Earth rotates on its axis in 24 hours, giving us day and night as it plays its own hide & seek with the Sun. In a major development, the Earth seems to be in a hurry this year in completing its days, as instruments have found June 29 to be the shortest day in recorded history.
The Earth completed its spin in 1.59 milliseconds less than 24 hours on June 29 this year, confirming speculations by scientists that the Earth’s rotation is slowing down. The minute change was detected by the atomic clock that is used to measure the rotational speed of the planet to the minutest detail.
This is a fluctuating change from the past when timeanddate in 2020 reported that the shortest day was 1.47 milliseconds, less than 24 hours, on July 19 of that year. Last year, the shortest day was fractionally longer than in 2020.
WHY IS EARTH’S ROTATION SHORTENING?
The Earth’s rotation is affected by major forces of nature including the oceans, tides, churnings in its inner and outer layers, and even the climate, which at the moment is going through consequential changes. While scientists are yet to conclude the reasons behind the downtrend in Earth’s rotational speed, it is being attributed to the Chandler wobble.
Atomic clocks measure the rotational speed of the planet. (Representative Image)
Chandler Wobble, according to Nasa, is a motion exhibited by Earth as it rotates on its axis. Scientists in 2000 solved this mystery and said that the principal cause of the Chandler wobble is fluctuating pressure on the bottom of the ocean, caused by temperature and salinity changes and wind-driven changes in the circulation of the oceans. While two-thirds of the Chandler wobble is caused by ocean-bottom pressure changes, the remaining one-third is by fluctuations in atmospheric pressure.
It’s basically an irregular movement of the Earth’s poles across the surface of the planet.
WHAT HAPPENS NOW?
Scientists are yet to fully comprehend the effects that this minute change will have when compiled over a century. They suggest that if the planet continues to rotate faster and complete days in less than 24 hours, it could force them to add a negative leap second.
However, adding it would raise more issues than solutions, especially in the world of information & technology. According to a blog published by Meta, which has been campaigning against the addition of a leap second, the clock moves from 23:59:59 to 23:59:60 before resetting at 00:00:00, and the addition of a negative leap second would mean a time jump. This, according to the Independent, would crash computer programs and even corrupt data as time stamps change.
More details about this slow trend in Earth’s rotation are expected to be revealed during the annual meeting of the Asia Oceania Geosciences Society.
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