Here's how it works:

* Light bends: Light bends as it passes through different mediums (like air). This bending is called refraction.

* Temperature gradients: Near the ground, on a hot day, the air is hotter than the air above. This creates a temperature gradient, where the density of air changes rapidly.

* Refraction: As light passes from the cooler, denser air to the warmer, less dense air near the ground, it bends upwards. This bending makes objects appear to be in a different location than they actually are.

Types of mirages:

* Inferior mirage: This is the most common type. It makes objects appear to be reflected in a pool of water on the ground, which isn't actually there.

* Superior mirage: This type makes objects appear to be higher than they actually are. This can be seen over cold surfaces like ice or water.

Let me know if you'd like to know more about the physics behind mirages!