Say Au Revoir To That Hunk Of Metal In France That Has Defined The Kilogram

The world is about to say au revoir to Le Grand K, a cylinder of platinum and iridium that has long reigned over the world's system of weight measurement.

Le Grand K was forged in 1879 and is held in a locked vault outside Paris — revered and kept under lock and key because its mass, a little over 2 pounds, is the official definition of the kilogram.

But this is will soon change. On Friday, the international General Conference on Weights and Measures will meet in Versailles, France, to vote on whether to redefine the kilogram.