Quantum mechanics

Quantum mechanics is a theory that describes the interactions of subatomic particles, combining several basic discoveries, such as the observation that energy is absorbed or radiated in discrete quantities or quanta (Quantum Principle) and the Uncertainty Principle stating that it is not possible to know both the exact position and momentum of a particle (e.g. a photon or electron) at the same time. Quantum mechanics is a very solid theory in many ways; it is on the same order of fundamentalness as thermodynamics.