Pepper's Ghost

Without applications of physics such as counter-weighted sets and backdrops, inclined planes, stage lighting instruments, and other mechanisms for deus ex machina, dramatic productions would revert to the words only—fine for Shakespeare and Becket, but not good for audiences who are accustomed to experiencing plays with the eye as well as the ear. Pepper's Ghost is a 19th-century stage illusion, based on basic optical principles, that can find its way into your introductory classroom.