On Schizophrenic Experiences of the Neutron or Why We Should Believe in the Many-worlds Interpretation of Quantum Theory

There are many interpretations of quantum mechanics, and new ones continue to appear. The Many-Worlds Interpretation (MWI) introduced by Everett (1957) impresses me as the best candidate for the interpretation of quantum theory. My belief is not based on a philosophical affinity for the idea of plurality of worlds as in Lewis (1986), but on a judgment that the physical difficulties of other interpretations are more serious. However, the scope of this paper does not allow a comparative analysis of all alternatives, and my main purpose here is to present my version of MWI, to explain why I believe it is true, and to answer some common criticisms of MWI. The MWI is not a theory about many objective “worlds”. A mathematical formalism by itself does not define the concept of a “world”. The “world” is a subjective concept of a sentient observer. All (subjective) worlds are incorporated in one objective Universe. I think, however, that the name Many-Worlds Interpretation does represent this theory fairly well. Indeed, according to MWI (and contrary to the standard approach) there are many worlds of the sort we call in everyday life “the world”. And although MWI is not just an interpretation of quantum theory – it differs from the standard quantum theory in certain experimental predictions – interpretation is an essential part of MWI; it explains the tremendous gap between what we experience as our world and what appears in the formalism of the quantum state of the Universe. Schrödinger’s equation (the basic equation of quantum theory) predicts very accurately the results of experiments performed on microscopic systems. I shall argue in what follows that it also implies the existence of many worlds. The purpose of addition of the collapse postulate, which represents the difference between MWI and the standard approach, is to escape the implications of Schrödinger’s equation for the existence of many worlds. Today’s technology does not allow us to test the existence of the “other” worlds. So only God or “superman” (i.e., a superintelligence equipped with supertechnology) can take full