For more than a century, a single metal cylinder in a Paris vault quietly defined what a kilogram was. After 130 years, ...

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 ...

For more than a century, the kilogram was defined by a physical metal object locked away like a treasure. The problem was ...

In a subterranean vault in a suburb of Paris lies a small, rarely seen metal cylinder known as Le Grand K. For 130 years, this golf-ball-sized hunk of 90% platinum and 10% iridium has served as the ...

The 'one kilogram to rule them all' was cast in platinum and iridium in 1879 and is kept in a triple-locked vault THE world says goodbye to the original kilogram on May 20, on World Metrology Day.

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 ...

It’s one of those things where if you think about it too much, your head might explode. We know there are 1,000 grams in a kilogram, and 1,000 kilograms in a metric ton, but how was it ever decided ...

Scientists from around the world are gathering in France today to decide the fate of the kilogram. For nearly 130 years, the kilogram has been based on a lump of metal called the Big K, locked in a ...

The kilogram may need to go on a diet. The international standard, a cylinder-shaped hunk of metal that defines the fundamental unit of mass, has gained tens of micrograms of mass from surface ...

One of the most iconic hunks of metal in the world is set to get a demotion. The official metallic cylinder that defines the mass of a kilogram may soon be set aside in favor of a measurement that is ...

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 losing ...

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 ...