11:28 · Score: 4, Insightful

I can't understand why this made /. since it shouldn't have made the (nonexistent) school physics paper. Oh, if you look through this little thing, there are things that automagically disappear. Doesn't matter if you look at the object from another angle and not through a lens, it isn't cloaked anymore. I think people need to understand that is not cloaking, it's just a very complicated explanation for a phenomena that's well known. So unless they have a lens that can surround an object from all sides that could cloak said object... then again it might just be easier to develop the theory behind just using energy waves, then inertia dampeners.
1. Re:This is beyond sad by Skarjak · 2014-09-27 13:57 · Score: 1
  
  Just like you, it only took a few seconds of video for me to be thoroughly underwhelmed. Why was this even made into an interview? This is extremely pedestrian.
  The other, more advanced technologies are being developped in the aim of eventually creating objects that can cloak themselves. What are you gonna do, carry your gigantic lens array with you so you can be invisible? Well then you'll have a problem, cause people will see the lenses... Or you, if they just look at you from any angle that isn't small. Why should anyone care? Why would these guys even compare this to the other work that's being done?
2. Re:This is beyond sad by Alef · 2014-09-27 23:54 · Score: 1
  
  What they have "invented" appears to be pretty ridiculous, yes, but you are attacking it from the wrong angle. What you are saying is that what they describe isn't suitable for a certain application, namely what you think when you hear "cloaking". Science isn't about finding applications, though, it's about making discoveries and understanding how nature works. There might be other applications that you can't think about right now, and if science would limit itself to what we now know is useful in some particular way, much of it would never be discovered.
  However, here is the real problem: Where is the scientific discovery here? All they have done is placed a series of lenses in a row, focusing the rays at some points, which means you need to be closer to the principal axis to block them there. (Notice how they never cover the centre of the "cloaked" area.) Lenses to that, though; focus rays. They have just named the volume surrounding the aperture "the cloaked region", fiddled with lenses to get it narrow, and written a paper about it. Pretty much any optical system containing lenses will have such a "cloaked region".
  It seems scientific funding today has gotten so concentrated on quantitatively measurable output (meaning the number of published articles) that people publish any little trivial idea they have, preferably multiple times with slightly different wording, or in very small steps to extend it over as many articles as possible.
Impractical at any scale by Syphilis · 2014-09-27 11:39 · Score: 1

Not only does it require a lens between you and the object, but it requires a lens behind the object as well.
You can do it with mirrors too! by 140Mandak262Jamuna · 2014-09-27 11:53 · Score: 2

I have seen a device that uses just mirrors and this obscuring. Many a times I am stuck behind a mob of people and did not have a clear view of the action going on the other size. Then they invented this miracle device that cloaks all the people in the middle and I could the other side unimpeded. It is typically made of cardboard and a couple of mirrors with decorated with color paper. Hurray for cloaking. Great!

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sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
It works! by reboot246 · 2014-09-27 11:53 · Score: 2

It's even cloaking the website!
Pictures or it didn't happen by myth24601 · 2014-09-27 12:11 · Score: 1

Pictures or it didn't happen.

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No matter where you go, there you are.
Acronym by FrankDrebin · 2014-09-27 12:14 · Score: 4, Funny

It's the ROchester MUltidirectional Lens ANgle cloaking system.

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Anybody want a peanut?
Re:Cloaking by Marxist+Hacker+42 · 2014-09-27 13:29 · Score: 4, Funny

Better yet:
1. Invent Cloak
2. Write Story giving directions
3. get slashdotted
4. website becomes invisible.

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SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
Re:Cloaking by Fnord666 · 2014-09-27 13:43 · Score: 3, Funny

What I find truly amazing is that there are still enough people around here to actually /. a site.

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'The tyrant will always find pretext for his tyranny.' - Aesop's Fables
Re: Link got me to '500 Internal Server Error' by RevGregory · 2014-09-27 16:30 · Score: 1

It seems down for me as well.
They probably just forgot to turn the cloaking device off.
Is cloaking really needed anymore? by BringsApples · 2014-09-27 23:30 · Score: 1, Funny

I mean, let's face it, at least in America, no one's looking at anything anyway. They're all face-down in their $device. And in the same manner as this ridiculous article where you have to stay away from the center of the lens, all you have to do is stay away from being on the people's device, or between it and them - and you're effectively cloaked to them.

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Politics; n. : A religion whereby man is god.
Oblig by Wolfrider · 2014-09-28 19:12 · Score: 1

" I solemnly swear that I am up to no good... "

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== WolfriderV6 == I'm willing to admit that *I just might* be wrong... Are you??
Re:What does the hidden object see? by gnu-sucks · 2014-09-29 07:40 · Score: 1

A complete blur on both sides. Since the light is extremely convergent, it won't make any sense to the eye.
These are the same optics in a telescope, by the way. If you were to look inside a telescope without the eyepiece, you'd get the idea right away of how it would look to be in the middle of this "new" idea.