alt Hacker NewsIMO metric is missing a critical measurement that is roughly the size of "a foot".
Most measurements in one measuring system have very similar equivalents in other measuring systems or useful approximations, like a pound being 1/2 a kilo, a liter being about a quart, or a meter being about a yard. Even various ancient chinese measurements can be similar like this.
Except the metric system seems to have eschewn the common measurement of "About the length of a human foot". It confuses me.
What do you call a footlong submarine sandwich in the metric system? A third-meter-long? A decimeter-long? It wouldn't fit into the power-of-ten based system.
Replies
It's because inhabitants of metric land neglect the decimeter, probably because it's too awkward of a word.
Define 1 metric hand = 1 decimeter, and you can cleanly convert between hands and meters (it's just a factor of 10 instead of the weird jump from centimeters to meters) and at the same time be able to approximate three metric hands to a foot.
I went to school with a 30cm ruler in the 80s. As a result I have an instinctual sense for that length.
In the UK 300 mm is, or at least used to be, referred to as a metric foot.
I lived all of my life in metric countries and I never felt that was missing. One foot is 30cm, two is half a meter, three one meter.
Subway (the fast food chain) calls them "30cm subs", or colloquially "a thirty".
The smaller sandwich is a "15cm sub", or "a fifteen".