Time travel only exists in novels, and according to the theory of relativity, the speed of an object can only reach 99.9% at most, so time travel can only exist in theory, and it is difficult to happen in the real world.
Traveling through time and space is a different space from one space to another in some way. In other words, time travel is feasible in theory by switching timelines.
Mankind can open the door to the past and the shortcut to the future, but it will also have inevitable consequences.