일반물리학 2 — Relativity: Problem 24

24 (Come) back to the future. Suppose that a father is 25.0 y older than his daughter. He wants to travel outward from Earth for 2.000 y and then back for another 2.000 y (both intervals as he measures them) such that he is then 25.0 y younger than his daughter. What constant speed parameter \(\beta\) (relative to Earth) is required?