(Top left) A ray of light in free space travels in a straight line. The undistorted coordinate system is shown. (Top right) The coordinates are transformed to exclude the cloaked region. Trajectories of rays are pinned to the coordinate mesh and therefore avoid the cloaked region, returning to their original path after traversing the cloak. (Bottom) In contrast, this cloaking scheme operates by cancelling scattering due to the hidden object. Here we show a high-refractive-index sphere hidden by a negatively refracting cloak.