By HUGO KUGIYAAssociated Press
If life is often a matter of split seconds, the universe is about to bestow upon us a generous gift: the leap second.
On Saturday, at exactly 6 p.m., one second will be added to our official record of time - Coordinated Universal Time.
The Earth is slowing down. And because time is a function of planetary movement, our days are getting longer and, depending on how you look at it, time is slowing down. This discrepancy is something we have become able to measure only since 1958.
When a 24-hour day, as measured by the world's atomic clocks, becomes more than nine-tenths of a second shorter than a solar day, those in charge add the leap second.
Eventually the 24-hour day as we know it will become a few minutes longer, although it will take millions of years. After hundreds of millions of years, the day will grow an hour longer. The rotation of the Earth and its orbital path around the sun (which is engaged in a perpetual gravitational tug of war with Jupiter) are inconsistent and always vary slightly.
These cosmic forces matter little in the lifetime of any single person until, eventually, a day in the life gains one second.
Most of us will not pause to notice the extra second. But our machines will. Our computers, and mobile phones, and global positioning devices, will all rest for one second at the appointed time as they calibrate to Coordinated Universal Time.
The official timekeeping devices of communication companies the world over, television stations, newspapers, indeed The Associated Press, also will hold their electronic breaths for one second. Perfect time is critical to our technological infrastructure, some of which operates at the speed of light. Measured this way, one second represents two-thirds the distance between the earth and moon.
For the average person, observing the leap second requires focus and effort. Most cannot feel the extra second of sleep to which we will be entitled. But for those wishing to witness the event, the process is relatively simple and requires a stop watch and a common cell phone with a time display.
At the precise moment the display reads 5:59 p.m., start the stopwatch. When the display changes to 6:00, stop the watch. It should read 61 seconds.
There. Your extra second will have been spent.
