Today, On Nov 16, 2018 the General Conference on Weights and Measures (CGPM) unanimously decided to fundamentally remake the SI system of measurement units. Perhaps the most important change is that the kilogram will not be defined via a physical artefact – the platinum-iridium cylinder – but in terms of the Planck constant. As a result, for the first time the entire SI system will be defined entirely on the basis of fundamental constants, which has been the aim for decades!
The change will become effective on the 2019 World metrology day – May 20, 2019.
More information can be found in the post CGPM votes unanimously to change the SI by Dr Steve Ellison at the Eurachem website.