Paris watchmakers worldwide on Saturday one of the strangest operations of his profession, finds some time ago.
The last minute of the 30th June is determined 2012 to be in 61 seconds duration are, timekeepers, in order to compensate for a "leap second" wibbly wobbly movements, add to our world. The ever so brief interruption of the second hand offset
progressive deviation from the solar time, ie the time required for Earth to complete by 1 day.
The planet needs a little more than 86.4 thousand seconds for one rotation of 360 degrees.
However, it wobbles on its axis and is supported by the attraction of the sun and the moon and the tides of the oceans, all of which affected the rotation of a fraction of a second slower.
As a result, the earth is not in accordance with the International Atomic Time (TAI) that uses the pulse of atoms to measure time with an accuracy of a few billionths of a second.
In order to avoid the sun and the TAI time moves too far, is the widespread indicator for Coordinated Universal Time (UTC) adjusted from time to time to give us the odd 86,401 seconds per day.
The changes began in 1972. Previously, the only time of the position of the sun or the stars measured relative to the earth, the Greenwich Mean Time (GMT) or its successor UT1.
This intervention will be 25 in order to add a "leap second" to UTC.
"Today's time is built, defined and measured with atomic clocks that are far more stable than the astronomical time," said Noel Dimarcq, head of the reference spacetime SYRTE the Paris Observatory, the news agency AFP said.
"This is to ensure that everyone is on the earth at the same time."
TAI is maintained for several hundred atomic clocks around the world, measuring variations in the cesium atom chemical element that can be broken by a single second in 10 billion bits smaller.
With such precision, "only one (atomic) is lost every second 300 million years ago," said Dimarcq.
Each time the discrepancy between the TAI and UT1 is too large, the International Earth Rotation and Reference Systems Service (IERS) jumps into action and announced a "leap second" - usually several months in advance.
The extra second to UTC, also known as universal time is added only at midnight, either in a 31st December or 30 June.
Capture time is so irregular as the rotation of the Earth itself. The last three shots were in 2008, 2005 and 1998. The year 1972 saw two additions, followed by the next seven years for a second in each year.
The vast majority of the seven million people worldwide are probably happy with indifference to the change of the Sabbath, except a few that are the remarkable fact that they live to see another second.
But among scientists, the question is irrelevant.
The second step has been much discussion among the member countries of the International Telecommunication Union (ITU) will now do that for them abolished in favor of the exclusive use of atomic time.
Every time when a second is added, the world's computers must be set manually, a costly endeavor, including the risk of error.
High precision, such as satellite systems and data networks must take into account some of the second jump, or the risk that a disaster of calculation.
