Definition of the word longitude

The word "longitude" originated from the ancient Greek word "meridiana," meaning a line of reckoning or meridian. However, it was not until the 17th century that the modern concept of longitude was introduced by astronomer John Flamsteed. Flamsteed realized that the position of a place on a map could be accurately determined by its latitude (the distance north or south of the equator) and longitude (the distance east or west of a reference meridian, typically Greenwich, England). This was a significant advancement over the previously used system of celestial navigation, which relied on the position of stars and could only determine latitude with accuracy. Initially, determining longitude was a major challenge, as there was no practical method to do so until the invention of the marine chronometer in the late 18th century. The chronometer allowed sailors to accurately determine their longitude by synchronizing their watches with time signals broadcasted from shore. The precise meaning of the term "longitude" changed slightly over time as its concept evolved. Today, it refers to the angular distance east or west of a reference meridian, measured in degrees, minutes, and seconds. Longitude is a crucial factor in modern navigation and positioning systems, as it enables accurate global positioning and route planning.