TECH

World Time Changing? Coordinated Universal Time (UTC) May Eliminate "Leap Seconds" In 2012

12/27/2011 07:06 pm ET | Updated Dec 28, 2011

The way we keep time is imperfect, and it's causing plenty of problems for modern society.

But what scientists at the International Bureau of Weights and Measures in Paris, France (BIPM) have been considering eliminating next month could fundamentally change the way we tell time, and most people don't even know it exists. They plan on deciding whether or not to eliminate "leap seconds" from Coordinated Universal Time (UTC).

Most people are aware of leap years, which add an extra day (tacked on to the end of February) every four years in order to adjust for the extra partial day in Earth's yearly rotation around the sun. But leap seconds serve a much less predictable purpose: adding a second to the clock in an unpredictable pattern to account for slight, unpredictable changes in the Earth's rotation on its axis, caused by things like the gradual slowing of Earth's rotation caused by the friction of ocean tides or the gravitational pull of the moon.

Simply put, every now and then we have to stop the clock for a second, so the Earth's rotation can catch up to our measurement of time.

According to a press release from BIPM, government representatives at the World Radio Conference of the International Telecommunication Union in Geneva, Switzerland will decide whether or not these adjustments are to continue when they convene in January 2012. While many might think this ruins our fundamental perception of time (or, perhaps, that it could diverge real astronomical time from our atomic measurement of time), scientists say the effect would likely be minimal.

In an interview with New Scientist, Felicitas Arias BIPM's "time director" explained that the difference between astronomical time and the unadjusted atomic time scale would be about half an hour in 600 years, so adjustments wouldn't be made in the near future:

It was agreed some years ago that we should not think of any kind of adjustment in the near future, the next 100 or 200 years. In about the year 2600 we will have a half-hour divergence. However, we don't know how time-keeping will be then, or how technology will be. So we cannot rule for the next six or seven generations.

In 100 years we will only see a 1-minute divergence, however, due to time zones, many already see up to half an hour in divergence from astronomical time.

While the change seems simple enough, it has major implications for technology, namely GPS systems that rely on precise timing to coordinate locations, BIPM discussed in a more recent release. By abolishing these pesky little differences (which occur about once every 1.5 years) greater safety can be ensured without sudden, unexpected stops in time.

Currently, BIPM calculates UTC based on an average of measurements from 400 atomic clocks around the world and UTC never differs from the time defined by the rotation of the Earth (UT1) by more than .9 seconds due to "leap seconds."

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