meridian
(noun)
an imaginary great circle on the Earth's surface, passing through the geographic poles
Examples of meridian in the following topics:
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Mapping the Earth
- Across the spherical Earth, longitude lines, also called meridians, stretch vertically from the North Pole to the South Pole.
- Similarly, the prime meridian is the line of zero degrees longitude (shown in red in the center panel of the above image).
- In most coordinate systems, the prime meridian passes through Greenwich, England.
- Longitude runs from -180 degrees (west of the prime meridian) to 180 degrees (east of the same meridian).
- The Western Hemisphere and the Eastern Hemisphere refer to the halves of the globe that are west and east of the prime meridian, respectively.
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Surfaces in Space
- For example, the surface of the Earth is (ideally) a two-dimensional surface, and latitude and longitude provide two-dimensional coordinates on it (except at the poles and along the 180th meridian).
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Seasonal Affective Disorder and Jet Lag
- The condition is not linked to length of flight, but to the trans-meridian (west–east) distance traveled.