I agree that the distinction between UTC (atomic time) and UT1 (Earth time) are not of everyday concern. Who among us is so schedule driven to worry about 0.9 s?
However, there are industrial and governmental concerns that do care about this distinction. GPS is perhaps one of the most widely known systems where that matters. It's a rough extrapolation but to a celestial navigator 4 s time error can cause up to 1 nautical mile error in position. By simple ratios (and forgetting the crudity of this analogy), a 0.9 s error in GPS time could cause a 400 m position error, which is why GPS transmits its own time signals. Otherwise the advertised GPS accuracy could not be achieved if people had to depend on Earth time to obtain a GPS position. Jim M R wrote: > > Thanks for clear explanation Jim > > But the difference between astronomical and atomic > time is so minute that it affects neither industrial > nor government nor household activities. > > I will like to see decimal time slowly creeping in our > day today lives. > > Madan .... -- Metric Methods(SM) "Don't be late to metricate!" James R. Frysinger, CAMS http://www.metricmethods.com/ 10 Captiva Row e-mail: [EMAIL PROTECTED] Charleston, SC 29407 phone/FAX: 843.225.6789
