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How To Cloak Objects At a Distance
KentuckyFC writes "All invisibility cloaks to date work by hiding an object embedded inside them. Now a group of physicists have worked out how to remotely cloak objects that sit outside a cloaking material. The trick is to make the cloaking material with optical properties that are exactly complementary to the space outside them. Complementary means that the material reverses the effect the space has on a plane wave of light passing through it. To an observer this space would appear to vanish. The scientists say that to cloak an object sitting outside the cloaking material, first measure its optical properties and then embed a "complementary image" of the object within the cloak. So a plane wave is first distorted by the object but then restored to a plane by the complementary image of the object within the cloak (abstract). An observer sees nothing. This method has another benefit. Objects hidden in conventional cloaks are blinded because no light enters the cloaked region. But objects that are remotely cloaked like this should still be able to see their surroundings."
You'll know when cloaking is really working when the monthly dupe of "cloaking, this time for real" stops showing up here.
"The trick is to make the cloaking material with optical properties that are exactly complementary to the space outside them. "
So if you are hiding a tank in the desert, paint it desert colors?
Oh wait more complex... desert != shiny...
use flat paint.
got it!
Do not look at laser with remaining good eye.
Wake me up when we can get into the ladies changing rooms without getting bitch slapped.
You'll know when cloaking is really working when the monthly dupe of "cloaking, this time for real" stops showing up here.
Because they managed to cloak the article?
The better question is, can they fire while cloaked? I hear the Klingons made substantial advances in that area.
"Gee, if we had enough money, we could make your troops invisible, Mr. General Sir."
The simple truth is that interstellar distances will not fit into the human imagination
- Douglas Adams
Dougal, this cow is small.
Those ones are far away.
Small...far away.
"That's nearly as mad as that thing you told me about the loaves and the fishes."
Squirrel!
Wouldn't pr0n constitute a complimentary image? Cuz I gotta tell ya with the right pr0n nearly everything around it disappears.
Everyone knows that a tachyon sub-space burst from the main deflector dish invariates the sublimated inverse proportional fields that all cloaking devices use.
Phase the array with multi-numinal values and any cloak in the perimeter will be dropped due to subversive nominal decay but only if you attune your tertiary sensing systems to compensate for the quadralinear flux.
This is all so simple, and I have to wonder about the credentials of /. editors that would post such elementary issues on this website.
I mean really, this is first trimester stuff that any recruit can do off the tops of their heads.
So we have the technology for an invisibility cloak. Now I just need an unbeatable wand and a funky "I see dead people" ring and I can be master of death. Suck on that, Voldemort!
How hard can it be if even girls manage it?
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
Ummm...howzabout just hiding behind a tree or ducking...
This must only work with translucent objects. The other method works with any object.
Get implants and shave.
This "cloak"-technology is just a re-adjustment of your mental reference framework:
Soon, you'll get these kindof presentations:
"This! is the best thing ever since the previous thing that was the best thing ever!" "Can I see?"
"It's right here, it's cloaked.. You can see it but you cannot perceive it. But believe me, it's there."
"If it's invisible, it must be good! *throws monnies*"
I think we can keep recursing like this until someone returns 1
This technology, if adopted by the military, will probably only be useful against civilians. Against another sophisticated military there will always be a way to detect what you're trying to hide through other means than visible light - magnetism/alterations in the earth's magnetic field (in the case of big chunks of metal, heat), RF emissions, overhead imaging, radar, sonar, etc.
You won't be able to hide your tank like this, but the small laser turrets to keep the neighbor's cat off the lawn might work... now if only those sharks would stop swimming.
Seven puppies were harmed during the making of this post.
Notquitecajun, will you stand up please. (gunshot)
This demonstrates the value of not being seen.
I am officially gone from
Wouldn't this method limit the cloaking mechanism to only work from one viewing angle? It seems to me the cloak would need to have hundreds of complementary images embedded in it to prevent someone from seeing it who took a step to the side. That, however, causes the problem of the complementary images distorting areas around the cloaked item, therefore making the cloaked item even more obvious. Is there something I'm missing?
All invisibility cloaks to date work by hiding an object embedded inside them.
This conventional kind is enough for me. Where can I get one?
The largest prime factor of my UID is 263267.
In TFA it admits that the solution would only be 2D and on a single frequency. This leaves me with a few questions.
1. Is the "cloak" effectiveness reduced as the observer gets closer to the object being cloaked?
2. How would they overlay the new image of the item being cloaked, would they use some type of projected hologram, or another physical system - such as attaching the image to the object?
Some people are only alive because it's against the law for me to hunt them down and kill them.
I've been doing this for a long time. I simply hold my hand in front of my eyes. Viola! Object remotely cloaked.
They should be working on the SEP field.
Hitchikers guide reference:
"The technology required to actually make something invisible is so complex and unreliable that it isn't worth the bother. The Somebody Else's Problem field is much simpler and more effective, and can be run for over a hundred years on a single torch battery. This is because it relies on people's natural predisposition not to see anything they don't want to, weren't expecting, or can't explain."
You don't even need a battery. Just build it to look like a sink full of dirty dishes in a student household and no one will see it.
Scientists: "We've made an invisibility cloak that will make your soldiers vanish!"
General: "That's amazing, let's try these out."
Scientists: "Right, Here is one you can try, but if you want more then we need money... a lot of money."
General: "Sorry, the deals off, the soldiers say they can't see out of it when they're inside it."
Scientists: "Give us a few minutes."
[Obligatory view of shed with hammering and sawing noises]
Scientists: "Okay, how about your troops just hide behind it?"
So, in plain English, they take a big photo of the background, put it in front of the object and make the object disappear from view. How incredibly ingenious.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
I'll go you one better - over in the Middle East, there were apparently some insurgents/terrorists/whoever using the tried-and-true method of hiding in a sandstorm before attacking or while attacking. It worked well in the good old days, but we now have these things called satellites and night-vision and infrared and technology, where they're pretty much sitting ducks now.
And here I always thought that explaining a joke was sure to ruin it.
All invisibility cloaks to date work by hiding an object embedded inside them.
I had no idea we had working cloaks! Cool. Having an invisibility cloak would make raiding the Sorority Girls' dorm so much easier for the Engineering house. Where can I get one? :-)
FOX NEWS.com should be BANNED from television and internet. Have the Congress take it over and give us Truespeak.
That's the oldest trick in the book, and it only works against objects that are polaron neutral against the subspace background. And since most variations of phase-harmonic shields break polaron symmetry any military warp-capable ship is immune.
... has been doing this for years.
No, no, no! It's saying that you can't be seen if someone else holds up a sheet that is the same color as the wall.
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I can sell you one. Would you transfer the money first? It's guaranteed!
Am I eval()? - http://www.monst3r.com.br
... in your argument is "against another sophisticated military".
However this is rarely the case. Nowadays most engagements the US Military is involved in are against people with little more than 25-50 year old weapons. The problem the US Military has is the on the ground war against these kinds of insurgents - this tech. would be invaluable against them, you could approach a camp on foot without fear of being seen.
The money will disappear, that's for sure. So I guess you really do have one, in a sense.
well I manage to cloak myself by securing a towel around my head... I figure if I can't see you, then surely you can't see me.
I remember reading about this somewhere, I think it's called an SEP Field... "An SEP is something we can't see, or don't see, or our brain doesn't let us see, because we think that it's somebody else's problem.... The brain just edits it out, it's like a blind spot. If you look at it directly you won't see it unless you know precisely what it is. Your only hope is to catch it by surprise out of the corner of your eye." -- Douglas Adams, HHGTG. In that series, a strange object can be effectively hidden from view while out in plain sight, by an "SEP field", which "relies on people's natural predisposition not to see anything they don't want to, weren't expecting, or can't explain."
no, because then you're behind/inside the cloak and your visibility in the cloaked direction is zero. you're not unbending the light with a complementary image. if the light source is behind you, you'd just look like a jackass holding up a bed sheet.
the method proposed in the article is to hide objects outside (hence, "How to Cloak Objects At a Distance") of a cloak using a complementary material. no materials have yet been developed to do this.
it doesn't even necessarily have to be a physical material. if you can use lasers or an EM field to bend(or unbend) light back to its original state, then you can simulate a virtual complementary material. you'd still need to determine the optical properties of the object that you want to cloak to create the complementary image, but you could theoretically create a mobile/non-stationary cloaking device this way.
I dunno, they've got a good point. If no light is getting in to the object being cloaked, then it's not just invisible, it's blind...so while you wouldn't see much in the Sorority Girls' dorm, you could have loads of laughs feeling up anything that crossed your path.
To be cloaked it doesn't need to stop light getting to it. It just needs to stop it getting back to the observer. But don't stand in front of a white surface.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
seems to me that having a cloak showing a "complementary object" is only going to work if the original object doesn't destroy information about the background. If it does, the object is going to show via the distortion of the background.
You would still be cloaked only from one side, and visible from other directions. Also, you wouldn't be able to see in the direction that you are cloaked from; if all of the light from that particular angle is passing around you, rather than reaching you, you would see the reverse side of the cloaking device/field as black. So, this technique would work if you were trying to hide from a sensor or observer at a particular angle to you, but wouldn't be particularly effective against a web of sensors that are sharing their results.
This, then, shall be your test. To the engineer who can build her own invisibility cloak, I say that she is worthy of raiding the Sorority Girls' dorm. To all those who dare not face the challenge, their punishment shall be downloading pr0n.
"The biggest problem with communication is the illusion that it has taken place."
Scientists are looking in the wrong direction in this matter. Like in so many other breakthroughs, they just have to watch how nature does it. What in nature can be totaly invisble without any kind of complex technology or huge power consumption? Easy: keys.
I'd like to see your source on that one, Assuming that sound can't move through the rest of the rifle(for sake of discussion) and will only escape out of the muzzle the shooters ear is about 1 meter away form the source. The Barrett M82 (using .50 BMG round) has a max effective range of 6800m with a muzzle velocity of 853 m/s. That means that it will take that round 7.79 seconds to go the max distance or 2.16 seconds to go the effective range of 1850 meters.
The speed of sound is 340.29m/s, so for the sound of the gun shot to go from the muzzle to the shooters ear 1 meter away will take apx 0.0029 seconds.
At 853 m/s the round will have only traveled 2.47 meters away from the muzzle.
Provided the target is less than 2.47 meters away then yes the will have a whole in them before you the shooter hears teh shot, but you said thousands of yards, which as we proved is just wrong. Now had you said that you the target will have a whole in you before you the target even hears the report then yes you would be right.
Oh and you totally misused the joke anyway of th GP. It was a Monty Python sketch. /All figures from GIS and wikipedia) //Math could be wrong, please correct me if I'm wrong
500 dollar reward for tip(s) leading to the arrest of the person(s) who stole my sig.
Well, if they're hiding in the sandstorm BEFORE the attack, sure.
But during? You'll be hard pressed to find a radio wave length that'll cut through what is essentially a huge but very fluffy stone and NOT cut through humans (tiny bit of water in the middle). Infrared will be blurred out. Radar will too.
What kind of advances have the military conjured into being that'll see through a sandstorm and tell you what's inside it (outside of lots and lots and lots of sand)?
If this technology ever becomes viable, I know what we should cloak first.
I'm so excited I just made water in my pantaloons!
Wake me up when we can get into the ladies changing rooms without getting bitch slapped.
Easy! These guys pulled it off years ago...
Don't tell me to get a life. I'm a gamer; I have LOTS of lives!
... I can still uncloak them in my mind.
Have gnu, will travel.
2) Become invisible using that material.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
Yes like Harry Potter's cloak. He can see through the cloth, but no one can see him.
FOX NEWS.com should be BANNED from television and internet. Have the Congress take it over and give us Truespeak.
I was thinking more like going one step further past the point where you are a tiny on the horizon to your enemy's eyes
Wow, are we really citing Harry Potter?
Unless you're European.
I understand that using feminine pronouns is the politically correct thing to do, but in the context of this sentence I think it's fair to assume that the engineer in question is most likely male.
http://www.youtube.com/watch?v=zekiZYSVdeQ
I am not a physicist, but it seems to me the proposed invisibility 'cloak' is just a mathematical trick, and its not clear to me that the mathematical model actually corresponds with the real physics of light/electromagnetic waves. And even if the model is sound, I don't believe materials with the desired properties can actually be made. Also, it seems, the method only works when the background light is uniform, i.e. monochromatic background light, i.e. no other objects are allowed anywhere in view, besides the cloak and the disappeared object.
assignment != equality != identity
They get on the radio and drop a bomb on your head from the plane you didn't know was there.
it will then be ignored.
Table-ized A.I.
Can we get some photos? I want to see this in action :-)
I mod down anyone who says "I will be modded down for this", regardless of the rest of their comment
Object * (1/Object) = 1
Why didn't we think of it before!
European chicks have beards?
To be completely cloaked, no light may be absorbed by an object, because otherwise that light will be missing on the other side so the object will be detectable. Thus, you can't have a perfect cloak and also be able to see.
So this could be useful for cloaking the interstellar fleet en route to blow up the bad guy's planet, but not much use in combat?
I expect someone else already pointed this out, but just in case... -Todd
Omne ignotum pro magnifico.
It's not just the school systems that frown upon non-standard answers, it's the majority of society. In many situations, propose an idea even slightly outside of the predominant group-think, and watch how many folks start to get offended/shoot it down without thought.
For example - I had a boss write a simple VB app that cut the time needed for his subordinates to do a specific task by at least 50% every time, sometimes as much as 80%, while improving the quality of the output. His boss shot it down and prohibited its use because my boss wasn't assigned to write software, and they had paid someone else to write less-effective software that used more bandwidth and provided a lower quality output.
In another case, we had a door clearance problem in a customer area due to carpet installation. Funding for a new door wasn't forthcoming, so a couple of us on the late shift lowered the false floor just enough to regain clearance. We didn't think much of it, since it solved the problem without needing any funding. However, that solution got a lot more attention (both negative and positive) than we expected. All of the regular visitors noticed. Some folks thought it was a great idea. Those responsible for the building bristled at the idea of a non-standard solution when we suggested it (after the fact, and played it off as a joke when we saw their response), so we had to tell them we bought a new door out of our own funds. (I guess spending hundreds of dollars on a new door is more acceptable than a few radians of rotation of a few large bolts in their eyes.)
Despite all of the feel-good seminars, I believe people in general still aren't accepting of ideas outside of their limited fields-of-view. If I recall correctly, in Japan, there is a saying that roughly translates to "The nail that sticks up is hammered down." Although U.S, citizens like to say that the saying does not apply to them, and individuality is encouraged, I think that the saying is applicable in many U.S. situations as well.
I hope that most reading this work for those without such a limited field of view. It is so much more enjoyable to go to work with bosses that encourage thinking.
Also, any waste heat will have to be radiated in the direction away from the shield; radiating heat toward the shield will either pass directly through it (revealing your presence) or warm up the shield (causing it to radiate heat and reveal its own presence). An all-sides shield would require storing any heat internally, limiting how long you can stay cloaked before you have to either reveal your presence or cook in your own juices.
Shaddup, you. His use of pronouns made the sentence super hot.
Gamertag: WyleType
Well, for instance, it can be used to cloak that silo you're hiding from the enemy, or the troop barracks, or a supply cache....
There are a LOT of things in war that can't be done at a distance, and there are a LOT of things you don't want the enemy to see when the war is on your turf, not theirs.
This would also be interesting combined with surveillance equipment. I wonder if two of these cloaks could cloak each other as well as a third object though? Otherwise, the cloak will be a dead giveaway.
You would still be cloaked only from one side, and visible from other directions. Also, you wouldn't be able to see in the direction that you are cloaked from; if all of the light from that particular angle is passing around you, rather than reaching you, you would see the reverse side of the cloaking device/field as black. So, this technique would work if you were trying to hide from a sensor or observer at a particular angle to you, but wouldn't be particularly effective against a web of sensors that are sharing their results.
So what they need to do is create a holographic array of emitters that cover a large enough slice of the 3D plane that the remote sensors can't detect the object with accuracy.
One other aspect that doesn't seem to have been noted much on here is that this method seems to be applicable to all kinds of radiation, not just the visible spectrum. Would it be possible to use this as some sort of a radiation shield when the radiation signature is known?
Oh come on. It's a kiddy movie, but it's still very entertaining. (And Hermione's grown into quite a beautiful young woman.)
FOX NEWS.com should be BANNED from television and internet. Have the Congress take it over and give us Truespeak.
>>>To the engineer who can build her own invisibility cloak, I say that she is worthy of raiding the Sorority Girls' dorm.
(1) If the engineer is a "she", then she doesn't need a cloak. She can just walk right in and pretend she belongs there. When a dorm has ~400 people living in it, it's not possible for the residents to know every face.
(2) Furthermore she'd probably be more interested in raiding the Frat Boys dorm. ;-)
FOX NEWS.com should be BANNED from television and internet. Have the Congress take it over and give us Truespeak.
ok i get it but that still makes no sense. thanks
Its not my fault, someone put a wall in my way.
I would agree that group-think is a defining characteristic of pretty much all human cultures , but as someone who has taught in Japan I can say that the US is a land of insane non-conformists compared to the Japanese. My favorite example: Sacred Assumption 1) all people in Japanese schools are Japanese (this isn't actually true, and there are in fact ethnic Koreans, Ainu, Okinawans and *gasp* people with a foreign parent, but don't mention that.) Sacred Assumption 2) All Japanese people have straight, black hair. (This isn't even true for people who are 'completely Japanese'.) Thus the result: At the high school where I taught any students with even sightly wavy or brown hair had to dye/straighten it, in the interests of a 'harmonic school environment' as one teacher put it. "The nail that sticks up is hammered down." indeed.
snig