Twin "Paradox" with no asymmetry Here is another variation of the twin paradox. Suppose we let both twins start their journey from a space station far from any heavenly bodies, so that the whole experiment can be carried out in free space. The twins Jack and John are equipped with identical "twin" shuttles and "twin" clocks synchronized at the departure point O. The twins travel in opposite directions along the same straight line. Other than the direction, their accelerating and cruising processes are pre-programmed to be identical as measured by their own speedometers, clocks and accelerometers. Thus, they start their journeys with the same accelerations, turn around with the same acceleration and come back to the space station with the same velocity and decelerations. What is the best way to explain that the clocks carried by the twins read the same time when they meet back at the station to compare clock readings or equivalently, that the age of the twins is identical? Shouldn't either twin claim that the other is younger? I know the resolution of the paradox depends on the fact that there is no asymmetry in this case but I am trying to understand the details of how both end up with the same clock readings since one twin sees the other twin's clock slowing down and vice versa.