Curvi Inc.

Why Are Shower Curtains Psycho?

Jamie Lee Curtis Recreates Her Mom's Psycho ScreamAm I alone, here? 

Standing tall at 6'3", I often felt cramped in my shower. Turns out I wasn't alone -- not in a Psycho kind of way -- but  millions of bathers also suffer from the daily shower curtain attack!

Too long have shower curtains crowded our space! Too long has the dreaded shower curtain effect brought that cold, wet curtain up against our bodies!

Today, we push back.

Naturally, my idea came while standing in the shower. From my small apartment in Manhattan's Lower East Side, I wondered how I could curve the curtain, instead of going through the expense and hassle of installing a curved shower rod? That was my Eureka Moment. Read my full story here.

Question: Why Do Curtains Cling, Anyway?

Answer: Because nothing holds them back.

Photo Credit: NPR.
Hence, the dreaded shower curtain effect: you turn on your shower and the cold wet curtain clings to your body. 
Rapid waterflow in your shower causes rapid airflows, whereby air tends to follow behind each water droplet as it zips though the air. So the air from the outside is trying to get inside to follow the rapid waterflow. Since you’re standing in a 3-walled enclosure, the only way the outside air can get inside your shower is by going under or around your curtain. That’s why the curtain swells inwards and clings to you.

If you’re really curious about why waterflow causes airflow, and why that, in turn, causes annoying curtain cling, look up “Bernoulli Principle”. It’s the same theory of fluid dynamics that makes a plane wing fly: high air pressure on one side, low air pressure on the other.

This phenomenon was discussed on NPR's All Things Considered in a segment by Joe Palca back in 2006. The story was amusing, especially for exposing how there actually had been some meansure of scientific controversy as to what actually caused the curain to swell inward:

"Traditional thinking went like this: the hot spray heats the air around it. As the hot air rises, it pulls cooler air into the shower from outside. With that cooler air comes the shower curtain. But this theory is lacking, Marshall says, because it overlooks one important fact. The curtain does the same thing in a cold shower."

 Earlier coverage includes this 2001 gem in Scientific American, where fluid dynamics simulations led to the vortex theory.