The days are getting longer: the reasons are mysterious

For the eye it is not yet perceived, but The days on earth are getting longer. According to the astronomical clocks, which are very different from those of our mobile phones, the days are slowly getting longer. Even if the record for the shortest day in the last half century was set in June 2022, the general trend is to slow the circulation and thus lengthen the days. The reason is still very mysterious.

However, it must be borne in mind that the length of days is never exactly 24 hours, i.e. 86,400 seconds, since daily changes or a significant impact, such as an earthquake, can change the length of the day.

To confirm this trend are the authors of the article published on Conversationwho are respectively Director of the Australian ARC Center of Excellence in Antarctic Science, Matt King and lecturer in the School of Geography, Planning and Space Sciences at the University of Tasmania, namely Christopher Watson.

The days are getting longer: an evolving planet

“Will the sun rise tomorrow? Can‘, he answered David Hume, one of the greatest advocates of empiricism in the eighteenth century. This sentence responds in a simplified way to what the idea of ​​a philosopher and a man of science is, or that human knowledge consists of experience and habit based on impressions and ideas. In fact, if even today we thought that the day consisted of 24 hours, that is, 86,400 seconds, it is good to know that it will not always be this way.

The Earth’s rotation has slowed down over millions of years due to the tides. Over the course of millions of years, this process has been Extends each dayto the point that in some billions of years This time adds up to a total of 19 hours.

On the one hand, the Earth slows down, on the other acceleration. In fact, over the past twenty thousand years, Matt King and Christopher Watson write, the Earth has been accelerating. After the last Ice Age, the melting of the ice caps lowered surface pressure and the Earth’s mantle began to move steadily towards the poles. An example that explains this phenomenon is that the dancer rotates faster when she brings her arms closer to her body, and this is the axis on which they rotate, thus also increasing the rotation of our planet. This process reduces the duration of each day by 0.6 milliseconds per century.

operations Slower And the acceleration So it’s normal, but there are also force majeure events like earthquakes that can instantly change the acceleration or deceleration of the Earth and so can also cause Differences in duration of days.

The Earth is slowing down: A new mystery for science

We are discussing the slowing of the Earth, but the most adopted hypotheses are those that trace the phenomenon to some extent to recent events, about fifty years ago, because it is visible thanks to technological innovations. In fact, this seems to be meteorological changes and therefore Climate change to change the length of days. It could actually be an increase in the melting of the ice caps, the massive eruption of the volcano in Tonga or who knows what other phenomenon.

Then scientists hypothesized that the change in the speed of the planet’s rotation is related to a phenomenon called “Chandler’s wobble”, which is a small deviation in the Earth’s rotation axis.