Berkeley, Calif., did nothing to change its rep as one of America's flakier places when scientists on the local campus of the University of California announced they'd invented an invisibility cloak. But it was hard physics and complex optics at work, not something illegal or brain-altering. Using nanowires grown inside a porous aluminum tube to create a sheeting 10 times thinner than a piece of paper, they proved that they could wrap an object in the material and bend light waves around it, making it effectively invisible. All of the usual caveats apply: the process is experimental, the cloaking is fantastically fragile, the costs would be prohibitive for anything remotely approaching practical use. Still, we now live in a world in which invisibility is a possibility. That's a good thing, right?