Scientists have extended Einsteins equations for faster-than-light travel. Time travel discussion focuses on closed time-like curves CTCs something Albert Einstein first posited. In higher orbits spacecraft travel slower because the force of gravity is less.
An example of a traversable wormhole metric is the following.
First consider what you know. Here a three-dimensional right graph shows the relationship between three different velocities. People think of time travel as something as fiction says. In higher orbits spacecraft travel slower because the force of gravity is less.