Why Do Mountains Appear to Move at Night?

Imagine you're looking at a tall mountain from far away, like watching a giant toy. When it's light outside, the mountain seems still and clear. But when it gets dark, your eyes have to work harder to see things in the distance. The air between you and the mountain acts like a special kind of glass, it bends and shakes the light coming from the mountain, making it look wobbly or like it's moving slowly. That’s why mountains seem to shimmer at night, just like how a hot road can make the sky look wavy on a summer day.