According to our current understanding of physics, time travel to the past is not possible, even if someone were traveling through space at the speed of light or close to it.
Einstein's theory of relativity, particularly the theory of special relativity, explains that time dilation occurs as an object approaches the speed of light. Time dilation means that time passes more slowly for a moving object relative to a stationary observer. As an object approaches the speed of light, time dilation becomes more pronounced, and the object's internal clock appears to slow down from the perspective of an outside observer.
While time dilation is a real effect, it does not allow for time travel to the past. Even if someone were traveling at near-light speeds, their own experience of time would not change. They would perceive time passing at a normal rate. However, when they return to the reference frame of a stationary observer, they would find that more time has passed for the observer compared to their own experience.
In other words, traveling at near-light speeds could potentially allow for time to pass more slowly for the traveler compared to someone in a different reference frame, but it would not enable them to travel back in time. The arrow of time, as we understand it, still flows forward, and the past remains inaccessible through any known physical means.
It's important to note that our understanding of physics could evolve in the future, and new theories may emerge that offer different perspectives on time travel. But based on our current scientific knowledge, time travel to the past remains purely speculative and not supported by the principles of relativity.