The CODATA Task Group on Fundamental Constants has released an updated set of values for over 300 physical and chemical constants, the first major update since the redefinition of the International System of Units (SI) in 2018. This update includes exact values for key constants like the Planck constant, elementary charge, Boltzmann constant, and Avogadro constant, which now define the SI system. These changes replaced older definitions based on physical objects or specific conditions, such as the mass of the International Prototype Kilogram.
The new values are based on the best available scientific data up to the end of 2018 and include significant improvements, such as a much smaller uncertainty in the fine-structure constant and more precise measurements of particle masses. Some long-standing issues, like the proton charge radius puzzle, have been partially resolved, though challenges remain with the gravitational constant and the muon magnetic-moment anomaly. The updated constants are recommended for use in science and technology worldwide and were published in major scientific journals.
Keywords: Fundamental Constants, CODATA, SI Redefinition
