Pepper's ghost

Pepper's ghost is a special effect used in some types of live performances to create a ghost-like image on stage. It works by using mirrors and a transparent sheet of glass (or plastic) to make it look like an image is coming out of thin air. To make the effect work, you first set up the mirrors so that they reflect the image of a person onto the transparent sheet. Then you make the room very dark so that the person's reflection appears very brightly against the transparent sheet, making it seem like they are floating in the air.