We keep getting closer to Harry Potter-style invisibility.
No, you still can't take a silky, comfy-looking garment, slip it around your body and magically go completely invisible, but science is getting closer to building a device that can be adapted to hide just about anything, with a few inevitable compromises. Until recently, some of the most successful cloaks worked only at a single optical frequency, while others worked only at certain angles with very small objects. Well, this week we've got something better.
John and Benjamin Howell of the University of Rochester in New York just announced a simple cloaking device that can be theoretically scaled to hide just about anything, including humans. How does it work? Well, it mostly works in the same way magic tricks have been working for decades. They do it with mirrors, as in this image where they disappear half a chair.
That's right, mirrors. It's not a new idea, but the array the Howells have constructed is an effective design, if a little cumbersome. And besides, the point isn't that they didn't come up with a new way to hide something. The point is they came up with something that can easily be scaled to basically any size, including human-size.
"The point we wish to emphasize is not the novelty but the ease of scaling to nearly arbitrary size,” the Howells said.
Of course, until we discover a material that achieves perfect invisibility, there are going to be catches to pretty much every design humans come up with. In this case, the Howell design only works from one direction, but even a unidirectional cloak could have some very impressive uses, especially if you can make it any size.
“The devices may have value, for example, in cloaking satellites in mid- to high-earth orbit,” the Howells said.
So, still no perfect invisbility cloak, but definitely something useful.
(Via Technology Review)