Buzz
It appears so harmless – yet, it's a different story. Fotosearch/Getty Images/Fotosearch RFYou're in the middle of a relaxing shower, enjoying your time. You’ve got the three essentials for an enjoyable bath: soap, shampoo, and Taylor Swift. (Of course, she’s not actually there. You’re just singing along to 'Fifteen.')
Even without Taylor, it's tough to stay grumpy in the shower. It’s like stepping into a magical waterfall world! A tropical getaway just a few steps from your DVR, and all those "Nashville" episodes waiting for you! You can practically picture your hair resembling Connie Britton’s soon, as you indulge in your conditioner dreamily.
Then, a terrifying shower monster reaches out with its cold, clammy hands, wrapping its damp, sweaty arms around your body. Suddenly, you find yourself in the role of Janet Leigh, battling the psycho that is your shower curtain.
As you struggle against the sticky demon, you cry out to a higher force: "Why must our shower curtains torment us like this?"
First, you’re not imagining things. Just like how the other lanes seem to always move faster in traffic, your shower curtain is genuinely billowing in toward you, almost in a predatory manner. People (specifically, internet dwellers) have even coined the term shower curtain effect to describe it.
But why does this happen? Is the curtain acting under some natural law? Does the plastic lining crave human skin contact? And in the Southern Hemisphere, does the curtain billow in the opposite direction?
Pull that plastic away from your skin and keep reading for more than you ever imagined you’d learn about your shower curtain's relentless grip.
Shower to the People
Some may consider it a bit extreme to delve into the details of a shower curtain, but the shower curtain effect is such a distinct phenomenon that it warranted scientific investigation, fueled by various contradictory and debated theories.
Full disclosure: that's an exaggeration. Nevertheless, the shower curtain effect did attract some followers with differing theories, and one individual, with plenty of free time, took it upon himself to explore the subject through a computer model.
Before we dive into the true cause, let's first examine the two most commonly discussed hypotheses behind the shower curtain effect.
- The Bernoulli principle explains that when fluid accelerates, its pressure decreases. This leads to a pressure imbalance: the air outside maintains the same pressure, forcing it into the lower-pressure air inside the shower, which causes the curtain to move.
- The buoyancy theory: The hot water in the shower produces warm, lighter air, which causes the cooler, denser air from the outside to rush into the low-pressure area, causing the curtain to draw inward.
Although both would make excellent titles for the "Bourne Identity" series, they're both incorrect. For one, the Bernoulli principle doesn't account for the type of droplets found in a shower. The buoyancy theory seems plausible – until you realize the curtain also sways inward during a cold shower.
Enter our protagonist: David Schmidt, an assistant professor of mechanical and industrial engineering at the University of Massachusetts Amherst in 2001. Schmidt challenged the Bernoulli and buoyancy theories. He developed a bathtub model and ran a two-week simulation that replicated 30 seconds of a shower.
The second-most famous "eureka" moment in bathtub history occurred when Schmidt discovered that as the droplets slow down, they transfer energy to the surrounding air, creating a swirling, twisting sideways vortex. The vortex's axis is perpendicular to the curtain, and its center creates a low-pressure area, drawing the curtain toward its eye, if you will [source: Schmidt].
