Travelers traveling to the desert on a summer afternoon have the illusion of having water at some distance. This illusion is called the deer deer marichika or mirage. The sandy land of the desert becomes warmer due to heat, causing the hot layers of air near the earth to become sparse. But they are relatively dense due to the upper layers being cold. In such a condition, the rays of light coming from the top of an object or tree are refracted by different layers of air and move away from the perpendicular. As a result, a situation arises in which there is complete internal reflection of these rays. Due to the full internal reflection of the rays of light coming from the top of the tree, the passengers begin to see the reverse reflection of the tree, giving them the illusion that there is water ahead, in which the reflection of the tree is visible is.