Significance
I show that quantum nonlocality is an artifact of the assumption that observers obey the laws of classical mechanics, whereas observed systems obey quantum mechanics. Locality is restored if observed and observer both obey quantum mechanics, as in the many-worlds interpretation (MWI). Using the MWI, I show that the quantum side of Bell’s inequality is entirely local. Thus, experiments confirming “nonlocality” are actually confirming the MWI. The mistaken interpretation of Bell’s inequality depends on the idea that the wave function is a probability amplitude, but the MWI holds that the wave function is a world density amplitude. Assuming the wave function is a world density amplitude, I derive the Born interpretation directly from Schrödinger’s equation.
Abstract
Quantum nonlocality is shown to be an artifact of the Copenhagen interpretation, in which each observed quantity has exactly one value at any instant. In reality, all physical systems obey quantum mechanics, which obeys no such rule. Locality is restored if observed and observer are both assumed to obey quantum mechanics, as in the many-worlds interpretation (MWI). Using the MWI, I show that the quantum side of Bell’s inequality, generally believed nonlocal, is really due to a series of three measurements (not two as in the standard, oversimplified analysis), all three of which have only local effects. Thus, experiments confirming “nonlocality” are actually confirming the MWI. The mistaken interpretation of nonlocality experiments depends crucially on a question-begging version of the Born interpretation, which makes sense only in “collapse” versions of quantum theory, about the meaning of the modulus of the wave function, so I use the interpretation based on the MWI, namely that the wave function is a world density amplitude, not a probability amplitude. This view allows the Born interpretation to be derived directly from the Schrödinger equation, by applying the Schrödinger equation to both the observed and the observer.