The leap second seriously distorts our measurement of time. But we have no easy alternatives

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Leap year has always been a little botch to align our calendar to what the Earth takes to go around the Sun, but there is another small botch that is even more problematic: that of the leap second, which has been making us Easter for several decades. The vast majority of the world wants to kill that uncomfortable time span, but doing it is much harder than saying it.

what is a second. as they explain in The New York Times, traditionally the second was measured in astronomical terms: it was 1/86,400 of the mean solar day (the time it takes the Earth to rotate on its axis). In 1967, metrologists redefined the measurement of time with atomic clocks, establishing that one second corresponded to 9,192,631,770 vibrations of a cesium 133 atom. And 86,400 of those seconds made up one day.

Second interqué? The problem is that the Earth’s rotation slows down slightly from year to year, and the astronomical day has ended up being longer than the atomic day. In 1972 metrologists began inserting an extra second—the so-called “leap second”—at the end of the atomic day. In practice, when atomic time is “off” one second, it stops for exactly one second to allow those scales to be re-adjusted. That year 10 leap seconds were added to the atomic scale, and another 27 have been added ever since.

GPS, GLONASS, BeiDou and Galileo: what are they and what are the differences

Let’s kill the leap second. Making these adjustments is not easy, especially in a world that is hyperconnected like the current one, so experts from all over the world advocate a radical solution: kill the leap second. It was attempted 20 years ago, but stumbling blocks remain such as Russia, which voted to delay the move because doing so would require major modifications to its GLONASS system. And here comes something curious.

GPS would be an alternative. All this conditions the operation of the UTC system with which the world coordinates its clocks. Its operation is tremendously complex, and the leap second does not help. An alternative to UTC would be the GPS global positioning system, which is managed by the US Space Force through atomic clocks.

Three Powerful Benefits… The first, that it is hyper-precise (it is capable of determining the time up to 100,000 millionth of a second). The second, that this information is free and publicly available. And the third, that does not take leap seconds into account (like the European Galileo system), which makes it an uninterrupted time flow system.

… a big drawback. The problem is that the GPS system is controlled by the United States and its military “without national or international supervision,” as they indicated. in a recent study the heads of the BEEP (Bureau of Weights and Measures), the international body that manages both the International System of Units (SI) and the UTC scale.

each one to his ball. The added difficulty is that GLONASS is based on UTC but other satellite navigation systems do not. Both GPS and Galileo are 18 seconds ahead of UTC, while Beidou, the Chinese system, is four seconds ahead.

Something similar happens with the way that large technology companies —which manage the clouds to which everything is connected— manage the leap second. Google is adding it fractionally throughout the day, while Meta, Alibaba or Microsoft add it as they consider best, they explain in NYT. One of the BIPM experts, Dr. Tavella, had his own opinion of the system. “It’s an anarchy.”

Buckle up, the negative leap second is here. As if that weren’t enough, the Earth’s rate of rotation is changing and began to speed up around the time the leap second was introduced. It is estimated that in a few weeks Earth time will catch up with atomic time, but by 2030, if that trend continues, Earth will be a second ahead of atomic time, so metrologists are preparing for something unprecedented: adding a negative leap second. . In fact, a second of our time will simply disappear. That has never been done, and the implications for our computer systems are unpredictable.

Deadline, 2035. Although there is reluctance, those who advocate the definitive elimination of the leap second propose 2035 as the deadline. From that moment on, atomic time would be used globally and the difference between that time and terrestrial time would end up being handled in some way, although how has not yet been specified. It is expected that on November 18 this resolution will be voted at a BIPM meeting in Versailles, and then perhaps we will know if the leap second has an expiration date or not.

Leap year has always been a little botch to align our calendar to what the Earth takes to go around…

Leap year has always been a little botch to align our calendar to what the Earth takes to go around…

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