There is a new standard in town, and it's sort of a big deal. This new standard is the definition of the kilogram, the unit of mass in the SI system—the International System of Units). It replaces the ...

Metrology, the branch of science dedicated to measurement, has created better and better systems of measurement for the kilogram based on fundamental principles rather than arbitrary chunks of metal ...

In November, scientists and diplomats voted unanimously to redefine the kilogram. They decided the kilogram will no longer be based on a physical piece of metal, but on a math problem instead.