It seems we physics students have all been sent on a quest to find the mind boggling explanation behind the mysterious and extraordinary devise known as MIRAGE, an ingenious holograph machine. And I here is my attempt to answer:
This misleadingly simple looking black disk is actually consists of two concave mirrors (some people say parabolic?) placed on top of each other so that their focal points lie exactly at the middle of opposite mirror.
(Like my penguins?)
When an object is placed on the bottom mirror where the focal point of the top mirror is located, light rays from the object travel to the top mirror and is reflected in a parallel line (since all rays from the focal point reflect parallel and vice versa). The reflected ray then hits the bottom mirror and because it is parallel to the second mirror as well the rays are again reflected but this time to the focal point of the bottom mirror, which is located at the opening of the Mirage. Thus a real image is produced at the focal point of the top mirror.
