Take a weight off: ‘Grand K’ kilo being retired

VERSAILLES, France (AP) — Humankind is about to sever one of the links between its present and its past. The so-called “Grand K” kilogram, a cylinder of polished platinum-iridium alloy that has been the world’s sole true kilo since 1889, is to be retired. Nations gathered in Versailles, west of Paris, are expected on Friday […]