Deep underneath the Parisian suburb of Saint-Cloud, in a vault that can only be opened by three people wielding three different keys, there lies a hunk of metal that is so crucial to the world of ...

You may have never heard of the solid metal cylinder known as Le Grand K, but it's most definitely impacted your life in countless ways. Le Grand K is kept in Paris, where it's been for over 120 years ...

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 U.S. National Institute of Standards and Technology called this Friday a “turning point for humanity,” even though the difference between this day and the day before weighs, theoretically, nothing ...