Few motifs of science fiction cinema have been more appealing to us than the subtle defiance of gravity offered by futuristic hovercraft. So every once in a while we check in to see how humanity is progressing on that front, and whether the promise of hoverboards will be delivered by 2015 as evidenced in Back to the Future Part 2. We’re not quite there yet, but we’re definitely getting off the ground, so to speak. Get ready to hover your brain around the art of quantum levitation.