While the ground beneath our feet feels solid and stationary, we navigate our planet using a complex, invisible grid. At the heart of this system is . Often paired with latitude, longitude is the crucial coordinate that tells us exactly how far east or west we are from a starting point. What is a Meridian?
When you see coordinates (e.g., 40.7128° N, 74.0060° W), the second number is your meridian longitude relative to the 0° line. GPS has modernized the concept, but it hasn't changed the fundamental principle: longitude is angular time. meridian longitude
: Each meridian is half of a Great Circle —a circle whose center is the center of the Earth. While the ground beneath our feet feels solid
Longitude is directly tied to time: