Time travel and faster-than-light (FTL) travel are both concepts often explored in science fiction, but they have distinct differences.
Time travel refers to the ability to move backward or forward in time, experiencing events that have already occurred or are yet to occur. It implies the manipulation of the arrow of time, allowing a person or object to exist in different points in the past or future relative to their original timeline.
There are various theoretical models and thought experiments regarding time travel, such as the "grandfather paradox" or the concept of closed timelike curves. These ideas involve potential contradictions and paradoxes that arise when causality is violated, leading to questions about the consistency and stability of the timeline.
On the other hand, traveling faster than the speed of light (FTL) refers to the hypothetical ability to move through space at a velocity exceeding the speed of light. According to our current understanding of physics, as described by Einstein's theory of relativity, objects with mass cannot reach or exceed the speed of light in a vacuum.
If an object were to travel faster than light, it would encounter several consequences, such as time dilation, length contraction, and an increase in mass. As an object with mass approaches the speed of light, its energy and momentum would theoretically become infinite, which is not consistent with our known laws of physics.
While time travel and FTL travel are distinct concepts, there are some science fiction stories that incorporate both elements. However, it's important to note that neither time travel nor FTL travel has been demonstrated or proven possible within the current scientific framework. They remain speculative concepts that continue to captivate our imagination and inspire creative works.