Wired News reported that a mechanical engineering professor at the University of Massachusetts won the Ig Nobel in physics for tackling the "shower curtain mystery".
Well, you know, he may have found something that contributes to the "shower curtain" effect, but it's not the real reason. I know, I've been experimenting with this for years! Next time you're in a shower, and the curtain is flowing inward, turn off the water, or stand in front of the water preventing it from creating the turbulance. Guess what, the curtain still flows inward. Feel the air comming in at the bottom. Notice that it's relativly cool compared to the air inside the shower. Open the curtain, and equalise the temperature both in and out of the shower. Once equalized, turn the shower on again, but using cold water this time to cool everything down. Guess what, it doesn't flow inward. And if it still does it will not be nearly as much as it was before. While the turbulance from the shower water can contribute the the effect, it's not the main force. The main force is the rising hot air comming out over the top of the shower curtain that creates a lower pressure zone at the bottom, sucking in the cooler air from outside, pulling the shower curtain in.
So now that I've found the REAL reason for the "shower curtain" effect,
where's my Nobel prize? ;-)
-- M. Scott Reynolds (c) 2001