Stories tagged invisibility_cloak

Nov
04
2007

An invisible tank: Right in front of that other tank.  (photo courtesy of wikimedia commons)
An invisible tank: Right in front of that other tank. (photo courtesy of wikimedia commons)
Great Britain has been making some progress in the field of “ways to kill people with out them seeing you do it.” In the past, we had to be satisfied with impersonal methods like booby traps and poisoning, but, with the help of science, before long we should be able to safely view our own nefarious deeds - while hiding in plain sight! Sort of.

The UK’s Ministry of Defense has recently unveiled a prototype “invisible” tank, and predicts that similar models will be ready for service (the service of blowing things up! Yeah!) by 2012.. Unlike a lot of other invisibility research, which often focuses on bending light around an object, the invisi-tank (as I like to call it) relies on “cameras and projectors to beam images of the surrounding landscape onto the tank.” I’m not sure if these cameras and projectors are on the tank itself, or nearby. That’s probably a secret.

A soldier who was present at the trials was quoted as saying, "This technology is incredible. If I hadn't been present I wouldn't have believed it. I looked across the fields and just saw grass and trees - but in reality I was staring down the barrel of a tank gun."

It is also believed that the Ministry of Defense is “testing a military jacket that works on the same principals.”

I recommend that you take a look at the original article. The picture of the scientist in charge of the project is great. He completely redefines the stereotypical image of a scientist. Oh wait, no, I mean he reinforces it.

May
07
2007

Ever since I first saw the action/horror film Predator I have had two objectives in life – one, to challenge Arnold Schwarzenegger in a battle of wits and physical strength, and two, to have my own invisibility suit*. Humble goals, I know, but I like to think that makes them more realistic.

While Governor Schwarzenegger has yet to return my calls, the recent work of some European scientists and mathematicians has brought my second dream one step closer to reality.Invisilibilty Cloak: A conceptual rendering of me wearing an invisibility cloak.
Invisilibilty Cloak: A conceptual rendering of me wearing an invisibility cloak.

Mathematical models and small-scale laboratory tests have shown that by surrounding objects with certain types of “metamaterials,” they could be rendered invisible.

Metamaterials are non-natural materials that gain properties through their structure instead of their composition. So, think of a metamaterial as something like a screen door, which you can see though because it was made with thousands of tiny holes in it, compared to something like plastic sandwich wrap (our “natural material”), which you can see through because the plastic itself is transparent. Maybe that’s not the best analogy, but it helps me get a grip on things.

Anyway, the idea with the invisibility cloak is that the metamaterial would bend electromagnetic radiation (like radar, microwaves, or visible light) around the object, sort of like, as one scientist put it, “river water flowing around a smooth rock.”

Unfortunately for me (and fortunately for Governor Schwarzenegger), the metamaterials required for this are a little more complex than a screen door, and the computer models that much of this research is based on use spherical, stationary objects as ideal candidates for invisibility cloaks. This could change as we are able to produce increasingly complex metamaterials, allowing things like submarines and airplanes** to be rendered invisible, but the days of something as oddly shaped and as mobile as I am having a personal invisibility suit are a long ways off. Shucks.

What do you think about the possibility of objects, vehicles, and maybe someday people being able to turn invisible? Awesome? Scary? Both?

*If you’re over seventeen, and not getting the Predator references, I highly recommend it. For younger invisibility fans, I suggest Harry Potter. For those of you who aren’t into invisibility, maybe Die Hard or Forest Gump would be more your speed – I don’t think there’s anything invisible in those movies.

**For more on invisible airplanes, see Wonder Woman .

Links to more info:
Invisibility at ScienceDaily
Invisibility Cloak Demonstration
Metamaterials

Oct
25
2006

Invisibility cloak: Could this be in the future?
Invisibility cloak: Could this be in the future?

Check this out!

Researchers at Duke University, Imperial College (London), and SensorMetrix have developed a cloaking device. Take that you pesky Romulans!

Before I get too carried away I should probably mention that the cloaking device does not cloak objects from sight, which is what I first think of when I think cloaking device, not yet anyway. Researchers demonstrated that the cloak they developed can deflect microwave beams so they flow around an object with little distortion, making it appear almost "invisible".

The researchers used metamaterials to create the cloak. The metamaterials have properties not readily observed in nature, such as the ability to help smoothly deflect microwave beams around an object. I quite honestly don't understand all the science - when I was reading about it I encountered several strings of words explaining metamaterials that left me dumbfounded, such as "the group velocity is antiparallel to phase velocity (as opposed to parallel for normal isotropic materials)." While that phrase makes me feel intellectually inadequate, it does not lessen my interest in the cloaking idea.

Watch a video about the "invisibility cloak" here.

Klingon spaceships used an invisibility cloak to hide their ship in the Star Trek series. A similar technology will be tested in as soon as 18 months.

John Pendry and colleagues at Imperial College London, UK, have calculated that materials engineered to have abnormal optical properties, known as metamaterials, could make light pass around an object so it appears as if it were not there at all.

Pendry's team has drawn up plans for a spherical metamaterial structure that would render an enclosed object invisible. Electromagnetic waves (Radar, light), instead of reflecting off the structure, would flow around it like water around a rock in a stream.

Read about it: