Question

Have you seen a mirage which is an illusion of the appearance of water on a hot road or in a desert?

Answer 1

Yes. A mirage is an optical illusion commonly seen on hot roads or in deserts. It occurs due to the refraction and total internal reflection of light.

• On a hot day, the air near the ground is much hotter and less dense than the cooler air above it.
• Light from distant objects or the sky passes through these layers of air and bends continuously because the refractive index changes.
• Near the ground, the light undergoes total internal reflection and bends upward toward the observer's eyes.
• The brain traces the light back in a straight line, making it appear as if it is reflected from the road surface.
• As a result, the road looks wet or appears to have a pool of water, although no water is actually present.

Thus, a mirage is caused by the refraction and total internal reflection of light in layers of air of different densities.