The chosen moment was at noon on that day, when the telegraph lines transmitted time signals to all major cities. The first was that we had already chosen Greenwich as the basis for our own national time zone system. GMT was then adopted by the United States on November 18th, 1883. The British Royal Observatory at Greenwich was considered the worldwide center for timekeeping and had been since 1675. Nevertheless, time, as shown by the clocks at the Royal Observatory, was not adopted officially by Parliament until August 2nd, 1880. These two solutions would help pave the way for GMT to become the worldwide time standard a little more than a century later. This meant they could calculate their longitude from the Greenwich meridian (also referred to as the “Prime meridian,” or longitude 0°). In 1767, the fifth Astronomer Royal, Nevil Maskelyne brought Greenwich Mean Time to a wider audience by introducing the Nautical Almanac as part of the great 18th-century quest to determine longitude.īritish mariners started keeping at least one chronometer set to GMT. Soon after, John Flamsteed was appointed as the first Astronomer Royal and moved into the new Royal Observatory. Highly acclaimed British architect, Christopher Wren was commissioned to design the domed building. In 1675, King Charles II offered the land to The Royal Society for Britain’s first national observatory. Greenwich was a royal park and palace on a hill to the south of the River Thames east of London, England. It wasn’t until the invention of the pendulum clock in the 1650s that it was possible to work out the relationship between mean (clock) time and solar time.īritish astronomer, John Flamsteed came up with the formula for converting solar time to mean time, and published a set of conversion tables in the early 1670s. GMT was originally set up to aid naval navigation when travel around the globe started to open up with the exploration of the “New World” (America) during the 16th century. It’s a way to standardize time so we can all know exactly what time it is for any location. If you own a sundial for instance, you’re aware that “noon” based on the position of the Sun can differ by as much as plus or minus 15 minutes from what a clock may read.īut each day measured by a clock has the same length, equal to the average (mean) length of a solar day. It differs from solar or astronomical time clock time because solar time varies throughout the year. In essence, “mean time” is what you would read off of a clock. You’ve heard of Daylight Saving Time, Standard Time, Eastern, Central, Mountain, and Pacific Time, but have you heard of the term Greenwich Mean Time, sometimes referred to simply as GMT, or Coordinated Universal Time (UTC), and wondered what the heck it is?
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |