Re: the partial return of imperial measures
10,000 km is the distance from the equator to the North Pole, as measured back in the day. Measurements today are a bit more precise, so just as a day isn't 86,400 seconds, the distance from equator to North Pole is a bit over 10,000 km.
The distance is also 90 degrees times 60 minutes = 5,400 minutes, so the nautical mile is about 10,000 km divided by 5,400 = about 1,852 meters.
Biting the hand that feeds IT
