Originally Posted by Interference
If, however, time is to be treated as a dimension (direction) it would be possible to step outside of this spacetime into time and back into spacetime again.
..because when we move through the other dimensions, we're always popping in and out or spacetime and cannot be observed other than at the starting point and the destination....
If time truly is a dimension like the others (give or take the unidirectional nature we seem to experienced), it has to operate like on:, i.e. to move from one point in time to another, we must pass through the intervening points. (This is one reason why I see time travel as fantasy, not SF: most time travel descriptions take on board that time is a dimension but then immediately throw away all the rules of movement along a dimension.)