This imperceptible trend for the general public is not always easy to manage for network administrators.
This is a detail that might surprise some, but the speed of rotation of the Earth is not perfectly fixed; it varies very slightly over time. On June 29, in an article spotted by Popular Mechanicsresearchers from the National Physical Labs (NPL) announced that this day had been the shortest on record since the invention of the atomic clock in the 1960s.
This measurement is based on records from the International Earth Toration and Reference Systems Service (IERS). It is an institution that takes care of collecting, validating and redistributing a whole lot of data on the rotation and orientation of the Earth.
Very different trends in the short and long term
As a general rule, if we reason on very long time scales, well beyond human life, the rotation of our planet slows down very slightly. It is simply a well-known consequence of its gravitational interaction with the Moon and the Sun. A article published in the prestigious magazine Science explains for example that the rotation of our cradle has slowed about 6 hours over the 2740 yearswhich corresponds to an increase of about 1.78 seconds per day.
But the IERS calculations show that the short-term trend is quite different, and even diametrically opposed. June 29 was cut by 1.59 milliseconds compared to the commonly accepted 24 hours. And this is not an isolated incident. According to the specialized site timeanddate.com, this record had already been broken 28 times in 2020, with an estimated lag of -1.47ms. This dynamic has continued to increase since then, with new surveys at -1.50ms on the 26th June, then to -1.59 ms three days later. These values have been compiled in the graph below.
It illustrates well the variability of this parameter, but also the trend it is currently following at our scale; despite annual and seasonal variations, it is clear that the average length of the day decreases over the years – and therefore the Earth rotates faster and faster.
A still poorly understood phenomenon
The origin of this strange variation remains to be explained… and for the moment, the researchers are still skeptical. Even experienced geologists exchange hypotheses on the fly on Researchgate, a portal very popular with researchers.
Some suggest it may be a consequence of the Earth’s internal geodynamics. Others believe that it is necessary rather to be interested in its orbit and its relation with the neighboring celestial bodies to complete this file. But as it stands, it still doesn’t exist no consensus.
But even if the question is obviously worth asking, the answer is not particularly important outside the framework of basic research. The consequences of these gear changes, on the other hand, are much more so.
Indeed, to compensate for the effect of the long-term slowdown described at the beginning of the article, the international community has agreed to introduce a system of ” leap seconds “. Since 1972, 27 seconds have thus been added to the universal standard, the Coordinated Universal Time.
This approach has worked well so far; but if the Earth’s rotation speeds up significantly, this sleight of hand could well become problematic. Indeed, a considerable part of the specialists believe that this time it would be necessary to introduce a “negative leap second” to dampen this recent acceleration. A prospect that already terrifies some professionals
Concrete consequences for the networks
The problem is that time management is an absolutely crucial component of modern networks. They rely heavily on so-called “timestamps”, sorts of virtual buffers that certify the date and time of an operation.
If these timestamps are wrong, then it can cause big problems for synchronization, authentication, archiving, and much more. The Windows Server documentation has a dedicated page to support this issue.
In a blog post, two Meta employees gave their point of view on the matter. They explain that each time one of these leap seconds has been introduced, engineers and system administrators have been faced with just this type of problem. ” They have caused problems throughout the industry and continue to present many risks “say the authors of the post. “ It devastates the community every time “, they lament.
The authors therefore argue in favor of a definitive locking of the current 27 leap seconds. They also explain that it would be more appropriate to look for a new system that would make it possible to compensate for these fluctuations without turning all the computer systems upside down. It will therefore be interesting to observe how the industry will respond to this problem and to follow the evolution of the speed of rotation of the Earth.