Game over for the original kilogram
By 
Katrina Krämer2017-07-28T08:23:00
The big K has performed admirably for over a century but all the data is in to redefine the kilogram using natural constants
As clocks across France struck midnight on 1 July they heralded the end of the kilogram as we know it. Until that moment, scientists could submit measurements that will be used to redefine four of the seven base units: the kilogram, the ampere, the kelvin and the mole. Next year, this work will end the rule of the 128-year-old kilogram artefact and change the foundations of every mass measurement.