  : Dark Formal We already agree that the crucial thing is the length of the spacetime trajectories. As the diagram I showed makes clear, the amount of acceleration experienced is not the essential difference. What is relevant is the amount of space-time trajectory between accelerations. Right now there are several sentences in the article that obscure that point and make it sound as if the presence or absence of acceleration is significent. That, as we all agree, is misleading. I'm planning to correct it. I hope that's OK.   