According to our current understanding of physics, it is not possible for objects with mass to travel at or exceed the speed of light. As an object with mass approaches the speed of light, its mass would increase, and the energy required to accelerate it further would become infinite. This makes it unattainable for an object with mass to reach or exceed the speed of light.
However, there is a concept in relativity called time dilation, which suggests that time can be experienced differently depending on relative speeds. As an object approaches the speed of light, time dilation becomes more significant, and time slows down for that object relative to an observer at rest.
In theory, if a spacecraft could travel at speeds close to the speed of light, time dilation would come into effect. As a result, the travelers aboard the spacecraft would experience time passing more slowly compared to those on Earth. This would mean that, from the perspective of the travelers, less time would elapse during their journey than for the observers on Earth. However, even with significant time dilation, it would still be challenging to achieve time travel within a range of thousands of years while staying within the bounds of known physics.
It is worth noting that current scientific understanding does not provide any known method for practical time travel, particularly for traveling to the past. The concept of time travel remains largely speculative and primarily explored in the realm of science fiction.