Ok, I just about managed to understand the twin paradox, with the help of these spacetime diagrams: http://www.math.ucr.edu/home/baez/ph...ox/doppler.gif

However, I am confused again. What would happen if the spaceship travelled outwards at a significant fraction of c, but on the way back, travelled at non-relativistic speeds? Would we get the same result? When i tried to work it out, it appeared to me that we would actually get an opposite result, but this seems like nonsense to me.

Any thoughts?