Is the proposed SI revision, according to the October 2018 BIPM documents, scientifically and formally satisfactory?

TL;DR

This paper critically examines the scientific and formal adequacy of the October 2018 BIPM SI revision, highlighting issues related to the definition, implementation, and consistency of fundamental constants and units.

Contribution

It provides a detailed analysis of the implications, inconsistencies, and practical challenges of the proposed SI revision based on fundamental constants.

Findings

Experimental uncertainties do not support the claimed precision of constants.

Inconsistencies affect the final database of constants.

The hierarchy between constants and units impacts future metrological structures.

Abstract

The use of the fundamental constants for the definition of the most important measurement units of the International System, was considered a good solution to found it on more solid bases. From further analysis, this solution was found implying a number of consequences underevaluated by the BIPM until the proposal presented for discussion in November 2018 to the CGPM, or at least never clearly explained to the signatories Countries of the Metre Treaty. This lack of clarity will affect the implementations of the revised System in the future. Following previous illustrations, this v.5 of the paper is focusing on some issues of direct impact on the correctness of the new definition and on its implementation: how many digits, supported by the latest experimental values, can be stipulated for the numerical values of the constants; why the present experimental uncertainties do not support the pretended precision of the constants; how inconsistencies affect some constant final database; why the CODATA LSA analysis alone is insufficient to support the stipulated precision of the constants; how the need should be explained of keeping the former base units, in order to preserve their present magnitudes; which is the true base-units/constants relationship; how the now-installed hierarchy between the constants and the base units makes changes in the future metrological pyramid; how to still use the present top national standards in future.