The meridian plus#

The meridians from West of Greenwich (0°) to the antimeridian (180°) define the Western Hemisphere and the meridians from East of Greenwich (0°) to the antimeridian (180°) define the Eastern Hemisphere. As there are 360 degrees in a circle, the meridian on the opposite side of the earth from Greenwich, the antimeridian, forms the other half of a circle with the one through Greenwich, and is at 180° longitude near the International Date Line (with land mass and island deviations for boundary reasons). The meridian through Greenwich (inside Greenwich Park), England, called the Prime Meridian, was set at zero degrees of longitude, while other meridians were defined by the angle at the center of the earth between where it and the prime meridian cross the equator. These two locations often conflicted and a settlement was reached only after there was an International Meridian Conference held, in which Greenwich was recognized as the 0° location. Toward the ending of the 12th century there were two main locations that were acknowledged as the geographic location of the meridian, France and Britain. The geodetic prime meridian is actually 102.478 meters east of this point since the adoption of WGS84. The astronomic prime meridian at Greenwich, England. The recommendation was based on the argument that naming Greenwich as Longitude 0º would be of advantage to the largest number of people. The second was that in the late 19th century, 72% of the world's commerce depended on sea-charts which used Greenwich as the Prime Meridian. The first was that the USA had already chosen Greenwich as the basis for its own national time zone system.

The meridian plus#

Ultimately the outcome was as follows: there would only be a single meridian, the meridian was to cross and pass at Greenwich (which was the 0°), there would be two longitude direction up to 180° (east being plus and west being minus), there will be a universal day, and the day begins at the mean midnight of the initial meridian. Twenty-six countries were present at the International Meridian Conference to vote on an international prime meridian.

As a result, a Conference was held in 1884, in Washington, D.C. Main article: International Meridian Conferenceīecause of a growing international economy, there was a demand for a set international prime meridian to make it easier for worldwide traveling which would, in turn, enhance international trading across countries. (post meridiem) used to disambiguate hours of the day when utilizing the 12-hour clock.

The same Latin stem gives rise to the terms a.m. Likewise, the Sun crosses the celestial meridian at the same time.

The term meridian comes from the Latin meridies, meaning 'midday' the subsolar point passes through a given meridian at solar noon, midway between the times of sunrise and sunset on that meridian. Multiple locations for the geographical meridian meant that there was inconsistency, because each country had their own guidelines for where the prime meridian was located. Many years later around the 19th century there were still concerns of the prime meridian. This prime meridian was used to provide measurement of the earth, but had many problems because of the lack of latitude measurement.

The first prime meridian was set by Eratosthenes in 200 BCE. 5 Effect of Prime Meridian (Greenwich Time).