When we measure the world, we measure it using base units like 'foot,' 'mile,' 'meter,' and 'second.' But who decides how big those units of measurement are? In the United States, those units are ...

The supreme arbiter of mass for humankind is a polished cylinder of platinum alloy just smaller than a golf ball. It was cast in London in 1879, unveiled a decade later in a ceremony in France, and ...

The new kilogram has finally arrived. Updates to scientists’ system of measurement went into force May 20, redefining the kilogram and several other units in the metric system. The revamp does away ...

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. In November last year, scientists and ...

In Sèvres, a small commune on the outskirts of Paris, lies a gleaming lump of metal the size of a palm. Le Grand K, or Big K as they call the platinum and iridium alloy, sits underground in a ...

How much is a kilogram? 1,000 grams. 2.20462 pounds. Or 0.0685 slugs based on the old Imperial gravitational system. But where does this amount actually come from and how can everyone be sure they are ...

After more than a century, the international prototype kilogram – a cylindrical chunk of metal stored in a French vault – doesn't weigh the same as its 40 replicas, distributed worldwide and used to ...

Out with the old — kilogram, that is. Scientists will soon ditch a specialized hunk of metal that defines the mass of a kilogram. Oddly enough, every measurement of mass made anywhere on Earth is tied ...

THE kilogram, the scientific unit of mass, is defined by a cylindrical lump of platinum and iridium, made in 1879 and stored in Paris. There are also around 40 copies of it in scientific ...

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 ...