invisibility cloaks scientists have been struggling to master for decades? This here is said cloak's perfect opposite, and it's bending our minds in ways you can hardly fathom. Ulf Leonhardt, a professor at the University of St. Andrews, has worked with a brilliant team of scientists in order to construct what he calls a universal mirror, or if we're being proper, an omnidirectional retroreflector. Unlike conventional mirrors which simply reflect objects at 90 degrees, this concoction reflects objects back at any angle. In other words, a device such as this would make aircraft, boats and satellites entirely easier to track with radar, but it'll have to mature quite a bit before it's ready for that kind of action. The current build is just a single centimeter high and ten centimeters in diameter, and as with invisibility cloaks, the main ingredient here is metamaterials that we won't pretend to fully understand. Just one word of caution, boffins -- don't let Geek Squad get ahold of this stuff.
[Image courtesy of Barbara Rich, thanks JR]