Quantum mechanics, with its superposition states, entanglement, and strange stuff (colloquially referred to as 'quantum woooo') is a theory of physics that is experimentally verifiable, describes elements of nature that we have already observed (post-hoc), and has successfully predicted elements of nature that we had not observed, but have since gone on to verify (anti-matter, for example). So it's a theory of some things (definitely not everything) that is very well tested and …show more content…
Now, the Hamiltonian evolution of a quantum state (its evolution in time) is described by the Von Neumann equation you sent earlier (basically it's a form of the Schrodinger equation); it's basically an 'ideal' equation, where there's no bath, and the information contained by the system is unchanged.
In order to model a system and environment, we create a quantum master equation, which is the Von Neumann equation with bits stuck on the end (just like adding air resistance to a Newtonian model in free space). These bits often take the form of Lindblad super-operators. Which are bits that satisfy a set of mathematical constraints that guarantee the state remains physical under the influence of the environment (no negative energy or other weird things). Which in turn lets you write your master equation as a Lindblad equation. Take a look at: