Applying the equivalence principle to quantum mechanics for all observ
ers in an inertial frame, a rather concrete realization of nature has
been proposed. A conclusion to this application is that time variation
of a physical quantity appears in the same form at each point of the
wave function representing an electron. A restriction on the macroscop
ic, that is, distant, observer provides the macroscopic description of
the electron through its translational behavior. Finally, by an assum
ption that an eigenvalue of a physical quantity is measured at every p
oint of the corresponding eigenwave(s), a deterministic theory of natu
re is complete.