Real holograms are 3D images created by interference of light beams. They should be able to be viewed from any angle and allow the viewer to see the object from multiple sides. Real holograms can be seen without the need for special lenses, screens or other props.
In this activity, students will construct a pyramid that creates a reflected image from a digital screen display. This is a modern take on an illusion first described in 1584 by Neapolitan scientist Giambattista della Porta and popularized for theatrical use by John Henry Pepper in the 1860s. When a real or recorded image is reflected in a transparent screen at a 45o angle, viewers see a reflected virtual image that seems to have depth and appear out of nowhere .
This illusion continues to be used in amusement parks, theatres and other venues.