Quantum Mechanics is a branch of physics that deals with the behavior and properties of matter and energy on the atomic and subatomic scale. It is a fundamental theory which seeks to explain the behavior and properties of matter and energy at the subatomic level. It is concerned with the investigation of phenomena where classical, Newtonian physics does not provide an adequate explanation. It is based on the idea that particles can exist in multiple states and that observation fundamentally alters the systems observed. In short, Quantum Mechanics attempts to explain the behavior of matter and energy within the universe on the most basic level, at the level of the atom.

See also: natural selection, scientific method, split brain, consciousness