From the page: "he means the Earth窶s mass is now slightly more concentrated around its axis. Like an ice skater bringing here arms in to spin faster, conservation of angular momentum means the Earth窶s spin has sped up making a day 1.6 milliseconds shorter. Interestingly (for certain values of 窶interesting), this actually makes a day closer to 24 hours long. See there are 86,400 seconds in 24 hours. The STI unit for seconds is set as 9,192,631,770 periods of the cesium atom and that hasn窶t changed but, because events like this earthqu"