The notion "force" keeps its meaning in quantum mechanics, though one is now dealing with operators instead of classical variables and though the physics is now described by the Schrödinger equation instead of Newtonian equations. This has the consequence that the results of a measurement are now sometimes "quantized", i.e. they appear in discrete portions. This is, of course, difficult to imagine in the context of "forces". However, the potentials V(x,y,z) or fields, from which the forces generally can be derived, are treated similar to classical position variables, i.e., .
What equation currently decribes the physics of force. What equation desribed the physics of force before the current Schrodinger equation? How are the forces derived from fields treated similarly to? What type of measurements result under Schrodinger equations when using operators instead of Newtonian variables? What notion keeps it's meaning through both Netonian and Schrodinger physics equations?