If there was a higher space time I think we might be able to travel forwards or backwards in time, if we knew how to. We would not destroy ourselves by going back in time and changing past events, like hooking our parents up with different people, because we would exist as separate entities than we once were by making the journey.
By going back in time, and changing things, we become the cause of a new reality within our lower world, whatever the changes may be, and cannot disappear because of our changes as a result. We are now just matter and energy that has simply broken off from the old reality, from which we once originated, and traveled to another time and place, within the same world. We have created a new reality within the world, as a result of the travel, and have erased the old reality, as a result of the new reality being created. We now simply exist there as if we had been there from the start.
We are no longer connected to the old reality from which we broke because the erasing of the old world by the new one severs our connection to it forever. As a result, we cannot affect ourselves by changing the past of our world because the new reality erases the old reality making the events that follow new events. This solves the controversy concerning time travel backwards because our causes to time cannot bite us in the butt as an effect.
If a higher space time exists then we are on the time of the higher world when we travel back in time. The procession of realities can only exist there in the higher world because they take place there in the space time of the higher world. We would probably be able to make it to the higher world by wormhole or warp drive technology, if it is possible. We could then travel at the speed of light, if possible, relative to our lower world within the space time of the higher one to time travel backwards. Any questions, comments, thoughts?