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

Light bends when you look through a glass of water. It does this because the path light takes changes when it moves between materials with different densities. Hot air and cold air have different densities too, and so when you see a place where hot air and cold air are mixing together, light will get wobbly because the density of air right in that spot is wobbly.