Leap Second to Be Enforced This Year

“Three, two, one, one, 2006!”

The New Year will start in England like this. “One” will be repeated to account for a “leap second” that will be added to the clock on December 31, the last day of 2005.

One second will be added to the universal time coordinated (UTC) at 23:59:59 on December 31, 2005 Greenwich Mean Time (GMT) (8:59:59 a.m. on January 1, 2006, Korea time).

The International Earth Rotation Service (IERS) in Paris, France, an affiliated organization of United Nations, has decided to add a leap second to the world’s calendar in order to adjust the atomic clock, the most precise clock on earth, to match the earth’s rotation speed.

The adjustment is needed because the earth’s rotation speed has come out of alignment with the atomic clock due to tides.

Leap seconds have been added occasionally since 1972, when the idea of a leap second adjustment began. According to the Korea Research Institute of Standards and Science, this year’s leap second addition will be the 24th time; the 23rd leap second was added on January 1, 1999.

The leap second has always been controversial. The United States insists that we adopt a leap hour every 500 to 600 years, rather than abolish a leap second, saying that a leap second adjustment can cause serious errors in computers and artificial satellites.

However, astronomers worldwide are fiercely opposed, claiming that time should be defined on the basis of the movement of heavenly bodies, and that the costs of adjusting expensive astronomical telescopes would be huge without a leap second.

Jin Lee leej@donga.com