1. The problem statement, all variables and given/known data The example below illustrates the relativistic phenomenon that synchronicity of events is not absolute but it depends on the reference frames. Spaceships A and B, while moving away from each other with a constant speed of v = 0.553c, are watching a competition between spaceships C and D. Spaceship C is heading towards planet C and spaceship D is approaching planet D. The winner is the spaceship that reaches its target planet first. The astronauts on spaceship B find, to their great surprise, that the spaceships C and D reached their planets at the same time. At that moment, planet C was at rC = (-250, 130, -130) ls, and planet D was at rD = (160, -290, -170) ls , where the xyz coordinate system is attached to spaceship B and the first, x, axis is parallel to the velocity vector of spaceship B relative to spaceship A. According to spaceship A, however, the race has a definite winner. According to spaceship A, how many seconds were between reaching planet C by spaceship C and reaching planet D by spaceship D? 2. Relevant equations Δτ = γ(Δτ' + βΔx') Where ΔT is the difference in time, given in light seconds, β = v/c. The ' notation represents the reference frame. γ = 1/(√(1-(v2/c2)) 3. The attempt at a solution Let the view from spaceship A be reference frame s. Let the view from spacesip B bence frame s'. xC' = |rC| = √((2502) + (1302) + (1302)) xD' = |rD| = √((1602) + (2902) + (1702)) Δτ' = 0 Δτ = γ(Δτ' + βΔx') Δτ = (1/1-(0.533))(βxD' - βxC') Δτ = β(1/1-(0.533))(xD' - xC') Δτ = 76679.6992 Which I'm told is incorrect. Could anyone help me out?