Invisibility carpet cloak can hide objects from visible light

[FLPanhandle]

http://www.physorg.com/news/2011-06-invisibility-carpet-cloak-visible.html

(PhysOrg.com) -- Most of the invisibility cloaks that have been demonstrated to date conceal objects at frequencies that are not detectable by the human eye. Designing invisibility cloaks that can conceal objects from visible light has been more challenging due to the strict material requirements. But in a new study, researchers have fabricated a carpet cloak that can make objects undetectable in the full visible spectrum.

“The carpet cloak means that you conceal the object under a layer, which we call carpet, but you see the carpet like a normal mirror, as if it is flat with no bump caused by putting the object underneath,” Zhang told PhysOrg.com. “This way, the observer won't recognize something is concealed underneath.”

In order to guide visible light around the concealed object, the researchers had to make light travel at different speeds while approaching the bump. They achieved this by designing the materials to have a variable refractive index, transforming them into metamaterials, since they don’t appear in nature. The researchers placed a silicon nitride waveguide on a transparent nanoporous silicon oxide substrate that they specially developed to have a much lower refractive index than that of the waveguide. Using nanofabrication techniques, the researchers etched tiny holes into the nitride to make a desired pattern, giving the waveguide the cloaking refractive index profile.


With this refractive index profile, along with the transparency of both the waveguide and the substrate, the cloak could completely conceal an object by producing a light beam profile identical to a beam reflected from a flat carpet with no object underneath.



The Romulans are going to be pissed.

This is cool science, but as for practical uses, I'm not sure what you'd use it for. You still see the cloak/carpet.

[Recursion]

1. Negative mu

Cool stuff; we played around with this in emags class back in grad school.

[Sabriel]

2. Only two more to go until we've developed all of the Hallows

One possible use I can see is to trip people by concealing objects under the carpet. Great for parties. Other than that....

[FLPanhandle]

3. One of our dogs like to crawl under the rug to sleep

This would be great for her. We'd never notice her hiding out in the house.

[Blue_Tires]

4. Science fails us all once again...

What happens when they start making women's clothes out of this stuff?:silly:

[sakabatou]

7. For clothing...

You'll probably just see floating head and arms.

[FLPanhandle]

8. The ultimate Burka

The fundamentalists wouldn't be able to see women at all.

[n2doc]

9. But I wanna see the bumps! n/t

[LiberalEsto]

5. I want this in wall-to-wall

in a nice neutral shade. On top of the furniture, if possiblle.

[FLPanhandle]

6. What nuclear power plant? I don't see any nuclear power plant.

http://img.wallpaperstock.net:81/green-field-wallpapers_8739_1024x768.jpg

Of course it would have to be a very large invisibility cloak.

[Motown_Johnny]

17. Hmmmm..... I wonder why all those power lines just stop.

[democrat_patriot]

10. Military - use it to hide tanks. depots etc? like camo netting

but more high tech?

[TalkingDog]

12. That's probably the eventual goal.

along with said nuclear power plants.

[Incitatus]

24. Perhaps entire bases from satellite detection. nt

[Bandit]

11. make light travel at different speeds

:rofl:

[Motown_Johnny]

15. light travels through different mediums at different speeds

http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html


^snip^


Does the speed of light change in air or water?

Yes. Light is slowed down in transparent media such as air, water and glass. The ratio by which it is slowed is called the refractive index of the medium and is always greater than one.* This was discovered by Jean Foucault in 1850.

When people talk about "the speed of light" in a general context, they usually mean the speed of light in a vacuum. This quantity is also referred to as c.

[Bandit]

20. I guess Einstein was way off base with his "Theory of Relativity" then

He posited that the speed of light was a constant...Never changing.....If the speed of light is a variable then the equation E=MC squared is meaningless

[Motown_Johnny]

21. nope, not even close

it is constant in a vacuum

it is constant within each medium

Einstein always understood this, it just doesn't come into play in his theory. He uses the constant to prove that time is relative and that gravity warps both time and space. Only the speed of light in a vacuum is relative to relativity (so to speak).

[snooper2]

18. I guess you've never worked with fiber optics...

[Motown_Johnny]

22. self delete

sorry I thought this linked to my post


my bad

[Motown_Johnny]

13. so you have this mirror on your wall, but it has a '72 Volkswagen behind it

for a quick getaway in an emergency



OK, maybe not a Quick getaway.

[ergot]

14. I made one of those myself but now I can't find it.

grr

[Motown_Johnny]

16. check behind the mirror

[RC]

19. If this really worked and someone was hiding under it, they wouldn't be able to see.

Because no light would be there to see with.

[Kablooie]

23. Kinda adds a new dimension to the phrase, "sweeping things under the carpet"