The idea of time travel, as depicted in movies and fiction, often involves concepts that go beyond our current scientific understanding. While it is an intriguing concept, the notion of moving so fast that one can travel through time is not supported by our current understanding of physics.
According to Einstein's theory of relativity, as an object with mass approaches the speed of light, its relative time slows down compared to an observer who is stationary. This phenomenon is known as time dilation. However, even if an object were to approach the speed of light, it would not allow for traveling backward or forward in time as commonly portrayed in movies.
In scientific theories, such as general relativity, the possibility of time travel typically involves extreme conditions, such as the existence of wormholes or the manipulation of spacetime through hypothetical constructs like "exotic matter" or "negative energy density." These concepts are purely speculative at this point, and their practical realization, if possible at all, remains highly theoretical.
Regarding your question about knowing the direction of time travel, it poses an interesting challenge. In many time travel narratives, individuals often have some means of discerning whether they have traveled into the past or the future. However, in reality, if time travel were possible, determining the direction of travel could be quite difficult.
One potential approach to discerning the direction of time travel could involve observing changes in the environment, such as technological advancements, cultural shifts, or geological transformations. For example, if someone traveled into the future, they might encounter unfamiliar technologies or witness the consequences of historical events. On the other hand, if they traveled into the past, they might witness historical events they are already familiar with or encounter cultural practices that have since been abandoned.
However, it's important to note that these are speculative scenarios and based on fictional depictions rather than concrete scientific knowledge. Time travel, as currently understood by science, remains purely theoretical and subject to ongoing exploration and debate.