Relativity Lite

ATrip to Alpha Centauri | 41 This sequence of events shows two things. The first is that the seeming “paradox” of each of us seeing our moving counterpart’s clocks running slowly is not only real but re- quired to compensate for the much larger reverse effects of acceleration on the clocks of the person who actually feels the effects of that acceleration. Without the former, the latter would be too large. The second takeaway is that it is the person experiencing the physical effects of acceleration whose clocks run slower over a round trip and who is therefore the younger twin.