1. The problem statement, all variables and given/known data Two spaceships are traveling with a relative velocity of 1.2x10^8 m/s, both carrying clocks. According to the captain of each ship, the other captains clock ticks more slowly than his own. By what factor do the clocks disagree? 2. Relevant equations 1/(1-(v^2/c^2))^1/2 3. The attempt at a solution The only formula I can think of that brings up the time dilation going on is the Lorenz Factor, as the only given value is the relative velocity of each ship. I interpreted this question as the ships are speeding at a little over 1/3 of the speed of light past each other if they are using each other as a frame of reference, So I simply plugged the velocity (which is relative to each captain, using the other ship as a reference frame) into the equation to get... so the clocks disagree by a factor of 1.291.... I am not sure what units I would even place there or if it is just a number with no units. Is this the correct line of thinking?