Elementary modern physics
We wish to consider some spesific events, namely the births and deaths of three men. In order that we may use the Lorenz coordinate transformations we consider to inertial systems, S1 and S2; S2 moves along the +X1 axis at a speed of 0,98c with the respect to S1. We might think of S1 record the simultaneous births of three men: Jim, born at S1’s origin, John, born at x1 = +10 light-yr (1 light-yr is the distance a light pulse will travel in 1 year) and Dick, born at S1’s origin. Both Jim and John remain at rest in S1 throughout their 70-year life span, according to the observers in S1. Dick, on the other hand, is born and remains at rest in the rocket ship, which is at rest in S2. With respect to S2 Dick also lives exactly 70 years. How long does Dick live according to observers in S1? How long do Jim and John Live according to observers in S2? How far apart are Jim and John according to observers in S2?
What is the point?