Secret of invisibilty unravelled by US researchers

[Dion]

Scientists at the University of California in Berkeley have engineered a material that can bend visible light around objects. This development could soon result in technology that can render tanks, ships and troops invisible to the eye.

The head of research, Professor Xiang Zhang, said in the case of invisibility cloaks or shields, the material would need to curve light waves completely around the object like a river flowing around a rock.

In essence, an observer looking at the cloaked object would then see light from behind it, making it seem to disappear.

http://www.theregister.co.uk/2008/08...hin_our_grasp/

[missdpuck]

Wow. Just so happens something similar on TV right now.

[Jude]

Journalist's impression of troops equipped with the new cloaking technology on exercise

So excellent

[CaptainCrunch]

If a tank had material that bent light waves around the tank, then wouldn't the people inside of the tank be effectively blind to the outside world?

[STeeLy]

Originally Posted by CaptainCrunch

If a tank had material that bent light waves around the tank, then wouldn't the people inside of the tank be effectively blind to the outside world?

I wonder that too, since there is no light hitting them... they see nothing...

[SebC]

Wouldn't it just look similar to a magnifying glass? I mean, we've seen stuff like this with gravity lenses, and it distorts the stuff behind it. Nonetheless, I wouldn't mind having, say, a cloak made out of this stuff.

[ricoFlame]

Originally Posted by Jude

Journalist's impression of troops equipped with the new cloaking technology on exercise

So excellent

LOL. frightening!

[Phanuthier]

Metamaterials, they actually discovered this about 2 years ago. I can't see what the difference between what they had then and this article. I thought US National Reserach Labs had bought all the rights to these and kept it confidential. It makes use of negative refractive indicies (affected by its electric and magnetic permuability of free space) to bend light around the object, making it invisible. I believe its surface plasmons (gold?) being used.
a
Seb - this is difference in that it bends like away from the object, more like water then light. A magnifind glass is a lens, where this is refraction.

And to CapCrunch, yes one of the issues is that the object being cloaked cannot look out either. I believe another issue is it does create a shadow.

(ps: sorry for the sucky spelling)

[Fozzie_DeBear]

Originally Posted by CaptainCrunch

If a tank had material that bent light waves around the tank, then wouldn't the people inside of the tank be effectively blind to the outside world?

If the system can capture the light on its way around the tank, maybe they can patch a video feed into the tank.

[Flames in 07]

I don't know what the big deal is, this isn't new, Kipper was turning his cloak on and off for the 08 series with SJ.

[icarus]

Pfft, they did this already in the Second World War with the Philadelphia Experiment. Of course some of the crewmen spontaneously combusted or ended up stuck in the walls, but they did it.

http://en.wikipedia.org/wiki/Philadelphia_Experiment

[Bring_Back_Shantz]

Originally Posted by Phanuthier

Metamaterials, they actually discovered this about 2 years ago. I can't see what the difference between what they had then and this article. I thought US National Reserach Labs had bought all the rights to these and kept it confidential. It makes use of negative refractive indicies (affected by its electric and magnetic permuability of free space) to bend light around the object, making it invisible. I believe its surface plasmons (gold?) being used.
a
Seb - this is difference in that it bends like away from the object, more like water then light. A magnifind glass is a lens, where this is refraction.

And to CapCrunch, yes one of the issues is that the object being cloaked cannot look out either. I believe another issue is it does create a shadow.

(ps: sorry for the sucky spelling)

Yeah, magnifying glasses are based on refraction as well.
All Refraction means is that light will bend when it enters a material where the speed of light is slower than it is in what it just came from.

[Sample00]

a Fata by chance?
but a good topic nonetheless.

http://forum.calgarypuck.com/showthr...sibility+cloak

http://forum.calgarypuck.com/showthr...sibility+cloak

[Russic]

Originally Posted by Fozzie_DeBear

If the system can capture the light on its way around the tank, maybe they can patch a video feed into the tank.

This was my thought. Someone inside could be controlling a small un-manned aircraft with cameras all over it.

[Traditional_Ale]

Originally Posted by Russic

This was my thought. Someone inside could be controlling a small un-manned aircraft with cameras all over it.

Or perhaps small un-manned tanks. Like battle bots. But they can flip any which way and correct themselves.

[Locke]

The Enterprise could still find them. If Cloaking technology still sucks in the 24th Century or whenever, it'll suck much more now.

Not to mention, just because they cant see you does not mean you cant be nuked or hit by random spray pattern fire. Or heard for that matter.

Making a tank essentially invisible is all well and great but the enormous tread-marks might be noticible or the huge turbo-diesel that you can hear from 4 blocks away might give your opponents a bit of a hint.

[CaptainCrunch]

I don't know if any of you played the Wing Commander series of games, but the three most frustrating things were the Strakha fighters that carried a cloaking device and they would pop up behind you from nowhere and missile you to death. The same Strakha fighters popping up in your carriers launch bay, blow the crap out of your carrier and then run away laughing at you. In the third game they had skipper missiles which were cloaked but would pop out every once in a while to re-orient themselves then cloak again, and they usually kicked the crap out of your cap ships.

They explained the cloak as bending visible light around it, but letting it leak slightly so the pilot could see out of it.

[jolinar of malkshor]

Originally Posted by CaptainCrunch

If a tank had material that bent light waves around the tank, then wouldn't the people inside of the tank be effectively blind to the outside world?

Would they be able to use something like Infra red or heat detection?

[Frequitude]

Originally Posted by Russic

This was my thought. Someone inside could be controlling a small un-manned aircraft with cameras all over it.

A good thought, but then the material would have to only work for a specific frequency of electromagnetic radiation (the visible light spectrum). Radio waves are identical to light waves, they just have a way longer wavelength.

I don't know if researchers are that far.

[Frequitude]

Originally Posted by Phanuthier

I believe another issue is it does create a shadow.

If all light bends around the object and continues travelling in the direction it came from, how could it create a shadow? Sunlight would bend right around the object and leave the backside.

edit:
...I suppose it wouldn't bend around perfectly, much like an eddy behind a rock (wow, second use of the eddy concept on CP in 15 minutes). Any surface in the object's "light eddy" would probably see a shadow I suppose.