NIST scientists have published the latest values for fundamental constants of nature in the journal Reviews of Modern Physics. These values are based on a least-squares adjustment of all relevant theoretical and experimental data available through December 31, 2018.
The 2018 values recommended by the Committee on Data of the International Science Council (CODATA) are the most recent available, updated every four years. Major improvements include a decrease in the uncertainty of the fine-structure constant and nearly two orders of magnitude improvement in elementary particle masses due to the transition to the revised International System of Units (SI) with its exact value for the Planck constant.
Inconsistencies within the data remain, such as disagreements among experimental determinations of Newton’s gravitational constant and the charge radius of the proton. The inconsistency for the magnetic moment of the muon between experimental and theoretical values is still unresolved.
The over 300 CODATA recommended values can be found at physics.nist.gov/constants, an interactive website allowing users to retrieve data on individual constants, groups of related constants, and correlations among constants. The Newtonian constant of gravitation, G, and the Planck constant, h, are the most frequently requested constants.
Source: https://www.nist.gov/news-events/news/2021/07/latest-values-fundamental-constants-published
Keywords: Constants, Standards, Uncertainty, Metrology, SI
