Earth may have recently experienced the shortest day in its entire history.

Contrary to common ideas, the planetary rotation is not constant. Recent studies by professors and researchers in mathematics have confirmed this fact. Of the atomic clocks have therefore been calibrated to follow the slightest variations in the speed of the Earth. Using this data, the scientists found the shortest day in the history of the planet.

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Scientists had once noticed the phenomenon of the irregularity of the periodicity of the Earth’s rotation. But today, concrete evidence could be presented. Thus, the day of June 29 was 1.59 milliseconds shorter than 86400 secondsi.e. exactly 24 hours.

Leonid Zotov, professor of mathematics, was one of the main actors behind this recent discovery. The results were published in the journal The Telegraph.

Planetary rotation is affected by oscillations

According to the researchers, the rotation speed of the planet evolves in a cyclical way. This variation in the time required to make a complete revolution is due to a periodic motion called Chandler oscillation.

In fact, this phenomenon was first observed in the late 1880s, when Seth Carlos Chandler noticed that the poles oscillate over a period of 14 months. However, this wobble slowed down in the early 2000s and in 2017 it reached its peak. lowest threshold.

Finally, although the Earth’s oscillations do not change enormously on a daily basis, they are important to follow, to keep the atomic clock up to date. In addition, a better apprehension of terrestrial oscillatory movements could make it possible to accurately coordinate GPS and Earth observation satellites.

“And between 2017 and 2020, we noticed that this oscillation disappeared. »

Leonid Zotov, professor of mathematics

The shape of the Earth also has a significant impact

Apart from external factors, the special topology of the earth also has a role to play. The researchers noticed that the earth’s oscillatory movements are not not always around the same axis (the line between the North and South poles).

Their studies revealed that the planet has a bulge at the equator, while the poles are slightly squashed, which means that the earth is slightly elliptical. Therefore, the rotation time of the latter cannot be the same at all times.

SOURCE: SCIENCEALERT

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