When you’re driving and it’s sunny outside, why does it look like there is water on the road ahead of you but once you get closer it’s gone?

6.21K views

When you’re driving and it’s sunny outside, why does it look like there is water on the road ahead of you but once you get closer it’s gone?

In: Physics

It’s called a mirage.

The asphalt on the road get so hot in the sun, in turn heating the air above it, so when the light from sky is coming down, it actually bends and goes back up.

Then you see the light from the sky, creating illusion of reflection that we associate with a water puddle.

[Wikipedia](https://en.wikipedia.org/wiki/Mirage?wprov=sfla1)

You’re seeing heat distortion. Hot air directly above the roadbed is refracting light from the sky in your direction. You’re seeing the sky, but since your experience tells you the only thing that looks like it reflects the sky like that is water, your brain tells you it’s water. As you close with the patch of hot air, the angles change and the phenomenon goes away.