You make a good point that we should avoid talking about perceptions. I guess I just assumed everyone knows to disregard doppler effect and delay-effects caused by c being finite. That way it does not have to be stipulated for every scenario. For example, if the female's ship is approaching at relativistic speed, she would appear in fast-motion not slow motion, but I referred to the slow motion because I already disredarded the doppler effect. I have been following your exchanges with MacM, and I am hoping that you or someone can finally explain away the reciprocal time dilation problem. I don't think it has been explain satisfactorily yet, but that does not mean that I reject SRT outright. Very well, I will try not to focus on the acceleration. I knew it was not supposed to be the cause but I did think that it was during this time that the clocks changed radically. In closing, let me ask one thing that might help me to finally grasp this: Is there supposed to be such thing as 'real' motion which induces time dilation and 'real' rest which does not induce time dilation? I thought relativity theory forbids a preferred frame of reference. Because if I cannot focus on acceleration in the twin paradox, then how can I possibly detect which twin will be younger unless I choose a preferred frame? Oh no, now I am totally confused. Check out this website. http://www.phys.vt.edu/~jhs/faq/twins.html (Scroll down to the short section at the bottom.) This is a pretty good explanation of the twin paradox, but there is one short section at the bottom of the page that treats the twin paradox without acceleration. What the #$^&*? ...Oh lord, now it looks like there is a preferred reference frame. Someone please tell me this is wrong! Please Register or Log in to view the hidden image!