The concept of going back and forth through time, often referred to as "time travel," is still largely speculative and hypothetical. While theories like general relativity allow for the possibility of time travel, the practical realization and feasibility of such travel, if it is indeed possible, are uncertain.
However, if we assume that time travel is possible and a person could travel back in time, it raises the question of whether their actions would change the future. This question is the subject of much debate and speculation among physicists and philosophers.
One possibility is that of a consistent timeline, where any actions taken in the past were already part of history and did not alter the future. This idea suggests that any attempts to change the past would be futile, as they would have already been accounted for in the timeline. This concept helps avoid paradoxes like the grandfather paradox, where a person goes back in time and prevents their own existence.
On the other hand, some theories propose the idea of a changing timeline or multiple timelines, where altering the past could create a new branch of reality or alternate timeline. In this scenario, a person's actions in the past would indeed affect the future but not necessarily the future from which they originated. This interpretation allows for the possibility of changing the course of events and creating different outcomes.
It's important to note that these ideas are speculative and still the subject of ongoing scientific and philosophical discussions. Currently, we do not have experimental evidence or a complete understanding of the nature of time and time travel to definitively answer these questions.