2008? Wait a second!
p2pnet news view | Cool:- 2008 is a leap year.
But only for a second.
Literally. 
A positive leap second will be introduced at the end of December 2008, says the International Earth Rotation and Reference Systems Service (IERS).
It says the sequence of dates of the UTC second markers will be:
- 2008 December 31,23h 59m 59s
- 2008 December 31,23h 59m 60s
- 2009 January, 1,0h 0m 0s
The last time this happened was at the end of December 2005.
The difference between UTC and the International Atomic Time TAI is, says the IERS:
- From 2006 January 1, 0h UTC, to 2009 January 1 0h UTC : UTC-TAI = – 33s
- From 2009 January 1, 0h UTC, until further notice: UTC-TAI = – 34s
“The aged Earth is slowing down in its daily rotation, at least in the current epoch,” says the US Department of the Navy Time Service, from whence came the chart above.
It goes on:
“Civil time is occasionally adjusted by one second increments to ensure that the difference between a uniform time scale defined by atomic clocks does not differ from the Earth’s rotational time by more than 0.9 seconds. Coordinated Universal Time (UTC), an atomic time, is the basis for civil time.
“Historically, the second was defined in terms of the rotation of the Earth as 1/86,400 of a mean solar day. In 1956, the International Committee for Weights and Measures, under the authority given it by the Tenth General Conference on Weights and Measures in 1954, defined the second in terms of the period of revolution of the Earth around the Sun for a particular epoch, because by then it had become recognized that the Earth’s rotation was not sufficiently uniform as a standard of time. The Earth’s motion was described in Newcomb’s Tables of the Sun, which provides a formula for the motion of the Sun at the epoch 1900 based on astronomical observations made during the eighteenth and nineteenth centuries. The ephemeris second thus defined is the fraction 1/31,556,925.9747 of the tropical year for 1900 January 0 at12 hours ephemeris time.
“This definition was ratified by the Eleventh General Conference on Weights and Measures in 1960. Reference to the year 1900 does not mean that this is the epoch of a mean solar day of 86,400 seconds. Rather, it is the epoch of the tropical year of 31,556,925.9747 seconds of ephemeris time. Ephemeris Time (ET) was defined as the measure of time that brings the observed positions of the celestial bodies into accord with the Newtonian dynamical theory of motion.”
Now you know.
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December 29th, 2008 at 10:39 am
Jon
What kind of Seconded Joke is this? =P
Paris arrived in Melbourne today
OMG like seriously!
December 29th, 2008 at 11:21 am
“The UTC second 60 gets added at midnight only at those locations where UTC == local time, i.e. places like England. For us in the rest of Europe, the leap second will be added an hour after local midnight, i.e. at 01:00:60 CET. Terje”
http://tinyurl.com/9g432u
December 29th, 2008 at 12:42 pm
Blame global warming!
December 29th, 2008 at 5:49 pm
Earth rotation slowed down by 3.5 millisecond a day after 35 years!
We are screwed!
Quick! Stop the European super colider!
December 29th, 2008 at 5:54 pm
At this rate of decline Earth will stop rotating in 68 thousand years.
Who turn off the power?
December 29th, 2008 at 9:27 pm
All those annoying end-of-year shows with Dick Clark-like people who never seem to age (an antithesis if wever there was one; they’re celebrating THE PASSING OF TIME) will have to chant, “FIVE… FOUR… THREE… TWO… ONE… STILL ONE…”