why air becomes “wobbly” (and, thus, kind of visible) when it’s hot

Question

why air becomes “wobbly” (and, thus, kind of visible) when it’s hot

In: 581

Answer 1

She air is heated, it travels up and mixes with cooler air. These two have a different density, which is why the hot air rises. Also, they have a different breaking index, meaning light reflects different. That is what you notice.