Renormalisation, however, does suggest that coupling constants[0] change with the energy level involved, which then leads to the nice idea that, given an approp

Renormalisation, however, does suggest that coupling constants[0] change with the energy level involved, which then leads to the nice idea that, given an appropriate theory, one could make all these runnings match at a certain energy and then get a grand unified theory (of the strong and electroweak force) which breaks down at lower energies and leads to our three different coupling constants of the gauge groups[1]. [0] Effectively the basic rate of things happening per particle/energy/volume of spacetime etc., originally assumed to be constant. [1] Effectively things happening faster for certain types of interactions (electromagnetic vs. weak vs. strong).