According to our current understanding of physics, if we were able to travel faster than the speed of light, it would violate the fundamental principles of causality and the concept of the arrow of time. The theory of relativity, which encompasses both special and general relativity, suggests that the speed of light is an absolute cosmic speed limit and that no information or object can travel faster than it.
The implications of exceeding the speed of light would lead to paradoxes and contradictions, such as the possibility of causality violations and time travel to the past. These paradoxes, including the famous "grandfather paradox" (going back in time to prevent your own birth), have been extensively explored in theoretical physics.
One possible way to understand this is through the concept of causality. Causality states that the cause of an event must always precede its effect in the fabric of space-time. If faster-than-light travel were possible, it would create situations where the effect (meeting yourself in the past) occurs before the cause (your departure in the future). This contradiction breaks our understanding of cause and effect relationships.
Furthermore, in the framework of general relativity, the existence of closed time-like curves (CTCs), which are paths that allow time travel, is still a topic of active research. While some theoretical solutions of Einstein's equations allow for the existence of CTCs, they usually require the presence of exotic forms of matter or configurations that are not yet understood or observed.
It is essential to note that our current understanding of physics suggests that traveling faster than light or backward in time is not feasible. However, scientific progress and future breakthroughs may lead to new insights that could potentially challenge or expand our current understanding.