Today, for us, the calendar is a time system. And everyone is familiar with the concept of a leap year: so that our calendars do not lie, every fourth February becomes one day less curly. And to make the calendars lie even less, every 400 years February 29 is cancelled.
But the concept of a leap second is much less common. What is this second?
The fact is that our planet turns around its axis not only in 24 hours (this difference, coupled with the inaccuracy of 365 days a year, leads to tricks with leap years), but also unevenly from year to year. In recent epochs, the rotation of the Earth is gradually slowing down. With dinosaurs, there were even less than 23 hours in a day!
Yes, and this slowdown, it turns out, is uneven ... Horror! That is, for our ordinary life, it is absolutely not horror, but for astronomers, it is it. What is a millisecond for you and me - but nothing! And for astronomers, light travels as much as 300 kilometers in that millisecond!
Seriously, this is exactly what is serious, since it affects the accuracy of determining the coordinates of space objects. Including, by the way, both satellites and all sorts of Travel. As a result - errors in the management of these devices and wasted gigantic (space) money ... Or even something worse.
Therefore, the concept of a leap second was once introduced into the world community. On behalf of the world community, this decision was made and then carried out by the International Earth Rotation and Reference Systems Service, based in Paris. This organization tracks, among other things, the mean solar time (UT1), calculating it from the angle of rotation of the Earth relative to quasars. More specifically, with respect to the International Celestial Coordinate System (ICRS)…
But we will not go into specific details. The fact is that when a discrepancy between this UT1 and the time we all live here (on Earth) is found - it is called universal coordinated, UTC, and is measured by super accurate atomic clocks - more than ± 0,9 seconds is added (or , in theory, is subtracted) this is the most leap second. This happens at midnight, either June 30 or December 31. Until now, it was just added, so after 23:59:59 it was 23:59:60, and only then 00:00:00.
It would seem that everything is fine. However, it was not there. As we have already said, the rotation of the Earth is somewhat uneven: it slows down now more, then weaker, and it is possible that, on the contrary, it will suddenly begin to accelerate. And to predict how it will go, modern science can not. Therefore, everything happens after the fact, without any algorithms. As a result, powerful failures of the world's computer systems occur. There have been cases when confused systems (for example, the popular news aggregator, also known as the social network, Reddit) freeze for almost an hour. No, thank God, a nuclear catastrophe did not happen because of this, but many entrepreneurs suffered significant losses ...
The inability of the kernel of a system such as Linux to handle leap seconds has also led to numerous crashes. In the Meta Corporation, in turn, they suffered with the “blurring” of these seconds by 17 hours. NASA sounded the alarm. Didn't recognize GPS leap seconds. And so on…
As a result: on November 22, 2022 in Paris, at a conference of the same service responsible for the rotation of the Earth, a decision was made by popular vote to abandon leap seconds. True, since 2035. And not forever, but for 100 years. In the hope that future generations of scientists will be able to penetrate where the current ones cannot penetrate.
So: goodbye, leap second! Or rather, goodbye in 2135 ... with our great-grandchildren ...
Wristwatch with UTC:
