0°0ʹ0" Prime Meridian

Friday, we took a boat ride down the Thames to Greenwich. This beautiful little town is famous for its Royal Observatory, where in the later 1800's the line known as the prime meridian was established. This was a very important discovery because it allowed the earth to be divided ino grids using latitude (distance from the equator-which had been in use for many centuries) and now longitude (distance from the prime meridian). Since measuring those distances involved time, Greenwich established the one and only "correct" time - Greenwich Mean Time. All other time zones are based on this. It's too bad I never learned all this in school - but it's much more interesting to me now!!


We all took turns standing on the Prime Meridian - here is Tom on the line!

The clock.....

Exact measurements- visitors are invited to see how their feet measure up to the exact distances that are marked here.

More visitors walk the line...

This is the "time ball" which was built after the Prime Meridian was established. Since it was very important that ships heading out to sea know exactly what time it was at home so that they could calculate their longitude, they would wait in the river until this ball was at the top of the mast. At exactly 1 PM, the ball drops. I guess this is where NYC got the idea for their New Year's ball drop - who knew?? To find out how longitude is then calculated using the time, please look it up :-) It's much too complicated for me to explain.