Countries consider time out on the 'leap second'

Jan 17, 2012 By FRANK JORDANS , Associated Press
Time could soon be up for the leap second -- the extra moment added to universal time to keep it in sync with the earth's movement -- as experts consider abolishing it later this week.

It's high noon for the humble leap second. After ten years of talks, governments are headed for a showdown vote this week on an issue that pits technological precision against nature's whims.

The United States, France and others are pushing for countries at a U.N. telecom meeting to abolish the leap second, which for 40 years has kept computers in sync with the Earth day.

Leap seconds are necessary to prevent atomic clocks from speeding ahead of solar time. They are added at irregular intervals, effectively stretching atomic time by a heartbeat to make up for the irregular wobble in the Earth's rotation.

Critics warn that scrapping the leap second would break the last link between the passing of time and the course of the sun across the sky. But backers say machines shouldn't any longer be tethered to the imprecise cycle of sunrise and sunset.

"This would be an important decision because the problem of introducing the leap second would disappear and we would have a more steady time than we have today," Vincent Meens, an official at the International Telecommunication Union who has chaired technical talks on the issue, said Tuesday.

Operators of cell phone networks, financial markets and air traffic control systems could then rely on the near-absolute precision offered by atomic clocks without having to worry about stopping their systems for the length of a heartbeat every year or two.

"Most of the people who operate time services favor discontinuing leap seconds," said Judah Levine, a physicist at the National Institute of Standards and Technology in Boulder, Colorado.

"The main problem is that the leap second is usually implemented by stopping the clock for one second. However, the world doesn't stop," he said.

Satellite navigation systems like GPS don't use leap seconds, which adds confusion, said Levine. "In addition, the leap second occurs in the middle of the day in Asia and Australia, which is particularly inconvenient."

In a world increasingly reliant on computers for mission-critical measurements, any glitch could be costly as well as fatal, said Elisa Felicitas Arias, director of the time department at the Paris-based International Bureau of Weights and Measures.

"You can make a dramatic error if, for example, you are trying to land an aircraft," she said, noting that rocket launches, too, are never scheduled on days when a leap second might occur. "This is something we are trying to correct."

Critics say the risks are overblown and leap seconds have been used successfully since 1972, despite being hard to predict more than six months in advance.

China has warned that any change could hurt astronomers, who need to be able to compare observations spanning thousands of years as part of their work.

Canada, too, has raised objections to the proposed plan, while Britain has warned that it could spell the end of Greenwich Mean Time, or GMT, as a meaningful measure.

"Leap seconds are an inconvenience to the telecommunications people, but there are many other users of time who should be considered," said Ken Seidelmann, a research professor at the University of Virginia in Charlottesville and former director of astrometry at the U.S. Naval Observatory.

Killing off the leap second would also result in atomic clocks slowly outrunning the solar day by a rate of about 90 seconds a century. After many thousands of years, atomic clocks would say it's midday when outside the sun has yet to rise.

"This is replacing a small problem with a big problem further down the line," said Daniel Gambis, an astronomer at the Paris Observatory and the man who alerted timekeepers around the world to the next leap second, due on June 30.

Arias said solutions could be found for such problems, but conceded that severing the link between the proposed new standard time - as measured by atomic clocks - and the solar time people are accustomed to might seem troubling to many.

Still, the time for change has come, she argued.

Unless a last minute consensus is reached, delegates at the ITU meeting in Geneva are expected to vote on the issue Thursday or Friday.

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User comments : 18

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Xbw
1.4 / 5 (11) Jan 17, 2012
Oh great. Now I have to rework my entire morning routine. How am I going to get to work on time?
rawa1
3.7 / 5 (7) Jan 17, 2012
I wouldn't recommend it. The sudden addition of second will lead to breaking of time arrow and into the space-time rip followed with phase transition of vacuum, which will end the world as we know it.
danlgarmstrong
5 / 5 (1) Jan 17, 2012
Why cant those who need an ultra precise time just adopt their own calendar? People already use more than one (we are soon going into the Year of the Dragon), and it should be no problem to convert the ultra precise date to any other convention.
Cave_Man
not rated yet Jan 17, 2012
I wouldn't recommend it. The sudden addition of second will lead to breaking of time arrow and into the space-time rip followed with phase transition of vacuum, which will end the world as we know it.


Unfortunately your ill conceived idea has been a rather neat argument for the destruction of mankind. Good one.
350
2 / 5 (3) Jan 17, 2012
Why not just calculate the leap seconds into the extra time alotted to a leap year and fix the discrepancy at the end by having one minute that lasts a couple seconds longer? Predictable, simple and satisfies everyone minus the programmers who have to add one extra line of code...
Kingsix
3 / 5 (2) Jan 17, 2012
Pretty much what I was thinking. Noone will care if the sun rises at 5:45 and 10 seconds instead of 5:45 and 11 seconds. Just increase the adjustment and increase the time between fixes.
verkle
1 / 5 (5) Jan 17, 2012
Sounds like the problem is in the programming of the atomic clocks, and they were made to run too fast (slight programming error of years ago...) Can we instead slightly lengthen the definition of an atomoic second?
LordHellFire666
not rated yet Jan 17, 2012
350, Kingsix, verkle:
Unfortunately it is not so "simple" to either change the length of the atomic second or introduce a 1 second leap at the end of the year. There are billions of clocks in the world. Some in software, other in hardware (such as a wrist or pocket watch). Software clocks in Operating Systems, such as Windows and OSX (or in BIOS, which is usually where the clock in a computer is located), could potentially be altered to work in this newfound fashion, but can you imagine the havok it would cause with the programs relying on the clock in the OS? If the program is made so it requires 1 minute to be exactly 60 seconds, but suddenly it is 60 seconds 1/365th of a second, this will cause computational errors. Also, if the clock is in BIOS, you'd have to get EVERYONE to update their BIOS firmware for it to work everywhere.
Finding a new way to keep track of time is not easy. The Y2K "bug" is nothing compared to the problems a new required definition of time would entail.
Kev_C
1 / 5 (2) Jan 17, 2012
Ah! The Y2K bug......again. I wonder how much money has been wasted arguing this 'new' totally pointless 'Time' argument? How many people have time pieces that are actually out by a couple of minutes, if not more? I know I have several clocks in my cottage and none of them are reading the exact same time. They are out by anything up to a couple of minutes. And don't even start with the mobile phones, computers or the digital clock in my car. Phew! All those time pieces to set and reset every couple of years because they are one second out.

Get a life people and stop making excuses for not doing what you should be doing. Change the time every time it needs changing. Solar time predates human existence and therefore has Grandfather rights. Problem sorted.
Now how long did that take me to sort out? Cheap at half the price. :)
Au-Pu
1 / 5 (3) Jan 17, 2012
The problem is in the atomic clocks.
The solution is to fix the atomic clocks
We need to stay synchronised with the natural world
If the pathetic programmers are unable to fix their atomic clocks then throw them out and bring in a new batch who can fix them
Dr_Doe
not rated yet Jan 17, 2012
"without having to worry about stopping their systems for the length of a heartbeat every year or two"
....Am I missing something, what's the problem here?

"After many thousands of years, atomic clocks would say it's midday when outside the sun has yet to rise."

Well, That definitely is something to worry about.....
antialias_physorg
not rated yet Jan 18, 2012
After many thousands of years, atomic clocks would say it's midday when outside the sun has yet to rise

There is a bias we would be introducing. think about weather data which is correlated times it is taken at. The differnce between "sun has already crept over the horizon" and "sun is still below horizon" has a marked influence on temperature data. Not adjusting for leap seconds would give us seemingly higher temperatures over the years at a certain date and a certain time. Measurements are so sensitive that such an influence would stand out after a short period of time.

...just one example I came up with within 20 seconds. Im sure there are man others where natural phenomena and times are considered in conjunction.
finitesolutions
4.6 / 5 (9) Jan 18, 2012
Since we are at it can we also change the year 0 from the year of Jesus' execution to something more meaningful?
Separation of time and religion will be great.
tkjtkj
not rated yet Jan 18, 2012
Of course, we could redefine the "second" to be a bit longer .. Perhaps not entirely perfect, as wobble is a bit irregular, but probably 'perfect enough' for a million years ..
I prefer the 'simply elegant' approach ;)
Ben74
5 / 5 (1) Jan 18, 2012
The problem is not with atomic clocks as their accuracy is better than a second over many millions of years.

It has to do with the fact that Earth does not rotate at exactly the same speed every day as some factors alter it, such as weather patterns, even major earthquakes. Also the Earth slows down by a tiny amount each year.
LuckyExplorer
not rated yet Jan 18, 2012
Did anyone really think or just babble when proposing to alter the lenth of a second?

Do you know anything about physics?
1 second is a basis for lots of physical units.

Simply:

F = m*a ...

F will not be the same as it was before!
You will not be able to compare older results with new ones easily.
Jaeherys
5 / 5 (7) Jan 18, 2012
@finitesolutions

Use human era time. Today's date is January 18, 12012 HE.
tkjtkj
3 / 5 (1) Jan 18, 2012
Did anyone really think or just babble when proposing to alter the lenth of a second?

Do you know anything about physics?
1 second is a basis for lots of physical units.

Simply:

F = m*a ...

F will not be the same as it was before!
You will not be able to compare older results with new ones easily.


Did anyone consider 'sarcasm'?