(submission) (sci/tech) Atomic Clock to add one second today, page 1

posted on Dec, 31 2005 @ 09:15 AM

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That's right folks, the New Year is postponed - by one second. An extra second will be inserted in universal coordinated time at 6:59:59 EST today. This is being done to bring atomic time into balance with the gradual slowing of the Earth's rotation.

news.nationalgeographic.com
2006 Postponed by One (Leap) Second

For those of you counting the seconds until 2006, add one.

The world's top timekeepers will insert an extra second—or leap second—just before midnight in coordinated universal time (UTC) on New Year's Eve. (That's the same as 6:59:59 p.m. eastern time on December 31.) UTC is determined by atomic clocks and is five hours ahead of eastern time.

Earth's rotation is ever so slightly slowing down, but atomic clocks remain unwaveringly consistent. The extra second will allow Earth to stay in sync with the ultraprecise clocks, which mark time based on the vibration of atoms.

The planet's slowing is mostly due to the friction of tides raised by the gravitational pull of the sun and the moon. In fact, a day is now about two-thousandths of a second longer than it was a couple centuries ago, scientists say.

Please visit the link provided for the complete story.

How is the disparity between the earth's rotation and the atomic clock calculated? The article didn't say. It did say that the Earth's rotation will eventually start to slow drastically as tidal forces influence rotational velocity. Twenty-three seconds have been added since 1972, and this is the first adjustment since 1998.

Could last year's tsunami be partly responsible? I've heard that strong El Nino currents can actually slow the Earth's rotation, as well.

I find all of this somewhat disturbing. We need to keep spinning, don't we?

[edit on 31-12-2005 by Icarus Rising]

Solasis

posted on Dec, 31 2005 @ 03:27 PM

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Meh, it's so slow so far that we'll all probably be dead by the time there's any drastic slowing. Leave it for our grandkids (or even farther along) to worry about.

It is very interesting, though. Do they just add a second whenever they realize "Oh, oops, we're falling behind!" or is it a regular thing? I'm too lazy to do the math or the research.

GradyPhilpott

posted on Dec, 31 2005 @ 04:31 PM

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Here are a few links to help folks to understand why leap seconds are necessary, why some people think they aren't and why we have varying time scales.

physics.nist.gov...

tycho.usno.navy.mil...

en.wikipedia.org...

tf.nist.gov...

www.livescience.com...

www.post-gazette.com...

www.leapsecond.com...

Leap Second Google Search

science.howstuffworks.com...

en.wikipedia.org...

Atomic Clock Google Search

Time Scales Google Search

Icarus Rising

posted on Dec, 31 2005 @ 04:48 PM

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Thanks Grady.

The article also stated that it would only be decades before the slowing started to become exponential.

But Earth is predicted to slow down "on a nearly exponential scale" in the decades to come as tidal friction increases, Chester says. And this is a conundrum that has sparked debate among the world's clock-watchers.

The pros and cons of leap seconds are explored, as well.

For example, an un-updated GPS navigation system could cause an oil tanker to run aground and spoil a pristine coastline. To avoid such a mishap, critics are pushing for the abolition of leap seconds.

On the other hand, if the atomic clocks and Earth's rotation are allowed to drift apart, eventually—as in, thousands of years from now—"high noon" will come hours before the sun crosses directly overhead.

All this is in addition to the extra day added every four years, I suppose. Clocks and calenders are starting to need more and more tweaking, it seems.

[edit on 31-12-2005 by Icarus Rising]