Influenced in particular by global warming, the Earth’s rotation speed is not as fixed as one might think. And if a difference of a fraction of a second between two days has little impact on you, computers and OS can clearly be disrupted.
Since 1967, scientists called metrologists have developed infinitely precise atomic clocks to ensure that time remains a universal value, shared on a global scale. This value is particularly necessary to adjust devices such as computers, communication systems, or even GPS infrastructures.
These same metrologists then noted a slowdown in the Earth’s rotation speed and developed a system to adapt to it. But this would not work if the planet were to accelerate, which has been the case for almost a decade. This could pose real problems for the world’s IT infrastructure, far beyond the minds of metrologists.
The Earth has been spinning faster and faster since 2016
Since time has been measured so precisely, the rotation of the Earth has not always been so regular, and we have been able to observe deviations of the order of a few milliseconds from one day to the next. other, more or less. And since the beginning of the 1970s, the tendency was rather to see the rotation of the Earth slow down, that is to say that it took slightly more than 24 hours to complete its revolution. This problem was resolved thanks to the creation of a “leap second”, added to computer clocks as soon as the observed shift exceeds one second. The last time this fix was added was in 2016.
Except that since this date, the trend seems to have reversed, and now, the Earth takes slightly less than 24 hours to rotate on its axis. This phenomenon peaked in 2020, where Earth broke its record for the shortest day no less than 28 times. Given the establishment of this trend, the leap second should be eliminated from 2035. But we must now find a solution in the other direction.
1.59 milliseconds might be a detail for you
To date, the shortest day on record took place on June 22, 2022 and lasted… 1.59 milliseconds shorter than the normally scheduled 24 hours. The creation of a negative counterpart to the leap second has of course been considered, but computers and other communication systems could react very badly to it. According to Duncan Agnew of the Institute of Geophysics at the University of California, San Diego, the programs “ assume they are all positive “, and a negative second would risk causing desynchronization between the computers and the satellites.
All the reasons for this acceleration in the Earth’s rotation are not known. But, for once, global warming could well be the cause of this phenomenon. We have known since the 1950s that the melting of ice tends to slow down its rotation. Without global warming, a negative second would have been necessary from 2026, compared to around 2029 at the current rate.
Sources: 20 minutes, Franceinfo
2