Earth's circumference mile in the seventeenth century and the metre in the eighteenth. Earth's polar circumference is almost exactly 40,000 km because the metre was originally calibrated on this measurement (1/10-millionth of the distance between the poles and the equator), which is almost exactly 21,600 nautical miles (being defined as one minute of a degree – i.e. 360 multiplied by 60). It has been described as "the single most important measurement" of the Earth, assuming the Earth to be a sphere (the Earth is an technically an ellipsoid, albeit with just 0.3% flattening). Earth's circumference lines are the foundation of the coordinate
Gauss (unit) Gauss (unit) The gauss, abbreviated as G or Gs, is the cgs unit of measurement of magnetic flux density (or "magnetic induction") (B). It is named after German mathematician and physicist Carl Friedrich Gauss. One gauss is defined as one maxwell per square centimeter. The cgs system has been superseded by the International System of Units (SI), which uses the tesla (symbol T) as the unit of magnetic flux density. One gauss equals 1 tesla (100 μT), so 1 tesla = 10,000 gauss. As with all units whose names are derived from a person's name, the first letter of its