An illusion device using metamaterials that makes one object look like another could one day be used to camouflage military planes or create “holes” in solid walls.

To make a cup look like a spoon, for example, light first strikes the cup and is distorted. It then passes through a complementary metamaterial which cancels out the distortions to make the cup seem invisible. The light then moves into a region of the metamaterial that creates a distortion as if a spoon were present. The result is that an observer looking at the cup through the metamaterial would see a spoon.