Day 17 - London: Greenwich Mean Time

Today we journeyed to the Royal Observatory in Greenwich. The point of the visit is to stand on the Prime Meridian. It was not overly crowded so we snapped a bunch of pics. My left foot is pointing at Dallas on the stone, but it’s hard to see in the picture.

Here’s some information about it from the web:

What is a meridian?

A meridian is a north-south line, selected as the zero reference line for astronomical observations. By comparing thousands of observations taken from the same meridian it's possible to build up an accurate map of the sky.

Why does the Prime Meridian run through Greenwich?

There were two main reasons for the choice. The first was the fact that the USA had already chosen Greenwich as the basis for its own national time zone system. 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 decision was based on the argument that by naming Greenwich as Longitude 0º, it would be advantageous to the largest number of people. Therefore the Prime Meridian at Greenwich became the centre of world time.

Eastern and Western hemispheres

The line in Greenwich represents the historic Prime Meridian of the World - Longitude 0º. Every place on Earth was measured in terms of its distance east or west from this line. The line itself divided the eastern and western hemispheres of the Earth - just as the Equator divides the northern and southern hemispheres. If you stand with one foot on one side and the other on the left, you are perfectly in the middle of east and west, according to the prime meridian line.

Back to Maggie

We went through Flamsteed House as part of the Royal Observatory and I’ll admit, I have never really thought about from where time came. It just was. But apparently this was not the case and it was extremely messy because everyone had their own time.

Navigation at sea was extremely inexact and yet, people were surprised when ships wrecked. Not until four ships sank in 1707 killing 1,450 (24 survivors) did someone think, “hey we need a better way of determine longitude at sea.” They thought they were off the coast of Brittany and heading into the English Channel but they ran straight into the Western Rocks. It remains one of the worst disasters in British maritime history.

Astronomers were instrumental in making time what it is today. They used many different methods to record and chart the earth’s movements.