Coordinates - Meridian

At the exact opposite side of the world from the Prime Meridian (180° longitude) lies the , where the calendar day officially changes. How Meridian Coordinates are Measured

While the concept is centuries old, meridian coordinates are more relevant today than ever: meridian coordinates

Meridian coordinates, or longitudes, are imaginary lines that run from the North Pole to the South Pole, intersecting the equator at right angles. These lines are also known as meridians. Each meridian has a specific longitude value, measured in degrees, minutes, and seconds, which indicates its position east or west of the Prime Meridian. At the exact opposite side of the world

: This is the "zero line" (0° longitude). It passes through the Royal Observatory in Greenwich, England , and serves as the global starting point for measuring longitude. Each meridian has a specific longitude value, measured

Therefore, the meridian coordinate (Pericardium 6) is universally described as "2 Cun proximal to the transverse crease of the wrist." This means you measure the patient’s thumb width, double it, and move toward the elbow.

Whether you are a navigator, a geography student, or someone curious about how GPS works, understanding meridians is essential to mastering global positioning. What Exactly Are Meridian Coordinates?