1. The problem statement, all variables and given/known data In a reference system S two athletes are aligned at a distance d relative to each other on the Y axis to make a run parallel to the x axis. Two starters, one next to each athlete, shoot their guns out at slightly different times, offsetting the advantage of better athlete. The time difference in S is delta T. For which time difference there will be a reference system S 'in which there is not compensation, and which time difference there is a reference system S' in which there is a real compensation ?. Determine explicitly the Lorentz transformation that leads to S' suitable for each of the possibilities listed above, calculating the speed of S' to S and the space-time positions (events) of each athlete in the S system. 2. Relevant equations Lorentz tranformation Equation 3. The attempt at a solution I don´t really understand the exercise, but firs I think you must asume that the coordenates of one of the athletes are at the origin, and the other has the displacement d. r1=(ct1,0,0,0) r2=(ct2, d,0,0) When you have two events ussually you use the space time interval (delta S)^2 =(ct2-ct1)^2-(x2-x1)^2-(y2-y1)^2-(z2-z1)^2 But i dont understant what it means no compensation real compensation?