Last week we had the laser gunship, this week it’s the invisibility cloak.
Sounds a lot like science fiction but you’d be surprised how close Army researchers are to actually attaining the Holy Grail of invisibility.
According to Dr. Richard Hammond, a theoretical physicist with the Optical Physics and Imaging Science department of the Army Research Office, engineers are closer than they’ve ever been to developing a material that can bend light around an object rendering it invisible to certain wavelengths — light being one of them.
So far scientists have successfully tested so-called “meta-materials” — ones that are man made and built at the molecular level — that can render an object invisible to microwaves, which has a larger wavelength than light, Hammond said.
“This is a new paradigm for the science of light,” he said during a DoD bloggers’ roundtable today. “It can be bent [using these materials] in an almost arbitrary way.”
There are some significant obstacles to making a usable “invisibility cloak,” however. The main one is the material itself. Since it has to be build at the molecular level, making enough material to cover, say, a truck is still out of reach, Hammond said. Also, so far the science is there to block one kind of wavelength, but not another. So you could render an object invisible on the UV spectrum but not the visible light one at the same time. And if you made something invisible to the human eye, it would be impossible without some kind of other sensor for whoever’s behind the object to see anything since you’re robbing him of light.
“But in early applications we could shield an object from radar,” Hammond added.
Closer to fielding is a similar technology using meta-materials that can enhance optics to see things at the cellular or even molecular level — “smaller than the wavelength of light,” Hammond said, or less than .5 microns.
These “Super Lenses” could be used to detect chemical or biological agents, focus visible light to a single point to “uncloak” cloaked objects or help recharge solar-celled batteries, and could be applied to microscope lenses to increase magnification ten times, Hammond said.
Hammond has been working with UC Berkley, University of Colorado at Boulder, Perdue and Princeton on these efforts under a three-year, $1 million grant.
– Christian
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If the stuff is expensive to make, the ideal early application might be a micro-UAV.
Where do we invest?
Many apps:
Security
Law enforcement
Prison security
Intelligence
“armoring” VIP cars.
“stealth” AF1?
& more
$$$$$$$$$
Hang on. Wouldn’t this render microwave and laser weapons useless? It’d just bend the uber-powerful beam straight around you and presumably you would not feel any ill effects.
Bummer for the chap standing behind you though…
“And if you made something invisible to the human eye, it would be impossible without some kind of other sensor for whoever’s behind the object to see anything since you’re robbing him of light.”
Took me a minute to figure out what this meant. Basically, inside the cloak it would be pitch black as all the light is being bent around you. I wonder if that might actually be useful somehow. Anyone think of any applications that require absolute darkness?
“Hang on. Wouldn’t this render microwave and laser weapons useless? It’d just bend the uber-powerful beam straight around you and presumably you would not feel any ill effects”
Excellent point. I’ve been following this for awhile and this is never mentioned.
Also, what happens when you emit infrared radiation?
It seems like this would be more useful for a new generation of stealth aircraft, since radar waves would just go around the aircraft and not get bounced back. Of course, then the stealthed aircraft wouldn’t be able to use radar. Interesting.
FLIR is all the rage, and in truth, all you have to do is stick a receiver antenna outside the “cloak” to receive sensor data from your AWACs. Either that, or you set it up so that only your sensors are uncloaked. It would still reduce a majority of your Radar Crossection, and make you look like a collection of flying “noise” around a center of…nothing.
There was actually a sci-fi book called “A Mote in God’s Eye” where the spacecraft used an “energy shield” with similar properties. Their solution was to stick probes and wiskers outside the field. Sure, they could “burn off” your sensors, but the ship underneath would be protected, and you had backup “wiskers” you could deploy…and deploying an antenna outside a cloak like that is alot smaller than seeing a whole freaking airplane, even if the plane is stealthed.
For simple applications that only had to fool, say, civilians, one idea would be to project an image of what is behind the ‘cloaked’ object onto its surface.
A bit of critical thinking is in order. From popular mechanics:
http://www.popularmechanics.com/science/research/4277607.html?nav=RSS20
So let’s assume all the technical challenges are met (they aren’t). The metamaterials work over the full visible spectrum (they don’t), it’s flexible enough to wear (it’s not), it doesn’t get dirty after five minutes (it would), and it works whether you’re moving or sitting still, up close or far away (you get it). Let’s pretend that metamaterials have been honed to perfection and that they are available for sale at a very low cost. Now let’s take a ride on the Skeptic Express.
First stop: Blending into the visible spectrum doesn’t really make you invisible. You’d still be plain as day in other parts of the electromagnetic spectrum. Specifically, infrared emissions would make you an easy find for anybody with an infrared camera, as well as for deadly, heat-sensing pit vipers (such a nuisance). And that’s just passive detection. You’d be even more visible to active detectors [...]
Before you get too worried that some sweaty U.S. Army guy is lurking over your shoulder clad in the Predator’s blurry battle armor (the military did fund part of the new research), remember this: So far the most cutting-edge research can only cloak tiny objects, under laboratory conditions, and on a limited range of wavelengths. You’re safe, for now, along with the privacy of cheerleading squads the world over. Thank heavens.
It doesn’t really matter if this achieved or not. Once it is, somebody else will come up with a way to defeat it.