A viewer looking through the red rectangle sees a ghost floating next to the table. The illusion is created by a large piece of glass or a half-silvered mirror, situated between viewer and scene (green outline). The glass reflects a mirror-image room (left) that is hidden from the viewer.

If the mirror-image room (left) is darkened, it does not reflect well in the glass. The empty room (top) is brightly lit, making it very visible to the viewer.

When the lights in the mirror-image room are raised (with the empty room being dimmed slightly to compensate), the ghost "appears" out of nowhere.

Pepper's ghost is an illusionary technique used in theatre and in some magic tricks. Using a plate glass and special lighting techniques, it can make objects seem to appear or disappear, or make one object seem to "morph" into another. Image File history File links Peppers_ghost_low_angle. ... Image File history File links Peppers_ghost_low_angle. ... Image File history File links Peppers_ghost_darkened. ... Image File history File links Peppers_ghost_darkened. ... Image File history File links Peppers_ghost_lit. ... Image File history File links Peppers_ghost_lit. ... Magic, including the arts of prestidigitation and conjuring, is the art of entertaining an audience by performing illusions that baffle and amaze, often by giving the impression that something impossible has been achieved, almost as if the performer had magic or supernatural powers. ...

In order for the illusion to work, the viewer must be able to see into the main room, but not into the hidden mirror room. The edge of the glass may be hidden by a cleverly designed pattern in the floor. Both rooms may be identical mirror-images; this approach is useful in making objects seem to appear or disappear. This effect can also be used to make an actor reflected in the mirror appear to turn into an actor behind the mirror (or vice versa). This is the principle behind the Girl-to-Gorilla trick found in many haunted houses. The mirror room may instead be painted black, with only light-colored objects in it. When light is cast on the objects, they reflect strongly in the glass, making them appear as ghostly images superimposed in the visible room. A haunted house is a building that supposedly is a center for supernatural occurrences or paranormal phenomena. ...

The world's largest implementation of this illusion can be found at the Disneyland theme park, in the Haunted Mansion attraction. The 90-foot-long ballroom scene is one immense Pepper's Ghost effect. Guests travel along an elevated mezzanine overlooking the empty ballroom. Animatronic "ghosts" perform out of sight, in black rooms beneath and above the mezzanine. The reflections in the glass create the appearance of three-dimensional, transparent ghosts swarming through the ballroom. This scene is also replicated in Disney parks in Orlando, Tokyo, and Paris. This use of the effect is notable for two other reasons: 1) it uses a vertical plane of glass that is parallel to the scene, and 2) the reflected objects are located both below and above the viewers. Disneyland Park is a theme park at the Disneyland Resort in Anaheim, California, USA. It is owned and operated by The Walt Disney Company. ... This article relates to the theme-park attraction. ... Audio-Animatronics or just animatronics is a form of robotics created by Walt Disney Imagineering for several shows and attractions at Disney theme parks, and subsequently expanded on and used by other companies. ...

John Pepper & Henry Dircks

The Royal Polytechnic was a permanent science-related fair, first opened in 1838. With a degree in chemistry, John Henry Pepper joined the institution as a lecturer in 1848. The Polytechnic awarded him the title "Professor." In 1854, he became the director and sole lessee of the Royal Polytechnic. The London Polytechnic also known as Polytechnic of Central London (PCL) was one of the British polytechnics. ...

In 1862, inventor Henry Dircks developed the Dircksian Phantasmagoria, a technique used to make a ghost appear onstage. He tried unsuccessfully to sell his idea to theaters. His method would require theaters to be completely rebuilt just to support the effect. Later in the year, Dircks set up a booth at the Royal Polytechnic, where it was discovered by John Pepper.

Pepper realized that the method could be modified to make it easy to incorporate into existing theaters. Pepper first showed the effect during a scene of Charles Dickens's "The Haunted Man," to great success. Pepper's implementation of the effect tied his name to it permanently. Though he tried many times to give credit to Dircks, the title "Pepper's Ghost" stuck.

External links

• A description and illustration of the illusion

References

1. "History of the University." University of Westminster. 18 Feb. 2006 <http://www.wmin.ac.uk/page-42>.
2. Steinmeyer, Jim. Discovering Invisibility. 1999.
3. Steinmeyer, Jim. Hiding the Elephant. New York: Carroll & Graf, 2003.
4. Steinmeyer, Jim. The Science Behind the Ghost. 1999.
5. Surrell, Jason. The Haunted Mansion: From the Magic Kingdom to the Movies. New York: Disney Editions, 2003.