Nerd Nite Orlando is an evening of entertaining yet thought-provoking talks across many disciplines, all while the audience drinks along in a casual bar atmosphere. Speakers present for 15-20 minutes each on a fascinating subject of their choice, often in an uncanny and unconventional way. Following each presentation is a brief question and answer session with the audience. The event happens at The Geek Easy 114 S Semoran Blvd Suite 6, Winter Park, Florida.

The most fascinating talk was by Travis Winkler about Pepper’s ghost which is an illusion technique used in theater, amusement parks, museums, television, and concerts. In 1862, inventor Henry Dircks developed the Dircksian Phantasmagoria, his version of the long-established phantasmagoria performances. This technique was used to make a ghost appear on-stage. He tried
unsuccessfully to sell his idea to theaters. It required that theaters
be completely rebuilt to support the effect, which they found too costly
to consider. Later in the year, Dircks set up a booth at the Royal
Polytechnic, where it was seen by John Pepper.

Pepper realized that the method could be modified to make it easy to
incorporate into existing theatres. 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. Dircks eventually signed over to Pepper all financial
rights in their joint patent. Though Pepper tried many times to give
credit to Dircks, the title “Pepper’s ghost” endured.

Theaters have had reasons to stage the appearances of ghosts for centuries. Early attempts at making ghosts appear involved trap doors, ramps and dollies that could make a figure appear to weightlessly appear in a scene. The Pepper’s Ghost technique does away with all the rope, pulleys and trap doors. The audience views a stage or room with various objects in it. On
command, ghostly objects appear to fade in or out of existence in the
room, or objects in the room magically transform into different objects. The effect is achieved with a carefully angle sheet of glass.

The basic trick involves a stage that is specially arranged into two
rooms, one that people can see into or the stage as a whole, and a
second that is hidden to the side, the “blue room”. The plate of glass (or Plexiglas
or plastic film) is placed somewhere in the main room at an angle that
reflects the view of the blue room towards the audience. Generally this
is arranged with the blue room to one side of the stage, and the plate
on the stage rotated around its vertical axis at 45 degrees. Care must be taken to make the glass as invisible as possible, normally
hiding the lower edge in patterning on the floor and ensuring lights do
not reflect off it. When the lights are bright in the main room and dark in the blue room,
the reflected image cannot be seen. When the lighting in the blue room
is increased, often with the main room lights dimming to make the effect
more pronounced, the reflection becomes visible and the objects within
the blue room seem to appear in thin air.

 Notable examples of the illusion are virtual pop stars and the appearance of “ghosts” at the Haunted Mansion at Disneyland. Hidden in the corner of the stage at Nerd Night was a glass box. It was unveiled and the used for a magic trick. Inside the glass box was a light bulb. The light bulb miraculously disappeared using the principles of Pepper’s Ghost. Even knowing how the trick was done, it was impressive given the theatrics of the performance.