Hi! First of all, sorry for my english, I'll try to do my best translating the exercise. I've been working on it this evening but I'm having some troubles: Problem: On the Star Wars film, there's a starship traveling at a velocity of 5c. This is nonsense, but we can assume this if we suppose that people on Star Wars had no idea of what they were saying and compare distances and time on different frames without any cares. a) Suppose that a starship travels from Earth to a close star, which is 1000 light years away. If the pilot, who doesn't know about relativity, uses his own time and this distance, from the earth and without moving, for calculate his velocity, at which velocity will he say he travelled? b) What will be his velocity seen from the earth? My solution: a) I found this section pretty easy, which makes me think that there's a mistake at some point. What I did is to find the distance on meters, by using that the star was 1000 light years away. Then, we knew the time he has been traveling, so we do v=distance/time to find the velocity we were asked to find. b) I don't know how to start here. The only thing we've done so far on relativity is the Lorentz transformation. Could someone enlighten me with some hint or a proposal of resolution? Thanks a lot for your time.