Why does the world use both metric and customary units?
Two Rulers, One World
Why does the world use both metric and customary units?
Here's a strange truth about our tidy planet: it can't agree on how long a foot is. Some places measure in meters and kilograms. Others measure in feet and pounds. Same world, two different rulers. Why on earth do we do this to ourselves?
For most of history, measurements were wonderfully, hilariously local. A "foot" really was somebody's foot. A "stone" really weighed about as much as a hefty stone. The trouble is, feet come in all sizes, and so do kings. Every town had its own slightly different idea of "big."
