system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does a heat mirage on the road that looks like a water puddle actually reflect things around it like an actual water puddle would?
gpt
When you see a reflection on a water puddle, you're seeing light that has struck the puddle from some other direction, bounced off it, and traveled up to hit you in the eyes.

For the heat mirage, what you are seeing is air that has been heated (say by blacktop or something), changing its refractive index. This means that as light passes through it, the angle it is moving at changes.

Some of that light, then, that was heading towards the road is bent away from its normal path, and traveled up to hit your eyes. Since your eyes can't tell the difference (they just know light is hitting them) you see the image back along that bent path and not the street that is actually there in a straight line.