Science has dealt another blow to those who draw their scientific knowledge from Star Wars films. Contrary to the famous line in the Empire Strikes Back,a new engineering approach called metamaterials can potentially cloak any size ship as long as you know what energy wavelength the other guy plans to use. So much for verisimilitude, George Lucas.
In brief, metamaterials assemble a repeated array of precisely-shaped materials to produce electromagnetic properties completely distinct from the raw material. For example a metamaterial lens tuned to the wavelength of visible light can apparently defy laws of physics by presenting a negative refractive index. That makes metamaterials useful for either making a microscope objective with infinite resolution or ‘warping’ light around a physical object, making it completely invisible from any angle. In effect, a cloaking device.
While wavelengths in visible light’s nanometer range remain out of reach for metamaterials engineers, the millimeter-scale wavelengths used in microwave applications like radar are much more accessible. The first metamaterials operated in that wavelength band, and now David Schurig and David Smith at Duke University have used it to build a functional radar cloak.
The cloak embodies the theory laid out by theorist John Pendry of Imperial College London and experimenters David Schurig and David Smith, who work in the electrical and computer engineering department at Duke University in Durham, North Carolina. In May, the team showed that, in principle, it’s possible to ferry electromagnetic waves such as light around an object by surrounding it with a “metamaterial”: an assemblage of tiny rods and C-shaped rings (Science, 26 May, p. 1120). The waves would then pass as if the object weren’t there, rendering it invisible.
The electromagnetic waves cause the electrons in the rings and rods to slosh, and the sloshing, in turn, affects the speed at which the waves travel through the material. If the speed varies in the right way within the cloak, the waves will curve around the object. The theory predicts only how the speed of the waves must vary; it leaves it to experimenters to design the material.
When Schurig, Smith, and colleagues worked out the details, they found that their two-dimensional device required only C-shaped copper rings nestled side by side. The team also simplified the parameters specified by the theory. The changes made the metamaterial easier to build but also left the cloak slightly reflective, as the team reports online this week in Science. “The goal of this paper was to demonstrate that we more or less have the mechanism and that we can design the materials to the parameters,” Schurig says.
Before we dictate surrender terms there remain a few kinks to work out:
The cloak is hardly perfect: Instead of an all-concealing sphere, it’s a ring that works only for microwaves zipping along in a plane. The microwaves must also be polarized perpendicular to the plane. And even then, the cloak reflects some of the waves and casts a slight shadow.
Keep an eye on this technology. Metamaterials only appeared on the scene a short time ago and already they have what essentially amounts to a working cloaking device. That is a staggering rate of technological progress, and suggests a major potential for good minds with decent funding (metamaterials will soon join carbon nanotubes in research grant nirvana) to make major leaps in concept and implementation.
***Update***
More here, where comments suggest that the tech may be well known in the defense community.
Walker
On a related note, it will be fascinating to see what effect this change in congress will have on the NSF funding situation. While there has been plenty of funding the past 6 years, it has all been military. The NSF has been crippled.
Of course, I should expect the posts about the mythical beast known as “private sector funding” now.
ThymeZone
Does this work on people? There’s a failed oilman former drunk politician spoiled rich kid guy in Washington DC that I’d like to make invisible. Just for a couple of years.
JWeidner
Jane, you ignorant slut.
There’s no such thing as a cloaking device, only the hand of God reaching out to make something invisible on demand. Any Republican worth his (or her) Foley values….I mean, family values will agree with me.
srv
I guess that’s why all the flying saucers have disappeared.
CaseyL
“No ship that small has a cloaking device” probably referred to the assumed technical difficulty in generating the field, either a lot of power (which a small ship presumably can’t generate) or a huge device (picture the Millenium Falcon listing to one side like Han after shore leave).
Most classical scifi techobabble relied on enormous machinery generating enormous forces – nuclear! electromagnetic! gravity! matter-antimatter! – not to mention the enormous shielding mechanisms to keep all that highly destructive stuff from going blooey.
Nano thisnthat wasn’t even on their, ahem, radar screen. That’s one of the things that’s so intruiging about nanoscience. It turns the Bigger Is Better paradigm on its head.
I got a kick out the cautionary note about how the cloak wouldn’t be complete:
“Captain? Sensors are detecting, um, half of a Warbird.”
“Indeed. What do you make of that, Number 1?”
“Either it’s a strangely tidy wrecked ship, or they got stuck with a low-bid cloaking device.”
“Captain – now the sensors aren’t picking up any Warbird at all.”
“Ah. The engineering officer must have hit the console in just the right spot.”
jake
And then the line would be: “No shit that small has a cloaking device.”
lard lad
I’m holding out for when they perfect the trionic initiators.
Bruce Moomaw
Cripes, next thing you know it’ll turn out that “parsec” isn’t a unit of time.
Zifnab
Still, this leaves one unanswered question, John.
How could they be jamming us if they didn’t know we were coming?
Zifnab
Actually, according to the Star Wars Universe, a parsec is a unit of distance. Han Solo apparently had the balls to take his ship through an asteriod field or some shit in order to make the Kessle Run so quickly.
… … …
/dork
maddie
Hooray! A true geek post. Perhaps now I can convince my Republican husband to start reading this blog. He has travelled much the same path as our host, John, over the past 12-15 months. His father is physicist who does research on laser defenses for the military. I’m sure this will do the trick.
And when I read Zifnab’s comment to him, he of course knew that a parsec was a unit of distance.
Thanks, Tim!
Bruce Moomaw
Look, I knew “parsec” is a unit of distance at the time.
(Note that in the original “Star Wars”, Lucas had his tongue so far in his cheek that its tip could be seen waggling out his left nostril. Then, when the thing turned out to be a monster hit beyond anything he had ever imagined, he had to start trying to take its mythos SERIOUSLY, something he was obviously unprepared to do. He probably hates Luke, Darth & company as passionately as Conan Doyle eventually grew to hate Sherlock Holmes.)
Area Man
Science? Pfft! You are clearly a secular anti-growth Moonbat.
Seriously, Ive been following this for awhile. The biggest bugaboo is that even if it is perfected, it works both ways. You can’t see out either.
Perry Como
So you’re saying it’s good for the White House?
DecidedFenceSitter
Actually, Kessel has a galatic maw of blackholes, and the closer you run to them the shorter the distance to Kessel it is.
Or at least that’s the Ret-con to have it all make sense.
Geekier than thou,
DFS.
jake
Where do you think they’re testing the prototype? No light goes in. No light comes out.
tBone
Damn. Beat me to it.
BIRDZILLA
How about a cloaking device that will cloak a constitution class star ship like the origional USS ENTERPRISE
Catsy
You wouldn’t have to encase an entire infantryman in these materials. Just fit them with rigid “cloak” body armor where possible, and conventionally camouflaged material at the flex points and around the face. It would still be an improvement in making them hard to see of several orders of magnitude.
This goes even moreso for vehicles and structures.