Abstract

We dedicate these papers to the memory of John Bell, whose contributions to, support for, and encouragement of the research program described here has meant more than words can say to those involved in it.In Schrödinger’s “cat paradox” example, a nucleus which has a 50% probability of decaying within an hour is coupled to a cat by a “hellish contraption” which, if it detects the decay, will kill the cat. If we take the point of view that what we see around us is real, what occurs in reality is one of the two following evolutions :(—> means “evolves in an hour into“).According to Schrödinger’s equation, the evolution of the statevector describing this situation isThe right hand side of Eq. (1.2) does not correspond to either the reality on the right hand side of (1.1a) nor to the reality on the right hand side of (1.1b).