‘An intelligent hell would be better than a stupid paradise.’ –Victor Hugo
I’m sure most of you have heard of the twin paradox “in which a twin makes a journey into space in a high-speed rocket and returns home to find he has aged less than his identical twin who stayed on Earth.” This paradox has been worked out for special relativity in Minkowski spacetime. Recently, Boblest et al. worked out the details using general relativity for an expanding universe. (…)
The twins in the paper have names: Eric and Tina. Eric stays on Earth while Tina accelerates away from Earth with constant acceleration α = 9.8 m/s2 until her clock shows 5 years have past. Then she decelerates by the same magnitude coming to a complete stop after ten years then begins her journey back to earth accelerating then decelerating in the same 5 year intervals. Finally, after 20 years has transpired on her clock she has returned to earth being now 20 years old. (…) Eric is nearly 350 years old when Tina returns.
