2024-08-23 06:53:02
Cosmology is one of the most challenging scientific disciplines. Over the past few decades, astrophysicists have made significant strides in our understanding of the universe, but humanity is still a complete ignorant when looking at the cosmos with transparency and honesty. We don’t even fully understand the cosmological behavior of our own planet. This is at least what the study published by several geoscientists from different research institutions in the Proceedings of the National Academy of Sciences invites us to conclude.
On this occasion, it is worth starting with their conclusion, which is the most striking: the rotation of our planet is slowing down. Moreover, it has been doing so for millions of years. At first glance, it seems reasonable to assume that the Earth’s rotation speed is constant as a result of the permanent gravitational interaction it holds with the objects in its surroundings and the almost total absence of variation in its mass. But it isn’t. It is not constant. And, furthermore, explaining this behavior is not easy at all.
The slowing of the Earth’s rotation follows a stepped pattern
This is not the first research demonstrating that the rotation speed of our planet is decreasing, but it is the first one that consistently records to what extent this deceleration is taking place. To reach this result, the involved scientists have analyzed sediment samples that date back no less than 650 million years. However, the most interesting aspect is that they set out to dissect eight sets of geological data that span the period from 280 to 650 million years ago.
These scientists have observed that one of the stable periods occurred during the enormous diversification of life that took place in the Cambrian
The first surprise revealed by their research is that the slowing of the Earth’s rotation has not been particularly smooth. The second is that it has not been constant. This simply means that the rate of slowing of our planet’s rotation varies over time. In fact, according to the scientists who authored the study mentioned in the first paragraph of the article, the deceleration follows a stepped pattern. Practically, this behavior suggests that periods of significant slowing alternate with others in which the rotation speed is essentially stable.
The stepped pattern that describes this behavior is unexpected. And difficult to explain. Nonetheless, these scientists have observed that one of the stable periods occurred during the enormous diversification of life that took place in the Cambrian, and the other during the greatest mass extinction known. The latter occurred at the end of the Permian period and triggered the disappearance of approximately 96% of marine species and 70% of terrestrial species. The devastation on our planet was such that this period is known as “the Great Mortality.”
The complexity of the phenomenon we are investigating has not prevented these researchers from concluding that in modern times, the slowing of the rotation has been caused by tidal dissipation. This mechanism has been triggered by the dissipation of orbital and rotational energy caused by the warming of the ocean surface waters, the behavior of the planet’s interior layers, or the dynamics of the Moon.
In fact, the natural satellite of our planet stretches and compresses as it moves away from and closer to Earth, causing a phenomenon known as “tidal heating.” Currently, these scientists are trying to establish links between changes in the Earth’s rotation and major environmental events. We will closely follow their work to report on the new conclusions they reach.
Image | SpaceX
More information | Proceedings of the National Academy of Sciences
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