The nautical league in the United Kingdom is a unit of nautical measurement that is traditionally defined as three nautical miles. A nautical mile, also known as a sea mile, is a unit of distance used in navigation and marine contexts. It is based on the circumference of the Earth and is approximately equal to one minute of latitude along a meridian.
In the United Kingdom and many other maritime nations, a nautical league is considered to be equal to three nautical miles, which is roughly equivalent to 5.556 kilometers or 3.452 statute miles (land miles). This measurement is used for maritime and navigational purposes, especially for calculating distances at sea.
It's worth noting that the use of traditional nautical measurements like leagues has largely been replaced by more standardized and precise modern navigation methods that rely on nautical miles and other internationally recognized units. Nonetheless, these older units of measurement may still be referenced in historical documents or traditional maritime contexts.
Earth's polar radius, often denoted as "r," is the distance from the center of the Earth to a point on the Earth's surface near either the North Pole or the South Pole. It represents the Earth's radius when measured from its center to a point along its polar axis. The polar radius is shorter than the equatorial radius because the Earth is slightly flattened at the poles and bulges at the equator due to its rotation.
The approximate value for Earth's polar radius is about 6,357 kilometers (or approximately 3,949 miles). This value may vary slightly depending on the reference ellipsoid used for modeling the Earth's shape, but the given value is a commonly used and accurate approximation for most purposes.
In contrast to the polar radius, Earth's equatorial radius (measured from the center to a point on the equator) is slightly longer, approximately 6,378.1 kilometers (3,963.2 miles).