Greenwich location of the standard time. Now, not only is the astronomers use Greenwich mean time, is in the newspapers were often appear this term. We know are everywhere in place of all time. If a major international things, with local time to record, will feel complex inconvenience. But the days will come a long easy to make a mistake. supra shoes usa.Accordingly, astronomers proposed a is acceptable to all of the records and and convenient method, that is in place for standard Greenwich time. Greenwich is south of London was the seat of the Greenwich observatory, it is the world of geographical longitude starting point. For the significant events of the world, all of the local time in Greenwich recorded. Once you know the GMT, people is very easy to work out a quite local time. As a universal time reference standards have been used DuoNian 120. Now, this one to the earth according to the "world" in atomic oscillation period may be made based on the "molecule" completely replaced.

The 1970 s an international agreement world and two time measurement system atoms. World rotating speed of the earth by slowing effects, have a certain error; Molecule with the atomic energy level transition vibration frequency timing, 10 million error 1 second, relatively accurate. For coordination of two kinds of standards, Greenwich observatory introduced in 1972 leap second concept, manual intervention molecule, namely in the earth's rotation in the slow world 1 second, the molecule dial the slow 1 second.air jordan shoes. As for ordinary people, almost a second, and slow a second will not affect life. To GPS clock institutions, communication, aerospace, electronics, and other time higher accuracy sector, time is not easy set-up. For example, global positioning system, telecommunications network set-up time want to be accurate to milliseconds, how to avoid errors become quite a challenge.

Some researchers called for the abolition of time measurement system of "double standard", as a single atoms timing standards. The international telecommunication union is scheduled for January next year in Geneva to vote on whether alternative world atoms. More than 50 researchers on November 3 to 4,, in London suburb meetings to discuss relevant issues. After the prime meridian GMT when defined as GMT. 1884 Washington international longitude meeting sure GMT international standard time. cheap supra shoes.1924 February 5 on, Greenwich observatory every hour to the worldwide release information. If the vote through atoms to replace world, meant that global time measurement system no longer with the earth since into the basis, only by atomic clocks sure; Molecule measuring mechanism international standard measurement will replace London Greenwich observatory, become the new "time guardian".