The leap second and the catastrophic consequences of the slowing down of the Earth’s rotation

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Planet Earth, which completed a full rotation on June 29, 2022, clocked 1.59 milliseconds shorter than 24 hours, a new record for the shortest day on record.

And the globe almost broke that record again this month, as it completed a rotation around itself in less than 24 hours by 1.50 milliseconds on July 26.

The Earth’s speed has increased recently, as in 2020 it experienced the shortest month ever measured, since the 1960s. That year, she set the previous record for the shortest day of 1.47 milliseconds in less than 24 hours, according to the Monte Carlo International website.

In 2021, the Earth continued to rotate at an increasing rate, although it did not break new records.

But when we observe it in the long term, it appears that the Earth’s rotation is slowing down. Every century, the Earth takes a few milliseconds more to complete one revolution.

If the Earth continues to rotate at an increasing rate, this may lead to the introduction of a negative leap second, to keep the rate at which the Earth revolves around the sun consistent with the measurement of atomic hours.

However, the negative second is likely to create problems for IT systems. Meta recently posted a blog post saying that adding the leap second is a “risky move that does more harm than good.”

This is because the clock will then jump from 23:59:59 to 23:59:60 before counting down to 00:00:00. Such time will lead to software crashes or data corruption due to time stamps on data storage.

The night of the thirtieth of June 2015 witnessed the addition of a “leap second” to the world’s atomic clocks, to adjust global time according to the gradual slowdown in the rotation of the planet.
The month of July came a little later this year by one second than usual, and time around the world froze to one second on the evening of the thirtieth of June 2015, due to the addition of a leap second to Coordinated Universal Time , which is the standard on which most of the time is organized and set Clocks on the planet.

The International Earth Rotation and Reference Systems Service, or IERS, which is tasked with tracking time around the world, said there was a need to add another second to UTC to account for the Earth’s irregular and gradually slowing to handle rotation according to NASA in Arabic.

The extra second was inserted a little before midnight in UTC, a little before midnight in GMT, and just before 8:00 PM EDT. Instead of the UTC clocks ticking and announcing the end of the day by moving the time from 23:59:59 to 00:00:00, it waited an extra second before declaring the day’s end as the time format was: 23:59 :60.

And the reason why this happens? The need to add a leap second is due to the fact that there are some differences between the time recorded by our atomic clocks and the time recorded by the Earth’s rotation as it orbits the Sun. But the question here: What is the reason behind this slowing down in the movement of the Earth? Dr. Tyson, an American physicist, said: “The moon slows down our planet.” He added, “It’s pulling us in with its gravitational pull, and if it succeeds, the Earth’s rotation will eventually slow down to the equivalent of a lunar month. Then the Earth and the Moon will be stuck in ‘ a condition of double tidal lock, and the result will be that both of them It will only show one face to the other.” “But if you do it mathematically, it would take a very long time for this tidal boundary between the Earth and the Moon to occur, possibly longer than the age of the Sun itself. So it’s not something we need to worry about right now.” Tyson adds. On the other hand, there are other factors that contribute to slowing down the movement of the Earth’s rotation, besides the influence of the moon, and these factors include: the violent movement observed by the molten core of our planet, the movement of the world’s oceans, the melting of polar ice, and the effects of solar gravity. Non-uniform delay Since 1972, timing has been maintained in accordance with the atomic time scale, based on an international agreement. Before the leap second was added, the Earth lost three thousandths of a second each day, and the atomic clocks just before the addition had a speed of just over six-tenths of a second. Therefore, the addition of the leap second ensured that the difference did not exceed nine tenths of a second. In addition to the leap second insertion that occurred on the evening of June 30, the period from 1972 to now has seen 25 leap second additions, the last of which was in June 2012. Leap seconds are added when necessary, as they are added either on June 30, or at the very end of the year, that is, on December 31. On the other hand, the year 1972 witnessed the addition of two leap seconds (noting that that year – ie 1972 – was itself a leap year). As for the period from 1973 to 1979, there was an annual addition of the leap second, specifically on New Year’s Eve. But from 1999 to 2011, a leap second was added to the time only twice, in December 2005 and 2008.


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