While attempting to wrap my head around the classical Twin Paradox, I asked myself the following. So far I have not been able to reach a well reasoned answer... which is no big surprise. :) Twins (A and B) are oriented in space such that A could be said to be standing on B but facing in the opposite direction. Both twins have a jetpack and clock. They are both tethered to a pole which is positioned 1ly/2∏ away. On this pole is mounted a third clock. All three clock are syncronized and the twins ignite their jetpacks and begin to accelerate in the opposite direction around the 1ly circumference path. They both finally reach and maintain a constant velocity of .5c in the first revolution and continue as this velocity for 100 years. Can one say the twins have equivalent accelerated reference frames? Maybe equivalent but opposite? I am unsure as to what constitutes a reference frame. From the perspective of the pole, the twin's clocks should be slower. But what of the twins with respect to each other? Shouldn't they both see the other's clock as slower and the other twin age at a slower rate?