The Meridian Line in Greenwich and Greenwich Mean Time (GMT)

Photo credit: © 9 Hertford Street

Greenwich is a wonderful area of London to visit – home to Queen’s House, the National Maritime Museum, the Old Royal Naval College, Cutty Sark, the Fan Museum and Greenwich Park. You also have the fascinating Royal Observatory where you will find the Meridian Line.

The Meridian Line defines the Prime Meridian of the world, being at Longitude Zero (0° 0′ 0″). Everywhere in the world is measured from its angle to the east or west of it, and if you visit the Line, you can straddle it so that, mind-blowingly, you have one foot on either side of the earth. At night, you can see the Meridian Laser, following the route of the Line. It’s quite a spectacular sight and in good conditions, can be seen at a distance of 36 miles with the naked eye, and 60 miles with binoculars.

In 1884, the Prime Meridian was appointed as the reference point for Greenwich Mean Time (GMT). Greenwich Mean Time is the annual average (or ‘mean’) of the time each day when the sun traverses the Meridian Line. The term GMT is used for the time zone UTC+00:00 (official UK time).

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