Tag Archives: Greenwich Mean Time

Cruisin’ on the Thames to GMT

Red Time Ball

Red Time Ball at Royal Observatory

While Kevin’s parents were in town, we took a cruise down the River Thames from Westminster Bridge to Greenwich.  Greenwich is probably best known for the place from which the world’s time is measured or Greenwich Mean Time (GMT).

The Royal Observatory, in Greenwich Park, is home to Greenwich Mean Time.  In 1884, GMT became the world’s time standard at an international conference. Those countries involved in the conference agreed that the Greenwich Meridian would become the world’s Prime Meridian, therefore, the world’s time and time zones would be measured from this point.

Prime Meridian

(image from wikimedia commons)

The Prime Meridian is Earth’s 0° line of longitude stretching from the North Pole to the South Pole and divides the Earth into eastern and western hemispheres (the Equator divides the Earth into northern and southern hemispheres).  So, generally speaking, local time east of the line is ahead of GMT and local time west of the line is behind GMT.

Each day, the Red Time Ball at the Royal Observatory, on top of the Flamsteed House, drops at exactly 1:00pm (13:00 GMT).   We made it just in time to see the ball drop and then set our watches accordingly.

And this concludes your (very) basic geography lesson for today…