The fact that the Earth is slowing down in its spin is not a new discovery however, a new research seems to indicate that the value may be slightly different.
This new study comes to contest the formerly known value of 2.3 milliseconds per century and claim a 1.8 milliseconds one.
The new study was carried out by researchers from the London, United Kingdom-based Royal Greenwich Observatory.
Research results were published earlier this week, on December 6, in the Proceedings of the Royal Society of London A journal.
Leslie Morrison, who has been working with the laboratory for almost 40 years, went to offer details.
The team’s research was based on the centuries old written recordings left behind by our ancestors. As such, the scientists had data which went back as far as 720 B.C.
Such recordings held very detailed descriptions of solar and lunar eclipses. Back in the days of the Ancient Babylonians, such astral events were quite impressive and important happenings.
Besides the 720 B.C. Babylonian tablets, the researchers also gathered written data from ancient Greece, China, and the ancient Arab regions.
Their study was especially targeted towards solar eclipses. During such an event, the Moon is situated in between the Sun and our planet. As such, it casts a shadow on Earth and also affects its tidal systems.
Tidal systems are the main factor to have clued in scientists about our planet’s slowing down. As the water that is being tugged by the gravity of the Moon sloshes against the solid Earth, it creates tides.
Tides, in their turn, create friction which was noticed as being higher during total solar eclipses.
By studying the ancient solar eclipse accounts, researchers have been able to determine a more precise slowing down rate.
Previous theories held that the length of our Earth’s solar day increases each century with 2.3 milliseconds. A solar day is the necessary time period required by a planet so as to complete a full rotation.
As the initial tidal effect measurements suggested that Earth is taking 2.3 milliseconds more each century, the new study reached a slightly lower value.
Based on the ancient to modernity data, researchers established that our planet’s spin is slowing down by 1.8 milliseconds each year.
Whilst the difference may seem insignificant, it could actually help reveal a great deal about Earth’s history.
Duncan Agnew, a University of California, San Diego Scripps Institution of Oceanography geophysicist that was not involved in the study went to offer further explanations.
According to Agnew, the slight difference in the rotation rate of the Earth will better explain how the Earth has changed throughout the centuries. It may also help reveal how the planet will potentially change in the future.
Agnew explained that since 720 B.C., the last know planetary ice age has ended. Since then, it has been gradually rebounding from the ice retreats.
Although the glaciers retreated some 12,000 years ago, the Earth took some time to recover its shape. As such, it also altered its rotation because of the weight difference.
Over the last 2740 years, the Earth is now predicted to have slowed down by almost 6 hours.
The new 1.8 milliseconds altered slowing down value should also help scientists generate better magnetic field models.
Friction affects the movement of the liquid ore situated in the outer core of the planet which gives rise to the magnetic field surrounding Earth.
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