why does the road make a reflection when your at a distance but when your up close it doesn’t?


Like when you watch the movies of the guys just walking down a stretch of road towards the camera you see a bit of reflection on the road. But when your up close it stops. How does that happen? I’ve seen it happen on tar and concrete and I still don’t understand

In: 0

It’s the same phenomenon that causes a mirage. Heat from the road warps the air as it rises, to the degree that it can reflect light.

Essentially it has to do with how light bounces off surfaces, and how your eyes process this information, so in gamer terms, your eyes have a specific draw distance it can render, afterwhich, the angle of which you see the surface at that distance makes most flat surfaces bounce that light towards you, making your eyes believe that there is a reflection there [idk if that makes sense, but that is how it was explained to me]

When the ground is too hot, the air near it is also hot, therefore less dense, and has a different refraction index than the air on top of it, that is colder, so the light ray bouncing from an object and going in the direction of the ground, instead of going in a straight line ends up curving upside, giving the ilusion to our eyes that the image is forming below the ground (a.k.a mirror on the ground). You need to be at a certain distance, that’s why when you move closer the illusion disapears in front of you but is created further (the “mirror illusion” moves with you).

The fact that the air is a bit turbulent (because of the high temperature near the ground), it makes the image seems “shaky” (like it was a reflection from water), that’s what a mirage is.

An image may help you understand what is going on: [https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSkbX88DLoHADPOot9z6Kz6lL2KU05Y4gWkyHrjiGoEa0eZOeentzvibyMJP5SHrg93Fb4&usqp=CAU](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSkbX88DLoHADPOot9z6Kz6lL2KU05Y4gWkyHrjiGoEa0eZOeentzvibyMJP5SHrg93Fb4&usqp=CAU)