According to our current understanding of physics, as described by Einstein's theory of relativity, if a person were somehow able to travel faster than the speed of light, it would lead to several paradoxical consequences. One of these consequences is the violation of causality, which is the principle that cause and effect must occur in a specific temporal order.
If an object or a person could exceed the speed of light, it would allow them to travel backward in time, arriving in a time period before they started their journey. This would create what is known as a "time travel paradox." For example, a person could theoretically travel back in time and prevent their own birth or alter past events in a way that contradicts what had already occurred.
These paradoxes and violations of causality have led scientists to believe that faster-than-light travel is not possible within our current understanding of physics. It is important to note that no experimental evidence or observed phenomena support the existence of faster-than-light travel. While science fiction often explores the concept of time travel, the consensus among physicists is that backward time travel is highly unlikely, if not impossible.