Jon Pratt is leader of the Fundamental Electrical Measurements Group at the National Institute of Standards and Technology in Gaithersburg, Maryland.
A Mathy Makeover For The Kilogram
Standardizing our mass measurements relies on an elaborate and exacting physics experiment.
Redefining the Kilogram
All the scales in the world are calibrated against a 125-year-old chunk of metal in a vault on the outskirts of Paris. Now scientists are looking to redefine the standard of what “kilogram” really means.