Originally Posted by Myriad
You have it backwards. QM is the theory with free parameters, fudge factors, coming out the whazoo. Like epicycles, wheels upon wheels. Like epicycles it does work pretty well for computation. But it is based on unphysical principles.
Along comes gravitational theory and the equations of motion and things are much simpler. Sometimes not as accurate when higher order effects are not accounted for, but still, a vast improvement from what was before.