If time travel were possible, the question of whether we should be careful not to alter the past is a subject of much speculation and debate. The idea of altering the past has been explored in numerous science fiction stories, and various theories and concepts have been proposed.
One common concept is the idea of a "temporal paradox" or "grandfather paradox." It suggests that if you were to travel back in time and alter an event, such as preventing your own birth or causing significant changes in history, it could create a paradoxical situation. For example, if you prevented your parents from meeting, you would never be born, which means you wouldn't have been able to go back in time to prevent their meeting in the first place.
To resolve these paradoxes, some theories propose the idea of a "self-healing" or "self-correcting" timeline. According to this view, any attempts to change the past would ultimately fail or result in events aligning in a way that preserves the original timeline. For instance, your actions might inadvertently lead to the circumstances necessary for your parents to meet, ensuring your own existence.
Alternatively, other theories suggest the existence of parallel universes or multiple timelines. In this scenario, when you travel back in time and make changes, you create a new timeline diverging from the original one. The changes you make in the past would only affect this new timeline, not the one you came from. Therefore, altering the past wouldn't have any direct impact on your own timeline or reality.
Ultimately, the consequences and rules of time travel, if it were possible, would depend on the specific mechanics and principles governing time travel in that hypothetical scenario. Until we have a complete understanding of time travel, it remains speculative and subject to interpretation.