Prime Meridian: And Antimeridian

At the Greenwich observatory, you can literally stand with one foot in the Eastern Hemisphere and one foot in the Western Hemisphere. It is one of the most photographed feet-in-two-places spots on Earth. There is a giant steel line embedded in the courtyard, and a green laser shoots northward into the London sky every night.

The Prime Meridian, located at 0° longitude, serves as the starting point for all longitudinal measurements. Since 1884, the Royal Observatory in Greenwich, London, has served as the international standard for this line. Every other location on Earth is measured by its distance east or west of this specific point. The establishment of Greenwich Mean Time (GMT) transformed the Prime Meridian from a simple geographical marker into the heartbeat of global synchronization, allowing ships to navigate safely and modern digital networks to operate across borders. prime meridian and antimeridian

It serves as the reference for Coordinated Universal Time (UTC) and Greenwich Mean Time (GMT) [25, 26]. At the Greenwich observatory, you can literally stand