A moebius is a theoretical twist in the fabric of space where time becomes a loop, from which there is no escape. Worf suggested the moebius as a possible explanation for the appearance in 2365 of a duplicate Picard from six hours in the future, as well as the energy vortex thought to be the cause of his time travel, which appeared a few hours later. (TNG: "Time Squared").
- Worf's description of the moebius was very similar to the temporal causality loop encountered by the Enterprise in 2368. (TNG: "Cause and Effect")