Once upon a time, the number of holes in a shower curtain and the number of hooks sold in a pack of rings was unified!
(I’m glad I’m not the only one that wondered who determined how many holes are in a shower curtain.)
Today, everyone assumes that a new shower curtain, liner, or set of hooks will fit everything else.
No one questions this.
Because they will fit.
During the standardization, I’m sure they discussed whether it should be 10 or 14 but settled on 12. I’m sure there was a debate about how much space should be between the holes. Eventually, everyone came to a consensus about what was best for everyone.
Why can’t it all be like shower curtains?
For more on this topic, visit ‘Being a Programmer, I Decided to Build a Mathematical Model for the Decay of a Shower Curtain’ – A rigorous anthropology of the humble bathroom accessory.
A standard shower curtain has twelve grommets and a standard pole carries twelve hooks. How did an even dozen come to be the standard? There are twelve months in a year because of the lunar cycle. The Egyptians and Sumerians we inherit our clocks from were fond of base-12 systems. A standard bathtub is five feet long, but a standard shower curtain is six feet by six feet. If the curtain and the tub were the same length you’d have to pull it taut every time. The extra space gives us a little slack. Is one grommet every six inches some mathematically perfect way to distribute the weight of the curtain? Add more grommets and they’d tangle more often. With less you’d be adding more weight to each tiny plastic hook, increasing the risk that one might snap through the course of everyday curtain opening and closing.
Will Hankinson