[U S Army EOD]

The reason for Knots is that a nautical mile represents one minute of angle of logitude at the equator. It is a measurement that is actually based on something where a statue mile is just something we made up along with most of our measurements. Of course a Knot is moving one nautical mile per hour and is used in navgation.

[TrappedInLiberalHell]

It is a measurement that is actually based on something where a statue mile is just something we made up along with most of our measurements.

Well, in truth, minutes of longitude are 'made up' as well. There's nothing saying that longitudinal lines have to be spaced as they are. They could just as well be based on the metric system, so that there would be 100 of them, or 1000. But I'm just picking nits. I believe the Bureau of Weights and Measures (if I have the name right) actually has metal bars kept under climatically controlled conditions that define common lengths like the foot and meter.