ETYM French, from mirer to look at carefully, to aim, se mirer to look at one's self in a glass, to reflect, to be reflected, Late Lat. mirare to look at. Related to Mirror.
Illusion seen in hot climates of water on the horizon, or of distant objects being enlarged. The effect is caused by the refraction, or bending, of light.
Light rays from the sky bend as they pass through the hot layers of air near the ground, so that they appear to come from the horizon.
Because the light is from a blue sky, the horizon appears blue and watery. If, during the night, cold air collects near the ground, light can be bent in the opposite direction, so that objects below the horizon appear to float above it. In the same way, objects such as trees or rocks near the horizon can appear enlarged.
1. An optical illusion in which atmospheric refraction by a layer of hot air distorts or inverts reflections of distant objects.
2. Something illusory and unattainable.