The phenomenon of total internal reflection is the reason behind the illusion of seeing water in the desert or on hot pavement.
Seeing water in the desert is an illusion caused by the temperature difference between air layers.
The phenomenon of seeing water in the desert or on hot pavements is an illusion that occurs due to the temperature difference between air layers.
The layer of air closest to the ground heats up more, while the air higher up remains cooler.
As the air heats up, it expands, causing its refractive index to decrease. The cooler air above is denser, which gives it a higher refractive index.
This difference in refractive index causes light to bend. The closer to the ground, the greater the angle of incidence of light rays. When the angle of incidence exceeds the critical angle for refraction, total internal reflection occurs, directing the light upward to our eyes.
Our eyes perceive light in a straight line, resulting in a reflection of the sky on the ground that creates the illusion of a puddle of water.
