If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?: Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life

by Stephen Webb

The Moon raises tidal bulges in the oceans (and, to a much smaller extent, in the continental land masses) and this acts as a frictional brake on Earth’s rotation. Every 50,000 years or so the day gets longer by about 1 second.