In a gedanken experiment (Fig. 26.17), two events that cannot be related by cause and effect occur in the same inertial reference frame O: (1) Strobe light A, at the origin of the x- axis, flashes; (2) strobe light B, located at x = + 600 m, flashes later. B’s flash 1.00 μs later. B’s flash cannot be caused by A’s flash. (Light travels only 300 m in the time between the two events.)
(a) Use qualitative arguments to show that there exists another inertial reference frame, traveling at a speed less than c, in which these two events would be observed to occur simultaneously.
(b) What is the direction of the velocity of the reference frame in part (a)?