Humanity just made a weighty decision. On Friday, representatives of more than 60 nations, gathered in Versailles, France, approved a new definition for the kilogram.
A half-kilogram standard at NIST versus the watt balance at NIST (Salwan Georges/The Washington Post)
Leaving behind ‘Le Grand K’
Jon Pratt with the watt balance instrument at NIST. (Salwan Georges/The Washington Post)