Deep below Paris, in a vault that can only be opened by the simultaneous turning of three keys held by three different people, is the international prototype kilogram -- the kilo against which all ...

A kilo is a kilo is a kilo, right? Wrong. Monday marks World Metrology Day, and this year's edition sees a big change in the way the kilogram unit is defined. Other WRAL Top Stories In November last ...

PARIS — A kilogram just isn't what it used to be. The 118-year-old cylinder that is the international prototype for the metric mass, kept tightly under lock and key outside Paris, is mysteriously ...

Scientists and policy makers from around 60 nations voted unanimously Friday to redefine the kilogram. The decision at the General Conference on Weights and Measures in Versailles, France was greeted ...