What is Stars twinkle due to atmospheric refraction?

Stars twinkle because the air around us acts like a wiggly glass that changes how light travels.

Imagine you're looking at a pencil in a glass of water, sometimes it looks bent or wobbly, right? That’s because the water and air make the light bend. The same thing happens with stars, but instead of water, we have the air above us.

The air isn’t always still, it moves around like a busy crowd. When starlight comes down through this moving air, it bends in different ways as it goes through the layers of air. Sometimes the light is bent more, sometimes less, just like when you look at something through wavy water.

This makes the stars seem to flicker or twinkle, kind of like a firefly that’s dancing in the sky. It's not magic, it's just the air playing hide-and-seek with the starlight!

So next time you see a star twinkle, think about how the air is bending and wiggling the light on its way to your eyes.