After decades of groundbreaking laboratory work, the world’s scientific and technical community came together on November 16, 2018, to redefine kilogram (kg), ampere (A), kelvin (K) and mole (mol) — four of the seven base units for the International System of Units (SI), informally known as the metric system. The event was the 26th General Conference of Weights and Measures and was hosted by the International Bureau of Weights and Measures...
