It’s official: We’re redefining the kilogram

Soon, our system of measurement will rely only on fundamental constants

Le Grand K

SPECIAL K  Carefully secured under bell jars, a metal cylinder known as Le Grand K defines the kilogram. Now, scientists are doing away with that benchmark, instead relying on a fundamental constant, the Planck constant, to define the kilogram.  

Courtesy of BIPM

Out with the old — kilogram, that is.