Scientists Closer To Invisibility Cloak

Aviran was one of many readers to submit news of a just-announced development in the ongoing quest to develop a working invisibility cloak, writing: "Scientists say they are a step closer to developing materials that could render people and objects invisible. Researchers have demonstrated for the first time they were able to cloak three-dimensional objects using artificially engineered materials that redirect light around the objects. Previously, they only have been able to cloak very thin two-dimensional objects" Reader bensafrickingenius adds a link to coverage at the Times Online, and notes that "the world's two leading scientific journals, Science and Nature, are expected to report the results this week." Tjeerd adds a link to a Reuters' story carried by Scientific American.

And then...

[PJCRP]

http://arstechnica.com/news.ars/post/20080811-meta-material-does-not-render-anything-invisible.html [arstechnica.com] Oh Ars.

Nature's Abstract

[eldavojohn]

"the world's two leading scientific journals, Science and Nature, are expected to report the results this week."

You can find the Nature abstract here [nature.com]. And if you have a subscription, you can read the full research and see the data they collected from experiments.

According to the Ars Technica article on this [arstechnica.com], the Science link will be here [doi.org].

There seems to be a few more papers and articles on this but if you're interested you can search for optical metamaterials with negative refractive indexes.

Look over there, a cloaked eye-catching headline

[sakdoctor]

This story has popped up here and there in the press today, but when I actually RTFA the actual breakthrough is negative refractive index materials, in the visible spectrum.
The application is not invisible tanks and infantry, but microscopy.

See here for photoshopped image that enhances the misleading headline http://news.bbc.co.uk/1/hi/sci/tech/7553061.stm [bbc.co.uk]

Re:War Application

[IceMonkiesForSenate]

I don't really see many applications for war unless they can allow the person underneath the cloak to see. That's one of the drawbacks to being invisible, since light goes around the cloak no light reaches the invisible person's eyes, and thus the person cannot see. However, I could see someone under fire activating the cloak, and just laying low for a while

Re:Old "news". Nothing to see here....

[icegreentea]

One day isn't that bad. I wouldn't call it old. Also, previous developments on meta materials (see the Microwave ones), have pretty much been accepted as a possible first step towards cloaks. The Scientific America article has one of the researchers saying:

"We are not actually cloaking anything," Valentine said in a telephone interview. "I don't think we have to worry about invisible people walking around any time soon. To be honest, we are just at the beginning of doing anything like that."

So, while they aren't saying 'this will become an invisibility cloak', to say that there is no active speculation about applying visible light metamaterials as a cloak is wrong. Article also ends with comment on how these would make superior lens for microscopes.

Re:Look over there, a cloaked eye-catching headlin

[Anonymous Coward]

That's not actually photoshopped, its for a different technology where they can project "3D" images onto a surface and it will appear to be far away. Lots of tiny glass beads and whatnot. If i drape you in that stuff and take a projector and project a car onto you, if there is the same car behind you, you will be camoflaged. The only downside is that you need all of these projectors and whatnot to project a background image.
 
Think Solid Snakes octocamo meets a movie theater.

Re:enage cloaking device

[bmajik]

I had to look up Snell's law quick, which doesn't mention wavelength as being a factor (I thought that the refective effects might vary according to wavelength), but then i noticed this at the bottom:

In many wave-propagation media, wave velocity changes with frequency or wavelength of the waves; this is true of light propagation in most transparent substances other than a vacuum. These media are called dispersive. The result is that the angles determined by Snell's law also depend on frequency or wavelength, so that a ray of mixed wavelengths, such as white light, will spread or disperse. Such dispersion of light in glass or water underlies the origin of rainbows, in which different wavelengths appear as different colors.

In optical instruments, dispersion leads to chromatic aberration, a color-dependent blurring that sometimes is the resolution-limiting effect. This was especially true in refracting telescopes, before the invention of achromatic objective lenses.

http://en.wikipedia.org/wiki/Snell's_law [wikipedia.org]
http://en.wikipedia.org/wiki/Dispersion_(optics) [wikipedia.org]

I would guess that any optical camoflauge technique has a function of input wavelength vs. camoflauge effectiveness, and that wavelenghths sufficiently on either side of "visible" would likely fall off of the effectiveness plateau.

Re:First - talk about "Dup, dup, dup, Dup of Earl.

[hubie]

Mono-layer substrates that are on average one atom (or molecule) thick are considered 2-d materials in physics. And depending on the context, such as the wavelengths or other length scale-setting parameters in use, 2-d can be much thicker.

Re:The reverse scenario might be more to your liki

[woot account]

Or, what if the South Ossetians had it when the Georgians bombed innocent targets simply because they sought to form their own democracy.