Faster Rotation of Earth May Shorten Time by One Second

The changing rotation of the Earth has unprecedentedly affected our sense of time and clocks, to the extent that for the first time in history, world timekeepers may have to subtract a second from the clock in a few years because the Earth is spinning slightly faster than before. A study published in the journal Nature suggests that clocks may jump by one second around the year 2029. Duncan Agnew, the lead author of the study and a geophysicist at the University of California, San Diego, told the Associated Press, "This is an unprecedented situation and a big issue, and although there has not been a massive change in the Earth's rotation that would lead to a disaster, it is a significant phenomenon." Agnew explained that the melting ice at both poles has reduced the planet's rotational power and has likely delayed the calculation of universal time by about three years. This is a complex situation involving physics, global politics, climate change, technology, and two types of time. The Earth's rotation takes about 24 hours, but the key word is "about." Agnew and Judah Levine, a physicist at the National Institute of Standards and Technology, say that the Earth has been generally slowing down for thousands of years, with its speed varying at different times. This slowdown is primarily due to tidal effects caused by the moon's gravity. Until 55 years ago, when atomic clocks were accepted as the official time standard, this issue was not significant because they did not slow down. This created two versions of time: astronomical and atomic, which did not match. Astronomical time was 2.5 milliseconds behind atomic time each day. These daily fractions of a second were added every few years to form complete seconds. Since 1972, international timekeepers decided to add a "leap second" in June or December to astronomical time to align it with atomic time. Instead of reaching midnight at 11:59 and 59 seconds, there would be an additional second at 11:59 and 60 seconds. A "negative leap second" would jump from 11:59 and 58 seconds to midnight, skipping 11:59:59. Between 1972 and 2016, with the Earth's slowing speed, 27 separate leap seconds were added, but the rate of slowing was decreasing. Levine stated, "In 2016 or 2017 or perhaps 2018, the rate of Earth's slowdown decreased to the point that the Earth began to speed up. Scientists are still unsure about exactly what will happen and when, likening this to predicting stormy weather, but they say the likelihood of a negative leap is much higher than it was 25 years ago. Yasmin Maqbali, the commander of the Crew-7 space mission, returned to Earth after six months. The Japanese lunar probe survived a tough night and reestablished communication with Earth. Exclusive: Countdown to the start of a simulated journey to Mars; an Iranian scientist is also involved in this mission. Atomic scientists: "The Doomsday Clock" is closer to midnight than ever.