Perceptual Illusion

Pepper's Ghost is a specialized illusion created by John Henry Pepper in 1862 and has often used in theatre, amusement parks, and concerts that is used to create a hologram, or perceived three-dimensional body in space. A powerful technique of playing with perception, Pepper's Ghost has been used to create 3D holograms of ghosts in the Haunted Mansion ride Disneyland as well as holograms of Tupac and Michael Jackson used at music festivals. 

In a Pepper's Ghost room, two rooms are constructed at a 45 degree angle from one-another with a sheet of plastic separating them. When an object (or projection of an object) appears one room, the body reflects light through the pane of plastic into the first room, making it appear that the three-dimensional object has appeared out of thin air. For our illusion, we used four plastic panes that reflected the cell phone video of a moving jellyfish into the air. Just as in a Pepper's Ghost room, the light reflects off the plastic panes to create a three-dimensional hologram that appears to be suspended in space. In our illusion, the four plastic panes allows for more degrees of freedom. When the jellyfish moves, the viewer's brain perceives it to be moving in and out of space.