Meridian Longitude: The Invisible Lines Shaping Our World From the precise timing of a global stock trade to the accuracy of a GPS navigation system, our modern world relies on a sophisticated, invisible grid stretched across the Earth. At the heart of this grid lie lines, the north-south lines that divide the planet into hemispheres and establish the foundation for time and location.
To prevent splitting countries or island groups into two different days, the actual International Date Line zigzags around political borders rather than strictly following the 180th meridian. The Longitude Problem: A Historic Scientific Quest meridian longitude
Pilots and captains use these coordinates to chart paths across featureless oceans. Meridian Longitude: The Invisible Lines Shaping Our World