the an initio way

we call the quantum physics an ab initio model because it deals with mathematical model for natural phenomena in the realm of subatomic particles ( such as electrons, photons and phonons etc.). The classical mechanics is also an ab initio model because it deals with mathematical models for larger objects. The classical electrodynamics is as well an ab initio because because it deals with mathematical model for charged particles, the first principle for classical electrodynamics is the coulomb’s force.