Reply: Pepper’s Ghost
Pepper’s ghost is a reasonably intelligent phantasm popularized by the scientist (and the namesake of the phantasm) John Henry Pepper when he showcased it as a scientific demonstration within the early 1860s. The setup of the phantasm is comparatively easy, however the impact is kind of spectacular.
The guts of the phantasm is using a sheet of glass (Plexiglas and plastic movie additionally work) positioned at a 45 diploma angle to the viewer (consult with the picture right here as we describe the impact). The viewer is positioned trying straight into the scene (the crimson sq. is the airplane of their view) and the glass is cocked away from them (represented by the inexperienced sq.). The room behind the glass pane is lit up and the unseen room to the facet of the viewers’s view is saved unlit through the starting of the phantasm. When the unseen room is lit up and the sunshine within the seen room is barely dimmed, the objects within the unseen room, just like the ghost prop seen right here, are mirrored off the floor of the glass in direction of the viewers, creating the phantasm ghostly particular person or object has simply appeared in that area.
Not solely has this phantasm been used to nice impact in haunted homes, carnivals, and even in performances (the looks of Michael Jackson on stage on the 2014 Billboard Music Awards was a really excessive tech and nicely executed Pepper’s ghost phantasm), it’s additionally received a really sensible software: teleprompters. One ingredient of the Pepper’s ghost phantasm is that the reflection is just seen to the viewer in entrance of the pane of glass and to not anybody behind it (the identical method that the reflection of a sundown off the home windows of your property is seen to the folks exterior, however to not the folks inside). In that method, a teleprompter can put textual content straight over the digicam lens (so a information caster can learn the information whereas trying proper on the digicam, for instance), however the viewers at house by no means see the phrases.
Picture courtesy of Wapcaplet/Wikimedia.