Frequently Asked Questions
Common curiosities about the mundane world, answered.
Why do tape measures have a small hole in the metal hook?
The small hole in the end of a tape measure is designed to hook onto a nail or screw head, allowing you to measure distances single-handedly without the tape slipping off the edge.
What are the ridges on the edges of coins for?
Historically, coins were made of precious metals. The ridges (milled edges) were added to prevent people from secretly shaving off the edges to steal the scrap metal, a process known as coin clipping.
Why is there a tiny hole at the bottom of padlocks?
The small hole at the base of most outdoor padlocks serves a dual purpose. It acts as a drainage hole to prevent water from accumulating and rusting the inner mechanisms, and it provides an entry point to pour oil or lubricant if the lock jams.
What is the zigzag side of a bobby pin for?
The zigzag side is actually meant to face downward, toward the scalp. The grooves are engineered to grip the hair and keep the pin locked in place, while the flat side is meant to face outward for aesthetics.