WHY do we see twinkling stars? It happens due to the fact t | Why?

WHY do we see twinkling stars?

It happens due to the fact that their light, as it flows through the atmosphere, passes through layers with different densities. The refraction is varied, with the layers of air constantly moving in relation to each other.

When the starlight moves from a lower-density layer to a higher-density one, it begins to flicker.