Greenwich meridian why

Everywhere on Earth has a position because we can assign them geographic coordinates. We measure these coordinates as lines latitude and longitude. Lines of latitude start at the equator. Latitudes and longitudes make up our geographical coordinate system. We use an ellipsoid to approximate the surface of Earth. Then, we use the ellipsoid to reference all latitude and longitude coordinates to it. A datum describes the shape of the Earth in mathematical terms. Each datum specifies:.

Coordinates pairs X, Y represent positions in two-dimensional space. How did the Victorian astronomers who created the Meridian get their calculations wrong? It comes down to the fact that the Earth is not a perfect sphere. These are the brighter stars, whose positions have been observed over long periods of time and can be used as reference points in the sky.

As a result, the vertical line to the stars and therefore the meridian line on the ground were slightly skewed. This has enabled scientists to determine the true vertical direction and in doing so produced a new meridian slightly to the east of the old one.

So what are the implications of this apparent inaccuracy, particularly given that it is the location from where every place on Earth is measured and from which all clocks are ultimately set? Fortunately, the answer is none, really. At that time, establishing an average time in a given village was to help sailors determine their longitude e n Wed The Royal Greenwich Observatory, located in this part of London, helped British sailors calculate their longitude in relation to the Greenwich meridian.

While many railway companies gradually adopted Greenwich Mean Time, like the Railway Clearing House in , it was not until that this was accepted as legal time in the United Kingdom. From the average weather of a fishing village on the benchmark timetable, Greenwich Mean Time was born. However, at that time, no division of the world into time zones had really been proposed.

Each nation set its time in relation to the path of the sun in the sky: when it reached its highest point, it was noon. Many cities then proposed to become the world meridian of reference, in particular London with the district of Greenwich and Paris, with the district of Saint-Sulpice.

Finalem ent, August 2, , after negotiations, Greenwich was adopted as world legal time.