Invisibility is perhaps the most ubiquitous of sci-fi dreams: Spy movies, video games, and classic cartoons all tantalise us with this trick. Researchers at the University of Rochester still haven't unlocked the secret to that elusive invisibility cloak either, I'm afraid. But they made a very cool optical illusion that looks the part.
With just a handful of lenses and some complex calculations, this team created an optical setup that bends light waves around a small object. When you look through the system, the object disappears -- even if you move your head around. It's the first 3D system where the background moves the way it should, but the hidden object remains invisible.
Of course, there's a catch: The illusion only works in a ring around the outer edge of the lens you look through. From 2:00 to 2:07 in the video above, you see how the "hidden" object becomes visible as it passes through the middle of the lens. So we haven't actually achieved invisibility cloak yet. Sorry. That doesn't make this optical illusion any less cool. [University of Rochester via Mashable]