The Earth has been spinning faster lately

Phys.org  January 7, 2021
The atomic clocks make it possible to measure the length of a given day down to the millisecond. Since such measurements began, scientists have found that the Earth was slowing its spin very gradually (compensated by the insertion of a leap second now and then) until this past year, when it began spinning faster so much so that some in the field have begun to wonder if a negative leap negative second might be needed this year. Scientists also noted that this past summer, on July 19, the shortest day ever was recorded—it was 1.4602 milliseconds shorter than the standard. Planetary scientists are not concerned about the new finding; they have learned that there are many factors that have an impact on planetary spin—including the moon’s pull, snowfall levels and mountain erosion. They also have begun wondering if global warming might push the Earth to spin faster as the snow caps and high-altitude snows begin disappearing. Computer scientists, on the other hand, are somewhat concerned about the shifting spin speed as so much of modern technology is based on “true time.” Adding a negative leap second could lead to problems, so some have suggested shifting the world’s clocks from solar time to atomic time…read more.