Knot your Average Mile
So just where did these other units come from and why are these special units used?
What makes a nautical mile different from a regular mile is that a nautical mile is based off of the circumference of the Earth and is equal to one minute of a degree of latitude. This contrasts with the “regular” mile aka statute mile which was based simply off of measurements of paces in ancient times by the Romans.
Nowadays, we can use GPS, radar, and many other methods to find our speed, yet we still call it the knot, an homage to sailors of the past who had to quite literally count knots.