  Early in the development of quantum theory Bohr introduced what came to be
called the Copenhagen interpretation. Specifically, the square of the absolute
value of the wave function was to be used as a probability density. There
followed lengthy arguments about this ranging from alternative universes to
Schr\"odinger's cat. Einstein famously remarked "I am convinced that He (God)
does not play dice." The purpose of this paper is to present a mathematical
model of the measuring process that shows that the Copenhagen interpretation
can actually follow from the fact that the time development of quantum systems
is governed by the usual one parameter group of unitary transformations
exp(iHt) and that probability enters into the theory in the way it usually does
in physics, namely, by having a large number of deterministic equations that
can only be handled probabilistically
