something that has always bothered me about this, is that if you can see the light coming from behind it, but not whats actually there, wouldn't it make the space appeared distorted inwards unless you can achieve a perfect -1 index of refraction?

Quoting from the article:

This answers your question, because the materials they use arn't "normal".

no it doesn't. regular materials bend light too, which is why a laser beam looks bent if you shine it into a tank full of water. so unless
the metamaterials negative index has the same absolute value as that of the material surrounding them, you would still see some sort of optical distortion, because light would flow around it at a different rate then it was flowing through the surrounding medium. for example to optically conceal an object in a pane of glass with an index of refraction n=1.5, the object would need to be surround by a metamaterial with an index of refraction n=-1.5, unless I completely misunderstand how this works.

Your theory fits, elfprince. Only two ways to make one go completely cloaked, as it were.

1) Shift out of phase.

2) Technology that can monitor your surroundings, and mimic the same surroundings, like some sort of cloak of some kind.

The bending of light would cause a distortion, there would be no way around that.

Well in some scenes you can see some slight distortion so it isn't perfect but its good enough that you don't see him clearly.

eh?

well there is, but only if your index of refraction is the opposite of your surrounding medium.


and this is one instance where Star Wars had it right about cloaking devices, at least with passive cloaking, the reason your cloaked is because no light is reaching you, and thus you're operating 100% "in the dark" and there's still other ways you can detect them since most metamaterials only are effective on certain frequencies anyway. active cloaking is an entirely different kettle of fish, and has at least been attempted. but to achieve active cloaking you have to measure + absorb + re-emit every signal that touches you, plus create destructive interference to any thing that is reflected off you. it *would* give you the opportunity to observe the waves hitting you and display them inside the cloaking device as well, but this sort of technology would require the entire "cloak" to be aware of its position and orientation over its entire surface and of its own reflective/absorptive properties. there have been tech demos of this sort of active camouflage, but its a LONG way off.

The shifting out of phase is a sci-fi theory that one can be pushed into a faster or slower flow of time, in a sense, I think. This way, other objects can no longer see you nor can they touch you.

well theirs the option of of vibrating at incredibly high speeds so that the light can pass through with very little distortion but how one would achieve this would be the issue. but all you need to do is move faster than the imaging device that is viewing you can see weather that be human eyes or camera, etc.

@tifreak: I wasn't sure if you speaking ala Dr-Who season 4, or ala :

second option == internal organ damage much?
first option == wouldn't they just be able to see you an instant in the future instead?




sonic boom much?

Well I never said anything about sound but it would work in the vacuum of space and if you contained the air around you their would be no sonic boom.
And for organ damage oh I did realize we were restricted to being able to transport humans. if you didn't figure it out yet I got my idea from the Artemis(sp) Fowl books and the organ damage would only occur if the acceleration was faster than your body could handle but if you found a way to change the current momentum of the entire body at once this would not be an issue. The entire body would accelerate at the same speed and would not notice the fact that it was ever moving in a different direction though that is impossible as far as current technology is concerned.

I was actually referring more to SG1. They manage to phase shift the planet to keep it from being attacked by bad guys.

And no, because you will always be ahead of them, they would have to utilize the same technology to catch up to you to see you. :S

You would need a very close to -1 index of refraction to make it completely undetectable, but even if the light only looks slightly distorted, that would still be very hard to spot - especially in a hot desert environment where the heat causes visible distortions all the time

@Tifreak: Scifi has only the most basic grounding in science, and usually not even that

Maybe so kllr, though scientists seem to be taking it up on themselves to bring those things we don't have yet to life.

I remember that something like this was in the news one and a half years ago, there is a picture of the invisible cloak here, there is also a link to The Times which might be more readable then Russian.

halo like invisibility?

nice find. those nanomaterials are insane. i read somewhere awhile back that the light bending properties are also being used to increase the efficiency of fiber optics or something.

but that depends on the surrounding medium. -1 index of refraction encased in glass or water would definitely look distorted.



I remember seeing the actually "cloak," but that was active camouflage, not the negative index of refraction sort of thing that was bothering me.



I was referring more to the vibrating thing with the organ damage, than the super-fast-acceleration thing the problem. with the artemis fowl idea is that if they're vibrating that tiny amount, the bulk of their body would still be visible and they'd just be fuzzy around the edge. "vibrating" someone enough to change them from a massive (having mass) object into a wave function would definitely make them disappear but I can't imagine you'd be able to turn them back safely

I was talking to some people from the Army and they were saying that they were making a Nano suit that was about 700lbs and felt like 20lbs when worn (from what I can remember). They said that when worn it is completely flexible almost like wearing regular clothing but where ever its hit hardens like bullet-proof steel.

Kind of incredible. It was a little Army bus that dropped by my high school and they had one of the suits inside the bus but it was behind glass. It was one of those things where they show you stuff to try and convince you to sign your life over to the Army. lol.

I haven't been able to find much online about it. If someone finds something on it I'd love to refresh my memory on the subject

I know the suit you are talking about. It uses a bunch of pneumatic actuators to boost the strength of human motions. Impressive, but not practical (at least, not yet) - its bulky, limits the range of motion, and has to be plugged in - kind of a major limitation

Hehe, indeed a very big limitation.

But hey, the first computer was as big as a room and had to be plugged in

With technology advancing as fast as it is I'm sure it won't be but a couple of years before it becomes more mobile. Incredible though.

That is different. While transistor technology has improved at an impressively exponential rate, very few other technologies have. Power technologies, such as batteries, haven't improved at nearly the same pace.