Ever wished you could have Harry Potter's invisibility cloak? Science, not magic, could make that a reality. Researchers at the University of California at Berkeley have created materials that have the potential to bend light and even redirect it around themselves, cloaking any object behind them. They are metamaterials, materials that gain unusual properties via their structures. While all materials found in nature have a positive refractive index, these man-made metamaterials have a negative one.