Leap second to be added to worlds clocks on December 31
December 9th, 2008 - 12:47 pm ICT by ANIWashington, Dec 9 (ANI): The U.S. Naval Observatory is going to add a leap second to the worlds 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 earths 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 earths 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)
- Leap second decision postponed till 2015 - Jan 20, 2012
- Japanese scientists develop atomic clock with improved accuracy - Apr 04, 2011
- Wait a second more before saying Cheers to 2009! - Dec 27, 2008
- World's smallest atomic clock in matchbox size - May 08, 2011
- "Galactic GPS" to detect gravitational waves passing near Earth - Jan 06, 2010
- Scientists design world's most accurate clock - Feb 05, 2010
- A clock 100-fold more accurate than its atomic cousins - Mar 11, 2012
- Omitting leap seconds might mean end of Greenwich Mean Time - Dec 18, 2008
- Supernova remnant erupts in enormous flares - May 12, 2011
- Atomic clock based on ytterbium atoms 4 times more accurate than before - Aug 12, 2009
- Asteroid with potential power of 15 atomic bombs to pass moon's orbit tonight - Apr 15, 2011
- World's most precise clock keeps time to 1 second in 3.7 billion years - Feb 05, 2010
- Most massive neutron star discovered - Oct 28, 2010
- PS1 telescope discovers a record breaking 19 near-Earth asteroids - Feb 25, 2011
- World's smallest atomic clock on sale for $1,500 - May 04, 2011
Tags: atomic clocks, atomic time scale, celestial bodies, coordinated universal time, earth rotation and reference systems service, earths rotation, eastern standard time, international earth rotation and reference systems serv, leap seconds, master clock facility, national institute of standards, national institute of standards and technology, national institute of standards and technology nist, precise determination, reference frame, reference systems, rotation of the earth, time utc, timescale, u s naval observatory