Why do we see mirage in
the desert?
The sand in the desert
gets heated to very high temperature during daytime. The layer of air in
contact with it also gets heated. The layer above it is slightly cooler and so
on. As we go higher, the air cools rapidly and the density and refractive index
increases. This makes the light ray coming from the sun to bend and distort as
it passes through the different layer. Total internal reflection takes place. People
imagine that they have ‘seen’ an oasis or town on the horizon. Sometimes the
blue sky is reflected from the land surface and there appears to be a lake or a
sheet of water.
