Meridian | Longitude

This is the starting point for measuring longitude, designated as 0° longitude. By international agreement, it passes through the Royal Observatory in Greenwich, London.

“Meridian longitude” is therefore a tautology: all meridians are lines of longitude, and every longitude value corresponds to a specific meridian (except the anti‑meridian, 180°).

In 1884, delegates from 25 nations gathered at the International Meridian Conference in Washington, D.C. They voted overwhelmingly to establish the transit instrument at the Royal Observatory in Greenwich, London, as the official .

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The breakthrough came from John Harrison, an English clockmaker, who invented the —a clock so accurate that sailors could compare ship time with Greenwich time to calculate longitude. It saved countless lives and made global sea travel reliable. meridian longitude

While meridians are imaginary lines, they are essential tools for mapping. They are not parallel, unlike lines of latitude; instead, they are widest apart at the Equator and converge at the poles [QGIS]. Understanding Longitude

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.

Explain how latitude and longitude work together to pinpoint a location.

What is the for this piece? (e.g., students, trivia lovers, tech professionals) This is the starting point for measuring longitude,

Airplanes and cargo ships use digital charts based on the World Geodetic System (WGS 84), which relies heavily on the traditional longitude grid. Pilots and captains map out great-circle routes—the shortest distance between two points on a sphere—by calculating changes across meridians. 3. Geographic Information Systems (GIS)

In 1844, the International Meridian Conference met in Washington, D.C., to solve this problem. Forty-one delegates from 25 nations voted to establish a single, universal starting line. They chose the meridian passing through the .

The time at the Prime Meridian (0°) serves as the global baseline.

Located opposite the Prime Meridian, this line marks the boundary where the date changes. 3. How Meridian Longitude Works In 1884, delegates from 25 nations gathered at

The hero was , a self-taught carpenter and clockmaker. He built the H4 marine chronometer—a watch so accurate it lost only 5 seconds over a voyage. Finally, sailors could carry "Greenwich time" with them. The moment they looked up at the sun, they could calculate their meridian longitude with precision. Navigation was never the same.

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Longitude is measured in degrees (°), minutes ('), and seconds ('').