Some upcoming summer days are actually getting shorter, literally. Even if it's only by milliseconds.
While the change won't be noticeable, Wednesday might technically be the shortest day you'll ever experience. That’s because Earth completed its rotation approximately 1.3 to 1.6 milliseconds faster than the average 86,400 seconds.
"In other words, we’re not traveling back toward the Mesozoic in terms of rotation," Popular Mechanics reports. "The planet will eventually continue its steady deceleration — this is, of course, its natural tendency, but surface changes like polar ice melt can also contribute to the Earth’s rotation slowing down."
This phenomenon is invisible to daily life but of significant importance to high-precision timekeeping systems such as atomic clocks, GPS, and satellite networks.
Scientists at the International Earth Rotation and Reference Systems Service attribute the acceleration to a subtle shift in the Moon’s orbital alignment, which, orbiting farther from Earth’s equator this summer, has reduced the “tidal braking” effect that normally slows our planet’s spin.
Others, such as Moscow State University astronomer Leonid Zotov, said the cause of this acceleration is unexplained.
"Most scientists believe it is something inside the Earth," he told Timeanddate.com. "Ocean and atmospheric models don’t explain this huge acceleration."
This spike in rotational speed marks the sixth occurrence of unusually fast days since 2020, with similar events expected to occur on July 22 and August 5.
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In response to the slight change, the International Earth Rotation and Reference Systems Service is now considering implementing a negative leap second, a rare adjustment that subtracts time from Coordinated Universal Time to resynchronize clocks with Earth’s rotation.
Such a correction has never been made before, but the growing trend may require one around 2029.
