November 2004

This is a great question. The answer is simple. Scientists make a huge project out of overanalyzing a phenomenon. Engineers get paid to solve problems, often with a minimum of analysis. We know who wins more Nobel prizes... but most everything that really matters was developed by an engineer. Including the hair combover!

Case in point. About 15 years ago, there was a letter in the prestigious MIT Technology Review, which used to be an alumni journal but was remade into a for-profit 'zine in 1999. The article described one man's quest to determine the root cause of why his shower curtain was blowing inward when he took a hot shower. This man, although it did not state so, was obviously a scientist, not an engineer.

Struggling with an affectionate shower curtain each morning, he postulated a least couple of theories about what was going on. If memory serves, his favorite theory was that convection currents were creating some type of chimney draft from floor to ceiling, which, through Bernoulli's principle, caused a low-pressure zone on the inside surface of the shower curtain. But how to prove the theory?

He came up with a measurement technique that he no-doubt considered ingenious. Before he turned on the shower, he stationed some lighted candles all over his bath tub, and presumed that by watching the direction that the flames flickered, he could deduce the direction of local wind currents and fit the data to a model. I don't believe he arrived at any conclusion, his letter was clearly a cry for help.

An engineer would see that this is wrong on many levels. What kind of fool would expect candles to stay lit once the shower is cranked up? Is a shower curtain made of flammable material, and why might this be important? Was he wearing a waterproof lab smock during the experiment, or must we envision his hairy butt as he bent down to observe the flickering candles? What kind of "journal" would publish this nonsense? Is this MIT alumni living in a sheltered environment, or is he allowed to interact with normal people?

Many fine thinkers have considered the problem of "shower curtain drift"... Searching the USPTO site, there are several patents that attempt to overcome this problem. One is for a shower curtain with pocket that collect water, to weight it down: US 6,591,432 Feinstein , et al. July 15, 2003 "Anti-drift shower curtain having water-collecting pockets"

Here's one that has sand in the bottom for weight: 6,550,525 Grisolia April 22, 2003 "Sand-weighted shower curtain:"

A shower curtain has a bottom hem that forms a closed pocket. Sand is contained in the closed pocket and provides weight to the shower curtain so the curtain does not blow away from the side of a tub during a shower.

and another one... 6,510,566 Bryce January 28, 2003, Shower curtain closure

This stuff makes a "real engineer" want to scream, "Dudes, you are all morons!" We know that the problem has been solved already, less than one shower out of 10 does this annoying trick. The MIT alumnus was asking the wrong question. Instead of "why does this happen?", he should ask "what am I doing wrong here?"

The answer to the latter question is in how his shower curtain rod was aligned with the tub. If you have it aligned to the inside of the tub, the installer was a fool. Gravity does not give the curtain enough restraint to keep it from blowing inward; this also leaves less room for shower activities. You wouldn't know this if you attended MIT... probably all of their showers are configured this way!

The proper way to align a shower curtain rod is plumb to the outside of the tub. Do this and you will NEVER have the curtain blow around, because gravity will hold it in place. Plus, you have more room for shower fun!

"But that looks stupid" I hear someone from MIT say. You are right. That is why showers are meant to use a shower curtain, and a separate shower curtain liner, you cheapskate. Consider that the curtain is allowed to drape vertically outside the tub, as shown below. This is the full solution, which is know to most people with below-average IQ and no college education.

Remember, an engineer solves problems, and doesn't waste time looking for esoteric explanations for nature's quirks. This weekend when you are looking for something to do, have a look at your shower curtain rod alignment, and share the magic that is Microwaves101.

Now get back to work!!!!

Check out the Unknown Editor's archives when you are looking for a way to screw off for an hour or so!