The de Broglie wave packet for a simple stationary state

A simple stationary state is set up by combining the two de Broglie waves from two particles traveling in one direction with equal and opposite velocities. By considering the waves forming this state from the point of view of all possible observers moving in the same direction, it is shown that the basic standing wave pattern does not alter, but that the particle will be confined to a small region stationary relative to this pattern. This region is similar in extent to that confining a free particle, the natural internal frequency of the particle being raised. This agrees with previous suggestions that a particle in a stationary state without angular momentum is stationary.