Researchers from Imperial College of London conducted a study involving a new material called metamaterial, which contains complex internal wiring. The details are quite technical, but basically, metamaterial allows scientists to create blind spots. Then, "by deflecting certain parts of the electromagnetic spectrum, an image can be altered or made to look like it has disappeared."
Find out more about how this just-discovered technology works after the break.
Because light slows down upon entering any material, when the light rays are manipulated, as they were in this study, stationary objects between two sides of metamaterial (or, in Harry's case, whoever is under the invisibility cloak) appear to disappear.
Sadly, metamaterial doesn't truly exist. While the study proved it could exist, the tests were completed using computer data instead of rays of light. Which means, unfortunately, invisibility cloaks are still the stuff of fantasy.