"fer j. de vries" <[EMAIL PROTECTED]> writes: > On this list many is said about the equation of time, the precession and > so on in relation to the milennium clock. > And in the quoted mail is said the clock should be accurate to the > minute in 10,000 years. > Is this possible at all? > > Think of the decrease of the earth rotation. > This affect, or at least a part of it, isn't predictable. > To synchronize the atomic clocks to the civil time, which still is based > on suntime, leap seconds have to be added. > These leap seconds can't be predicted precisely. > So at this time it is unknown how many will be needed in the coming > 10,000 years. It will be many more then 60 I think. > And this correction will be needed to synchronize the milennium clock.
I assume that leap seconds will be added as needed so that in Greenwich averaged over a year noon clock time agrees with noon sun time. The Millennium Clock will be synchronized to mean sun time. In this case there will be no drift. A problem doesn't develop until the day is so much out of synch with the clock mechanism that the error can accumulate during a long period of cloudy weather to a half-swing of the pendulum. I suspect this will take much longer than 10,000 years (though I have been proven wrong in my suspicions on other topics in this list). Future generations can fine tune the clock for this eventuality by lengthening the pendulum a tiny bit. Art Carlson
