Melting Polar Ice Sheets Are Slowing Earth’s Rotation. That Could Change How We Keep Time

[Stevicus]

Melting Polar Ice Sheets Are Slowing Earth's Rotation. That Could Change How We Keep Time

As ice melts into water and flows toward the equator, it redistributes mass around the Earth, affecting the planet's spin, a new study finds

www.smithsonianmag.com

I had heard about adding "leap seconds" in order to make corrections, although this article is talking about the possibility of having to subtract a leap second, which could have greater ramifications.

The findings suggest climate change’s wide-ranging impacts might also include global timekeeping.

“This is another one of those ‘this has never happened before’ things that we’re seeing from global warming: the idea that this effect is large enough to change the rotation of the entire Earth,” Duncan Agnew, the author of the study and a geophysicist at the University of California, San Diego (UCSD), tells Scientific American’s Avery Schuyler Nunn.

For most of human history, we have demarcated the passage of time by Earth’s rotation, with a second defined as a small fraction of the period it takes for the planet to spin once around its axis. But Earth’s spin rate changes slightly over time. So, in 1955, scientists started measuring seconds using the resonance of cesium atoms, a more stable timekeeping method.

Despite the accuracy of these “atomic clocks,” they diverge slightly from Earth’s rotation due to the planet’s variable spin rate. To compensate, officials have occasionally added one second to our clocks to realign them with the Earth’s rotation. Such “leap seconds” were added 23 times between 1972 and 1999.

Factors that influence the Earth’s spin rate include the friction of ocean tides, caused in part by the tug of the moon’s gravity. Even the sun’s gravity and earthquakes can have an impact, according to Science News’ Carolyn Gramling.

One large influence is the spin of Earth’s core, which has been slowing down, according to the study. In turn, the solid part of the planet is rotating more quickly. This acceleration has brought the Earth’s rotation more in line with atomic clocks—since 1999, only four leap seconds have been added.

So, the Earth's core is slowing down, while the solid part of the planet is rotating more quickly, so they've only had to add leap seconds four times since 1999.

If Earth’s spin rate continues to slightly increase, eventually officials won’t need to add leap seconds anymore. Instead, they might have to do something unprecedented: subtract a leap second. And this could cause major problems for timekeepers.

Despite their short duration, leap seconds are far from insignificant: Adding one can lead to major failures in computing systems, Elizabeth Donley, chief of the time and frequency division at the National Institute of Standards and Technology (NIST), who was not involved in the research, tells Nature News’ Elizabeth Gibney. Leap seconds can disrupt satellite, financial and energy transmission systems that depend on precise clocks, writes NBC News.

Subtracting a leap second could cause major problems. But the melting ice could cause the rotation to slow down, giving scientists more time to work on the question before a decision to eliminate a second has to be made.

While some systems have software to allow for the addition of a second, few allow for a second to be erased, according to the paper.

“A negative leap second has never been added or tested, so the problems it could create are without precedent,” Patrizia Tavella, a member of the Time Department at the International Bureau of Weights and Measures in France, writes in an article accompanying the new study.

Melting ice sheets play into this process in the opposite way, Agnew suggests. Working against the accelerating rotation caused by the changes in Earth’s core, ice melt shifts mass toward the equator, which actually slows the planet’s spin.

What would be the ramifications of a negative leap second? Apparently it can cause major failures in computing systems, although they said that would happen with Y2K - but nothing really happened.

It seems it shouldn't be that big a deal to simply reset the clock, but then again, I recall a time when most people's VCRs eternally flashed "12:00" because they couldn't set the clock.

Does anybody really know what time it is?

 

[SalixIncendium]

Does anybody really care?


Sorry, but that's what you get for putting a Chicago earworm in my head.

 

[Stevicus]

Does anybody really care?


Sorry, but that's what you get for putting a Chicago earworm in my head.

We've all got time enough to cry.

 

[Twilight Hue]

Melting Polar Ice Sheets Are Slowing Earth's Rotation. That Could Change How We Keep Time

As ice melts into water and flows toward the equator, it redistributes mass around the Earth, affecting the planet's spin, a new study finds

www.smithsonianmag.com

I had heard about adding "leap seconds" in order to make corrections, although this article is talking about the possibility of having to subtract a leap second, which could have greater ramifications.








So, the Earth's core is slowing down, while the solid part of the planet is rotating more quickly, so they've only had to add leap seconds four times since 1999.



Subtracting a leap second could cause major problems. But the melting ice could cause the rotation to slow down, giving scientists more time to work on the question before a decision to eliminate a second has to be made.



What would be the ramifications of a negative leap second? Apparently it can cause major failures in computing systems, although they said that would happen with Y2K - but nothing really happened.

It seems it shouldn't be that big a deal to simply reset the clock, but then again, I recall a time when most people's VCRs eternally flashed "12:00" because they couldn't set the clock.

Does anybody really know what time it is?

Givin how time is messed up with daylight savings , I don't think a few seconds really matters.

 

[Stevicus]

Givin how time is messed up with daylight savings , I don't think a few seconds really matters.

I wouldn't think so either, although they're saying it could mess up computer systems which depend on precise clocks.

 

[Nakosis]

Melting Polar Ice Sheets Are Slowing Earth's Rotation. That Could Change How We Keep Time

As ice melts into water and flows toward the equator, it redistributes mass around the Earth, affecting the planet's spin, a new study finds

www.smithsonianmag.com

I had heard about adding "leap seconds" in order to make corrections, although this article is talking about the possibility of having to subtract a leap second, which could have greater ramifications.








So, the Earth's core is slowing down, while the solid part of the planet is rotating more quickly, so they've only had to add leap seconds four times since 1999.



Subtracting a leap second could cause major problems. But the melting ice could cause the rotation to slow down, giving scientists more time to work on the question before a decision to eliminate a second has to be made.



What would be the ramifications of a negative leap second? Apparently it can cause major failures in computing systems, although they said that would happen with Y2K - but nothing really happened.

It seems it shouldn't be that big a deal to simply reset the clock, but then again, I recall a time when most people's VCRs eternally flashed "12:00" because they couldn't set the clock.

Does anybody really know what time it is?

I've always wondered if we venture off into space, will we keep an earth-time standard?

Maybe basing time off something not stable is not such a great idea.
Then what should the passage of time be based on and how long would a minute be?

 

[Revoltingest]

And yet, I hear this in the news....

Earth is spinning faster than it used to. Clocks might have to skip a second to keep up.

The planet is headed towards what one expert called a "negative leap second."

www.cbsnews.com

 

[JustGeorge]

Maybe the earth is confused.

 

[Revoltingest]

Maybe the earth is confused.

I think that we have more than one thing going on.
But the net effect is to spin faster....for now.
The moon will ultimately continue slowing us down.
(I don't want to be slower than I already am.)

 

[JustGeorge]

I think that we have more than one thing going on.
But the net effect is to spin faster....for now.
The moon will ultimately continue slowing us down.
(I don't want to be slower than I already am.)

I could use more moon power in this house...

 

[Revoltingest]

I could use more moon power in this house...

Be careful how you ask your kids for "moon" power.

 

[Nakosis]

And yet, I hear this in the news....

Earth is spinning faster than it used to. Clocks might have to skip a second to keep up.

The planet is headed towards what one expert called a "negative leap second."

www.cbsnews.com

If the earth is spinning faster does that mean I've lost weight?

 

[Stevicus]

I've always wondered if we venture off into space, will we keep an earth-time standard?

Maybe basing time off something not stable is not such a great idea.
Then what should the passage of time be based on and how long would a minute be?

It probably wouldn't have much value in space, except they might need to maintain some awareness of what time it is on Earth. I'm reminded of the opening scene of Planet of the Apes when Charlton Heston was looking at the chronometers comparing "Ship Time" with "Earth Time."

So, a second was still a second on board the ship, even if a considerably longer period of time was passing on Earth.

 

[JustGeorge]

Be careful how you ask your kids for "moon" power.

We're used to it around here.

One kid can't keep pants up(no plumber's crack, a baker's pair); I don't think he's aware when they slip.

My husband is of the type that intentionally buckles his pants under his buttcheeks. He wears boxers, but they sometimes become thread bare. My oldest has been slowly threatening to do the same, becoming a mini version of his stepfather...

The youngest almost always has his pants on correctly, and when they slip, he curses them for being stupid, and fixes it.

 

[Revoltingest]

If the earth is spinning faster does that mean I've lost weight?

Yes.
The diet is working, eh.

 

[Revoltingest]

We're used to it around here.

One kid can't keep pants up(no plumber's crack, a baker's pair); I don't think he's aware when they slip.

My husband is of the type that intentionally buckles his pants under his buttcheeks. He wears boxers, but they sometimes become thread bare. My oldest has been slowly threatening to do the same, becoming a mini version of his stepfather...

The youngest almost always has his pants on correctly, and when they slip, he curses them for being stupid, and fixes it.

You have my sympathy.

"Baker's pair"?
Not even in urbandictionary.com.