Re:how far away is it? (Score 1)

If they expend power needed to travel at 10c according to newtonian mechanics, it will take (in their perception) 1/10 the time of travel at 1c to get there.

I don't quite understand what you mean here, it makes little sense talking about newtonian mechanics when the speed is near 1c. If travelling at 1c the Universe will be infintesimally short to the traveller (due to length contraction), and thus wherever he goes he will be there in no-time.