Wormhole effect

The wormhole effect was a time distortion which affected people inside a wormhole created by a starship because of antimatter imbalance of the engine.

In the mid-2270s, Captain James T. Kirk ordered Lieutenant Commander Hikaru Sulu to take the USS Enterprise into warp while in the confines of the Sol system to intercept V'ger at the earliest opportunity. His first officer, Commander Will Decker and chief engineer Commander Montgomery Scott opposed Kirk's order, but Kirk had Sulu take the Enterprise to warp anyway. The Enterprise later became caught in a wormhole, communications with Starfleet Command were jammed, distortion overloaded the power systems, navigational deflectors went inoperative, and the entire crew underwent the "wormhole effect".

With engines disabled Enterprise would automatically emerge from the wormhole once forward velocity slowed to sublight, but an asteroid also caught in the wormhole would collide with the ship within seconds. Decker ordered Lieutenant Pavel Chekov to fire a photon torpedo, thereby saving the ship. (Star Trek: The Motion Picture)

Earlier, while in transit from 2258 to the 32nd century, the crew of USS Discovery also experienced a similar visual effect as they passed through a wormhole, though without the apparent temporal distortion or any hazards from asteroids. (DIS: "Such Sweet Sorrow, Part 2")