Fundamental Constants
Universal physical quantities whose numerical values are constant in space and time throughout the cosmos.
SI unit
Various
In depth
Fundamental constants determine the structure of physical laws and the scale of nature. The 2019 SI revision fixed exact numerical values for seven fundamental constants to define all measurement units.
Examples in the real world
Speed of light in vacuum (c), Planck's constant (h), elementary charge (e), Boltzmann constant (kB), and Gravitational constant (G).