ok forget my original question. Lets say you have two people each traveling at .5c away from earth in opposite directions in a closed universe. They are both in inertial frames the whole time (not that it would matter if they werent) and have completely equal reference frames. What happens when they each go halfway around the universe and reach each other again? each will have watched the other's clocks slow down.
as they move away they keep looking at each other (through earth) with very powerful telescopes. When they are within 10 second of each other they turn their telescopes around 180 degrees.