Slashdot Mirror
Plan For Cloaking Device Unveiled
Robotron23 writes "The BBC is reporting that a plan for a cloaking device has been unveiled. The design is pioneered by Professor Sir John Pendry's team of scientists from the US and Britain. Proof of the ability of his invention could be ready in just 18 months time using radar testing. The method revolves around certain materials making light "flow" around the given object like water."
I, for one, welcome our new invisible overlords.
http://www.chmodoplusr.com/
Granted I didn't RTFM, but proof of my ability to turn, say, a brick into 20 pounds of diamonds could also be ready within 18 months.
Forget the government, I know a lot of this I could do with this. And most of them violate the constition, and morality, and decency, and privacy, and...
will be pissed. :D
I long for a month where slashdot doesn't announce a new design for a cloaking device...
Slashdot: news for Apple. Stuff that Apple.
AP Wire (2019): In the news today, once again the military claims to have "lost" an F-22 somewhere on the grounds of Andrews Airforce Base (AFB). Said Captain J. Andrews (no relation): "I could have sworn I parked the thing right over there. Last night's storm must have blown the locator-ribbon off the nose or something."
--Udo.
This is good if the enemy doesn't have a Comsat or a Science Vessel.
There is a Japanese research group which has a cloaking system (well, technically its more of a very adaptive camoflague -- significant drawbacks, such as the requirement to have a camera focused on the object you want to cloak, make it less than useful for military applications). Its essentially useless currently, but it makes for very fun tech demos.
I A/xv/oc.html
http://projects.star.t.u-tokyo.ac.jp/projects/MED
My favorite one is the breakdancing guy in the bottom video.
Help poke pirates in the eyepatch, arr.
Doesn't this vialate our treaty with the Klingons?
In the pr0n business
\u262D = \u5350
I'd like to point out that this is brilliantly advanced... in theory. It's completely possible and will likely be buildable... in theory.
I RTFA, and frankly, it sounds like confirmation of the idea that mathamatics in general is WAY ahead of the other sciences. Things that are perfectly possible in theory are out of our grasp in the real world... right now, at least.
Even as a mathmatician, the fact that there's so much theory and so little actual DOING has me worried. There's a tiny flaw in the use of 'metamaterials' to make objects invisible... we don't HAVE metamaterials.
Though, it beats sticking my head in the sand by a long shot.
The split ends are horrible.
No, Mr. Green. Communism is just a red herring.
They claim that certain "metamolecules" have the power to make light behave like water, and flow rather than scatter. I quote:
"A little way downstream, you'd never know that you'd put a pencil in the water - it's flowing smoothly again.
"Light doesn't do that of course, it hits the pencil and scatters. So you want to put a coating around the pencil that allows light to flow around it like water, in a nice, curved way."
The truth is, water scatters when hitting something, too. It just doesn't *matter*, because all particles of water look the same to us. So, if the water particle that would have been in the middle without the disruption ends up on the far right, it doesn't matter!
However, we are very, very good at telling different pieces of light apart. At best, this will provide very good camo, where pieces of color from the environment behind you show up on you instead. At worst, the disruption from light working in unexpected ways will make this "invisibility" be a very noticeable beacon. You know how your eyes always flick to something that moves (animated ads, anyone?) This would be like that.
I would think a little different.. the Stealth Bomber is "Stealth" against active radar.. but can still be seen via passive radar..
.. they could see the stealth bomber fly through and if your field is dense enough they would be able to track it easily
abet harder to set up a passive radar system but not imposable..
when you send out the radar wave and look for what bounces back that is active.. when you have something on the other side of your target looking for that wave - that is passive.
if you setup two towers and the broadcast to each other and you fly between them they can tell even if they can see it actively... if you set up a perimeter of them say 3-4-5 or more and they all talk back and forth
with this type of tech the item would be invisible to active and passive radar.. although I bet it would show some type of ghosting effect for areas near it via passive scan.. it would be very hard to track.
'...if only "Jumping to a Conclusion" was an event in the Olympics.'
Here's a picture of the prototype...
One of these days I'm moving to Theory - everything works there
If I'm not mistaken, since this bends the light around the object, none of the light actually hits the object, correct?
So no invisible surveilance cameras or human beings- the light would miss the lens of the camera or the eye of the human and they'd be completely blind.
No, it violates our treaty with the romulans stupid!
Romulans actually.
And no it doesn't, because we've got a couple of centuries until we actually sign it.
Yes, in UK and Australia (and probably other Commonwealth nations, although I don't have personal experience outside of those two -- Canada I think follows American usage) "mathematics" always shortens to "maths" when describing a field of study ("My worst subject at uni was maths"), the process of computation ("Help me, I can't get the maths to work out here"), etc etc.
Help poke pirates in the eyepatch, arr.
The BBC article mentions a couple of articles in the current issue of Science. Here's the text from their research abstracts:
Controlling Electromagnetic Fields
J. B. Pendry, D. Schurig, D. R. Smith
Using the freedom of design that metamaterials provide, we show how electromagnetic fields can be redirected at will and propose a design strategy. The conserved fields--electric displacement field D, magnetic induction field B, and Poynting vector S--are all displaced in a consistent manner. A simple illustration is given of the cloaking of a proscribed volume of space to exclude completely all electromagnetic fields. Our work has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.
Optical Conformal Mapping
Ulf Leonhardt
An invisibility device should guide light around an object as if nothing were there, regardless of where the light comes from. Ideal invisibility devices are impossible due to the wave nature of light. This paper develops a general recipe for the design of media that create perfect invisibility within the accuracy of geometrical optics. The imperfections of invisibility can be made arbitrarily small to hide objects that are much larger than the wavelength. Using modern metamaterials, practical demonstrations of such devices may be possible. The method developed here can be also applied to escape detection by other electromagnetic waves or sound.
Unfortunately, I don't seem to have access to the full papers.
No.
Reading TFA, it strikes me as being similar to something posted on /. a month or two ago promising the same thing. TFA is light on details, but if I remember the previous article correctly and they're a similar principle (that's a lot of ifs), then this is only useful for objects about the size of the wavelength of light being used. In other words, objects smaller than 3cm for microwaves, objects about a meter for radio, and about 500 nanometers for visible. That being said, it's useless for military applications since most military vehicles are larger than 1 meter. It's also useless for people since you'd have to be about a thousand times smaller than the width of a human hair in order to hide.
We do not live in the 21st century. We live in the 20 second century.
All they have to do is cover the planes with animated ads and most of us would never be able to see them!
My eyes instinctively ignore them these days if the browser doesn't block them to begin with.
She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
I'll believe it when I see it.
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
Or a bag of flour.
I have freaks! I did something right...
In American English it's Math, but in British English (as used by the BBC) it's Maths.
Various articles point out that the lensing structures bending the light have to be smaller than the light's wavelength. That means for visible light spectrum, which is around 400-700nm, your meta-material structures have to be molecular-sized. This is much smaller than what's required for radio or microwaves, which are centimeters to meters in length.
So either you'll have to nano-engineer your cloaking shell from the molecular level, or else you'd have to find a way to convert the light that strikes it into a lower frequency (higher wavelength) that you can handle more easily. If you had some super-efficient down-converter/up-converter material coating the surface of your cloak, this might then enable you to bend the light without having to go all the way down to nanometer size for your meta-material lensing structures in the cloaking material itself.
I can imagine the color green would be particularly useful to cloak against, because that would allow you to be invisible in front of vegetation/greenery.
It's very unlikely this development will 'cloak" anything.
Small matter of "index of refraction".
You'll note the picture in the article shows light rays hitting the object "head-on". What happens to rays that hit at an angle? Even if they exit at the same angle, are they exiting along the same axis, or displaced? The article doesnt say.
Also most substances have significant reflection at each air-substance boundary-- how will this device handle that issue?
Nice try, but still quite a long way from making an object "invisible".
How about artillery?
All you need is the tip of a radio antenna to receive coordinates from a satelite. That antenna could even be a dragged wire that would be flush with the ground.
The satelite itself might not be able to benefit from this technology... unless it was nuclear powered. Can't exactly hide those solar panels from light.
Slowly waving my hand - "This is not the sig you are looking for."