Mirage is an illustration of

A mirage is an optical phenomenon caused by the bending of light rays through atmospheric layers of varying temperatures and densities. On hot days, the air near the ground is warmer and less dense than the air above, creating a refractive index gradient. As light from the sky or distant objects travels downward, it undergoes continuous refraction, gradually bending away from the normal as it moves into rarer (hotter) layers. When the angle of incidence eventually exceeds the critical angle for these air layers, total internal reflection (TIR) occurs, causing the light to curve upward toward the observer's eye. The brain interprets these rays as traveling in a straight line, resulting in an inverted image that appears like a pool of water or a reflection. Thus, mirage formation is an illustration of both refraction and total internal reflection.