"Leap second" to be added to world's clocks on December 31.
Washington, Dec 9 (ANI): The U.S. Naval Observatory is going to add a "leap second" to the world's clocks at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC) on December 31, 2008.
This corresponds to 6:59:59 pm Eastern Standard Time, when the extra second will be inserted at the U.S. Naval Observatory's Master Clock Facility in Washington, DC.
This marks the 24th leap second to be added to UTC, a uniform time-scale kept by atomic clocks around the world, since 1972.
Historically, time was based on the mean rotation of the earth relative to celestial bodies and the second was defined in this reference frame.
However, the invention of atomic clocks defined a much more precise "atomic time" scale and a second that is independent of the earth's rotation.
In 1970, an international agreement established two timescales: one based on the rotation of the earth and one based on atomic time.
The problem is that the earth's rotation is very gradually slowing down, which necessitates the periodic insertion of a "leap second" into the atomic timescale to keep the two within 1 second of each other.
The International Earth Rotation and Reference Systems Service (IERS) is the organization that monitors the difference in the two timescales and calls for leap seconds to be inserted or removed when necessary.
Since 1972, leap seconds have been added at intervals varying from six months to seven years, with the last being inserted on December 31, 2005.
The U.S. Naval Observatory is charged with the responsibility for the precise determination and dissemination of time for the Department of Defense and maintains its Master Clock.
The U.S. Naval Observatory, together with the National Institute of Standards and Technology (NIST), determines time for the United States. (ANI)
Copyright 2008 Asian News International (ANI) - All Rights Reserved.
Provided by Syndigate.info an Albawaba.com company
|Printer friendly Cite/link Email Feedback|
|Publication:||Asian News International|
|Date:||Dec 9, 2008|
|Previous Article:||How to improve lab mice's suitability as research models.|
|Next Article:||CT scans reveal that dinos were complete airheads.|
|Wait a second more before saying "Cheers to 2009!".|
|Another positive Leap Second was introduced on 31 December 2008.|