Along with a teleportation device and a time machine, the invisibility cloak is on the short list of awesome sci-fi inventions I thought I'd never see in my lifetime. Now it appears there's hope, at least on the invisibility front. Extreme Tech reports that University of Texas at Austin researchers "have created a new, ultra-thin Harry Potter-like invisibility cloak." This isn't science's first shot at invisibility cloaks. While researchers have been experimenting since at least 2006, most prototypes have been clumsy and flawed -- exactly the qualities you don't need in a good invisibility cloak. Even David Smith, a Duke University professor who worked on the early cloaks, said at the time, "It's not yet clear that you're going to get the invisibility that everyone thinks about with Harry Potter's cloak or the Star Trek cloaking device." Which is like using a time machine that gets you only halfway to the period in history you want to visit, or a teleportation device that doesn't put your molecules back together. It's sort of a ripoff. But that's what Consumer Reports is for. The big advance made by the Austin team is that the cloak is a mere 166 micrometers thick, putting it in fabric territory. A major advance, since well-fitting cloaking outerwear is much more functional and practical than, say, a cloaking box or barrel. The researchers go into a lot of detail about the technology in the New Journal of Physics, but, quite frankly, it takes the fun out of whole thing. Here, however, ExtremeTech's Sebastian Anthony explains why Mary-Kate and Ashley Olsen won't be unveiling a line of invisibility cloaks any time soon:
The one problem is that their patterned material scattering technique inversely scales with wavelength — so, while it’s possible to hide an 18cm cylinder from 3.6GHz microwave radiation, they can only hide micrometer-scale objects from 400-800THz visible light. One micrometer is 0.001 millimeters; the width of a red blood cell is about six micrometers.
Which simply won't do on the catwalk. Now read this: