Why your shower curtain attaches to your leg (Ig Nobel) | Ludwig Explains

Añadido: 2026-05-25

[00:00:00]You turn on the shower. The curtain creeps inward and sticks to your leg.

[00:00:04]What's pulling it? The usual answer.

[00:00:07]Hot water makes hot air.

[00:00:09]Hot air rises. Low pressure inside.

[00:00:13]Curtain gets sucked in.

[00:00:15]Plausible. Also wrong. The curtain does the exact same thing with cold water.

[00:00:20]So, it isn't really about heat at all.

[00:00:22]The real story comes from a fluid dynamicist named David Schmidt.

[00:00:27]He simulated the air flow in a shower with computer fluid dynamics and won an Ig Nobel for the result.

[00:00:34]The falling droplets of water drag air down with them. That sets up a horizontal vortex inside the shower.

[00:00:41]Air spirals down with the spray, outward along the floor, up the inside of the curtain, and back across the top. The vortex near the inside of the curtain has slightly lower pressure than the room behind it.

[00:00:54]The outside atmosphere pushes harder.

[00:00:56]The curtain gets nudged inward, exactly the way you felt. It's the same toroidal circulation that herds tea leaves to the center of your cup, and that carves the inner banks of river bends. A different scale, the same loop. Subscribe for more making the confusing click.