>[!abstract] >A Krasnikov tube is a speculative mechanism for space travel involving the warping of spacetime into permanent superluminal tunnels. The resulting structure is analogous to a wormhole or an immobile [[Alcubierre drive]] (and like them requires exotic matter with negative energy density) with the endpoints displaced in time as well as space. The idea was proposed by Sergey Krasnikov in 1995. > >The tube is a distortion of spacetime that can be intentionally created (using hypothetical technology) in the wake of travel near the speed of light. The Krasnikov tube allows for a return trip that takes travelers back to the time right after they left. Experiencing the effect requires that the traveler race along the tube at speeds close to that of light. ("Krasnikov tube", 2025). ## References - Krasnikov tube. (2025, January 30). In *Wikipedia*. https://en.wikipedia.org/w/index.php?title=Krasnikov_tube&oldid=1228928406