If someone left the earth on a space craft traveling .99% the speed of light for a distance of one light year, and time slowed on the space craft relative to the earth, approximately how much time would the person on the space craft experience when arriving at the destination? (I'm leaving out acceleration to simplify the question.) Since observers from the earth would see the space craft arrive one year after it left, and they would observe time running slower on the spacecraft through the entire trip, it seems that the people on the space craft would only experience a short amount of time when they arrive. If the spacecraft was able to instantly stop and turn around, two years would have passed on the Earth when they arrived home. This would mean that only a short amount of time would have passed for the crew of the spacecraft. I remember watching a science show a few years ago where they said if you could travel at the speed of light, you would be able to go anywhere in the universe instantaneously, from your own perspective, although your destination may no longer exist because of the amount of time that may have passed for the rest of the universe. If true, this should answer my question, but I'm not confident that my memory is correct.