A unique look at the history of units of measurement | Hey Ray
When it comes to measuring things, there are some odd units of measurement out there. While measuring in feet is standard, there are many weirder ways to measure.
Did you know a hand is a unit of measure? That is four inches, and how you measure a horse. A horse is also a measurement. That is eight feet! Where are you going to put that horse? In a barn, which is also a unit of measurement in nuclear physics.
Most of those you will never hear about in a weathercast. The unit of measure we are going to focus on may seem like some nautical nonsense. If you are getting a forecast for an area near a body of water, you may hear the word "knots". That is a unit of speed equal to one Nautical mile per hour.
While a statute mile, or the more common term for a mile, is equal to 5280 feet, a nautical mile is longer than a statute mile. It is 1.1508 miles to be exact.
According to the National Weather Service, a nautical mile is different from a land mile because it is equal to one minute of latitude. If you remember, latitude and longitude are measured in degrees, minutes and seconds.
So, if you are on a body of water, you measure your speed in knots. Remember that is one nautical mile per hour, so 1.15 miles per hour, making it faster than a land mile or statute mile.
Winds on bodies of water are forecast in knots, and the speed of your watercraft is, too. Just remember, knots are a little faster than miles per hour!
The term knot comes from 17th-century sailors, according to the National Ocean Service. They say these sailors used a device called a "common log," which is a coil of rope with uniformly spaced knots tied in it, attached to a piece of wood shaped like a slice of pie.
That wood floated behind the ship and the rope was let out freely. When the specified time had passed, the line was pulled in and the number of knots on the rope between the ship and the wood was counted.
The speed of the ship was said to be the number of knots counted.
