Alidar Jarok wrote:
There are practical reasons to not want to go on a craft that can travel that fast. It's not the 10 years or so it would take to travel to Alpha Centauri, but the thousands of years that would pass back on Earth that would prevent me from wanting to take the trip.
At .1c a little over 40 years would pass on earth for you to reach Proxima Centauri at 4.2 light years distance. Time dilation on board ship at that speed would be negligible.
At .5c, 8 years would pass on earth while on board only about 7 years would pass.
I think you have some confusion as to how time dilation works.