Earth’s rotation isn’t constant. Billions of years ago, a day lasted only about 18–19 hours, gradually slowing to today’s 24 hours due mainly to the Moon’s tidal pull. Recently, slight changes in Earth’s core, oceans, atmosphere, and melting ice have caused tiny fluctuations, making some days milliseconds shorter and raising the possibility of a future negative leap second. Want more interesting content like this ? Follow gravitonomy :) Via : Unknown No copyright infringement intended. Kindly DM for Credit/Removal/Collaboration :) #science #motion #physics #rotation #atomicclocks