6a20.35 Optic mirage

PURPOSE: The illusion of an object appears levitating above a pair of parabolic concave mirrors.

DESCRIPTION: An object appears to float in air on top of this fascinating optic mirage disc.  But the projected real image of the object is a mirage, there's nothing there! The object is actually below, resting at the bottom of  two concave curved mirrors. The real image displays the unusual parabolic optical effect. It is 9" in diameter. Even when viewed by a video camera and projected to the class, the object appears to be really float on top of the parabolic dish.

This is a commercial apparatus that forms the real image of an object placed onto the bottom mirror.  The two concave parabolic mirrors with the correct focal length and spacing project the real image of the object, making it appear to levitate on the opening of the upper mirror. The illusion can be viewed within a limited angle, so it is most effective for individual observation or the class can see it with a video camera.

A ray drawing can be made to show how the image is produced by the double reflection from two concave mirrors.

EQUIPMENT: .

SETUP TIME: 1/2 hour.