Scientists at the National Physical Laboratory in England recorded the shortest day in history last June 29 - 1.59 milliseconds less than the standard 24 hours.

Scientist Leonid Zotov told CBS News, "Since 2016 the Earth started to accelerate. This year it rotates quicker than in 2021 and 2020." Zotov and his colleagues believe that the Earth's tides caused the fluctuation.

Data taken from the International Earth Rotation and Reference Systems Service shows that the year 2020 had 28 of the world's shortest days on record since atomic clocks were developed. The shortened days are reported to be caused by the Earth's rotation which continues to speed up compared to its average in 2021.

Scientists are not entirely certain as to what caused this phenomenon and what this trend might mean for the Earth's future. This occurrence could signal the beginning of a period of shorter days on Earth.

Seattle Times reports that current competing hypotheses include the prevalence of earthquakes and other seismic activity, ocean circulation, movement within Earth's molten core and climate change whose melting of glaciers affects shifting weight pulls on the Earth.

While the continuing increased rotation of the Earth and milliseconds long decrease might seem irrelevant to some, one possible implication of the increasing shorter-than-usual days is the existence of a negative leap second. Where leap years contain an extra day, a negative leap second would mean that clocks would skip one second.

Scientists say that the negative leap second can negatively affect current machinery and technology. Meta engineers Oleg Obleukhov and Ahmad Byagowi shared in a post that "the impact of a negative leap second has never been tested on a large scale; it could have a devastating effect on the software relying on timers or schedulers. In any case, every leap second is a major source of pain for people who manage hardware infrastructures."

While not every day is shorter, the universal way in which time on Earth is measured may need to change if this phenomenon continues to persist.

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