Phase slip, in the words of renowned physicist, Dr. Emily E. Entanglement, "is a phenomenon wherein the fabric of time-space is momentarily disrupted, causing localized distortions in the space-time continuum." In simpler terms, it's like a time-space whoopee cushion, but with more math.
Phase slip has been featured in numerous works of science fiction, including the classic novel "The Time Traveler's Dilemma" and the movie "Phase Slip: The Musical".