Universal Constants as Manifestations of Relativity.

We study the possible interpretation of the "universal constants" by the classification of J.~M.~L\'evy-Leblond. $\hbar$ and $c$ are the most common example of constants of this type. Using Fock's principle of the relativity w.r.t. observation means, we show that both $c$ and $\hbar$ can be viewed as manifestations of certain relativity. We also show that there is a possibility to interpret the Boltzmann's constant in a similar way, and make some comments about the relativistic interpretation of the constant spacetime curvature and gravitational constant $G$.