S01E2 How does a flame know which way is up?

This episode explains the common phenomenon of a shower curtain moving inwards during a shower. It identifies the cause as a difference in air pressure created by the moving water and entrained air. This movement of water generates a low-pressure zone inside the shower stall, while the air pressure outside remains higher. Consequently, the higher external pressure pushes the lightweight curtain towards the area of lower pressure, a principle related to fluid dynamics and Bernoulli's principle.