Why do roads shimmer when it’s hot? © Getty Images

Why do roads shimmer when it’s hot?

Asked by: Matilda Wicks, Brighton

As the sunshine beats down on the road, the road surface becomes hot, making the layer of air above it expand and become less dense. This in turn changes the way light passes through it from points further down the road.

Advertisement

However, the effect is not uniform. The rising air is turbulent, so its density and thus optical properties are constantly fluctuating. This is what creates the shimmering effect we see as we look down the road.

Read more:

Advertisement