A more fundamental International System of Units

Abstract

The universally accepted method of expressing physical measurements for world commerce, industry, and science is about to get a facelift, thanks to our improved knowledge of fundamental constants.

The Permeability of Vacuum and the Revised International System of Units

“…The new values of the constants will be based on determinations that have been published, or at least accepted for publication, by 1 July 2017, and which were used by the International Council for Science’s Committee on Data for Science and Technology ( CODATA ) to recommend values and uncertainties of the four fundamental constants needed to revise the present SI [Mohr 2018]. The four values will later be fixed (i.e., will become exact), and the full set of seven fixed constants will define all units in the revised SI [Newell 2014]. …”

Quantum Hall Effect: Discovery and Application

“…The base unit of electricity, the ampere, will be connected to a fixed value for elementary charge, whereas the biggest change is expected for the kilogram, which will change from a prototype to a fixed value for the Planck constant. Such a change became feasible with the development of Kibble balances, in which mechanical forces are compensated by electrical forces (50). Thanks to the Josephson and QHE, such experiments allow us to establish a direct relation between mass and the Planck constant.…”

Dimensional analysis as the other language of physics

“…We focus especially on the constants c, e, h, and k B , as the SI will begin to make use of them as base quantities in "A more fundamental International System of Units" starting in 2018. 5 In Sec. III, we then review the standard methods of dimensional analysis as used to predict the dependences (or constraints) on physical systems in an a priori way.…”