Meridian — Longitude

The Prime Meridian serves as the starting point for all longitude measurements, designated as . Prime Meridian, Longitude & Latitude - Britannica

A meridian is an imaginary line of longitude on the Earth's surface that runs north-to-south, connecting the North Pole and the South Pole [NOAA]. The term "meridian" comes from the Latin meridies , meaning "midday," because all points on the same meridian experience solar noon at the same time [NOAA]. meridian longitude

The 180° meridian (located in the Pacific Ocean) is where East meets West. This line serves as the basis for the International Date Line . The Prime Meridian serves as the starting point

longitude) has not always been in Greenwich. Historically, various countries used their own capital cities as the 0∘0 raised to the composed with power reference, such as Paris, Rome, or Copenhagen [UH Manoa]. The 180° meridian (located in the Pacific Ocean)

Unlike lines of latitude (parallels), which are parallel to each other, meridians have unique geometric properties: