The Quantum SI

Abstract

This article gives an overview of the new SI and a few details as to how it was set up. Those interested in the story of how the kilogram was fixed by tying it to the Planck constant can go straight to Section 5. Otherwise, apart from the introduction given as Section 1 which also presents excerpts from the relevant official documents on the key aspects of the new system, Section 2 gives a brief timeline of the history of the decimal metric system, Section 3 gives a few details of the procedural steps—from the setting up of a standard of measurement to its percolation to the public, taking the time standard as an example, and Section 4 attempts to give a flavour of the actual process of the setting up of a standard.