A word cloud representing usage of NIST’s Fundamental Constants website between June 2018 and June 2019. The size of the symbol for a constant indicates how often its value is accessed. Usage data is from 200,000 unique page views..
Credit: K. Olsen/NIST
Four scientists from the National Institute of Standards and Technology (NIST) have reported the latest values for the fundamental constants of nature on June 30 in the journal Reviews of Modern Physics.
Maintaining and improving standards are important aspects of work performed at NIST. In collaboration with researchers around the world, NIST scientists regularly collate the world’s most accurate values of the basic constants that appear in the laws of nature as currently understood. Examples are the masses of the electron, muon, and light nuclei as well as coupling constants such as the Newtonian constant of gravitation and the fine-structure constant. Equally important are physicochemical constants such as the Boltzmann constant.
The 2018 values of constants and conversion factors of physics and chemistry recommended by the Committee on Data of the International Science Council (CODATA) are the most recent available because CODATA updates the material every four years. The values are based on a least-squares adjustment that takes into account all relevant theoretical and experimental data available through 31 December 2018.
In the publication, major improvements as well as inconsistencies within the data are discussed. The former includes 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. Further, because the elementary charge, Boltzmann constant, and A ..
Support the originator by clicking the read the rest link below.
