A mirage is an optical phenomenon caused by the refraction of light rays as they pass through layers of air with varying temperatures and densities. Since the speed of light changes slightly based on the density of the medium, drastic thermal gradients can bend the light path, causing objects to appear shifted, distorted, or duplicated in the distance. This effect is particularly noticeable on hot days, when the ground heats the overlying air mass, creating temperature inversions. By bending light rays that originate from a source, the mirage creates the illusion that the light has traveled from a different apparent location, often mimicking the reflection of a visible liquid surface.