If you “saw” “Michael Jackson” “perform” at the Billboard Music Awards last month, you may be wondering just how they pulled that off, since MJ’s been dead since 2009. The seemingly high-tech, hologram-esque performance was made possible thanks to what is actually a rather old-timey invention: Pepper’s Ghost.
It’s An Illusion, Michael
Commonly used in amusement park haunted houses and dark rides, as well as live theater, Pepper’s Ghost uses plate glass, Plexiglas, or plastic film, paired with special lighting, to create a number of illusions. Using the Pepper’s Ghost technique, objects and people can be made to seemingly appear and/or disappear, fade into transparency, or morph into another form.
The illusion, popularized by 19th century British scientist John Henry Pepper, must be set up so that viewers can see into a specific “main room,” but not into the hidden “blue room” beside it. A sheet of reflective glass is angled between the two rooms, its edge often disguised by a pattern on the floor.
The blue room is often built and furnished as a mirror-image of the main room, so that the two rooms match up in their reflections. This setup is used to make objects seemingly appear and/or disappear or to create morphing illusions. Alternately, the blue room may be painted black (cue the Rolling Stones) with only light-colored objects in it. This setup is used to create ghostlike images appear in the visible room.
Origins of Pepper’s Ghost
Pepper’s Ghost was not “invented” by Pepper—he merely brought it more into the public consciousness. The earliest known reference to the illusion comes from Giambattista della Porta, a 16th century scientist and scholar perhaps most famous for inventing the camera obscura. In his book Magia Naturalis (“Natural Magic” – 1584), Della Porta writes of “How we may see in a Chamber things that are not”—essentially Pepper’s Ghost.
Pepper joined the Royal Polytechnic Institute of London, a science-focused institution, as a lecturer in 1848, and became the Institute’s director in 1854. In 1862, Henry Dircks created the Dircksian Phantasmagoria, a variation of the then-popular phantasmagoria theater style, using a Pepper’s Ghost-like illusion. Dircks eventually brought his performance to the Royal Polytechnic Institute.
Upon seeing the illusion in action, Pepper developed a variation that could be used in existing theaters without the need for significant and costly stage modifications (a necessity for Dircks’ variation that had caused many theater owners to turn him away). The first demonstration of Pepper’s take on the illusion was a rousing success. Despite his efforts to give due credit to Dircks, the name “Pepper’s Ghost” stuck.
In addition to “Michael Jackson”’s “performance” at the Billboard Music Awards, Pepper’s Ghost and similar illusions are used in myriad entertainments. The Haunted Mansion attractions at Disneyland and Disney World use Pepper’s Ghost to create many of the ghoulish apparitions for which they’re famous. Modern theatrical troupes use Pepper’s Ghost in stage shows, particularly for Halloween or horror-themed performances.