Consider some particle P that is defined by a chain of repetitive events. And let each repeated cycle be parsed into two sets of quarks, noted by and , that are out of phase with each other. This is expressed mathematically as
The compound quarks and are called phase components of P. If these two sets are composed from the same selection of quarks, then a description of the whole cycle is unaffected if there is any confusion or mix-up about the sign of the phase. This robust indifference to the phase is useful, so we give particles like this a special name: If
then we say that P has phase symmetry. Alternatively, if then we say that P has phase anti-symmetry. The most important examples of particles with phase symmetry are protons and electrons. So it is possible to make descriptions of protons and electrons that ignore the phase.
Sensory interpretation: When the phase indicates whether an event is diurnal or nocturnal, then indifference to phase means that a description does not depend on whether it is day or night. So physicists in different time-zones can easily work together when considering particles like protons and electrons.