Quantum Measurement, the Simplest Interpretation

Many different interpretations of the Quantum Theory have appeared over the one hundred years since its first formulation. The paper presents a detailed physical analysis of the process of quantum measurement, which is crucial in the development of a sound interpretation of the theory. The process of quantum measurement can be decomposed into three elementary steps, and the projection of state (or collapse of the wave function) is applied at the last step, the reading of the result of measurement by an observer. This determines a crystal clear simplest interpretation of the process and the alternative interpretation, supported by many interpretations of the theory, is obviously much more complex, so that Ockham’s razor can be applied. Once this is established, a corresponding interpretation of the quantum state follows. We discuss some important issues as the superposition of states (or Schrodinger cat states), the wave particle duality and the non-local process associated to entanglement. In conclusion, many of the proposed interpretations of Quantum Mechanics appeared along the last decades can be firmly rejected, but there are open questions.