Travelling near the maximum speed of light isn't just a matter of stepping on the gas. You don't just end up going faster.
When you travel near the speed of light, time and mass start to behave strangely.
For instance, if a cow were to travel at 100
% of the speed of light,
it would have the momentum of an object that weighed 2, 999.998
kg (6, 613.863
pounds). That's almost 4
times the cow's normal mass.
If it were to travel at that speed for 1000 years it would arrive having aged only 1 year.
Neat huh?! This isn't science fiction. This is science fact which is verified daily at particle accelerators that accelerate particles to relativistic speeds.
On a separate note, I'd like to point out that this sort of time travel has potential value in the realm of computing.
If we could just accelerate the entire Earth up to close to the speed of light relative to Mars, we could do calculations using computers on Mars. It would be equivalent of having
computers which ran at any speed we wanted.