According to our current understanding of physics, time travel into the past without altering the timeline is not possible. The concept of time travel often involves paradoxes and logical inconsistencies.
One of the most well-known paradoxes is the "grandfather paradox." It suggests that if you were to go back in time and prevent your grandfather from meeting your grandmother, you would never be born, which would create a contradiction. Resolving this paradox and others like it is a significant challenge.
While various theories and ideas have been proposed in the realm of science fiction, such as multiple timelines or parallel universes, they remain speculative and lack scientific consensus or empirical evidence. time travel into the past remains purely hypothetical and falls outside the boundaries of our current scientific understanding.