Wednesday 8 July 2015

What's the buzz behind the 'leap second'



Instead of the usual transition from 23:59:00 to 00.00.00 on any other ordinary day, the day on June 30 went from 23:59:00 to 23:59:60 before arriving at 00.00.00 on July 1.

There was a bit of a buzz in anticipation of the clock running down to midnight recently, on June 30th, a day which marked the end of the first half of the year,.

The transition from 23:59:00 to 00.00.00 that night was filled with some rather intriguing and perplexing thoughts – all due to a phenomenon known as a ‘leap second’.

It was feared the said phenomenon would unleash its wrath on cyberspace, wreaking havoc on financial markets and all other manner of mischief.

I have heard of a leap year but not a leap second. #Dumbfounded.

So what is a leap second and why is there a need for one?

I soon found out that it isn’t really a new phenomenon (pardon my obliviousness). In fact, the leap second has been incorporated into the timekeeping of computers around the world since 1972. #Eurekamoment

However, adding a leap second can be perilous, as seen in recent accounts.

“Last time a leap second was added, on a weekend in 2012, Mozilla, Reddit and LinkedIn all crashed. In Australia, more than 400 flights were grounded as the Qantas check-in system went down, requiring the job to be done manually,” the Guardian Science correspondent, Hannah Devlin said.

Leap seconds meddle with the software controlling huge computing systems and the internet generally isn’t up for that sort of mess.

Last time a leap second was added on a weekend 2012.

In the previous adjustment of a leap second in atomic clocks in 2012, a number of tech giants and market players were hit badly with their systems being crashed-- in some cases for hours. Source:http://hexus.net/

CNN’s David Goldman explained, “The code for most large scale systems is based on UNIX, software that traces its roots to 1970 -- two years before leap seconds ever existed.

“Computers check in from time to time with the International Earth Rotation and Reference Systems Service's (IERS) network to make sure that they are telling the time correctly like wristwatches, they have to be "rewound" every now and then.”

According to Goldman, “The IERS is an alternative to the atomic clock, which precisely measures a day in 86,400 seconds but doesn't account for the fact that a day is not exactly 24 hours. When the IERS determines that we're all living about a second ahead of where we should be, it declares a leap second.”

IERS would inform computers that the final minute of that day according to Greenwich Time would have 61 seconds when leap seconds run its course.

So, instead of the usual transition from 23:59:00 to 00.00.00 like any other ordinary day, the end of June 30 went from 23:59:00 to 23:59:60 before arriving at 00.00.00 on July 1.

Due to the problems observed in 2012, it understandably raised some concerns this time around. However, the Internet didn’t crash, due to preemptive measures taken by stakeholders.

As to why there is a need for a leap second, who better to provide the answer than a bunch of rocket scientists?

The National Aeronautics and Space Administration (NASA) in Astronomy Now, said the need for a ‘leap second’ was due to “the gravitational tug of war between Earth, the moon and the Sun” which gives rise to a form of decelerating force, leading to the gradual slowdown of the Earth’s rotation.

So basically we need this extra second, to account for the gradual slowdown of Earth’s rotation.

But whether we need it or not, depends on who you ask though.

Britain, Russia and China seem to favour it, justifying that the technical challenges are manageable. The US and France however are strongly against it, said Hannah.

The battle will likely continue until a decision about the leap second is made by the special UN body, the International Telecommunication Union that, looks over matters pertaining to information and communication technology. 

- Source: AFP

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