Slashdot Mirror
Scientists Make Item Invisible to Microwaves
Vicissidude writes "A team of American and British researchers has made a cloak of invisibility. In their experiment the scientists used microwaves to try and detect a copper cylinder. Like light and radar waves, microwaves bounce off objects making them visible and creating a shadow, though it has to be detected with instruments. If you can hide something from microwaves, you can hide it from radar and visible light. In effect the device, made of metamaterials — engineered mixtures of metal and circuit board materials, which could include ceramic, Teflon or fiber composite materials — channels the microwaves around the object being hidden. When water flows around a rock, co-author David R. Smith explained, the water recombines after it passes the rock and people looking at the water downstream would never know it had passed a rock. The first working cloak was in only two dimensions and did cast a small shadow, Smith acknowledged. The next step is to go for three dimensions and to eliminate any shadow."
...that would love to be invisible to microwaves.
The article mentions that doing the same thing to light waves should be possible.
How long do you think till you can pick up a Cloak of Invisiblity at your local MegaMart?
At some point there will always be a shadow
I'm unsure about the water claim, although it is true that you can't tell the difference that doesn't mean that it's not different, the water has been moved all over the shop, but it looks like it hasn't been affected.
Other than that if they make something invisable from visable light then it wouldn't be able to see anything, so a person would be blind or a bot would be virtually impossible to navigate, because you couldn't see it or track it...
Still, very interesting idea.
*''I can't believe it's not a hyperlink.''
This title is absurd. Invisibilty?
The research is very kewl though, and i hope it progresses. But why not lay off the stupid titles, and produce results based on kewlness or usefulness, instead of what can be termed with a popular buzzword. Information Technology is bad enough from its buzzword infusion. Must we destroy legitamte research/discoveries as well?
Have you read my journal today?
This will allow for more variety in TV Dinner desserts, because they can just shield it so only the stuff that needs to get nuked will get nuked. w00t!
Unpleasantries.
You know you are a fat geek when...
the first thing that came to your mind when reading this summary was:
"Oh cool, no more burnt and undercooked mini-pizzas!"
I really should go outside more often.
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
...are belong to US, baby!
Fluids and rays don't exactly behave the same way. Fluids follow the path of least resistance. Rays just go in a straight line until they hit something.
The days of the digital watch are numbered.
In your statement, "like light and radar waves", I'm going to assume that you meant light within the visible spectrum. Radio waves and microwaves are also light, just outside of the visible spectrum. They both have wavelengths longer than infrared light.
Sorry to jump down your throat, but this is one of my pet peeves.
.. where no man has gone before.
They may be onto something.
Proof by very large bribes. QED.
They could've posted a pict...
Oh, wait. Never mind!
If we can hit that bull's-eye, the rest of the dominoes will fall like a house of cards... Checkmate.
Girls locker room. Too obvious? Those lucky copper cylinders! I want to hear everything!
..from my ass, so to speak, but I imagine you could leave certain frequencies uncloaked, enough to slip in, say, remote video from a drone flying nearby or surveillance cameras in the area or GPS satellites in the case of bots. Perhaps a super-advanced version could shift cloaked frequencies on the fly in order to prevent jamming/detection of the video source even. I dunno, if this works in the first place it seems like there should be ways around the "blindness."
picpix image polls. create - share - vote. fun!
This was already addressed to some degree in the SciFi book "The Last Mortal Man". The reasoning for making them illegal was that the criminal element used them to evade law enforcement. I'm sure the DHS would have alot to say about this.
The simple truth is that interstellar distances will not fit into the human imagination
- Douglas Adams
What!! This is awful!! It means my microwave item-detecting device, which I walk around with to detect objects and random items, will now be obsolete!!
You might be able to channel some energy around an object, but:
"The next step is to go for three dimensions and to eliminate any shadow..."
Uh, yeah. This is a bit like saying "now that we've learned to jump 2 feet in the air, the next step is to jump up to the moon." That's a hell of a difference i nmagnitude and it's going to take enormous improvements in scientific understanding to achieve, if invisibility cloaks are ever possible at all.
clearly, you would make goggles that can filter from a non visible part of the light. Like IR.
The Kruger Dunning explains most post on
...in my home.
Only funny thing about it is.... I can't find it.
I bet if I could find it though, I'd win the Nobel prize.
Slashdot: stuff for news, nerds that matter, matter for news, stuff that nerd
Cloak of Invisibility Coming Soon
I don't think this follows, at least when we're talking about metamaterials. So far no one has invented metamaterials for optical wavelengths, as metamaterials rely on complex structure that's somewhat wavelength specific. It's easier to play "fool the photon" with microwaves (because of the longer wavelength) or X-rays (because of the higher energy) than it is with visible light. (Xiang Zhang's experiments in extending near-field effects of visible light are a very different mechanism, and are lumpedin with metamaterials simply for lack of a better term.)
Socialism: a lie told by totalitarians and believed by fools.
Romulan Bird of Prey? (Or equally, the small Klingon ships also armed with the cloaking device?).
:-)
Sorry, grew up on waaaay too much startrek
Ah, so the ship is the cloaking device! So much for putting on pointy ears and stealing it.
...as they are unable to explain why using their new invention disables their other new invention, the prototype phaser weapon.
Apparently, he had an accident with the targetting mechanism.
O'WONDERWe're working on it.
I'll go out on a limb on a series of "ifs" (and maybe a bag of physics naivetes), but let's say we perfect this manner of imperceptibly "derefracting" light. And let's say we also complete the ambitious work identifying and manipulating gravitons, still hypothetical. Could we "cloak" spaces and matter from any interaction with our universe, not just electromagnetic? Maybe the Stong and Weak Forces would remain for interaction, but practically, outside the tiny diameter of a nucleus, could anyone notice?
Could a "gravity cloak" create subspaces operating as independent universes? Could we contain matter too highly interactive for current use safely? Like a tiny black hole conveniently near a device it's powering, or a pair coupled into a wormhole for "faster than light" travel through custom-folded space? Vast amounts of stuff crammed into pocketsized spaces.
Maybe the old playground philosphers choosing between "teleportation or invisibility superpowers" will finally have a lab to figure out which is really better.
--
make install -not war
Sounds like a better version of stealth. I recall reading that an early attempt at a stealth ship did TOO good of a job of dispersing microwaves (compared to background reflection of empty ocean) and showed up as a moving 'hole' on surface radar screens. Assuming that this technology could be applied to bending light around an object, it would need to do so without creating obvious distortions.
[Insert pithy quote here]
The majority of slashdot readers have been invisible to human women for *years* now.
Wake me up when scientists can do *that*.
52 Weeks, 52 Religions with John Hummel
I make myself invisible to microwaves by unplugging them, or turning off the lights.
...
Sneaky little buggers, always watching you and beeping at you to take your dinner or coffee out
-- Tigger warning: This post may contain tiggers! --
Yes, I know - this won't do that much against baryonic radiation, but for e/m . . .
Seems to me, even given perfect invisibility, that the object in question would radiate energy all by itself.
Do some spectranalysis, and you immediately know something fishy is going on. (Copper won't radiate like the ground, for example)
Please explain this to me, nerds:
If you're inside an invisibility cloak that is bending all the light around you (=stone in water analogy), then surely you couldn't see what's outside the cloak coz no light reaches the inside, right?
"The first working cloak was in only two dimensions and did cast a small shadow, Smith acknowledged. The next step is to go for three dimensions and to eliminate any shadow."
... and that led to a device that is not optimal. I know how to make a much better one.
Right, and my "overunity" (perpetual motion) device has an calculated energy output equal to 100.1% of its input. But due to a few minor engineering losses that reduce the output, the current working model only produces 99.9% of the input.
The next step is to go for that last 0.2%. I did this work very quickly
And if you'd like to be in on the ground floor, I am letting a very few people buy stock in my enterprise now.
"How to Do Nothing," kids activities, back in print!
Cloaking devices are nice and all, but wake me when they've started work on a Chameleon Circuit.
It seems to me what they are doing is just a fancy magic trick, just like in this picture: http://en.wikipedia.org/wiki/Image:UNSIBA-5_Unsich tbarkeit_mit_Spiegeln.jpgFrom the Wikipedia
Whew, get me one of these and I'll be safe from the microwave overlords at last!
Half the time I'm right, the other half you're wrong.
If you bend the lightwaves around yourself so that they can continue moving past you, what light waves can enter your eyes, exactly? You'd be in pitch darkness, unable to see a damn thing because the light can't get to you because it's being bent around you. If you choose to allow some light through so you can see, then other people would see blackness there because there's light that's not getting reflected by anything... again, useless.
File under 'M' for 'Manic ranting'
Here's a picture.
the wires posted this one recently, but the science article came out in May. Old news?
You know this can only lead to DRM for TV Dinners...
Already done. Scientests have been invisible to human women long before slashdot was even conceived
Public use of any portable music system is a virtually guaranteed indicator of sociopathic tendencies. -- Zoso
But for something with such obvious military applications, I wonder if they have really been beaten to the punch by 10 years by some deep black Skunkworks research team, courtesy of about 2 orders of magnitude more funding.
After all, the F-117 first flew in 1977 - it's 30 year old technology. I bet they've not been sitting on their hands since then.
Is the world coming to an end?
Zonk's title is actually more accurate than the original !
hehe, sounds interesting but a bit overhyped. Seems like a long way from a 2-dimensional version to 3. I am not even sure what one would see using 2 dimensional version, how do you hide 2 of 3?? Would not that leave only a line, but with no width you can't see the line, but then it would be complete but its not so.....
Sorry, had to...
"Diplomacy is something you do until you find a rock." --Richard Pound
For all you people who want to spy on your hot neighbor (including myself, come on, I live near the University of Florida), I have to ask. If you are redirecting light around yourself, you won't be able to see anything yourself. No light will reach your eyes. I suppose something special would need to be employed for this to work. I remember reading about this when studying the effects of light within black holes but please correct me if I'm wrong.
I will forever be a student.
Amazing stuff.
Obligatory Soundbite Catchphrase
Does anyone have any pictures?? What's it look like? What would we see?
people who sell talcum powder might just have a new market...followed by paintball gun manufacturers.
A goal is a dream with a deadline
To expand: light following the path of least time is known as Fermat's principle. Fermat's principle can in turn be derived from Feynman's path integral formulation of quantum mechanics; it is related to the principle of least action. Feynman's book QED: The Strange Theory of Light and Matter has a lay derivation of Fermat's principle from path integrals (due to constructive superposition of quantum phase differences).
In their experiment the scientists used microwaves to try and detect a copper cylinder.
Grammatically speaking, usage should be "try to detect". "try and detect" presumes that you are going to try and you are going to detect. If you know that you're going to detect, you don't need to reference "try".
I'll be able to heat up my Chef Boy-R-Dee without taking it out of the can!
...following the principles of Heisenburger's Uncertain Cat...
We finally have the same technology as the predator monsters from the movies. We could use it for hunting and have little pin sized sensors that pick up inferred light and body heat and direct it back to a special mask that we could wear.
I'd like to have a car that redirects Radar and Laser waves so i never get another speeding ticket. All other forms of light is could ignore. That would be awesome, driving by a cop at 90 and him not even picking you up on his radar gun.
This is a violation of the Treaty of Algeron, the romulan empire will not stand idly by and watch as you disturb the delicate peace between our peoples! Hand over your research and all of your devices to Romulan high command at once, or they will be taken from you.
You didn't point out a single spelling mistake in the original post. You're certainly not the Definition Nazi.
Just paint the copper cylinder pink and turn on a cheap and simple Somebody Else's Problem Field.......
While if we marked the molecules on the water and tracked its passage, yes of course we would know that it isn't exactly the same as it was before. But it doesn't matter. They aren't looking for a 1 to 1 correspondence. It doesn't matter that the water molecule that we see isn't the same one we expected when it came down the stream. All that matters is that their is A water molecule that LOOKS the same heading in the right direction.
Also making something completely invisible to the naked eye would be a disaster for a person who was being invisible. But the person or thing doesn't have to be COMPLETELY invisible. For example, if a ninja were trying to be invisible, a pair of eyes are a lot easier to hide than an entire body. Just make the rest of the body invisible and move your eyes to where people aren't looking.
Or if you were making a plane invisible. Make the entire plane invisible except the windshield. Sure you could see people inside if you were looking at the plane from the front. But most people would be looking at one from the ground where you can't even see the windshield.
So they made a window?
tedivm
No tube that small has a cloaking device!
They are still looking for the prototype. It is around here somewhere...
It is by the juice of the coffee bean that thoughts acquire speed, the teeth acquire stains. The stains become a warning
Now where did I put that invisible robot killing machine?
There's a photo of it here. It's sitting there in the middle of the table (actually, just a little to the left of the middle).
Seriously though, how funny would that demo be... "I've created this material lattice that re-directs visible light such that nobody can ever see it ! oh wait, I had it here somewhere... D'oh !"
Basically, neat trick for radar/MW, lousy for visible light. Why even go there ?
"Whoever would overthrow the liberty of a nation must begin by subduing the freeness of speech."--Benjamin Franklin
[Yawn] Wake me up when they have invented a Bag of Holding.
>The cloaking has to be designed for specific bandwidths of radiation.
You can use lots of different frequencies for radar. This is so cool it must have lots of uses but a cloaking device doesn't seem to be among them.
"from the on-our-way-to-vulcan-level-tech dept."
Goodness, Zonk, don't you know anything?! The Vulcans didn't use cloaking devices; the Romulans and Klingons did (as well as some rogue Federation types)! I was about to say "your geek license has been revoked", but decided against it. Thanks for posting the link to this article.
When water flows around a rock, Smith explained, the water recombines after it passes the rock and people looking at the water downstream would never know it had passed a rock.
Is that even true? It seems to me that the flow pattern of two identical channels, one with a rock and one without, would differ in a way that would be detectable downstream -- at least if you knew what it was supposed to look like without a rock.
Terrorists can attack freedom, but only Congress can destroy it.
Make one of these that works for X-Rays.
Wrap a gun in it, put in carry on bags.
Pass right on through the machine, nothing noticed.
Need help treating your acne? Come here!
I don't know about making something invisible to microwaves, but apparently the microwave at the office can make a hot pocket invisible. I put it in and set it to two minutes, go to the bathroom, and when I come back it's nowhere to be found.
"In addition to hiding things, redirecting electromagnetic waves could prove useful in protecting sensitive electronics from harmful radiation, Smith commented."
I remember when Darpanet was being developed as a military technology to interconnect disparate computing platforms for the express purpose of improving the flow of intelligence throughout the US Armed Forces. Hardly looks like the modern internet now, does it?
I for one welcome our invisible overlords!!!
wait.
Multispectral sensors. While you may be able to fool some of the wavelengths all of the time and you may be able to fool all of the wavelengths some of the time, you'll never be able to fool all of the wavelengths all of the time.
Coding with assembly is like playing with Legos. Coding an application in assembly is like building a car with Legos.
This will be great for personal use but not much for military vechiles/planes/watercraft. A personal cloak of invisiblity will get you past the doors of the local sorority while wearing infared goggles(makes everything shades of red), but for combat vechiles its useless since most militarys use multiple types of scanning devices(radar used by stingray missles, infared used by redeye missles).
Because of this article, I've discovered how to cloak forum content. In concept, it should work on MS word and text documents also- but has never been tried. I present to you- forum cloaking in action. //start cloak//
//cloak disabled//
Did you (not) see that? 3 lines of text- hidden and cloaked.
We'll report back once we have more to show.
Then again, by the time we develop an FTL drive (if we ever develop an FTL drive), this technology or its descendent technology could be useful.
Now all I need is a bag of holding and an Axe Handle +1, +3 versus Web Ragers and I'll be invincible!!!
There are many tongues to talk, and but few heads to think. -Victor Hugo
Correct me if I'm wrong, but wasn't this already posted back in May 06? So what's different with this story?
"On a scale from 1 to 10, people are stupid"
There's this thing called a pinhole camera, it's a relatively new advance.
And, folks, here's a case indicating the limits of moderation by the unwashed masses. A pinhole camera is the very oldest type of camera. Having no lens, it can be made with a box and (gasp!) a nail. It is known to have been known about by the Chinese somewhere in the 5th century B.C, and Aristotle in 4th century B.C. Oh, how a small bit of research in widely available knowledge could have saved the parent poster from looking like a dolt!
But this worthless (and incorrect) piece of wisdom gets moderated up by the clueless who don't take the time to understand what the !@# they're reading.
Just when I start to get hope for mankind, I see something like this...
I have no problem with your religion until you decide it's reason to deprive others of the truth.
Is it still detectable with passive radar methods?
Briefly, a passive radar system will monitor the background radar/microwave "noise" that gets emitted by hot objects, radio masts and the like. If they detect a lack of signal in a specific area, then logically that means something is deflecting or absorbing the microwaves.
There's this thing called sarcasm, it's a relatively new advance. By stating a clearly false proposition in the proper tone of voice a touch of humour can be added while still conveying to the reader the intended meaning. Of course on the Internet the tone of voice can be lost, but what sort of moron would fail to realise this?
My first thought is, naturally, how can we apply this to masers? If you could "switch" this material's negative index of refraction very quickly--say, through physical deformation with a piezoelectric transducer, which should interrupt the properties of the lattice--wouldn't you have yourself a very nice solution for generating short pulses? Put one of these right before the output coupler and switch it at a high rate, and you have your pulsed maser.
that having only read the summary this seems genuinely cool. Of course, it's also genuinely scary, but that's the price of progress I suppose.
The higher the technology, the sharper that two-edged sword.
Ahh but slashdot got there first before the scientists with websites that are made invisible to anyone who wished to view them.
Video Game cheats, hints a
That just means it's only invisible from one direction/orientation (it's a shield, not a cloak).
THIS THING CAN TURN ON A DIME, MACROSSZERO STYLE ALSO FUCK BETA, ~NYORON
Forget about David Smith, has anyone seen Dr. Robert Banner? He was standing near the gamma ray generator last I saw... right next to that conspicous hole in the wall.
Much Madness is divinest Sense --
To a discerning Eye --
Much Sense -- the starkest Madness
What's the point of Slashdot having archives if the stuff in the archives is nothing but dead links? All URLs are "temporary", of course, just like everything else in the universe is. But when you link to Yahoo News URLs, you're guaranteeing that you're posting a URL that will be obsolete before all the other URLs where the article is hosted are.
When you link to Yahoo News on pages that are supposed to be archived, God kills a kitten.
Please, think of the kittens.
Eh?
Motorcycle riders acheived this years ago.
With microwave protection, Peeps will be unstoppable!
Ok, lets try a little experiment.
Take something like a wind tunnel, only filled with flowing water.
Instead of a small stream of smoke (or whatever they use in a wind tunnel), set up a horizontal grid injecting about a dozen different coloured dye streams.
Put in your rock, hit the big red button marked GO. Observe the colour of the water on the other side of the rock. Are the dye streams in their proper positions?
Not bloody likely.
This method of invisibility will only be effective if the object to be rendered invisible remains stationary against a uniform background, and maybe not even then. Set against a background of, for example, a larger than life poster of your local dictator on the side of a building, what you will see is a rather obvious blur in the shape of a guy holding a gun. Obvious, because it clearly doesnt fit in with what you should be seeing if there was nothing there.
Still, i'm sure its wonderfull science and engineering, and many usefull things will come from all the money being thrown in this direction. So by all means continue with these attempts at invisibility, just toss out that water analogy and the baby who came up with it please.
You shall know him by his Sig
That story has a totally misleading title. I even filled a complaint about it in BBC Complaint section, which follows:
---- cut & paste --------
I'm writing because I feel cheated by the above news story, which is entitled "Experts create invisibility cloak". Is it now the most popular story in BBC's website, according to the top stories link, but it is totally misleading.
INVISIBILITY means "not visible; not perceptible by the eye", that CAN NOT BE SEEN. Now, the story isn't about making something NOT BEING SEEN, but about a cloack that deflect microwaves! The story even reads:
"In principle, the same theoretical blueprint could be used to cloak objects from visible light. But this would require much more intricate and tiny metamaterial structures, which scientists have yet to devise."
So, the title could be easily corrected to "Experts give huge step towards invisibility", but to assert that they "created an invibility cloack" is totally wrong and misleading. BBC has alwasy been a brand synonymous to credibility in news. However, I'm sure that if stories like that keep hiting the front page, just to attact readers, that will suddenly deteriorate. I'm ashamed.
------------------
I feel so pissed off when I click a link to a news story that has the clear intention of misleading. Praise God that I don't watch Fox News.
If you can hide something from microwaves, you can hide it from radar and visible light.
It's an open question whether metamaterials for visible light are practical. Even if they are, there's a big difference between an "invisibility box" and an "invisibility suit". We already have "invisibility boxes" constructed of various rigid materials (magicians use them), but an "invisibility suit" is a thin, fairly flexible, irregularly shaped covering, and that's a much harder engineering problem. Many engineering problems simply don't have solutions under real world constraints and constructed from real-world materials, even if physical principles permit a solution in some kind of generic sense.
But a moving object is still traceable, as it will physically disturb the environment around it. A human will trample vegetation, break branches, or leave footprints etc. A tank will leave track prints, stir up a whole lot of dust, and many other such things.
So this technology would be most useful for hiding static vehicles/persons, or perhaps even moreso for hiding buildings (think, a whole, semi-invisible bunker).
I wonder how it would affect sound waves as well. Perhaps sonar would pick up things that radar would not. After all, a mirror or glass might be used to distort or reflect light, but does little against sound...
Finding your keys will be a whole lot harder if you leave them in your invisibility cloak's pocket.
I have to say that although this is an interesting trick, it doesn't seem to be quite as useful as people might at first imagine. For a kick off, it seems to be round and one would therefore suppose that a 3D one would need to be a sphere. Is that useful? I suppose that you could put your tank inside a huge sphere and roll it around, but guiding it and firing the gun sounds a bit tricky. Somehow I don't think that making a none-spherical one which works over a broad range of incident angles is going to be at all easy. I suppose that you might be able to make a spherical bomb.
Next, as the article mentions, what about bandwidth. For it to be useful against radars you are going to need at least a 10:1 bandwidth which again, doesn't sound easy. There is slightly better news for visible light, where a bit less than 2:1 will work.
Finally, I can't believe that it doesn't reflect any radar energy back. It might only reflect 10% or maybe even only 1%, but when you consider the dreaded R^4 factor in the radar equation that still doesn't buy you a lot of stealth.
After a great deal of thought, I have come up with a possible application for the current 2D, limited bandwidth version.
Suppose that you have a radar on, for example, a ship. It is often the case that since only one radar can be on top of the tallest mast, the others have some of their field of view partly obscured by other masts. If nearby masts were covered in this stuff then the radar should be able to see right through them and thus maintain a 360 deg field of view. In this case the 2D nature is fine for wrapping around the mast, and the limited bandwidth doesn't matter since we presumably know the frequency on which our radar operates.
I'm sorry to have to post this here, but it's the closest that I can get to the top. I hope that Vicissidude (the article submitter) sees it. Anyway ...
the scientists used microwaves to try and detect a copper cylinder
"to try to detect".
Also, for Zonk:
from the on-our-way-to-vulcan-level-tech dept.
"on-our-way-to-romulan-level-tech".
Click the "Preferences" link near the top of this page (under the "Slashdot" logo), then click the "Comments" link on the page that comes up.
On that page, near the bottom, there is a combo box labeled "Comment Post Mode".
Change it to "Plain Old Text", then click the "Save" button at the bottom of the page.
That should do it.
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana