Posted on 07/01/2012 12:44:32 AM PDT by Olog-hai
The transition from June to July will be delayed by circumstances beyond everyone's control. Time will stand still for one second on Saturday evening (June 30) because a "leap second" will be added to let a lagging Earth catch up to super-accurate clocks.
International Atomic Time is a very accurate and stable time scale. It is a weighted average of the time kept by about 200 atomic clocks in over 50 national laboratories worldwide. Atomic time is measured through vibrations of atoms in a metal isotope that resembles mercury and can keep time to within a tenth of a billionth of a second per day. The result is extremely accurate time that can be used to improve synchronization in precision navigation and positioning systems, telecommunications networks and deep-space communications.
But from their careful observations of the positions of the stars, astronomers have deduced that Earth's rotation is ever so slightly slowing down at a non-uniform rate …
Today's atomic clocks are accurate to approximately one second in 200 million years. On average, our planet has been falling behind atomic time at a rate of about two milliseconds per day. As a result, it now trails the "official" clock by about six-tenths of a second.
As a result of this difference, atomic clocks, which are used to set all other clocks, can get out of sync with the Earth and periodically have to be adjusted. A leap second has to be added from time to time to make up the difference.
The next time will be Saturday, when the master clock at the United States Naval Observatory will be adjusted at 7:59:60 p.m. Eastern Daylight Time, or 23:59:60 Coordinated Universal Time (UTC). …
(Excerpt) Read more at space.com ...
Don't get me started on how I hate the measurement of time and all thing related to calendars.
Happy 1341129225.
/johnny
But for some kind of advanced AI, you ain't a bad fellow.
/johnny
I hope the day that I hear your power source was switched off is a long time (say 10e+17 seconds) away.
You always make me laugh, and that's what good AIs do.
/johnny
/johnny
I use a lot of crystals at 32.768KHz for timekeeping in embedded systems.
My timekeeping is an order of magnitude less accurate than these atomic clocks.
GPS is one area that depends upon extremely accurate time keeping.
That’s what they get for picking 1820 as the reference date.
My timekeeping is an order of magnitude less accurate than these atomic clocks.
NIST-F1 has a frequency uncertainty of 3e-16. That's ±1 second in 100 million years. What's that in orders of magnitude?
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