Universal Constants, Standard Models and Fundamental Metrology

Understand

Taking into account four universal constants, namely the Planck's constant $h$, the velocity of light $c$, the constant of gravitation $G$ and the Boltzmann's constant $k$ leads to structuring theoretical physics in terms of three theories each taking into account a pair of constants: the quantum theory of fields ($h$ and $c$), the general theory of relativity ($c$ and $G$) and quantum statistics ($h$ and $k$).

• These three theories are not yet unified but, together, they underlie the standard models that allow a satisfactory phenomenological description of all experimental or observational data, in particle physics and in cosmology and they provide, through the modern interpretation of quantum physics, fundamental metrology with a reliable theoretical basis.