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On June 29, 2022, the planet completed its full orbit in less than its standard 24 hours, 1.59 milliseconds (just over a thousandth of a second).
The world nearly broke the record once again this month, with 1.5 milliseconds less than 24 hours on July 26.
The speed of the Earth has been increasing lately. In 2020, the planet experienced the shortest moon measured since the 1960s. The shortest day of all time was also measured that year on July 19 at 1.47 milliseconds below 24 hours.
The following year, the world continued to spin at a generally increasing rate, although it did not break a record.
But looking at much longer periods, the Earth’s rotation slows down. Each century, the Earth takes a few milliseconds longer to complete one full rotation.
It’s not clear what caused this, but scientists speculate that the slowdown could be due to processes in the inner or outer layers of the planet’s core, oceans, tides, and even changes in climate.
Some scientists suggest that the reduced duration of days may be related to Chandler’s wobble. The term in question refers to a small deviation in the Earth’s axis of rotation. According to scientists Leonid Zotov, Christian Bizouard and Nikolay Sidorenkov, who will be at the Asia Oceania Geographical Sciences Society next week, it’s like the tremor observed when a spinning top starts to accelerate or slow down.
If the Earth continues to rotate with increasing speed, this may result in the application of negative leap seconds to keep the Earth’s orbital speed of the Sun consistent with the measurement from atomic clocks.
However, negative leap seconds can create potential problems for IT systems. Meta recently blogged that the leap second “mainly benefits scientists and astronomers” but that it is “a risky practice that does more harm than good.”
The risk is that the clock goes from 23:59:59 to 23:59:60 before resetting at 00:00:00, and such a time warp crashes programs or corrupts data due to timestamps on data stores.
Similarly, when a negative leap second occurs, the clock changes from 23:59:58 to 00:00:00. Meta predicts this could have “a devastating impact on software that relies on stopwatches or timers.”
Coordinated Universal Time (UTC), the primary time standard by which the world organizes clocks and time, has undergone 27 leap seconds updates.
Meta engineers wrote:
We support the wider community effort to stop new leap seconds practices in the future and stay at the current level of 27, which we believe will be sufficient for the next millennium.
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