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Resource Letter FC-1: The physics of fundamental constants



Peter J. Mohr, David B. Newell


This Resource Letter is a guide to the literature describing both experimental and theoretical work on the determination of values of certain fundamental physical constants. In this Letter, fundamental physical constants are taken to be the experimentally determined parameters in the equations that describe the basic laws of physics as they are currently understood. Some of these constants represent practical limits of theory since they have not been calculated, even if it were possible in principle. The numerical values of these constants are needed to make quantitative predictions by theory for comparison to the results of measurements. In fact, numerical values of the constants are periodically determined as being those that give the best agreement between the theoretical predictions and the experimental measurements. The selection of constants included here is based on the general requirements that their values have been accurately determined and that they have a well-defined place in a fundamental theory such as quantum mechanics or relativity. This includes universal constants that apply to physical laws as well as properties of particular particles such as their mass. In view of the critical role of the system of units for expressing the values of constants, literature on changes that may be made to the SI definitions in the near future is also surveyed. Not included here is the broad topic of possible time variation of the constants.
American Journal of Physics


fundamental constants, SI units


Mohr, P. and Newell, D. (2010), Resource Letter FC-1: The physics of fundamental constants, American Journal of Physics, [online], (Accessed May 30, 2024)


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Created April 1, 2010, Updated June 2, 2021