If it seems like the days are getting shorter; they are and have been since the summer solstice in June. But the earth recently recorded its shortest day for a totally different and unusual reason: the earth is spinning faster. Scientists have found the development puzzling, although they have theories as to why it is happening and how it may impact our lives.
June 29, 2022 was 1.59 milliseconds shorter than the average day, scientist Leonid Zotov told CBS News. The normal length of a day is 24 hours, or 86,400 seconds. But in recent years, Earth’s rotation has accelerated, shrinking milliseconds on some days. “Since 2016, the Earth has started accelerating,” said Zotov, who published a study last March about what could be causing the changes in the Earth’s rotation. “This year it’s spinning faster than in 2021 and 2020.”
This increased rotation does not shorten every day, but only occasionally. But if this continues, the primary way of measuring time on Earth – a universal, high-precision method known as atomic time – may have to change. A negative leap second might need to be added, in which the clocks would simply skip a second. “Since we cannot change the clock arrows attached to the Earth’s rotation, we adjust the scale of the atomic clock,” Zotov said.
But not all scientists are in favor of the negative leap second. In fact, Meta engineers Oleg Obleukhov and Ahmad Byagowi recently wrote a blog post criticizing the idea. They said it could lead to serious technological issues, such as data corruption. The concept has never been tested.
Some scientists theorize the Earth’s tides. Others believe that the constant melting and refreezing of the polar ice caps speeds up and slows down the Earth’s rotation.
“This is the law of conservation of momentum that applies to our planet Earth. Each atom on the planet contributes to the momentum of Earth’s angular velocity as a function of distance from the axis of Earth’s rotation,” Obleukhov and Byagowi told CBS. . “So once things are moving, Earth’s angular velocity can vary.”
“This phenomenon can be visualized simply by thinking of a spinning figure skater, who manages angular velocity by controlling their arms and hands,” they said. “As they extend their arms, the angular velocity decreases, preserving the skater’s momentum. As soon as the skater retracts their arms, the angular velocity increases. The same is happening here right now due to rising temperatures on Earth. Ice caps are melting and lead to increased angular velocity.”
In 2020, the planet experienced 28 of its shortest days in the past 50 years. The United Nations-affiliated International Telecommunication Union began adding leap seconds occasionally in June or December. The first leap second was added in 1972, and 26 have been added since.
According to Ars Technica, during a leap second, the clock jumps from 23:59:59 to 23:59:60 at 00:00:00. The middle “leap second” has caused technical problems in the past: a leap second added in 2012 caused crashes at Reddit, Gawker and Australian airline Qantas. In 2017, a leap second destroyed Cloudflare.