  Based on an observation that the basic mode of a common microwave waveguide
is a solution to the Klein-Gordon equation, quantum mechanics is modeled as the
wave-function propagated inside a waveguide. The guide width is determined by
the rest-energy and the potential energy. Moreover, a geometrical optics model
of the propagation illustrates how the width as a function of distance
determines the velocity and accelerations of the particle. The model entails
the disappearance of action-at-a-distance problem, and that interactions are
conveyed via the potential, i.e. by photons.
