Mirage

The mirascope consists of two parabolic mirrors that project a hologram from the center of the bottom mirror to an empty space at the top. The geometry of a single parabolic mirror is such that all light leaving the focus is reflected directly upward in parallel paths. When the second mirror is placed upside-down on top of the first, it creates an inverted image at the second focus.

A mirage is an optical phenomenon that creates the illusion of water and results from the refraction of light through a non-uniform medium. Mirages are most commonly observed on sunny days when driving down a roadway.