On November 20, delegations from around the world will travel to Dubai for a conference to discuss international agreements on radio frequencies, satellite coordination and other complex technical issues. Among them is a rather annoying problem regarding the measurement of time. Details are provided by The New York Times.
For 50 years they have been balancing carefully and precariously two different ways of measuring time. One method, based on the rotation of the Earth, is as old as timekeeping by humans. It is an ancient and common sense reliance on the position of the Sun and stars. The second, significantly more accurate method relies on a constant and reliable frequency from the changing state of cesium atoms to provide the precision necessary for the digital devices that control our lives.
Let’s replace leap seconds with minutes
The problem is that the times on these clocks diverge. This is because astronomical time, referred to as UT1, tends to be behind or ahead of atomic time (TAI) by ±3 milliseconds per day. Therefore, every few years since 1972, the two times are synchronized by inserting leap seconds, when the atomic clock inserts the 60th second so that the astronomical clock can catch up.
It is, however difficult to predict exactly when a leap second will be neededcausing increasing headaches for tech companies, states and world timekeepers. “Having to deal with leap seconds drives me crazy,” says Judah Levine, head of the Network Synchronization Project at the National Institute of Standards and Technology (NIST) in Boulder.
On the eve of another international discussion, Levine wrote an article proposing a new solution in the form of a leap minute. In a nutshell, it’s about synchronizing the clocks less often—perhaps once every half century—and essentially letting atomic time deviate from cosmic time by 60 seconds or even a little more. “We all need to relax a bit,” says Levine.
One world, two times
The difficulties date back to the early 1970s, when atomic time was introduced. Until then, the world relied heavily on astronomical time. It seemed logical—the sun rose and it was day, then it set and it was night, and so on, although there were slight irregularities caused by the slowing of the Earth’s rotation and other natural forces. Most of the time people didn’t notice these deviations, but the machines were already able to record them.
After the introduction of atomic time, accurate time became necessary for an increasing number of situations and applications, such as air traffic control and the timing of stock trades. “Cesium clocks became commonplace, and immediately there was a problem,” Levine describes. “Astronomical and cesium clocks began to diverge.”
Introduction of leap second in 1972 it codified that a second was added whenever the two times differed by more than 0.9 seconds. It had at least three goals: to maintain time’s connection to nature and the tradition of astronomy, to accommodate digital technology, and to align and synchronize the two times. In the last 50 years, leap seconds have been used 27 times.
And another problem came
At the turn of the century, another problem arose, which was caused by a new group of stakeholders: the big technology companies. Companies like Google, Amazon, and Facebook have developed their own methods for aligning astronomical and atomic time, essentially bypassing the leap second.
For example, Meta, instead of changing time in leaps and bounds, “blurs” the leap second in millisecond increments over 17 hours. “We’ve made a mess of time all over the world,” says Patrizia Tavella, Director of the Timekeeping Department at the International Bureau of Weights and Measures in Paris.
The Vatican and Russia are against it
Last year, Tavella discussed the leap second with Father Paul Gabor, an astrophysicist and deputy director of the science group at the Vatican Observatory in Tucson. She found that his concern was that “removing this idea could cause some uneasiness because people feel connected and want to stay connected to nature”.
Levine understands Gabor. “The public has a great distrust of scientists as people who propose something that seems to defy common sense,” he said. Still, he says, the persistence of daylight saving time seems to be an admission that people don’t mind “changing the connection between time and everyday astronomy”.
The leap minute also has other opponents. They are especially the Russians, who emphatically, albeit somewhat erratically, argued for the preservation of the leap second. It can be assumed that the Russian GLONASS satellite system is built to take leap seconds into account, and that a change in the current time measurement methodology could have major consequences for it.
This brings the world community to the World Radio Conference, which will be held from November 20 in Dubai. A debate about the leap second is on the agenda, but American time scientists are not optimistic that the debate will produce any results. Indeed, any proposed change would require consensus of all participating countries including Russia.