TIME FOR YOUR 'LEAP SECOND' RESOLUTIONS.

Byline: Patricia Farrell Aidem Staff Writer

VALENCIA - A huge quake rupturing Earth's crust, heavy snow in Siberia or even high winds in the Andes Mountains can alter the planet's rotation and change time, if only by a single second.

And for people like retired astronomer Skip Newhall, a second is a big deal - big enough that he's planning his first, and possibly last, ``leap second'' party today at his Valencia home to note the extra blink of the clock between 3:59:59 and 4:00:00 p.m. local time.

``We're going to have 30, 35 people,'' Newhall said Friday. ``I've got three different time readouts. One will have a 60 in the second spot - clocks don't usually do that - and I have a couple of clocks that aren't going to read right.

``I'm going to have everyone give a chorus of 'boos' for those.''

Leap seconds have been occurring since 1972 in either January or June - every one to seven or so years as needed to maintain Earth, not man-made clocks, as the ultimate timekeeper, said John Mosley, an astronomer at the Griffith Park Observatory. The leap second is actually aimed at midnight, Greenwich Mean Time.

But now there is talk among the world's weights and measures agencies of abandoning the practice of adding seconds as needed to keep up with Earth's imprecise rotation, Mosley said.

Proponents say it would be a simpler way of keeping time. The astronomy community argues that Earth, not humans, should dictate time, even though it means adding a second every few years.

``If you let a mechanical clock be the ultimate source, it's simpler, but then the Earth is going to get out of sync with the calendar,'' Mosley said. ``The problem is March starts happening when it's still winter. It's sort of like abandoning the gold standard when you abandon the Earth as the time standard.''

For Newhall, he's billing his get-together as possibly the last time anyone alive now will experience a leap second. If the world's time gurus determine it would be simpler to catch up with Earth by adding a leap hour, it would be about 3,600 years before the seconds added up, he said.

``This might never happen again in our lifetime, in our great-great-great grandchildren's lifetime,'' he said.

Sitting in his living room among an eyepopping collection of electronics, run by some 10 remote controls lined up on his coffee table, are the three clocks that he has labeled by manufacturer and system of timekeeping.

To the untrained eye, they differ by the color of the readouts: teal, amber and red.

It took some research in recent weeks for Newhall to determine which of his three antenna-tuned atomic-digital clocks (he also has a standard face clock and two atomic watches - one for each wrist) would accurately reflect the time when the leap second occurred.

The lower-tech Spectracom red numeral clock was the only one whose manufacturer said testing had showed the 60 would appear in the seconds slot. The others, by the same manufacturer, will either hold 59 or 00 for an extra second.

``I want to scold them for not doing a better job,'' he said of Symmetricom clocks.

Newhall, a descendant of the Santa Clarita Valley's pioneering family, was an astronomer for Jet Propulsion Laboratory for 35 years before retiring eight years ago. It's a safe bet he was never late for work.

He spends hours a week in his roomful of computers, noting he gets about 800 hits a second on his Web site (http://sn.to) from users who want to know real time, mainly to set computer clocks.

A watch that's a few minutes off is intolerable to Newhall, who said he's matured beyond the days when such an inaccuracy would trigger his adrenaline.

And while super-accurate time isn't crucial to the average person, it matters for those who launch satellites or work power grids, Mosley said.

``When you're switching energy grids, you've got to be dead-on,'' he said. ``When you and I go shopping for chicken, it doesn't matter so much.''

Patricia Farrell Aidem, [phone]

pat.aidem(at)dailynews.com

ONLINE

Check out Skip Newhall's Web site at http://sn.to.

To see when leap seconds have been added since 1972, go to http://en.wikipedia.org/wiki/Leap-second.

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(1 -- color) Skip Newhall invited 30 to 35 friends over to his house in Valencia to watch his three atomic-digital clocks take note of today's leap second.

David Crane/Staff Photographer

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