While latitude is measured in degrees north or south of the Equator (a naturally occurring midpoint between the poles), longitude (the coordinate derived from meridians) has no natural zero point. The Earth spins on an axis, offering a physical reference for north and south, but it does not naturally distinguish east from west. Therefore, the definition of meridian coordinates relies entirely on an arbitrary, political, and historical choice: the Prime Meridian.
Meridians are spaced by degrees (0°–180° east or west), and each degree subdivides into minutes and seconds for finer precision. Modern systems often use decimal degrees to simplify calculations: 45.672° E instead of 45° 40' 19.2" E. Lina preferred decimals for fieldwork; they fit tidily into her handheld device and synced easily with satellite data. meridian coordinates
: Paired with latitude, they pinpoint any exact location on Earth. While latitude is measured in degrees north or
Every meridian is approximately the same length because they all pass through the poles. Meridians are spaced by degrees (0°–180° east or
| Feature | Meridian Coordinates | Trigger Points | | :--- | :--- | :--- | | | Energetic (Qi flow & Zang-Fu) | Neuromuscular (Referred pain) | | Movement | Distal points affect proximal organs | Usually local or regional pain | | Example | ST-36 treats digestion (leg to stomach) | Trapezius point treats neck pain |
The future of medicine may not involve discarding meridian coordinates, but integrating them. Imagine a smartwatch that calibrates your "Cun" measurement and then vibrates at when your stress biomarkers spike.
In 1884, an international conference held in Washington, D.C., established the Royal Observatory in , as the location of the Prime Meridian (0° longitude).