Duke University Creates Perfect, Centimeter-scale Invisibility Cloak

MrSeb writes "Scientists at Duke University have created the first invisibility cloak that perfectly hides centimeter-scale objects. While invisibility cloaks have been created before, they have all reflected some of the incident light, ruining the illusion. In this case, the incident light is perfectly channeled around the object, creating perfect invisibility. There are some caveats, of course. For now, the Duke invisibility cloak only works with microwave radiation — and perhaps more importantly, the cloak is unidirectional (it only provides invisibility from one very specific direction). The big news here, though, is that it is even possible to create an invisibility cloak of any description. It is now just a matter of time before visible-light, omnidirectional invisibility cloaks are created."

Comments

Optimism.

[Anonymous Coward]

"It is now just a matter of time before visible-light, omnidirectional invisibility cloaks are created."

Wow. Just Wow. Just because we sent men to the moon, it does not mean that we'll be traveling to other galaxies soon.

Unless of course by "just a matter of time", they mean like a hundred thousand years.

Re:Optimism.

[CastrTroy]

I always like to refence this Hitchhiker's Guide quote

Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.

There's a big different between going to the moon and even something like going to Mars. It only took Apollo 11 astronauts 3 days to get to the moon. Even the shortest trips to Mars have taken close to 300 days. And Voyageur 1 has been travelling for 25 years and is only now reaching the edge of the solar system.

While warp speed and worm holes could allow matter to travel vast distances over short periods of time, I don't know if actual things could travel though a worm hole or at warp seed without being torn apart.

Haven't they learned from Star Trek?

[Tastecicles]

Surely it's gotta have a tailpipe...

Perfect?

[guttentag]

From the Oxford English Dictionary:

Perfect
adj. /'perfikt/
Having all the parts and qualities that are needed or wanted, an no flaws or weaknesses.

If there are caveats, it's not perfect. Don't slap false labels on things to make them sound more impressive. Call it what it is.

I don't think so...

[some1001]

The idea that we're "soon" to have invisibility cloaks that are both omni-directional *and* handle visible light is an unfounded one. True, maybe the underlying foundations are set well and the science is understood. But here's the issue: metamaterials ("invisibility cloaks" as a rule, fall into this category since they're properties are determined by the structure of the materials - not the material itself) have specific patterns in the structure. Microwave radiation has a wavelength between 1 mm and 1 m. Visible light has a wavelength of 390 to 750 nm. We are talking about four orders of magnitude.

The structure of the metamaterial needed to handle visible light is going to be out of our reach for quite some time until we can design a better way of handling structural details on the nanoscale and beyond (right now, the best methods are self assembled, and those methods usually aren't good for the massive complexity you'd desire).

Well, that's easy.

[Minwee]

I already perfected a centimeter scale invisibility cloak which works in visible light, but is unidirectional.

It involves using a digital camera, a printer, one square centimeter of paper and a bit of tape. Naturally, there are some limitations to where it can be used, but those are just details for the engineers to deal with.